Water Cooled Screw Chiller

Water Cooled Screw Chiller-An Ultimate FAQ Guide by TopChiller.

What is Water Cooled Screw Chiller?

Water Cooled Screw Chiller is a premium quality cooling device that configures excellent operational efficiency by rejecting system heat. Water coolant collects the heat produced by an application. At the same time, the wasted heat is finally discharged by the water-cooled condenser.

It assures a noise-free and quiet operation by installing a reliable screw compressor. Different safety devices and control units increase durability and reliability.

Environment-friendly behaviour, easy maintenance, and feasible installation have made Water Cooled Screw Chiller popular among diverse applications.

Water Cooled Screw Chiller Designed by TopChiller

What is the Basic Composition of Water Cooled Screw Chiller?

The Water Cooled Screw Chiller consists of the following main components as given below:

Evaporator

Shell and tube type evaporator is integrated for heat exchange between refrigerant and coolant. The shell is filled with refrigerant while the chilled water flows in the tubes of the evaporator.

The main benefit of this evaporator is that it provides a large surface area for heat exchange and protects the reduction of refrigerant charge.

The shell is constructed with stainless steel and coppers tubes for durable and corrosion-resistive performance.

Compressor

The screw compressor is the main component fabricated with radial and axial bearings. Switches for oil level, thermistor, and economizer are also connected for regulated operation.

Semi-hermetic compressor put compression force efficiently over refrigerant and increase its pressure and temperature.

Condenser

A water-cooled condenser is used to dissipate the heat collected from the system. It consists of copper coils in which the refrigerant flows for rejecting its heat. At the same time, chilled water circulates over it.

Expansion Device

It consists of an expansion valve and orifice for reducing the pressure of the refrigerant. When refrigerant passes through the valve, pressure is released by the gas expansion.

Control Unit

The control unit is integrated with different protection devices to maintain the working of all components at the set point.

Cooling Tower

The cooling tower discards the heat from condenser water and again cools it so that water may get ready to release heat from the refrigerant.

A cooling tower is installed at the place where heat can be dissipated without interrupting any other system.

Water Cooled Screw Chiller Compressor

What are the Fundamental Features of Water Cooled Screw Chiller?

A Water Cooled Screw Chiller collects heat from processing machines and rejects it outside by the use of chilled water. It has some fundamental features for its operation as given below:

• Energy-efficient, semi-hermetic screw compressor increasing pressure of the refrigerant.
• Single or more than one compressor arranged as per application requirements.
• Shell and tube type evaporator mediating heat exchange between coolant and refrigerant.
• Thermostatic, reliable expansion valves for pressure releasing or throttling.
• PLC based microprocessor controller interconnected with different automatic safety devices.
• Integration of heat recovery system to warm surroundings of low ambient temperature.
• The water pump and water tank provide a consistent water supply to the condenser.
• R134A/R407C/ R410A or R510A refrigerant can be installed to continue the refrigeration cycle.
• Water-cooled condenser for efficient heat discharge from the refrigerant by the chilled water supply.
• Automatic safety devices mainly control the flow rate, temperature, and pressure of Water Cooled Screw Chiller.
• Construction of coils with copper metal and shell with steel protects it from corrosion.
• Stainless steel body prevents the unit from corrosion, assuring longer service life.
• Built-in oil separator, easy maintenance, and installation.
• Efficient and quiet operation, robust designing and accredited certification.

Water Cooled Screw Chiller Refrigerant

What is the Working Principle of Water Cooled Screw Chiller?

Water Cooled Screw Chiller is intended to provide cooling for different industrial applications working on compression and evaporation principles. The working process is given below:

Step 1

The cooling process starts when a low-pressure refrigerant enters the heat exchanger. Hot water also enters in heat exchanger coming from an application.

The low-pressure liquid refrigerant absorbs the heat from the water and converts it into a low-pressure gas.

Step 2

After releasing its heat, the water gets cooled and enters again into the system to induce a cooling effect. In comparison, the gaseous refrigerant leaves the evaporator and is sucked by the compressor.

Step 3

The suction valve of the screw compressor sucks the gas into the compressor groove. The screw rotors of the compressor rotate and compress the gas passing through it.

Compression is applied over refrigerant at the upper and lower parts of the rotor until it reaches a discharge line.

Step 4

Gas refrigerant leaves the compressor with high temperature and pressure and enters into the condenser.

Step 5

The water-cooled condenser has chilled water circulation coming from the cooling tower and refrigerant. Chilled water absorbs the heat from the high-pressure refrigerant and converts it into a liquid state.

Step 6

While the hot water returns to the cooling tower for recovering its chilling effect by rejecting heat in the environment.

Step 7

After the condenser, the refrigerant passes from the expansion valve that expands the liquid to release the pressure. Low-pressure liquid refrigerant again enters the evaporator and continues the refrigeration cycle.

Which Accessories Can be Integrated With Water Cooled Screw Chiller?

Different accessories options can be integrated with Water Cooled Screw Chiller for different required operations as given below:

• Vibration Isolators
• Flow Switches
• Differential Pressure Switches
• Acoustic Enclosure for Compressor
• Power Disconnect Switches
• Suction Service Valve (Isolation Valve)
• Power Factor Connection

Which Compressor is Used for Water Cooled Screw Chiller?

Screw Compressor

A screw compressor is used for Water Cooled Screw Chiller for putting compression force over the refrigerant. It is highly reliable and performs a quiet operation. It is equipped with an economizer, thermistor, radial, and axial bearings for regulated working.

Parts of Screw Compressor

Two screw rotors rotate and apply compression force over refrigerant, increasing its temperature and pressure. Compression occurs at the upper and lower sides of the screw rotors mitigating the axial load.

At the ends of the screw rotor, the suction pressure is applied over the refrigerant. It decreases the axial load of the compressor.

Oil injection is also used to level the COP of the unit. Single screw compressors connected in series are fabricated with oil separators that prevent the mixing of oil and refrigerant.

The screw compressor is also integrated with the capacity control system. This capacity control is made possible by controlling slides processed by a microprocessor.

So this compressor, with its different working features, acts as a core component of the Water Cooled Screw Chiller.

What are the Major Applications of Water Cooled Screw Chiller?

Water Cooled Screw Chiller is renowned for its energy-efficient cooling operation having low-cost maintenance and power consumption. For its diverse number of benefits, it is widely used for a diverse number of applications as given below:

• Chemical Processing
• Pharmaceutical Industry
• Food and Beverage Industry
• HVAC system
• Die Casting
• Printing
• Large Buildings
• Plastic Industry

Applications of Water Cooled Screw Chiller

What are the Advantages of Using a Water Cooled Screw Chiller for your Business?

Water Cooled Screw Chiller is available either in a single unit or with multiple unit configurations to meet the needs of different heat loads. It offers a large number of advantages for various applications as given below:

Environment-Friendly Behavior

It doesn’t need ambient fresh air for heat dissipation collected by the refrigerant. Therefore it has more durability and environment-friendly behaviour. Refrigerant is installed with no ozone reduction potential.

Durability

Corrosion resistive material such as stainless steel and copper is used for the unit’s overall construction, ensuring durability. Except for, indoors installation also assure long service life.

Quiet Operation

Screw compressors are energy efficient and reliable integration with vibration isolators mediating quiet operation. Noise-free operation assists installation for applications where noise is considerably irritating.

Energy Efficiency

The compressor is an economizer that ensures energy-efficient performance with low power consumption. Cooling tower integration also prevents power consumption at a high rating.

Adaptation with High Ambient Temperature

Installation of cooling tower and water pump assists heat rejection efficiently even in high ambient temperature.

The applications facing a high temperature can be cooled down by installing Water Cooled Screw Chiller.

How Does a Condenser of Water Cooled Screw Chiller Discharge System Heat?

System Heat Discharging

A water-cooled condenser is integrated with Water Cooled Screw Chiller for final heat dissipation from the high-pressure gas refrigerant.

Gas refrigerant enters in a water-cooled condenser fabricated with water piping and coils. Chilled water comes from the cooling tower and circulates over the high-pressure gas refrigerant.

All waste heat collected from the system is discharged from the refrigerant by chilled water. As a result, refrigerant converts into a liquid state and leaves the condenser coils.

While the hot water moves back to the cooling tower and discharges the waste heat over there. After getting cooled, the water re-enters in the condenser for next cycle processing.

What are the Features of Control Unit of Water Cooled Screw Chiller?

The control unit is integrated with Water Cooled Screw Chiller to control the temperature, pressure, voltage, water flow rate, and current for reliable operation.

Features

It is fabricated with a diverse number of features as given below:

• A comprehensive and coloured display screen for visualization of all installed functions.
• Automatic operation of the unit due to remote control functions installation.
• Some functions are manually scheduled to maintain a setpoint on holidays or weekdays.
• Indication of any problem or disorder by self-diagnosing function installation.
• Optimum control and regulation of the unit by improved control functions.
• The help function provides dictations about the action or solution to sort out the error.
• The automatic setting of the sensors at the setpoint is done by sensor function.
• Repeating key operations assists in resetting desired values for different parameters.
• Function for a fan of cooling tower regulating its cooled temperature at set point.
• Preventing function of the control unit maintains the temperature, voltage, and pressure of the condenser for accuracy in operation.
• Function controlling the startup of low loading inside the unit.
• Peripherals inspection and checking by interlocking check function.
• Time display function dictating about the runtime of pump and list out the number of running operations at a time.

Water Cooled Screw Chiller Control Unit

What is the Function of Automation Safety Devices for Water Cooled Screw Chiller?

An automation safety device is connected with a Water Cooled Screw Chiller increases its durability. A safety device prevents over-current production, phase change, and pressure change.

Safety Device for Compressor

It also prevents the compressor from damage by regulating external shocks.

Safety Device for Chilled Water and Cooling Water

There are also safety devices for water cooling as well as chilled water. These safety devices prevent the water from higher or lower chilling and retain its required range. Chilled water flow switches control water flow rate automatically.

Interlocking contact and run/stop signals provide safety devices connected to the water pump. It prevents water from freezing.

So make sure to connect the chiller, water tank, and chilled water pump in the same line during operation. Except this, there are many other safety devices as:

• Condenser high pressure protecting device
• Overcurrent protecting device
• Oil protection unit
• Unit for differential oil protection

What is the Function of Lubrication System in Water Cooled Screw Chiller?

Capacity Controlling

The lubrication system is interconnected with the screw compressor. The primary function of the lubrication system is capacity controlling and sealing of internal body parts.

Differential oil pressure puts the force on the cylinder piston and valve increasing compressor capacity.

Lubrication of Bearings

The bearings of the screw compressor are being lubricated by lubrication oil. Its function is to increase the working efficiency of the compressor. It also makes the sealing layers for absorbing compression heat.

The lubrication oil is separated from the refrigerant by using an oil separator. If temperature increases, the viscosity of lubrication oil also decreases, causing leakage and compressor damage.

Water Cooled Screw Chiller Bearing Lubrication

What is the Capacity Control System of Water Cooled Screw Chiller?

The capacity control system is configured with a Water Cooled Screw Chiller compressor for different application loads. It consists of a piston, slide valve, piston ring, etc.

Increase in Capacity

A piston rod connects the slide valve with the piston. The piston is derived from the cylinder by the use of oil pressure. Due to positive pressure, the lubrication oil flows from the oil tank and is charged to the cylinder.

This positive pressure is greater than the pressure on opposite sides of spring and gas pressure.

This pressure difference causes the moving of the piston and slide valve to the right side. Ultimately, an increase in compressor outlet and refrigerant capacity occurs.

Decrease in Capacity

When the solenoids valves are kept open, the piston and slide valve moves towards the left side. This occurs through the bypass of high-pressure oil.

Some amount of refrigerant also moves back to the suction line, causing a decrease in refrigerant at the discharge line. In this way, the total refrigerant capacity decrease.

How to Clean Evaporator/Condenser Piping of Water Cooled Screw Chiller?

Cleaning of Evaporator/Condenser Piping

• For efficient heat exchange between water and refrigerant, there is a need to clean the piping of the condenser/evaporator.
• Check the evaporator tubes to shut down the Water Cooled Screw Chiller for a seasonal break. Clean all of the dust and rusting of tubing. If the tubes are pleated with rusting, replace them with a new one.
• For removing dry dust and other debris in condenser or evaporator tubes, use the vacuum to clean it. In other cases, use the water mixture and detergent for tube cleaning.
• After washing with water, make sure to dry the tubes with a drier so that water may not be retained inside tubes. If water may be retained in tubes, it causes rusting.
• There is a chance of dust accumulation in condenser coils due to the open system. So the coils should be cleaned at least once a time a year. If water contamination occurs, then start cleaning of tubes more frequently.

Water Cooled Screw Chiller Evaporator Cleaning

How is a Leakage Test Performed for a Water Cooled Screw Chiller?

A chiller should be inspected and repaired at least once a year for proper maintenance and working credibility.

Any leakage in pipes or tubing of a Water Cooled Screw Chiller can be found out by leakage test method as given below:

Leakage Test Method

• First of all, take the nitrogen gas and fill it until the pressure reaches 2 to 9kg/cm²
• Also, put the checks of soapy water at each connection point.
• Then make sure to retain pressure for 30 minutes and check the leaks.
• Mark all leak points and then release the pressure from the unit.
• Repair all of the damaged or leak points in the pipes or tubing of the unit.
• Again perform the leak test to check the repaired parts by the increasing nitrogen gas pressure than before.
• After checking, repair the small leaks if you may found.
• After test completion, discharge nitrogen gas from Water Cooled Screw Chiller.
• Make sure to close the evaporator valves while performing the leak test.

What is Quality Assurance Certification of Water Cooled Screw Chiller?

Water Cooled Screw Chiller is accredited with standardized certification after quality assurance testing.

This quality assurance certification increases its credibility and reliability for many applications. These certifications are:

• AHRI 550/590 certification for quality assured vapour compression cycle.
• ANSI/ASHRAE 34 certification ensures the safety of refrigerants.
• ASME quality assurance for boiler and pressure vessel.
• Whole unit manufacturing under EN ISO 9001 standardization.
• GB/T 18430.1 quality assurance for water cooling processing through the vapour compression cycle.
• GB150/151 assures the quality and reliability of shell and tube type evaporator and steel coil.

Pressure and leak test are performed in the factory for quality assurance as per international standardization.

What is an Oil Recovery System for Water Cooled Screw Chiller?

The oil recovery system in the compressor of Water Cooled Screw Chiller is given below:

• The oil is gathered at the lower part of the screw compressor to lubricate its bearings and capacity control.
• After that, oil is filtered through oil filters and sprayed over bearings by passing from the internal oil passage.
• The oil is also sprayed simultaneously on the piston of capacity control by the outside capillary.
• Then it passed from solenoid valves of capacity control and entered the compressor’s inlet.
• From the inlet, oil is sucked in compressor grooves to lubricate compressor rotors for efficient working.
• While the oil on bearings entered from rare side flows back to the compressor inlet. This is the oil recovery system of the compressor.

The oil level should be maintained in the compressor. If it goes down, add more oil.

In case of a low oil level, the abrasion may occur in the bearings and rotors of the screw compressor, decreasing working efficiency.

How to Maintain your Water Cooled Screw Chiller?

A chiller needs to be maintained to increase reliability, working efficiency, and durability. The maintenance process for Water Cooled Screw Chiller is given below:

Cleaning

Ensure daily cleaning of the whole unit to prevent dust accumulation in different parts. Daily cleaning also prevents rusting.

Daily Inspection

Check out all components and bring their performance to the record. If you find a decrease in the efficiency of any component, amend it or replace it with a new one.

Checking Leaks

Check out all of the piping and tubing by performing a leak test. If you find any refrigerant leakage, turn off the Water Cooled Screw Chiller and repair the leaks.

The significant loss of refrigerant can cause a gradual degradation in the unit’s overall performance.

Tubes Cleaning

Scaling and debris accumulation may cause a problem in fluent heat exchange in evaporator tubes. Make sure to clean the evaporator’s tubes/coils, preventing them from scaling and dust accumulation.

Maintenance of Oil

Also, check the oil level to be regulated at the standard set point by compressor sight glass.

Check the oil recovery system if the oil level goes down on sight glass. Add the oil through the oil valve for ensuring reliable operation.

Off-Season Maintenance

If you have to stop working Water Cooled Screw Chiller for a seasonal break, remove refrigerant from the unit to a separate container. For ambient temperature lower to 0⁰C, drain all water to prevent the unit from freezing.

Water Cooled Screw Chiller Maintenance

How to Troubleshoot your Water Cooled Screw Chiller?

Different problems and troubleshooting actions of Water Cooled Screw Chiller are given below:

1 Change in Temperature

The problem in the temperature sensor may be occurred by a short circuit, malfunctioning of the mainboard, or disconnecting of the sensor.

The problem can be troubleshot by checking sensor wiring, repairing it, or replacing it with a new one.

2 Low Refrigerant Pressure

If the refrigerant pressure between condenser evaporator is low then set point, the overall operation of the unit will be disturbed.

Sort out the problem by inspecting condenser and evaporator pressure, checking the wiring, and replacing the damaged parts.

3 No Cooling Production

If the chiller does not produce cooling or make low cooling, then set the point. The problem can be condenser damage, phase change, or low compression over the refrigerant.

The problem is resolved by checking the valves of the cooling tower, assuring the cleaning of condenser coils, or replacing it with a new one.

4 Damage of Compression Valve

Sometimes the pressure of the refrigerant gets lower or increases from the normal set point. This may occur to the malfunctioning of compression valves.

This can be troubleshot by repairing valves and compressor operation and checking the work of pressure switches.

5 Interlocking of Water Flow

If interlocking occurs at water flow pumping due to flow signals disconnecting, wrong wiring, or pump stopping.

Check the wiring and amend it, turn on the pump and reset the required values of water flow rate for regular flow.

Water Cooled Screw Chiller Troubleshooting

TopChiller: Your Best Water Cooled Screw Chiller Supplier and Manufacturer

As a professional water-cooled screw chiller manufacturer with 20 years of experience in refrigeration systems, TopChiller has a full range of models water cooled screw chillers.

Each water-cooled screw chiller designed by TopChiller is a compact structure with steady quality.

We have full protection devices for each water cooled screw chiller including compressor overheating protection, low-temperature protection, high/low pressure, anti-freezing, phase-missing, anti-phase with overload, water flow switch, and startup latency.

Various refrigerants such as R134a, R407c, R410a, and R404a are all available depending on screw chiller working conditions, application requirements, and ambient temperature.

Compared with an air-cooled screw chiller, this water-cooled screw chiller is more efficient in cooling performance which is a requirement in the condenser water pump and a cooling tower.

Besides the above features, TopChiller water-cooled screw chiller also has optional functions for special requirements including soft-starting, economizer for higher efficiency, complete stainless steel non-ferrous chilled water circuit for high water quality requirement, electronic expansion valve, and remote control for monitoring the screw chiller working status.

Water-cooled screw chillers are widely used for various industries applications such as HAVC, big building&hotel air conditioning, central chilled water supply, chemical processing, die casting,food&beverage processing, pet food, Pharmaceutical, plastic processing, automotive, energy&power project, packing, and printing.

TopChiller aims at providing a water-cooled screw chiller with stable quality, operation efficiency, and energy savings.

A water-cooled screw chiller is suitable for air conditioning applications, industry-type process cooling, and large-scale district heat source systems.

As a professional water-cooled screw chiller manufacturer, TopChiller provides all technical support to clients.

Please contact the TopChiller team to get the best water-cooled screw chiller solution.

Water Cooled Screw Chiller: The Complete Buying Guide from TopChiller

What Is Water Cooled Screw Chiller?

Water-cooled screw chillers are devices used to dissipate heat from a location where the heat is not unwanted. Cost and efficiency are two crucial factors when considering the production of products.

To have a clear idea of the water-cooled screw chiller, please have a view of the below video. It is a brief introduction to a water-cooled screw chiller.

As water-cooled screw chillers are equipped with cooling towers, they are more efficient than air-cooled chillers and are commonly used to cool products and machinery in a wide range of industrial applications including injection molding, tools, and die-cutting, beverage, lasers, machine tools, semiconductors and more.

Water-cooled screw chillers are also applied inside sophisticated diagnostic devices as they are efficient in preventing the temperatures of the machines from getting higher than expected.

How Does A Water Cool Screw Chiller Work?

The cooling process starts with a low-pressure liquid or gas mix entering the evaporator where the heat from the water changed to a low-pressure gas.

Then the gas went to the compressor to get compressed into a high-pressure gas, which then enters the condenser where ambient air or condenser water expels heat to transform it into a high-pressure liquid.

The heating and cooling of the refrigerant and its change from a gas to a liquid are so-called the water-cooled screw chiller refrigeration cycle.

Now let’s take a deep look at the key components of a water-cooled screw chiller.

Key Components of a Water Cooled Screw Chiller

1. Cooling Tower

Generally, the cooling tower is installed on the roof and is where the unwanted heat ends up.

Cooling towers are used to cool condenser water with the help of evaporation.

After the water is pumped to the cooling tower, it will flow down to the basin of the cooling tower, and heat is released through evaporation during this process.

After the heat is released from the water, the water will return to your water-cooled screw chiller barrel through piping and absorb more heat, then the water will go back to the cooling tower to get the heat released and the cycle continues.

TopChiller can provide you with a full set of water cooling systems including water cooled screw chiller, water pumps, and water cooling tower.

But how to install a cooling tower? Please watch below the video of the water cooling tower installation guide.

2. Semi-hermetic Screw Compressor

A screw-driven compressor is primarily used to compress the refrigerant with two interlocking rotating helical rotors.

Hanbell Screw Compressor

The screw compressor contains one or two screws that can compress the low-pressure refrigerant to a higher pressure refrigerant.

TopChiller water-cooled screw chillers are equipped with a highly efficient, semi-hermetic compressor.

This compressor enables 0%-100% step-less capacity control and achieves the highest part-load efficiency, thus bringing about a huge saving on the electricity costs.

Handbell semi-hermetic screw compressor is the regular compressor brand we are using for standard chiller models.

Hanebll screw compressor technical features:

Full product range- RC2 series compressor consists of 26 models with displacement ranging from 98/118 m3/hr up to 1539/1847 m3/hr (50/60Hz) compatible with different refrigerants and applications.

Multinational patents of high-efficiency screw rotors- The new 5:6 high-efficiency screw rotor profile is patented in Taiwan, the UK, the US, and China.

This new large-volume, high-efficiency rotor profile is designed especially for modern refrigerant characteristics.

High-efficiency screw rotors are accomplished by using precision CNC machining centers, rotor milling machines, rotor grinding machines.

Strict ISO 9001 process controlling and the application of precise inspection equipment, such as ZEISS 3D coordinate measuring machines, ensure high-efficiency, high-quality, low noise, and low-vibration HANBELL RC2 series screw compressors.

High-efficiency motor- Premium grade low-loss core steel with special motor cooling slot and refrigerant guide vane which pilot the cold suction refrigerant gas through the motor provides the highest operating efficiency possible no matter how strict operating conditions are.

Long life bearings and high reliability- The screw compressors utilize a combination of 10 axial and radial bearings and α axial balance pistons to ensure longer bearing life and higher compressor reliability.

Double-walled rotor housing- Double casing structure with high-strength inner ribs has been designed to minimize noise and ensure rigidity.

The rotor housing is made of high-strength gray cast iron FC25 that is extremely stable.

therefore no expansion will occur even at the high-pressure condition.

These casings are machined by computer-aided machining centers and inspected by precision measuring machines to enhance reliability.

Direct flange-on oil separator- A vessel made of ductile material FC 500 specially designed to withstand high pressure and provide the highest efficiency of oil separation.

Simple oil management, three-staged oil separator(models above RC2-1020), low-pressure-drop demister to ensure the minimum refrigerant dilution in the oil and maintain high oil viscosity.

Precise capacity control- The slide valve for capacity control is located in the compressor chamber.

The slide valve is actuated by injection of pressurized oil into the cylinder from the oil sump as well as the bypass of oil through the solenoid valves in each oil line with a pressure differential.

Perceptive protection modules- RC2 series screw compressors are equipped with PTC thermistors and motor protection modules that could monitor discharge and motor coil temperatures as well as phase sequence and phase loss.

Accessories also include an oil level switch to monitor the level of oil, a pressure differential switch, and a pressure relief valve for the optional application.

Adaptable with additional cooling- Liquid injection connection port located at the motor casing and in the compression chamber, oil cooler connection port, and a middle-pressure economizer connection port for customer’s desired application.

RC2 series compressors not only continue RC series compressors’ characteristics of high efficiency & reliability design mentioned above but are also designed with the following newly added advantages to meet customers’ needs more adequately:

1. Design the fittest high-efficiency motor for respective refrigerant, operation conditions, and electrical power.

2. Dual capacity control of steps or continuous create more accurate and reliable mechanism (Option)

3. Part load effective economizer application.

Bitzer Screw Compressor

3. Condenser

The condenser for a water-cooled screw chiller usually connects with the cooling tower for heat dissipation purposes.

The water-cooled condensers of screw chiller work as the air-cooled condensers do, but they require two different steps to achieve heat transfer.

First, the heat will be transferred from the refrigerant vapor into the condensing water by a water-cooled shell and tube condenser.

Next, the temperature of the condenser water gets warm and will be pumped into the cooling tower where the unwanted heat is transferred to the ambient air.

The condenser used in TopChiller® brand water cooled screw chiller is featured by a shell and tube type heat exchanger that is easy for cleaning and its high quality helps the whole chiller work at an optimized efficiency level.

Structure-diagram-of-shell-and-tube-condenser

But there is another important issue, how to clean and maintain the water-cooled condenser?

The water-cooled shell and tube-type condenser are prone to scale formation after long-term use.

If it is not disposed of in time, the scale will affect the heat transfer effect, increasing the condensing temperature of the water-cooled screw chiller, which will result in a decrease in cooling capacity and an increase in this water cooled screw chiller power consumption.

Therefore, the water-cooled type condenser should be frequently cleaned of scale.

There are three main methods for preventing and removing scale:

A. Mechanical descaling method:

Mechanical descaling is a method of descaling a condenser of a steel cooling pipe with a soft shaft washer and is particularly suitable for a vertical shell and tube condenser.

The methods of operation are as below:

1. The refrigerant in the water-cooled condenser is withdrawn.

2. Turn off all valves connected to the condenser and the refrigeration system.

3. The cooling water of the condenser is normally supplied.

4. The umbrella-shaped gear scraper connected by the soft shaft washer is rotated and descaled from top to bottom in the riser of the condenser.

And the cooling heat generated by the friction between the scraper and the pipe wall is cooled by the circulating cooling water. Flushed dirt, rust, and other dirt are washed into the pool.

In the descaling process, according to the fouling thickness of the condenser and the degree of corrosion of the pipe wall, and the length of the used pipe, the hob with the appropriate diameter is selected.but the diameter of the hob selected in the first pass descaling is smaller than that of the cooling pipe.

The inner diameter should be appropriately small to prevent damage to the pipe wall, and the second round of descaling should be carried out with a hob close to the inner diameter of the cooling pipe.

The descaling can remove more than 95% of the scale and rust of the condenser.

The method of mechanical descaling is to use the bevel gear-shaped hob to rotate and vibrate the hob during the rotation of the cooling tube and remove the scale and rust in the condenser cooling tube after the descaling is completed.

The water in the condensate pool is completely removed, and the dirt, dust, and other dirt removed from the bottom of the pool are cleaned and refilled.

B. Chemical pickling and descaling method:

The condenser is cleaned with the prepared weakly acidic descaling agent to make the scale fall off and improve the heat transfer efficiency of the condenser.

The method of operation is:
1. Prepare the descaling solution in the pickling tank, start the pickling pump, and let the descaling agent solution circulate in the condenser tube for 24 hours. Under normal circumstances, the scale is removed after 24 hours.

2. After stopping the pickling pump, use a round steel brush to brush back and forth in the pipe wall of the condenser pipe, and rinse the scale and rust with clean water.

3. Repeat the cleaning of the detergent solution remaining in the tube with clean water until it is completely clean. The chemical pickling and descaling method are suitable for vertical and horizontal shell and tube condensers.

C. Electromagnetic water descaling method:

The working principle of the electronic magnetic water device is to dissolve calcium, magnesium, and other salts in the cooling water flowing through the condenser in water in a positive and negative ion state at normal temperature.

When the cooling water flows through the transverse magnetic field of the magnetic water at a certain speed, the dissolved calcium and magnesium ions receive the induced electric energy, the charge state changes.

And the electrostatic attraction between the ions is disturbed and destroyed, thus changing its crystallization condition makes the structure of the crystal lose.

The tensile and compressive resistance is reduced, and the hard scale with strong adhesion cannot be formed, and the loose sludge is discharged with the flow of the cooling water.

This descaling method can effectively prevent the generation of a new scale, and can also remove the original scale because the ion loses the scaleability after using the electronic water magnetizer, which loses the protective effect on the original scale.

In addition, the magnetized cooling water has a certain amount of inductive electric energy.

At the same time, due to the different expansion coefficients of the steel pipe and the scale in the condenser, the original scale gradually cracks, and the magnetized water invades the crack without interruption.

This will also destroy the adhesion of the original scale makes it gradually lose and falls off on its own and is continuously taken away by the circulating cooling water.

The descaling method of the electronic magnetic water device is simple and easy to operate, has low labor intensity, and performs descaling and prevention of scaling without affecting the normal operation of the refrigeration system.

The significance of descaling and energy saving:
Once the condenser is scaled, the thermal resistance increases, so the thermal resistance increases, and the heat transfer coefficient value decreases.

Because the condensation temperature is inversely proportional to the heat transfer coefficient, the condenser temperature rises and the condensing pressure increases accordingly.

The more serious the fouling of the condenser, the more significantly the condensing pressure is increased, so that the power consumption of the refrigerator is increased, and the power consumption of each operating device of the refrigeration system is correspondingly increased, resulting in a waste of electric energy.

4. Oil Separator

Some oil in the chiller will come out when the refrigerant is compressed by the compressor.

If the oil is not removed in time, it will flow through cooling components after leaving the condenser, which will hinder heat transfer and even reduce the capacity of the evaporator and condenser.

The oil separator is to make the oil detached from the refrigerant and minimize the amount of oil flowing in the water-cooled screw chiller.

As a result, it is particularly crucial to prevent oil from gathering in the unit.

Water-cooled screw chillers manufactured by TopChiller® contain oil separators that are smaller in size and have fewer moving parts, which make them more effective in the removal of oils in the refrigerant and also lower in terms of failure rates.

A double screw compressor integrated with an oil separator maximizes the efficiency of the water-cooled screw chiller.

5. Evaporator

The evaporator of the water-cooled screw chiller is where the chilled water is formed.

In a shell-and-tube evaporator, the liquid refrigerant at low pressure enters the shell and flows through the tubes, absorbing heat from higher-temperature water that flows through the tubes.

When the water has reached a particular temperature, it will send the heat back to the refrigerant in the evaporator and get evaporated.

In the meantime, the water temperature cools down when the heat is extracted by the refrigerant.

Generally, the evaporator is installed between the compressor and the expansion valve.

Water-cooled screw chillers manufactured by TopChiller® are featured by shell and tube heat exchanger, and also provides options for plate heat exchangers.

All are suitable for R22, R407c, R134a, R404A, and many other refrigerants.

Here we must pay more attention to one important point. As all know, for regular water cooled screw chiller, we are using tap water or well water as the cooling water source, also the inlet and outlet chilled water tap water, or freshwater.

But sometimes there are lots of end-users using seawater, marine water as the water cooling sources, to cool down marine water, brine water, sulfuric acid, or other chemical liquid.

In this case, the regular shell and tube heat exchanger can’t be used due to all these coolants and liquid are strongly corrosive.

So we must go for a titanium material shell and tube heat exchanger as an ideal solution for a chemical factory, seawater cooling, marine or brine chiller, and shrimp or seafood hatchery.

Titanium material shell and tube heat exchanger can cool the corrosive liquids including hydrochloric acid, sulfuric acid, nitric acid, chromic acid, acetic acid, and hydrofluoric acid, seawater, marine or brine water directly.

Please check below titanium material shell and tube heat exchanger:

Please contact the TopChiller refrigeration expert to customize your water-cooled screw chiller.

6. Expansion Valve

The expansion valve connects the evaporator and condenser to keep the pressure difference between the two sides, and controls the fluid flow of the refrigerant into the evaporator and eventually into the compressor as well.

The pressure has to be reduced if we need to reduce the temperature and thus, some kind of restriction is required for this to take place.

Expansion valves enable users to regulate the capacity load based on the requirements of the production process.

TopChiller® designed thermostatic expansion valves for water-cooled screw chillers to ensure the unit is operating at the optimized level.

The thermostatic expansion valve is a restriction device that can adjust the refrigerant pressure and maintain a superheat at the outlet of the evaporator.

What’s more, it can achieve stable evaporator temperature as well as maintain the pressure according to the required saturation temperature by simply employing an evaporator pressure regulating valve to the chiller.

Both air-cooled screw chiller and water-cooled screw chiller consist of the screw compressor, evaporator, condenser, oil separator, and expansion value.

But what are the advantages of water-cooled screw chillers compared to air-cooled screw chillers?

The Advantages of Water Cooled Screw Chiller Compared to Air Cooled Screw Chiller

Both kinds of chillers operate based on similar principles to complete the heat transfer but they use different components to cool the condensers.

Water-cooled chillers use water consumption while air-cooled chillers need air.

The major difference is that a water-cooled screw chiller requires a cooling tower and the water-cooled screw chiller is worth considering as it has the following advantages compared to an air-cooled screw chiller.

1. Quiet Operation

Water-cooled screw chillers are more silent than air-cooled screw chillers when they are in operation.

Noise in some workplaces can be annoying, especially in hospitals or other business offices.

Air cooled screw chillers generally create more noise because of their fans.

2. Environment Adaptability

As water cooled screw chillers do not need ambient air while they are operating, there are no strict requirements for the ventilation conditions around the unit.

If the ventilation is minimal around an air cooled screw chiller, the operating performance will be badly affected because they rely on the ambient air for cooling.

Therefore, water cooled screw chillers are the better choice in places where the air recirculation is restricted.

The air cooled screw chillers, require open areas such as roof, parking lot, or ground level area to utilize the air for cooling.

3. Energy Efficiency

Although air cooled screw chiller may cost less than water cooled screw chiller in terms of the purchase price as water cooled screw chillers require cooling towers and water pumps, etc.

However, the compressor costs and the energy consumption costs for air cooled screw chillers are generally higher due to their basic operating design.

However, water cooled screw chillers are more energy-efficient as water cooled screw chillers are equipped with cooling towers that allow the cooling system to operate at low consumption costs.

Water-cooled screw chiller VS air-cooled screw chiller:

The air-cooled screw chiller is suitable for medium and small systems with tight water sources in the region the longer the annual operating hours, the more advantageous the air-cooled refrigeration unit is.

Also, the annual comprehensive cost of the air-cooled chiller is lower than that of the water-cooled screw chiller.

But water-cooled screw chiller If the system is managed and the water supply is controlled below 3%, the initial investment of the air-cooled screw chiller compared with the water-cooled screw chiller is difficult to recover.

This article is a comprehensive analysis and comparison of air-cooled/water-cooled screw chiller, and just hope to be useful to everyone.

First, the comparison of two screw chillers

1. The water-cooled screw chiller must be equipped with a cooling tower. For the open cooling circulating water system, since the cooling water absorbs heat, it is in contact with the air, and CO2 escapes into the air.

The dissolved oxygen and turbidity in the water increase, resulting in a cooling circulating water system. Big problems: corrosion, scaling, bacterial growth, sludge.

If the water quality is not treated, the refrigeration equipment will be seriously damaged, and the heat exchange efficiency will be greatly reduced, resulting in a waste of energy.

Therefore, it is very important to carry out corrosion inhibition, scale inhibition, sterilization, and algae treatment on the water system.

The water-cooled screw chiller must be equipped with an electronic water treatment device or a strong magnetic water treatment device.

Otherwise, the heat dissipation efficiency is too large. The longer the use time, the worse the system effect. The annual water treatment cost is high, and the effect cannot reach 100. % descaling.

The quality of cooling circulating water is the key. The processing of cooling circulating the water is divided into physical and chemical methods.

2. Water-cooled/air-cooled screw chillers can be used on small systems. Most of the large screw chiller units are water-cooled screw chillers.

The initial investment in water cooling is less than that of air cooling. But with the cooling tower and the machine room\electronic water treatment instrument, etc., there is no place to go!

Besides, in terms of long-term operation, the cooling efficiency of water-cooled chiller will decrease relatively, and the air cooling will drop. Very small.

3. The air-cooled screw chiller adopts air cooling mode, which eliminates the cooling tower, cooling water pump and piping system that is essential for the cooling water system, avoids condensation of the condenser, blockage of water pipes, and saves water resources in areas with poor water quality.

It is the most economical and simple machine for maintenance and repair of the air-cooled screw chiller.

The air-cooled screw chiller has a slightly higher one-time investment than the water-cooled screw chiller, but the annual operating cost is lower than that of the water-cooled screw chiller.

The construction cost of the equipment room is the least in various air-conditioning cold and heat source systems, and the maintenance cost is about half of the cost of water-cooled screw chiller.

The air-cooled screw chillers are louder in noise level than water-cooled screw chillers and can only be installed outdoors.

Most of the water-cooled screw chillers are installed in the basement or outdoors.

4. The service life of water-cooled screw chiller is 15-20 years; the service life of an air-cooled screw chiller is around 6-11 years.

The COP value represents the energy efficiency ratio of the air-cooled  screw chiller. The water-cooled screw chiller refrigeration efficiency is higher than the air cooled screw chiller.

The higher the cop value, the higher the air-cooling efficiency and the better energy saving. (COP = air cooling nominal cooling capacity / compression input power).

Air cooled screw chiller’s  COP value is 3.44; while water-cooled screw chiller COP value is 5.2.

This is a big difference in the cost of cooling performance.

2.  The technical and economic comparison of the air cooled screw chiller and water cooled screw chiller 

Considering that the number of air-cooled condensers of large refrigeration units is too large, it is usually difficult to arrange.

On the other hand, too small water-cooled screw chillers are also unfavorable for use, so for medium-sized air-cooled screw chillers and the same amount of cooling.

Now compare a model of water-cooled screw chiller with the same air-cooled screw chiller with main unit and evaporator:

The annual operating time of the screw compressor is 1000 hours to 3000 hours, and the annual running time of the cooling tower and the pump is 1400 hours to 4200 hours.

In summary, The initial investment of air-cooled screw chillers is relatively high, and the power consumption per unit of refrigeration capacity is also slightly higher than that of water-cooled screw chillers.

However, the annual comprehensive cost of air-cooled screw chillers is the same as that of water-cooled screw chillers.

The longer the annual running time of the screw chiller, the more favorable it is to the air-cooled screw chillers.

The initial investment recovery period of the air-cooled screw chiller compared with the water-cooled screw chiller is shorter.

The amount of water replenishment of the water cooled screw chiller is an important factor affecting its cost.

Strengthening maintenance management and reducing water consumption are important aspects of reducing the cost of water-cooled screw chillers.

Industrial Applications of Water Cooled Screw Chiller

Different types of screw chillers are used in various industries.

However, today let’s talk about the most common applications of water cooled screw chillers.

1. HVAC

Heating, Ventilation and Air Conditioning (HVAC) systems are used to dehumidify the air and to cool the temperature to create a comfortable interior environment despite the different external conditions.

Water cooled screw chillers have become an essential part of HVAC systems and are being used in various facilities, including restaurants, hospitals, hotels, office buildings, supermarkets, etc.

TopChiller® water-cooled screw chillers are suitable for being a key component for HVAC systems.

As a long-time chiller supplier for many medical facilities, TopChiller® water-cooled screw chillers can provide an exact cooling effect as required.

Whether you require a water-cooled screw chiller for an HVAC system, your facility will be comfortable and the occupants can find peace of mind even in the hottest time of the day.

2. Milk Cooling

Keeping milk at a cool temperature during processing is very important. The milk could go bad easily in a short period if it’s not stored in a certain environment.

Therefore, water cooled screw chillers are very popular for milk cooling as they can extend the storage life before the milk is transported to the market for sales.

The milking machines will automatically pump the milk into a storage tank for pasteurization which will generate heat during the process.

Water cooled screw chillers manufactured by TopChiller® can remove heat from pasteurization and reduce the temperature of the milk to an appropriate point.

The major purpose of using a water-cooled screw chiller is maintaining milk at a low temperature prevents the milk from deteriorating.

3. Die Casting

Die casting is a process in which the molten metal is pushed into a steel mold under high pressure into mold cavities.

In the metal casting process, there are five steps involved: clamping, injection, cooling, ejection, and trimming.

The cooling water is required when the molten metal is injected into the mold and the metal will be in final shape after it is solidified and cooled down.

TopChiller® water cooled screw chillers are efficient in cooling die casting machines and can provide premium reliability and achieve high efficiency at all operating conditions.

Excellent design and high value make water cooled screw chillers supplied by TopChiller® are being used by many industrial companies from different countries all over the world.

Trouble Shooting of Water Cooled Screw Chiller

It is annoying if your water cooled screw chiller always alarm or error happens.

Let’s study some common alarms and error we always meet:

1. Low exhaust temperature, oil level protection

Phenomenon: After the power is turned on for about 1~2 minutes or 2~3 minutes, the oil level protection occurs, the water-cooled screw chiller alarms and stops; when the oil level is protected, the oil does not see the oil in the compressor oil sight glass; the exhaust temperature of the unit is always up, only 40 Around °C

Analysis: Before the start-up, the oil heater is not heated to more than 8H, so that all the oil in the compressor accumulates in the evaporator, resulting in poor heat exchange effect of the evaporator, easy to bring liquid with suction, so the exhaust temperature is low every time.

The low gas temperature affects the separation effect of the oil separator, which ultimately causes the compressor to be oil-deficient. We also need to check for oil leaks.

Disposal: Recycle or release all the refrigerant and oil in the system, then refill the refrigerant according to the factory procedures, add lubricating oil; the unit runs normally.

The main reasons for the protection of the oil level of the water-cooled screw chiller are:

A. Oil leakage.

Phenomenon: Turn on the water-cooled screw chiller and do not see the oil level when stopping.

B. The oil level switch is damaged.

Phenomenon: start-up, the oil level is full when stopping, oil level protection occurs;

C. There is too much refrigerant in the oil.

Phenomenon: The oil level is full when starting, and the oil level is not seen after starting. After a long-term shutdown or a long-term power failure, the electric heating time is not enough.

2. The safety valve is opened

Phenomenon: The water-cooled screw chiller safety valve is opened.

Analysis: There are multiple water flow switch protections on the touch screen.

The initial judgment is that the cooling water pump suddenly stops, the high pressure rises, and the opening pressure of the safety valve is exceeded.

Disposal: Replace the safety valve and refill the refrigerant.

After starting the machine, the parameters are normal, but the high pressure is high and the cooling water flow is small. It is also the reason for the safety valve to open.

There are two cases in which the water-cooled screw chiller safety valve is opened:

1. The evaporator safety valve is opened.

Generally occurs when the water-cooled screw chiller is in shutdown:
During the transportation of the water screw chiller, it is exposed to the sun; The screw chiller was installed on the roof without any shading measures.

The safety valve is not tested or updated for a long time.

Cause: In this case, the refrigerant pressure exceeds the opening pressure of the evaporator safety valve. The safety valve is open.

2. The water-cooled condenser safety valve is opened:
This occurs when the unit is turned on: the high voltage rises rapidly due to sudden causes.
A. The cooling water pump is powered off;
B. A cooling tower fan is powered off;
C. The cooling water system is dirty.

Reason: In this case, the refrigerant pressure will suddenly rise, the high-pressure protection will not be able to move, or the action will be high. The high pressure has exceeded the opening pressure of the safety valve.

Special Note: After the safety valve of your water cooled screw chiller is opened, the copper tube of the evaporator may be cracked due to a large amount of leakage of the refrigerant.

A water ingress accident occurred. The safety valve is a safety device and the safety valve must be tested every year as required.

3. Water cooled screw chiller  cannot be loaded

Phenomenon: The water cooled screw chiller cannot be loaded during operation, and it is always maintained at 50% operation, and the chilled water temperature cannot be reduced.

Analysis: The high pressure of this water cooled screw chiller was found to be above 17kG. According to the control of the screw chiller, at this time, to prevent the high pressure from continuing to rise.

The screw chiller is actively unloaded, and it is normal from the signal of the solenoid valve. The temperature difference between the cooling water reaches 10 ° C or more. The cooling water pump has a small flow rate.

Handling: Replace the water pump. The water cooled screw chiller is operating normally.

There are many reasons why the screw compressor is not loaded, and the organic group actively unloads, which has the reason for the compressor itself.

High-pressure unloading problems are more common, mainly due to the high condensing pressure of the unit. Also, need to pay attention to the compressor oil circuit blockage.

4. Water cooled screw chiller cannot be loaded

Phenomenon: There are two main situations
The water cooled screw chiller has high-pressure protection within 3 minutes of starting;
The screw chiller has high-pressure protection during operation;

Reason: There are many reasons, and it is necessary to check them one by one, but the most common cause is the problem of the water system:

• The cooling tower is dirty and the heat exchanger copper tube is fouled.
• The cooling tower has a small capacity.
• Small water flow;
• The screw chiller unit is at the highest point on the roof and the water pipes cannot be drained.
• The screw chiller electronic expansion valve is stuck;
• The maintenance of your screw chiller has a short vacuum time when flushing the refrigerant.

Note: After scaling, the performance of the heat exchanger is very large.                                                  It is difficult to clean the dirt by the method of passing bubbles. It is necessary to use the syrup.

5. Water cooled screw chiller low-pressure error/alarming

Phenomenon: There are two main situations:
The water cooled screw chiller has low voltage protection within 3 minutes of starting;
The water-cooled screw screw chiller has low voltage protection during operation;

Reason: There are many reasons, and it is necessary to check them one by one, but the most common cause is the problem of the water system:

• The heat exchanger copper tube is fouled.
• The unit is at the highest point on the roof and the water pipes cannot be drained.
• Small water flow;
• The unit electronic expansion valve is stuck;
• Refrigerant leaks.

The method of starting the refrigerant and adding the refrigerant is very wrong.

When flushing the refrigerant, it is often added first. After adding it, add the refrigerant utilizing booting.

When discharging refrigerant and adding tank refrigerant, the chilled water pump must be turned on, otherwise, the shell and tube may be frozen.

Water-cooled screw chiller debugging process and troubleshooting

The water-cooled screw chiller is mainly composed of a semi-hermetic screw compressor, a shell and tube condenser, a dry filter, a thermal expansion valve, a shell and tube evaporator, and an electric control part.

Please note!

When the operating temperature of the water cooled screw chiller unit is low in winter (below 0 degrees), it is recommended to increase the anti-freezing measures to protect the operation of the unit.

The water-cooled screw chiller must drain the water in the heat exchanger and the outdoor water pipe during the winter period, otherwise, it is easy to freeze. The screw chiller is damaged.

Because the water-cooled screw chiller is not operating in the winter, it is recommended to drain the water in the waterline or add enough ethylene glycol solution to the line as a precautionary measure to refill the water when the next operating season arrives.

First, the water cooled screw chiller normal operating status

The height of the refrigerant liquid level: R134a water-cooled screw unit evaporator liquid level: Under the condition of stable working conditions and water flow, the height of the liquid surface is just the best.

Exhaust gas temperature: Under nominal conditions, the exhaust gas temperature should be in the range of 45 °C-65 °C (R134a) and 50 °C-75 °C (R22) (exhaust temperature and evaporator and condenser outlet temperature) related).

Compressor oil sight glass: The high oil sight glass is full, and the oil level of the low oil sight glass is not lower than 1/2 of the oil sight glass.

High and low-pressure values: high-pressure value is not higher than 1.14MPa (R134a) and 1.8MPa (R22), low-pressure value is not higher than 0.18Mpa (R134a) and 0.3MPa (R22), the oil pressure difference is 250kPa, suction and exhaust pressure difference It is 0.4 MPa.

Saturation pressure: At any time, the corresponding saturation pressure at the inlet temperature of the evaporator and condenser should not exceed the design pressure of the container.

Otherwise, the safety valve will start to jump and the refrigerant will leak out (the water temperature should not exceed 45 °C).

Exhaust superheat: Refrigeration exhaust superheat is between 10 °C and 20 °C, and the suction superheat is 0.5 °C – 3 °C. Adjusting the suction superheat depends on the exhaust superheat and the evaporator level.

Outlet water temperature: The evaporator outlet water temperature should be controlled within the range of 3-20 °C; the condenser outlet water temperature should be controlled within the range of 21 °C-45 °C.

Voltage and current: The maximum allowable phase voltage imbalance is 2% and the phase current imbalance is 10%. The phase voltage imbalance is greater than 2% and must not be turned on.

Second, debugging common troubleshooting problems of  water cooled screw chiller

Suction superheat adjustment: Suction superheats = suction temperature – evaporator saturation temperature on the outlet side of the evaporator.

Adjusting the suction superheat depends on the exhaust superheat and the evaporator level.

Suction superheat mainly determines whether the expansion valve selection is appropriate.
The purpose of adjusting the suction superheat is to prevent liquid shock; to fully exert the performance of the evaporator.

Inhalation superheat target value: 0.5 ~ 3 °C.
The suction superheat is lower than the target value, indicating that the expansion valve opening is large, which easily leads to a liquid hammer.

If the suction superheat is higher than the target value, the expansion valve opening is too small, which will result in low evaporator utilization and impact on capacity.

If the suction superheat is too high, the expansion valve opening may be too small, which may cause low pressure to be too low.

The low-voltage fault of the unit: R134a low-pressure alarm value is 0.18Mpa. R22 Low-pressure alarm value is 0.3Mpa Unit low-pressure alarm Possible causes:

Less refrigerant.
The electronic (thermal) expansion valve is faulty or has a small opening.
The compressor suction shut-off valve or the liquid line valve is closed (on alarm).
The sensor is damaged or the collected data does not match the actual value.

Differential pressure alarm: To avoid the shortage of oil supply to the compressor, sufficient pressure difference must be ensured during the operation of the unit to ensure the normal return of the compressor.

The oil level is too low: during the operation of the unit, attention should be paid to the state of the oil mirror of the press, the state of the return line and the liquid level of the evaporator, and the liquid level of the evaporator and the superheat of the exhaust.

Pay attention to the following points when the oil level of the press oil sight glass drops:
Observe the high and low-pressure side view liquid mirror of the return line, whether the high-pressure side oil mirror has oil flowing quickly, and whether the low-pressure side glass returns oil.

If it is found that the oil flow is not smooth, it is necessary to check whether the return line of the return line is not open or the opening is too small;

Observe whether the liquid level of the evaporator is suitable.

It is usually better to use the liquid level to flow over the first row of heat exchange tubes.

If the low pressure cannot return the oil because the liquid level is too low, the evaporator can be opened and the evaporator level can be increased by adjusting the superheat degree. rise.

If the oil or exhaust temperature is too low due to the liquid suction caused by the liquid level being too high, the opposite adjustment is made.

Observing the system pressure difference, the pressure difference is too small can also lead to insufficient oil return.

The pressure difference can be established as soon as possible by adjusting the water temperature.

Undercooling: Undercooling = liquid saturation temperature – condenser outlet refrigerant temperature

The degree of undercooling mainly determines whether the refrigerant filling amount is appropriate.

The purpose of adjusting the degree of subcooling is to ensure that the refrigerant entering the expansion valve is a liquid and prevents the liquid from flashing before the expansion valve.
Undercooling target value: 4 ~ 6 ° C

If the degree of subcooling is lower than the target value, the refrigerant may be less filled or the number of supercooled tubes may be less.

The refrigerant may be added or the supercooled pipe may be added.

If the degree of subcooling is higher than the target value, the refrigerant may be excessively filled and the refrigerant may be properly discharged.

Common error and alarm analysis of water cooled screw chillers

1. High-pressure fault:

The screw compressor discharge pressure is too high, causing the high-voltage protection relay to operate. The compressor discharge pressure reflects the condensing pressure.

The normal value should be 1.40~1.60MPa, and the protection value should be set to 2.00MPa.

If the long-term pressure is too high, it will lead to an excessive operating current of the compressor, easy to burn the motor, and easily cause damage to the valve port of the compressor exhaust port.

What should be done is to control the discharge pressure of the compressor in a safe range.

The reasons for the high-pressure fault are as follows:

• The cooling water temperature is high and the condensation effect is poor;
• The cooling water flow is insufficient to reach the rated water flow rate;
• Condenser fouling or blockage;
• Excessive refrigerant charge;
• A non-condensable gas such as air or nitrogen is mixed in the refrigerant;
• False positives caused by electrical faults.

2. Low-pressure fault:

The suction pressure of the compressor is too low, resulting in the action of the low-voltage protection relay.

The venting pressure of the compressor is the evaporation pressure, the normal value should be 0.40~0. 60MPa and the protection value is set to 0. 20MPa.

If the suction pressure is low, the amount of return air is small, the cooling capacity is insufficient, and the electric energy is wasted.

The heat of the compressor motor for return air cooling is poor, and the motor is easily damaged! The solution is the same as the high-pressure fault, try to keep the compressor within the normal pressure range.

The reasons for the low-pressure fault are as follows:

• Insufficient refrigerant or leakage;
• Insufficient flow of refrigerant water, less heat absorbed;
• Electrical faults cause false positives;
• The outside temperature is low.

3, low valve temperature failure:

Thermal expansion valve outlet temperature reflects the evaporation temperature, which is a factor affecting heat transfer, generally, it is different from the refrigerant water effluent temperature difference of 5.0 ~ 6.0 ° C.

When a low valve temperature fault occurs, the compressor will stop. When the valve temperature rises, it will automatically resume operation with a protection value of -2.0 °C.

The reasons for the low valve temperature fault are as follows:

• A small number of refrigerant leaks generally manifested as a low valve temperature fault rather than a low-pressure fault;
• The expansion valve is blocked or opened too small, and the system is not clean;
• Insufficient flow of refrigerant water or blockage of the evaporator;
• False alarms caused by electrical faults, such as poor valve temperature contact

4. Compressor overheating fault:

The thermistor is embedded in the winding of the compressor motor, and the resistance is generally 1kΩ.

When the winding is overheated, the resistance value will increase rapidly.

When the winding exceeds 141kΩ, the thermal protection module SSM will act to cut off the unit operation and display the overheat fault and the fault indicator light.

The reasons for the compressor overheating fault are as follows:

• The screw compressor load is too large and the overcurrent is running;
• Screw compressor overcurrent operation caused by electrical failure;
• The overheat protection module M is wet or damaged, the intermediate relay is damaged, and the contacts are defective.

5. Communication failure:

The control of each module by the computer controller is realized through the communication line and the total interface board.

The main cause of communication failure is poor contact or open circuit of the communication line, especially the interface is affected by moisture oxidation, and the unit is bad.

If the electronic board or the total interface board is faulty, the address dial switch is improperly selected, and the power failure can cause a communication failure.

The above five kinds of fault phenomena are the most common, and understanding these fault phenomena and judgment ability and solution has an irreplaceable effect on extending the service life of the screw chiller.

Why TopChiller® Can Be a Reliable Supplier for Water Cooled Screw Chillers?

1. Optimum Performance of  Water Cooled Screw Chiller

TopChiller® water cooled screw chillers are helpful to improve energy efficiency, and by using a semi-hermetic dual screw compressor, these chillers can realize step-less capacity control.

Working at high noise levels will affect the health of the workers and it’s also important that companies should focus on noise reduction, especially in workplaces sensitive to sounds.

Running noise created by TopChiller® water cooled screw chillers is also very low as there is little friction in the compressor.

The screw compressor can serve for a long time thanks to the high-quality oil separator inside.

The safety protection devices are also the main reason that TopChiller® water cooled screw chillers have a longer lifespan than other brands of chillers.

Their features include but are not limited to the following functions: overheat protection, overcurrent protection, over-pressure protection, over-temperature protection, flow rate protection, anti-freezing protection, low-level coolant protection.

These protection methods prevent the chillers from being damaged by overload situations and the chillers can maintain smooth operation and long service life.

2. Decades of Professional Experience in Screw Chillers

TopChiller® was founded in 2003 and has been specialized in the research and sales of industrial cooling equipment and replacement parts since then.

Decades of expertise have helped TopChiller® earn clients from over 58 countries and regions. All water-cooled screw chillers manufactured by TopChiller® are CE marked and comply with standards products sold in European countries.

TopChiller® also earned a series of awards conferred by the government in China for energy-saving and technology innovation.

3. Worry-Free After-Sales Service

As the chillers are used for production every day, it’s very crucial to make sure they are operating smoothly without malfunction issues.

If by any chance your water cooled screw chiller goes out of order, quick technical assistance must be available on hand to solve the problem.

At TopChiller®, we have a professional team in charge of quality inspection before the shipment and maintenance support.

For every water cooled screw chiller purchased from TopChiller®, its quality must be carefully checked before shipment to ensure the client will receive a satisfying chiller.

In the meantime, TopChiller® also provides a comprehensive range of services for pre-sales questions and after-sales issues, covering everything from product inquiries to maintenance support.

All clients can still expect professional and personal care and reliable services from our support team at any time.

All of our water-cooled screw chillers come with an 18-month warranty and we are always ready to offer lifetime technical support to our valued clients.

4. Customizable Water Cooled Screw Chillers

There are many factors involved when selecting the right water-cooled screwchiller for industrial production. Different screw chillers in different sizes have cooling capacities.

It’s very important to assess if a chiller can just fit your specific requirements and help bring maximum profitability to the production process.

TopChiller® has developed a wide range of water-cooled screw chillers that also come with various specifications for the customers to choose from.

In the meantime, we also accept customization requests to help your business reduce operating costs and create more profits.

DM23C temperature controller for water-cooled screw chiller operation manual

Description of Keypad of Controller
1. The layout of the controller

2. Description of LEDs
Power supply LED

When the unit is powered on, the LED will illuminate in RED color indicating the unit is connected to the power mains.
When the display enters into screen saver status, the LED will flash in RED color.
Running LED
When the screw chiller is switched on, the LED will illuminate in GREEN color indicating the unit is in On status.
Error alarming LED
When the screw chiller is working, if any alarm appears, the LED will begin to flash in YELLOW color.

User Operation and setting

1. Power supply to the screw chiller
All screw chillers leave the factory completely cabled and ready for connection to the power supply and for the external interlocks to be connected to the terminals provided inside the electrical box.

It’s necessary to install a main switch near the unit to connect or disconnect the unit from power mains.

Electrical connections must be carried out by qualified personnel in respect of current legislation.

For all electrical work refer to the electrical wiring diagrams in this manual.

You are also recommended to check that the characteristics of the power mains are adequate for the absorptions of the screw chillers, also bearing in mind the possibility of other equipment being used at the same time.

For the functional connection of your water cooled screw chiller brings the power supply cable to the electrical box and connect it to the terminals when your water cooled screw chiller is powered on, the controller will be switched on.

2. Operation main interface
The first display is the count down interface as below:

After over the countdown within 10 seconds, they will enter into the startup the interface as below:

Display the environment temperature in the start-up interface as above

No display the environment temperature in start up the interface as above

NOTE: About the environment, temperature display can be set up based on that needed or not.
Detail explains how to set up, please refer to page 17 [ tem 2: Sensor setup ]

Description of every button in the startup interface as below:
WorkMode: working mode
Heat: heating mode
Cool: Cooling mode
R/S Mode: control mode
Manu: manual control
Time: Timing control
Week time: week timing
If: be of no effect
Effi: in effect
Call-In: control water in temperature
This temperature is the setup temperature
Anti-HT: anti-heat protection will be displayed when heating mode
Anti-ice: anti-freeze protection will be displayed when cooling mode
C.In°C: water out the temperature on the user side
E.In°C: water in temperature on the user side
Run: press this button to start up the unit
Stop: press this button to turn off the unit
Query Err: press this button to check the current alarms list
User setting: press this button to enter in the user setting parameter menu. (need password)
Query Sta: press this button to check the parts state list
History: history error record
Unit Sta: unit state
The machine is idle: the unit is standing by
The machine is alarm: unit is in alarm
Guide: user guide

1)Startup the screw chiller
In the main operation interface, press the RUN button to start up the unit,
The following window will come up on the display,

Press ENTER to confirm to start up your water cooled screw chiller
The RUN LED will illuminate in green color.
Components parts start up the sequence step by step as below :
the first running part is the air conditioning water pump
the second running part is the well water pump after several seconds
the third running part is the compressor after 3 minutes and the energy
the compressor will run based on the energy load from 0-25%-50%-100% step by step
After above, The water-cooled screw chiller  will be completely started up

2)Shut down the screw chiller
In the main operation interface, press the STOP button to turn off your screw chiller
The following window will come up on the display:

Press Enter to confirm the operation,
Components parts start up the sequence step by step as below :
the first stop part is the compressor, the RUN LED will turn off at the same time
the second stop part is the well water pump after 3 minutes
the third stop part is the air conditioning water pump after several minutes
After above, The screw chiller will be completely shouted down

3)Change the operating mode
Please refer to Item 1:Set user parameters

4)View the status of the main components
On the main operation interface, press the Query sta button to view the state of the parts interface as below:

Description of every button in the startup interface as below:
CM State % : compressor state
Stop: in stopping
Running: in running
0 (25/50/100) : energy load from 0/25%/50%/100%

A /C Pump: air conditioning water pump state
Stop: in stopping
Running: in running
Well Pump: well water pump state
Stop: in stopping
Running: in running
Exit: Press this button to go level up and return to the main operation interface
Unit: Press this button can enter into the Unit Status Query interface
Hcurve: Hour curve (display the water out and water in temperature curve within one hour)
Curve: Day curve (display the water out and water in temperature curve within one day)
Note: the Hcurve button and the D curve button is the same

Input: Press this button can inquiry and display 24 routes switch input’s name and state in every backboard.

Please see the below interface :

Press the Up/Down button to select the page number
Press Subb(-)/Add(+) is no use
Press exit to go level up
Please see the below table for detail opposite item
 running LED
If the LED illuminate in highlight indicating the component is running
If the highlight is off indicating the component is in standby status.

NOTE：
1、【control condenser fan】 when setup “discharge temperature”, that can not see; when setup “middle-pressure switch”, that can see.
2、【outside circle pump function】 when setup NO, that can not see. Or can see in the above interface
3、For Digital variables input, If there is no Digital variables input in the unit, that can set up “NO” and not connect with an electrical line; if setup “OFF”, need short circle when connecting with the electrical line.

output: Press the Output button and enter into the relay output interface display and inquiry the name and state of 20 routes input in every board. Please see the below interface :

Press the Up/Down button to select the page number
Press Subb(-)/Add(+) is no use
Press exit to go level up
Please see the below table for detail opposite item
 running LED
If the LED illuminate in highlight indicating the component is running
If the highlight is off indicating the component is in standby status.
Theory: Press this button can see the interface.

5)Alarm report and compressor work time
On the main operation interface, press the History button to check the alarm report and the compressor work time as below interface:

Press the Up/Down button to select the Item
The press enter button is confirmed and entered into
Press exit to go level up

a)Item 1: Query errors
Press the Up(Down) button and enter button, then can enter into the query error interface as below:

Press the Up/Down button to select the Item
By number: to check the alarm by the number if the alarm happened
By times: to check the alarms history by how many times this code has happened
By time: to check the alarms history by when it happened, the new alarm is on the top of the list
The press enter button is confirmed and entered into
Press exit to go level up

b)Item 2: Query compressor work time
Press the Up(Down) button to choose Item 2 and press the enter button, then can enter into the query error interface as below:

This interface displays the compressor run add-up time.
Press exit to go level up

6)Guide Item
On the main operation interface, press the Guide button to see the controller explain and version as below interface:

This interface display will support the controller summary and version for reference.
Press the Up/Down button to select the Item
The press enter button is confirmed and entered into
Press exit to go level up
3. User operation interface
Press the user set button on the main interface, then will display the interface as below:

On this interface, need to input the password (12345678) and then can enter it into the next interface:
If the password is not right, then will come up the below interface:

Please press the enter button to go lever up the main interface and try it again:
If the password is right, then will come up the below interface:

Press the Up/Down button to select an item
Press enter button and enter into the item which is chosen
Press the Exit button to go level up

1)Item 1:Set user parameters
Choose Item 1 and press the enter button, then can enter into the below interface:

In this item, you can modify work mode, Control temperature, Week timing, and once the timing
Press the Up/Down button to select the item,
Then press the Subb(-)/Add(+) button to modify the content and parameter
After one item is modified press the Up/Down button to select another item
Work mode: screw chiller unit working mode (NOTE: This item will be not changed when the unit is running.)
Cool: setting the unit in cooling mode
Heat: setting the unit in heating mode
Control temperature: unit water in temperature setting
Week timing: work time setting for every work
inef: be of no effect
effi: be effected
Once timing: If the unit is running, this setting time will be the shutdown time
If the unit is stopping state, this setting time will be the start uptime
Unset: no setting the once timing
00:00: use the week timing setting as this setting timing
NOTE: When to choose this Item and setting, Subb(-)/Add(+) button chooses the Unset or timing (00:00)
When choosing the timing (00:00), the Up/Down button chooses the hour(front 00) and the minute/second(back 00)
Then press the Subb(-)/Add(+) button to set the timing
When the operation is finished press the Exit button to go level up

2)Item 2:Set week timing
On the user setup interface, choose Item 2 by the Up/Down button and press the enter button to enter into the below interface:
This operation can set up the start and stop timing for the unit as every week.
This setting function is the unit will start and stop as the setting time for automatic within every week.
This can set up 7 days in one week and 3 times for starting and stopping time in one day.

The detail operation is as below :
Press the Up/Down button to choose the idiographic setting Item hour(00) and minute/second(back 00)
Press the Subb(-)/Add(+) button to modify the time number
Press the Clear button to cancel all of the time numbers if the setting is wrong.
When the operation is finished press the Exit button to go level up
NOTE: The MAX. display number of times in the pane is 23:59.
00:00 is been of no affect setting time.
It needs set up in effect for Week timing in the [Item 1] interface, then your setting can use.

3)Item 3:Use or not
On the user setup interface, choose the Item 3 by Up/Down button and press the enter button to enter into the below interface:

This interface function is to choose and control the compressor is to run or not.
The detail operation is as below:
Press the Up/Down button to choose every compressor
Press the Subb(-)/Add(+) button to modify
Use: The compressor is running
Unuse: The compressor is not running
When the operation is finished press the Exit button to go level up

4)Item 4: Set user time
On the user setup interface, choose the Item 4 by Up/Down button and press the enter button to enter into the below interface:

This interface function is setting the current time and will display it in the main interface.
This setting will not affect SYSTEM TIME. Same as a bell.
The detail operation is as below:
In this item, you can set the clock according to the local time
Press the number button to input
Press the button to confirm the input and choose the next Item
When the operation is finished, then press the Exit button to go level up

5)Item 5:Set contrast
On the user setup interface, choose the Item 5 by Up/Down button and press the enter button to enter into the below interface:

You can adjust the contrast at any time according to the requirement through this operation.
The detail operation is as below :
Press Add(+)/Subb(-) button to adjust.
Press the Return button to confirm and go level up.

6)Item 6:Set display mode
On the user setup interface, choose Item 6 by the Up/Down button and press the enter button.
Press Enter button can change the screen color from BLUE to WHITE and vice versa.

7)Item 7:Select language
On the user setup interface, choose the Item 7 by Up/Down button and press the enter button to enter into the below interface:

Choose the English or中文 button, then press the Exit button to confirm and go lever up.
8)Item 8: Adjust the screen
On the user setup interface, choose the Item 8 by Up/Down button and press the enter button to enter into the below interface:

Please operate as the clue on display in the interface.

9)Item 9: Modify user password

On the user setup interface, choose the Item 9 by Up/Down button and press the enter button to enter into the below interface:

The detail operation is as below :
Input the right password and press the button to confirm
If the password is right, it will request you to input the new password.

Press the button to confirm the input and it will request to repeat the 2nd time new password input.

If the 2nd time new password input is different from the first one. It will display as below:

Press Enter to repeat the above steps and to set up the new password.
Press the Enter button to confirm and go level up.

Machine setting
Press and hold the top left corner on the main interface for 3 seconds, then input the right password and enter into “unit setup”, only manufactory and debugging people have the right to operate. Please see the below interface:

Input the right password (12345678)
If input the password id wrong, press button the to cancel
Press the button to confirm and enter into the machine setting interface as below

On the above interface, the operation is as below :
Press the Up/Down button to select an item
Press enter button and enter into the item which is chosen
Press the Exit button to go level up

1. Item 1: Machine type setup
Below is the Machine type setup interface:

On the above interface, the operation is as below:
Press the Up/Down button to select an item
Press Subb(Add) button to modify
Press the Exit button to go level up
Temperature CTRL. Object: Temperature Control Mode
in: control water in temperature
out: control water out the temperature
Remote switch type: Line(Remote) control type
Dial: Dial or Manual
Pulse: Pulse
Screen protection time:
10Min: the time for Screen protection

Below table is the description for the setting item:

NOTE：
1、Used to the remote control unit. If setup “Manual”, base on the [ Line control switch ] and setup “ON”, if the switch is on and the unit will be start-up;

if the switch is off and the water-cooled screw chiller will be shut down.

If the switch “OFF”，the setup and result are reversed to above.

If setup “pulse”, press the line control switch, base on the screw chiller unit state, and decide whether start-up or shut down, the “start” and “Stop” key on the touch is available.

2、The screen protection function, if not touch the screen within 10 minutes, the system will into the screen protection state, touch the screen lightly, and can be back.

3、If set up the [outside pump function] is NO, that will not see Or will seen.

1. Item 2: Sensor setup
Below is the Sensor setup interface:

On the above interface, the operation is as below :
Press the Up/Down button to select an item
Press Subb(Add) button to modify
Use: set up to use this sensor
Unuse: set up to nonuse this sensor
Press the Exit button to go level up

Below table is the description for the setting item:

NOTE：
1、[ outside circle pump temperature sensor ] will be seen when using it and under the automatic mode.
2、Above said the sensor can not set which stand for the water-cooled screw chiller must use this sensor., here display just for reference.

When the sensor will setting “Un-use”, the alarm will be of no effect, when the water-cooled screw chiller is running, it will not administer the action or not display the temperature number.

2. Item 3: Time parameter setup
Below is the Time parameter setup interface:

On the above interface, the operation is as below :

ΠPress the Up/Down button to select item

 Press Subb(Add) button to modify

Ž Press the Exit button to go level up

Below table is the description and setting range for the setting item

NOTE: 1 [delay after contactor start(part wiring NO.1) ]and [delay after contactor start(part wiring NO.2] will be displayed only when setup part wiring start-up; [delay after contactor start(STAR)] and [delay after contactor start(Corner) ]will be displayed only when setup staring start-up;

       2 [compressor operation time of un-full load]、[compressor operation time of forcing full load] use to solve the problem of compressor return oil.

Because worry to lead to the lubricating system bad and happen the lack of oil and harm the compressor’s life if the compressor will be operated under un-full load for a long time.

It is forbidden to uninstall when the compressor will reach the time [compressor operation time of un-full load] but not and will be forced to enter the full operation but not. Except happen stop or compressor fault or communication fault that compressor opposite backboard etc.

3 When the two parameters will be set up with “0”, that stands for nonuse the return oil valve. Usually, the compressor does not use the return oil, then uses the two-parameter, use to solve the problem of the compressor return oil.

When the compressor is running, the return oil valve will start to act, then open the return oil valve (Run oil EM valve time), then close the return oil valve (Shut oil EM valve time), then open the return oil valve (Run oil EM valve time) again, then go on.

1. Item 4: Input setup

Below is the Input setup interface:

On the above interface, the operation is as below :

ΠPress the Up/Down button to select item

 Press Subb(Add) button to modify

Ž Press the Exit button to go level up

Below table is the description and setting for the setting item

NOTE：

1、[control condenser fan] when setup “discharge temperature”, that can not see; when setup “middle-pressure switch”, that can see.

2、[outside circle pump function] when setup NC, that can not see. Or can see in the above interface

3、For Digital variables input, If there is no Digital variables input in the unit, that can set up “NC” and not connect with an electrical line; if setup “NO”, need short circle when connecting with the electrical line.

4、NO stands for “normal open”, NC stands for the “normal close”

1. Item 5: Temperature parameter setup

Below is the Temperature parameter setup interface:

On the above interface, the operation is as below:

ΠPress the Up/Down button to select item

 Press Subb(Add) button to modify

Ž Press the Exit button to go level up

Below table is the description and setting range for the setting item

1. Item 6: Temperature control parameter setup

Below is the Temperature control parameter setup interface:

On the above interface, the operation is as below:

ΠPress the Up/Down button to select item

 Press Subb(Add) button to modify

Ž Press the Exit button to go level up

Below table is the description and setting range for the setting item

1. Item 7: Initialize parameters

Below is the Initialize parameter operation interface:

On the above interface, the operation is as below:
Press the Up/Down button to select an item
Press enter button to confirm and enter into
Press the Exit button to go level up
Initialize machine para: Initialize all of the machine setup parameters to set up the windows default
Initialize error record: Initialize and eliminate all of the history error records
Initialize comp work time: Initialize compressor running add-up the time and reset to 0
Initialize user parameter: Initialize all of the user setup parameters to set up the windows default
1)Item 1: Initialize machine para
Use the Up/Down button to choose this item and press the enter button to enter into the interface as below:

Then press the enter button to confirm and go level up.
NOTE: The operation of Item 2 / Item 3 / Item 4 are all same as Item 1.

1. Item 8: Modify machine password
The operation of this Item is the same as the MODIFY USER PASSWORD.
Please refer to page 15 [tem 9:Modify user password]

Manufacturer setup
Press the top corner on the main start interface, then will display the interface as below:

Input the right password and press the button to confirm, then will enter into the manufacturer setup interface:

On the above interface, the operation is as below:
Press the Up/Down button to select an item
Press enter button to confirm and enter into
Press the Exit button to go level up

1.Item1: Set manufacturer para
Use the Up(Down) button and press the enter button, then enter into the below interface:

On the above interface, the operation is as below:
Press the Up/Down button to select an item
Press Subb/Add button to modify
Press the Exit button to go level up

Water Cooled Screw Chiller Installation guide

Note: For your reference only, TopChiller reserves the right to change the data without previous notice； Please kindly contact Us in time if you have special requirements.

A water-cooled screw chiller has been designed to be utilized in commercial and industrial air conditioning. Units are suitable for indoor installation.

The products are used in hotels, supermarkets, office buildings, exhibition halls, airports, and gym central air conditioning systems.

Water-cooled screw chillers are also fit for the requirements of precision air conditioning systems of electric, pharmaceutics, biology, spinning, mechanism, etc.

Where noise is a concern, water-cooled screw chillers provide the ideal solution for sound-sensitive environments. The compact design makes installation more flexible.

Water-cooled screw chillers are designed with high-efficiency scroll or semi-hermetic screw compressors, shell and tube heat exchangers, and various safety devices.

The water-cooled screw chillers are incorporated with a microprocessor control system allowing them to monitor and manage all the functions and to communicate with an external management system.

The water-cooled screw chiller is completely assembled in the factory, supplied with full refrigerant charge and control types of equipment, to reduce installation time and costs. The installation normally requires just hydraulic and electrical connections.

The R22&R407C range consists of 34 models, and the capacity is from 180 to 4120 KW. The unit can supply chilled water with the temperature of 5-15 ℃

The R134a range consists of 29 models, and the capacity is from 130 to 2500 KW. The unit can supply chilled water with the temperature of 5-15 ℃

The features of Water cooled screw water chiller system

1. Featured famous brand accessories, efficient, energy-saving, and durable screw water chiller

①Famous brand compressor, thermostatic expansion valve, heat exchanger tube, computer-control, ensure the unit efficiency, energy saving, durable

②Insulation materials used a flame retardant, to avoid fire accidents caused by human factors and ensure the safe operation of your screw water chiller.

2. The complete control screw chiller unit, multiple security measures to ensure the safe operation of the screw chiller
①Control function
Startup and Shutdown Control
selection of remote or short-range control
unit’s program setting
Return water temperature control settings
Automatic control of energy regulation
High-temperature low-temperature alarm limits
Anti-freeze protection settings
Compressor start and stop program management
Compressor manually management
Time management unit
Water pump management
Programmable temperature management
Fully functional operating parameter display
Fault alarm and diagnostic functions
②Unit with security features
Compressor phase sequence protection
Compressor overload, overheat protection
The system with high and low-pressure protection device
The system is equipped with the necessary safety valve, release valve, drain valve
Electrical components with electric shock protection
Frost protection
With the water cut-off protection system

3. Highly intelligent unit control system with centralized monitoring and remote control interface

①Use of foreign brands unit microcomputer control, intelligent control unit, English display, friendly interface

②High degree of automation, functional and program management to achieve unit commitment, timing control, pump management, full-function fault alarm, and fault self-diagnosis function. RS485/RS232communication interface with the same time, user-focused monitoring and implementation unit remote monitoring.

③With three levels of password protection to prevent the program and setting parameters are free to be changed.

④When the unit fails, automatically and immediately stop running, the alarm output signal and show the cause of malfunction and fault in the place, to facilitate the timely troubleshooting and maintenance unit.

⑤Compressor and pump interlock control; for synchronized actions and compressor valve

4. Multi-loop cooling system designed to improve unit reliability and anti-jamming capability
The family unit such as the use of two sets or two or more compressor units, according to each compressor for a refrigeration circuit design.

Mutual backup between each compressor to improve the reliability of the unit and anti-jamming capability.

5. Relying on the performance of advanced test equipment to ensure the unit is stable, safe, and reliable
TopChiller company has advanced “laboratory of water-cooled chillers, ” each air conditioner are operating
strictly in the factory test, to ensure the safety unit in poor condition and reliable operation, the factory’s products are qualified.

6. TopChiller water-cooled screw chiller structural features:
Match the famous brand and efficient compressor Host well-known brands of semi-closed with screw compressors, semi-hermetic screw compressor compared with piston compressors has the following advantages:
①Fewer parts (about piston compressor’s 1 / 3), simple structure, less wearing parts, high reliability, long life.
②Compressor suction and discharge uniformly continuous, low exhaust temperature, vibration, on the wet compression is not sensitive, strong resistance to fluid strike
③Unit EER ≥4.4W/W，Unit EER of large units of up to4.8W / W
④In the energy adjustment, the screw compressor advantages, the implementation of 25 – 100% non-class energy regulation

Matching high-performance dry-type evaporator with tube heat exchange tube evaporator
①Using the most advanced and efficient DAE  evaporation heat transfer pipes, the inner surface of the long thin spiral ribs, and spiral processes, the heat transfer coefficient, and heat capacity greatly increased.
②Optimization of the internal structure of the evaporator design, configuration, with the efficient liquid receiver, solve the system refrigerant distribution uniformity issues.
③Improved refrigerant water baffle seal structure to solve the problem of baffle leaks, greatly enhancing the efficiency of the evaporator heat exchanger to ensure units achieve higher levels of performance.
④Unique technical of heat exchanger cooling process’s design, a reasonable match for the system to ensure the cooling process and the waterside of the balance between cooling capacity, give full play to the high-performance heat exchanger; also match a reasonable system, and the unit more energy efficient.
⑤In the dry-type evaporator, the frost protection switch is also installed, release valve, to ensure the safety and cleanliness of the dry-type evaporator, and ease of maintenance.

Matching high-performance shell and tube water-cooled condenser with tube heat exchange.
①Using the most advanced and efficient DAE condensing heat transfer pipe, the outer surface of the long thin spiral ribs and spiral processes, the heat transfer coefficient and heat capacity greatly improved
②Internal structure of the optimal design, which greatly improved the condenser corrosion, anti-fouling ability, give full play to the condenser heat transfer, thus ensuring the unit achieve a higher level of performance.
③Shell and tube condenser is also installed with the safety valve, release valve, to ensure the safety of shell and tube condenser, ease of maintenance, and cleaning.

Anti-vibration unit designed to ensure unit low noise, low vibration
①Set the spring under compressor unit or rubber shock absorbers, damping efficiency more than 85% efficiency, that vibration transmission rate is less than 0.15, reducing unit vibration and system vibration, thereby reducing running noise of your screw chiller.

All the pipes are anti-vibration plastic pipe clamps, to avoid generating units and system vibration and noise

Matching famous brand refrigeration system accessories.
①For TopChiller brand water cooled screw chiller use famous brand spare parts, such as removable drier-filter, external balanced thermostatic expansion valve for liquid solenoid valves, sight glass, high and low-pressure control, air-exhaust temperature controller, etc, to ensure that units have a high level of performance
②Unit by 100% inspection of all materials before passing into the factory to ensure that the refrigeration system is of high reliability.

Matching advanced, highly reliable intelligent control systems and control technology
①Control system except with stand-alone automated configuration and function, also have shown multi-unit operation, according to the return water temperature automatically determine the air-conditioning system is part of the unit operation or all of the unit operation
②With RS485/RS232 communication interface, easy to achieve monitoring and remote monitoring by users.
③Control multiple units with the balance of the compressor to run functions to ensure efficient operation of the screw chiller unit.

Method of your screw chiller energy adjustment
Water-cooled screw chiller according to the temperature of returned chilled water to the logical calculation and control this unit and start running down. Each screw unit uses no stage energy regulation, energy-efficient unit operation to achieve
The water-cooled screw chiller structure is reasonable, installation, convenient for maintenance and management.

①unit with a unique stackable structure and form of the box-type frame structure, compact and strong, has good mechanical strength, small footprint. The appearance of high-strength unit Powder coating, corrosion rust, beautiful appearance.
②Modular design, product adaptability, parts interchangeability, and flexibility for a variety of models can be combined, in the most efficient way to provide users with the most attentive service.
③Screw chiller layout is reasonable, according to human engineering, installation, and maintenance space optimization settings to facilitate routine cleaning, maintenance, and repair.
④Machine in the form of units, low-pressure parts wrapped the insulation layer, the system has sufficient fluoride fuel, arrived at the scene and just to connect waterway pipe. You can open the unit when power is ready
⑤The computer will automatically start the pump motor, compressor, and refrigeration units, delay, interlock, protection and temperature regulation, and coordination of automatic control. Since then, the screw chiller under the control of the computer running by setting the temperature and the evaporator inlet temperature according to changes in energy regulation automatically
⑥Water cooled screw chiller installation flexibility, both on-site control can also be a remote control, easy for inspection and maintenance.

OPTIONAL FOR USER
Electronic expansion valve
Desuperheater is optional.
Electronic controller with the BMS system.
Low noise compressor cabinet or outside full cover
Channel Steel base

Working Principle of the Water Cooled Screw Chiller

The screw compressor absorbs low-pressure, overheat cooling medium steam from dry type evaporator, and passes through a compressor to be compressed to become a high-temperature, high-pressure, gaseous cooling medium, then go into condenser from discharge pipes to translate heat energy to cooling water and generate hot water for heating.

The high-temperature and high-pressure gaseous cooling medium are condensed normal temperature liquid state medium by circulating water, and then dry filter dries water and clean impurity of liquid state medium.

After going through the magnetic valve, expansion valve, and throttle, the pressure of the cooling medium becomes low-pressure from high-pressure when entering the evaporator.

In the evaporator, middle, low-temperature cooling medium absorbs heat energy from circulating water to evaporating continuously and becomes low-temperature, low-pressure overheat gaseous cooling medium when it arrives at the outlet of the evaporator and finishes one circulation to achieve the purpose of heating/cooling.

Screw chiller unit performances listed in the tables are given for the condition of clean exchangers (fouling factor = 1).

For different fouling factor values, unit performances should be corrected with the correction factors shown above.

ETHYLENE GLYCOL SOLUTIONS

The use of ethylene glycol solutions allows units to operate at lower leaving water temperatures and prevent freezing in chiller heat exchangers.

The use of low freezing point solutions causes a change in the main thermodynamic properties and performance of the screw water units.

The major parameters affected by the use of glycol solutions are the following:

– Cooling capacity

– Power input

– Flow rate

– Pressure drop

The table below lists correction factors referred to as the most common ethylene glycol m solutions.

Water-cooled screw chiller cooling  principle

When the screw chiller unit runs in cooling mode, well water as a carrier carries out heat from industrial applications.

Cooling medium absorbs heat from the evaporator and cools water into 7 ℃, then cooling water is sent to room, cooling medium goes through the compressor and becomes high-temperature, high-pressure overheat steam, goes into the condenser and pull out heat by well water

Curve 1: cooling outlet temp. 7℃
Curve 2: cooling outlet temp. 10℃

IMPORTANT!
READ BEFORE PROCEEDING!
GENERAL SAFETY GUIDELINES

This screw chiller unit is a relatively complicated apparatus.

During installation, operation, maintenance, or service, individuals may be exposed to certain components or conditions including, but not limited to: refrigerants, oils, materials under pressure, rotating components, and both high and low voltage.

Each of these items has the potential if misused or handled improperly, to cause bodily injury or death. It is the obligation and responsibility of operating/service personnel to identify and recognize these inherent hazards, protect themselves and proceed safely in completing their tasks.

Failure to comply with any of these requirements could result in serious damage to the equipment and the property in which it is situated, as well as severe personal injury or death to themselves and people at the site.

This document is intended for use by owner-authorized operating/service personnel.

It is expected that this individual possesses independent training that will enable them to perform their assigned tasks properly and safely.

It is essential that, before performing any task on this equipment, this individual shall have read and understood this document and any referenced materials.

This individual shall also be familiar with and comply with all applicable governmental standards and regulations about the task in question.

1. Screw chiller installation space requirements:
A. For easy operating and maintenance, the space among the equipment should be 1.5-2.0 meters. And also we should reserve enough space for both the heat exchanger sides to draw out the heat exchanger, for the other 2 sides at least the serviceman can pass through.

B. When the equipment operating, the temperature of the compressor discharge pipe and the shell of the condenser will be higher than the ambient temperature, so the room temperature will be increasing, then not good for the workers inside. To avoid the high temperature inside, the ventilator should be installed in the room, to make sure that the room temperature is lower than 35℃.

C. The room should be insulated to avoid noise outside.

2. Screw chiller lifting and carrying
After the water-cooled screw chiller is transported to the place where it will be installed, during lifting, we need to be very careful and avoid damage to your screw chiller.

Especially the compressor, control system, and pipes can not be damaged. Where the lifting rope touches the equipment, the block pads should be placed.

For the very heavy equipment, there should be support rods between the ropes above the equipment to reduce the pressure on the ropes.

When carrying, it is better to use a crane or forklift. During the lifting, the ropes should be tightened with the equipment, and make the equipment balance and no incline.

And the ropes can not be touched with the heat exchanger and the panel and the top directly.

See below:

During the lifting, the strength of the rope should be triple more than the equipment weight, and make sure that no one is under this screw chiller.

Please refer to the weight from the nameplate on the screw water chiller.

3. Foundation
Usually, there is no need to build the special anti-vibration foundation, because of the water-cooled screw chiller working balance, slight vibration.

For easy operation and drainage, the foundation can be 20~30cm above the ground, the surface should be level.

4. Water-cooled screw chiller installation
Every water cooled screw chiller has been tested carefully before leaving our factory,

to make sure of the quality and performance, please be careful during carrying and installation, no any damage to the compressor, control system, and pipes.

A. Before unpacking the water-cooled screw chiller, move it to the closest place where installed and make it upwards.

B. After the water-cooled screw chiller is placed on the right foundation, we must do the level correction, not more than 0.02% required.

C. The size of the chilled water and freezing water pipe connected with this screw chiller should be as per the regulations and not too small. And flow switch should be fitted on the pipe and should be interlocked with the compressor.

D. To observe the working conditions and changes of the screw chiller and whole system, the thermometers and pressure gauges should be fitted on the inlet and outlet of the chilled water and freezing water pipe.

E. The power supply should be sufficient and not over ±10%. Equipment should be earthing very well.

5. The connection of the water system.

A. The chilled water and freezing water pipe should be insulated to avoid the loss of the heat or cool and the condensate.

B. To ensure the water quality, the strainer and water softener device should be installed on the water inlet pipe; otherwise, the user should take responsibility.

C. The pipe size should be as per the regulations and our design.

D. The Pressurization Unit (Expansion vessel) should be installed on the water system, which should be located on the top of the system. And the auto discharge valve, water pump, and flow switch should be installed as well.

E. The auto discharge valve should be located on the top of the system. After the water system is connected, and the leak test and pressure test both are OK, then open this valve and release the air in the system, after that close it.

If the water inside is not good quality or the pipe is not clean, please clean the strainer 30days after working.

F. When the initial operating of the whole cooling system, shut off the inlet/outlet valve firstly, open the bypass valve, then open the outlet valve and shut off the bypass valve after the water pump is working for a while.

G.Multi pieces of equipment installed in parallel, the water segregator（Manifold）, water collector and the water balance valve should be installed.

H. The drain valve should be installed in the lowest place of the system.

The water quality standard

7. Power cable connecting
A. Please refer to the wiring diagram to use the right size cable.

B. The equipment earth wire should be earthed properly. And it can not be connected with the gas pipe, water pipe, telephone line to avoid the electric shock.

C. Make sure the right phase sequence.

External wiring, unless specified as an optional connection in the manufacturer’s product line, is NOT to be connected inside the micro panel cabinet.

Devices such as relays, switches, transducers, and controls may NOT be installed inside the micro panel. NO external wiring is allowed to be run through the micro panel.

All wiring must be by TopChiller’s published specification and must be performed ONLY by qualified TopChiller personnel.

TopChiller will not be responsible for damages/problems resulting from improper connections to the controls or the application of improper control signals.

Failure to follow this will void the manufacturer’s warranty and cause serious damage to property or injury to persons.

START-UP procedure

1. Pre-starting check
OIL HEATERS

If the oil heater is de-energized during a shutdown period, it must be energized for 12 hours before starting the compressor or remove all oil and recharge compressor with new oil.

Remains energized as long as the fused disconnect switch to the starter.

The oil heater is thermostatically controlled and remains energized as long as the fused disconnect switch to the starter.

CHECKING THE OIL LEVEL IN THE OIL RESERVOIR

Proper operating oil level -the middle of the upper sight glass.
If the oil is excessively high after the start-up, the excess oil may be drained from the oil filter drain valve while the compressor is running.
If the oil level is low, the oil should be added to the compressor.

Comply with Local regulations when removing or disposing of Refrigeration System oil!

2. Pre-Starting
Before starting the water chiller, pls observe the Control panel. Make sure the system is ready to start.
To pre-start the water chiller, pls use the following procedure:

A. The oil heater must be energized for 12 hours before starting the water-cooled screw chiller.

The water-cooled screw chiller will not start if the oil is less than 40℃. If not possible, the compressor oil should be drained and new oil must be charged into the oil sump.

B. All Control setpoints should be programmed before the water-cooled screw chiller is started.

Before the start, the clock must be programmed for the proper day and time. Any set points which are desired to be changed may be programmed.

C. Check and make sure that the earth wire is connected properly and avoid the electric shock, and the electric leakage protector is recommended to use.

D. Check the insulation between the compressor motor, the phase balance, the phase sequence. Check the control box and other power facilities to comply with the nameplate requirements.

Check the protection device and the thermostat setting etc, make sure that the action is proper and the earthing is well.

E. Check and make sure that the compressor discharge valve is open, otherwise, the compressor may be damaged by the extremely high pressure.

F. Check the chilled water and the freezing water system are connected properly and make sure that the medium quality is suitable for the equipment.

Make sure that the air handling unit, expansion vessel, water strainer, etc. will work properly. And all the necessary valves in the pipe system should be open.

G. After starting the circulation pumps, make sure the water flow rate and the water pressure gauge, and the thermometer. And before the start, please make sure the below:

3. Water Cooled Screw Chiller Start-Up

A. If the water pump is manually operated, pls start the pump firstly.

The Control will not allow the water chiller to start unless the liquid flow rate is established through the water chiller.

(A field supplied water flow switch is required.) If the liquid pump is wired to the Control, the pump will automatically start, therefore, this step is not necessary.

B. After checking the above data and making sure that it is right, then start the water chiller, pls press the RUN button on the interface of the control panel. This button will automatically start the water chiller.

When the cooled screw chiller is working, if any alarm appears, the LED will begin to flash in YELLOW color.

C. Check Oil Pressure display. After the compressor started, the LP gauge value should be 0.2～0.5MPa, if lower, please check the dry filter, may be an indication of a dirty filter, which should be replaced when pressure loss is 30% or more of the original pressure;

When a new screw chiller system is firstly operated under normal full load conditions, the oil pressure should be recorded as a reference point with which to compare subsequent readings.

Also please check the expansion valve is open or close. If the pressure is still lower than 0.2Mpa, then please recharge the refrigerant.

The actual bearing oil pressure will vary with compressor suction and discharge pressures.

MAINTENANCE

1．CHECKING SYSTEM FOR LEAKS
A. LEAK TESTING DURING OPERATION
The refrigerant side of the system is carefully pressure tested and evacuated at the factory.

After the system is in operation under load, the high-pressure components should be carefully leak tested with a leak detector to be sure all joints are tight.

If a leak exists frequent purging will be required or refrigerant will be lost. If any leaks are indicated, they must be repaired immediately.

However, if it is necessary to repair a welded joint, the refrigerant charge must be removed.

B. VACUUM TESTING
With the refrigerant charge removed and all known leaks repaired, and then the system needs to be vacuumed and the Vacuum test should be conducted as follows:

Step1. Connect a high capacity Vacuum pump, with an indicator, to the system charging valve and start the pump

Step2. Open wide all system valves, including the clean and gauge valves. Be sure all valves to the atmosphere are closed.

Step3. Operate the Vacuum pump until -0.096Mpa

Step4. Hold the Vacuum obtained in Step 3 in the system for 8 hours; the slightest rise in pressure indicates a leak or the presence of moisture, or both. If, after 8 hours, the pressure continued, the system may be considered tight.

Be sure the Vacuum indicator is valved off while holding the system Vacuum and be sure to open the valve between the Vacuum indicator and the system when checking the Vacuum after 12 hours.

Step5. If the Vacuum does not hold for 12 hours within the limits specified in Step 4 above, the leak must be found and repaired.

2. REFRIGERANT CHARGING
After the Vacuum test is finished, the system should be charged with a small amount of refrigerant mixed with dry nitrogen so that a halide torch or electronic leak detector can be used to detect any leaks too small to be found by the soap test.

Do not use excessive amounts of refrigerant; use only enough for proper leak detection.

The refrigerant charge is specified for each water chiller model (See nameplate). Charge the correct amount of refrigerant and record the level in the evaporator sight glass.

The refrigerant charge should always be checked and trimmed when the system is shut down.

The refrigerant charge level must be checked after the pressure and temperature have equalized between the condenser and evaporator.

This would be expected to be 4 hours or more after the compressor and water pumps are stopped. The level should be at the center of the sight glass.

The refrigerant level should be observed and the level recorded after initial charging.

PREVENTIVE MAINTENANCE

It is the responsibility of the owner to provide the necessary daily, monthly, and yearly maintenance requirements of the system.

IMPORTANT:

If a water chiller failure occurs due to improper maintenance during the warranty period;

TOPCHILLER will not be liable for costs incurred to return the system to satisfactory operation.

In any operating system, it is most important to provide planned maintenance and inspection of its functioning parts to keep it operating at its peak efficiency.

Therefore, the following maintenance should be performed when prescribed.

1. COMPRESSOR CHECK

Oil Filter
The oil filter is used to ensure proper lubrication quality for the compressor.

These filters should be inspected for excessive debris, and if found containing excessive debris, report this to the local Service office for evaluation.

The oil filter should be replaced when the operating oil pressure is bigger than 0.18Mpa from the oil pressure measured.

COMPRESSOR MOTOR
A. Check motor mounting screws frequently to ensure tightness.

B. Motor windings annually to be checked for deterioration of windings.

COMPRESSOR OIL
Oil has been charged before leaving the factory.
A. Check the reliability of oil pressure differential control.

B. Check the discharge/Suction, oil level.

C. During the operation, the oil level must be observed, and the oil level should be at the bottom of the oil glass. When shut down, the oil level should be half of the oil glass.

D. Every Spring and Fall season is the preventive maintenance time.

If you find that the oil color is black or there is cupper particle or oxygenation impurity, the oil should be changed with the same type of oil, and also clean the dry filter.

This work should be carried on the serviceman skilled.

Note: When recharging the gas and the oil, they should be dried and filtrated firstly to avoid the water and the impurity inside.

2. PRESSURE TESTING
The water chiller should be pressure tested annually. Any leaks found must be repaired immediately.

If frequent purging has occurred, the water-cooled screw chiller must be pressure tested as soon as possible to prevent air and moisture from entering your water-cooled screw chiller.

Air and moisture are the worst enemies of the DX system and experience have shown that water chillers that are maintained tight are systems that will provide trouble-free efficient operation.

3. EVAPORATOR AND CONDENSER
The major portion of maintenance on the condenser and evaporator will deal with the maintaining of the waterside of the condenser and evaporator in a clean condition.

The use of untreated water in cooling towers, closed water systems, etc. frequently results in one or more of the following:
A. Scale Formation
B. Corrosion or Rusting
C. Slime and Algae Formation

It is therefore to the benefit of the user to provide for proper water treatment to provide for a longer and more economical life of the equipment.

The following recommendation should be followed in determining the condition of the waterside of the condenser and evaporator tubes.
A. The condenser tubes should be cleaned annually or earlier if conditions warrant.
B. The evaporator tubes under normal circumstances will not require cleaning. If however, the temperature difference between the refrigerant and the chilled water increases slowly over the operating season, it is an indication that the evaporator tubes may be fouling or that there may be a water by-pass in the water box requiring gasket replacement.

4. CLEAN THE WATER CHILLER SYSTEM

After a long work, there will be some deposited calcium oxide or other minerals on the surface of the pipe in the evaporator, and if the thickness is increasing, then it will cause higher power consumption and higher discharge air pressure, and lower the suction pressure.

5. ELECTRICAL CONTROLS CHECK

A. Electrical devices——We need to pay more attention to the working voltage, current, and phase sequence of the water chiller, and check the contractors and make sure that well connected, and there is no oxygenation, rust, or external impurity, etc on the touch pint.

All electrical controls should be inspected for obvious malfunctions.
It is important that the factory settings of controls (operation and safety) not be changed. If the settings are changed with our approval the warranty will be affected.

B. Periodic check the loss of the electrical wire (The working vibration may cause the loss), if so, then please tighten it.
C. Periodic check the reliability of the electric device, you need to replace the failure or unreliable one.
D. We must often pay attention to the temperature conditions in the electric box, making sure good ventilation. We need to replace the aging wire because of the heating.

6. Shutdown in winter

When shutdown in winter is needed, we need to make the refrigerant into the condenser and close the valves. Purging the surface and drying it with compressed air.

To avoid dust, the water chiller needs to be covered. Open the drain valve, and all the water inside needs to be drained completely when winter to avoid the pipe frozen and broken.

If the water chiller has been shut off for a long time in winter, the water in the system must be drained completely to avoid the pipe frozen and broken when the water temperature is lower than 0 ℃.
7. Startup next year

After a long time shut down, and then startup, the following procedures need to be done:
Check and clean up the water chiller
Clean the water pipes system
Check the water pump and regulation valves.
Tighten all the wire connectors.

When the main switch is OFF position for a long time, then the main switch should be switched on 24 hours before the start-up to preheat the compressor oil.

According to the different seasons and ambient temperatures, at least 12 hours are required.

And the source side water temperature range is 10～35℃, so the temperature of the underground water should be not lower than 10℃.

8. Safety operation notices:

If the compressor discharge valve is not opened wide enough, don’t startup.
After the compressor started, please don’t push the Emergency switch unless abnormal occurs.
When you weld the refrigerant systems, you must release the system pressure firstly to avoid the harmful light-gas caused by the refrigerant and the light fire reacted, even the explosion occurs.
When you start up the system, please start the water pumps firstly, after that you can start the compressor.

When you shut off the system, please shut off the compressor firstly, and keep the user side freezing water pump working till the water temperature in the evaporator is higher than 20℃, after that, you can shut off the water pump.
Please often check and collate the flow switch and the low-temperature protection probe to avoid frozen broken while both are a failure at the same time.
While you open the electrical box door, avoid the electric shock.

The fuse can not be replaced by copper wire or iron wire. Otherwise, the water chiller may be damaged.

Please don’t touch the discharge airline to avoid the scald.
Don’t change the setting value of the protection devices by yourself.
If you heard an abnormal noise from somewhere, please shut it down immediately. Then start up only if all the malfunctions are solved.

9. Usage notices:

If you set the water temperature lower than 0℃, antifreeze needs to be added to the freezing water.
Periodic purging of the water system.
When the ambient temperature is abominable and lower than 0℃ in winter, we need to pay more attention to the frozen. And antifreeze or other methods need to be considered.

10. Malfunction analysis and solutions:

The water chiller should be managed by a professional or rich experienced person, and operate and maintain the water chiller properly and normally according to this manual.

Otherwise, the malfunction because of the improper use is not our responsibility and maintenance scope, and the repair costs need to be charged by the buyer.

Malfunction analysis and solutions

11. Warranty
24-month warranty – We promise all water cooled screw chillers are warranted to be free from defects in material and workmanship.

If the defect appears within 24 months from the date of original installation, whether or not actual use begins on that date, then the product does meet this warranty.

A new or remanufactured part, at the manufacturer’s sole option, to replace any defective part will be provided without charge for the part itself;

PROVIDED the defective part is returned to the distributor through a qualified servicing dealer.

THIS WARRANTY DOES NOT INCLUDE LABOR OR OTHER COSTS incurred for diagnosing, repairing, removing, installing, shipping, servicing, or handling of either defective parts or replacement parts. Such costs may be covered by a separate warranty provided by the installer.
THIS WARRANTY APPLIES ONLY TO PRODUCTS IN THEIR ORIGINAL INSTALLATION LOCATION AND BECOMES VOID UPON REINSTALLATION.
LIMITATIONS OF WARRANTIES – ALL IMPLIED WARRANTIES (INCLUDING IMPLIED WARRANTIES OF FITNESS FOR A PARTICULAR PURPOSE AND MERCHANTABILITY) ARE HEREBY LIMITED IN DURATION TO THE PERIOD FOR WHICH THE LIMITED WARRANTY IS GIVEN. SOME STATES DO NOT ALLOW LIMITATIONS ON HOW LONG AN IMPLIED WARRANTY LASTS, SO THE ABOVE MAY NOT APPLY TO YOU. THE EXPRESSED WARRANTIES MADE IN THIS WARRANTY ARE EXCLUSIVE AND MAY NOT BE ALTERED,
ENLARGED, OR CHANGED BY ANY DISTRIBUTOR, DEALER, OR OTHER PERSON
WHATSOEVER.

ALL WORK UNDER THE TERMS OF THIS WARRANTY SHALL BE PERFORMED DURING NORMAL WORKING HOURS. ALL REPLACEMENT PARTS, WHETHER NEW OR REMANUFACTURED, ASSUME AS THEIR WARRANTY PERIOD ONLY THE REMAINING PERIOD OF THIS WARRANTY.

THE MANUFACTURER WILL NOT BE RESPONSIBLE FOR:
1. Normal maintenance as outlined in the installation and servicing instructions or owners manual including filter cleaning and/or replacement and lubrication.

2. Damage or repairs required as a consequence of faulty installation, misapplication, abuse, improper servicing, unauthorized alteration, or improper operation.

3. Failure to start due to voltage conditions, blown fuses, open circuit breakers, or other damages due to the inadequacy or interruption of electrical service.

4. Damage as a result of floods, winds, fires, lightning, accidents, corrosive environments, or other conditions beyond the control of the Manufacturer.

5. Parts not supplied or designated by the Manufacturer, or damages resulting from their use.

6. Electricity or fuel costs or increases in electricity or fuel costs from any reason whatsoever including additional or unusual use of supplemental electric heat.

7. ANY SPECIAL INDIRECT OR CONSEQUENTIAL PROPERTY OR COMMERCIAL
DAMAGE OF ANY NATURE WHATSOEVER. Some states do not allow the exclusion of incidental or consequential damages, so the above may not apply to you.

This warranty gives you specific legal rights, and you may also have other rights which may vary forms area to area.

Conclusion

To select the right screw chiller, you have to make sure that you find a reputed manufacturer of water-cooled screw chiller like TopChiller®.

Before ordering the right screw chiller, you need to calculate the amount of water that is required to be chilled, then decide on the requirement.

In this way, you can find the right water cooled screw chiller and as a result, your production will achieve efficiency to the maximum level.

TopChiller® is committed to sustainable development and the concept has been integrated into our corporate culture.

The water cooled screw chillers supplied by TopChiller® are energy efficient and suitable for both air conditioning, and for milk cooling, die casting, and many other industrial applications.

The cooling capacity of our premium water cooled screw chillers ranges from 40 Ton to 680 Ton and their operating sound levels are very low in all conditions.

TopChiller® water cooled screw chillers are widely used by all kinds of industrial companies all over the world.

If you are not sure which kind of water cooled screw chiller you should choose for your system, our chiller experts are always here to help.

Please contact us right away by sending an inquiry to check what your system requires. Choosing between water-cooled and air-cooled screw chillers is not an easy decision.

However, with decades of expertise, we will help you find which one is the best option for your company.

TopChiller having enough confidence that you will find using our water cooled screw chillers will help a lot with production efficiency and cost reduction.

Water Cooled Screw Chiller-The Ultimate FAQ Guide by TopChiller

Water Cooled Screw Chiller is named after a screw compressor and water cooled condenser used in this chiller system. It has a relatively higher efficiency than that of air cooled screw chiller.

Water Cooled Screw Chiller delivers effectively large cooling solutions to provide cooling in large industrial factories like chemical plants, automobile factories, ink printing industries, etc

It is specially designed for industrial cooling applications as it uses less power than individual chilling plants and air conditioners.

It can be used for the central air conditioning system in large facilities.

To meet the highly efficient and energy-saving requirements of your application, A Water Cooled Screw Chiller is equipped with a high-quality screw compressor and a touch screen system that is very easy to operate.

A screw compressor has energy-efficient features such as low noise, high-quality stable performance, energy-saving, and a longer lifespan.

What is a Water Cooled Screw Chiller?

A Water Cooled Screw Chiller is an industrial type refrigeration system that uses a screw compressor which is one of the processes leading to fluid chilling.

All the working features of a Water Cooled Screw Chiller depend upon the screw compressor.

A screw compressor of a Water Cooled Screw Chiller has different parts and working chambers such as a rotor, a suction valve, an electrical motor, and a lubricant section.

A Water Cooled Screw Chiller has two rotors that depend on a timing gear to compress the refrigerant. These two rotors are named a male rotor and a female rotor.

The male rotor is connected to the motor directly. It is the driving part, while the female driver receives the driving action.

When both of these rotors rotate, the volume in the grooves decreases. As a result, it compresses the refrigerant.

A Water Cooled Screw Chiller uses two types of screw compressor given below;

• Single Screw Compressor
• Double Screw Compressor

You can choose from these two types of screw compressors based on the requirement of your application.

Water Cooled Screw Chiller is used in large-scale industries like plastic industries, welding industries, cement, concrete cooling industries, and dye costing industries.

What is the Working Principle of a Water Cooled Screw Chiller?

A Water Cooled Screw Chiller works on the basic principle of vapor compression or vapor absorption to remove the unwanted heat from your application. All its working depends on its main components described in the next section.

It starts working when you press the start button. As soon as you turn it on, the refrigerant will start moving from the refrigerant cylinder to the screw compressor.

The screw compressor compresses the refrigerant at a very high speed and increases the pressure of the refrigerant.

This high-pressure refrigerant starts flowing from the screw compressor with high velocity through the delivery system to the evaporator.

This compressor then drives to the evaporator through pipes. The evaporator of a Water Cooled Screw Chiller has a series of pipes that produces heat from the system in pipes. That is having flowing water.

In the evaporator, the refrigerant absorbs the heat that coming from your application.

At this stage the refrigerant has enough heat and pressure, it starts moving towards the condenser.

The condenser will remove its heat by using water and eject the heat into the atmosphere. A condenser then sends this liquid refrigerant to the thermal expansion valve.

The expansion valve of a Water Cooled Screw Chiller passes the liquid refrigerant through the pressure induction process. It lowers the speed of the liquid refrigerant to make it ready for the next circulation.

What are the Components of Water Cooled Screw Chiller?

A Water Cooled Screw Chiller is designed with high-quality components to provide cooling in industrial applications.

The main components of a Water Cooled Screw Chiller are described below:

• A Cooling Tower

The cooling tower of a water-based screw chiller is installed on the roof. This component is placed where the heat ends up.

This component is responsible for cooling the condenser water by using the evaporation process.

When the water is pumped to the basin of a cooling tower, the heat dissipates through evaporation.

This cooled water will return to the Water Cooled Screw Chiller through pipes and it absorbs more heat.

After that, the water will again repeat the cycle by going back to the cooling tower.

• A Screw Compressor

A Water Cooled Screw Chiller uses a screw compressor. It is composed of two interlocking rotating rotors to compress the refrigerant.

The function of a screw compressor is to compress the low-pressure refrigerant to a higher one.

• A Condenser

The condenser of a Water Cooled Screw Chiller is connected with the cooling tower to release heat.

The condenser is the component that exactly differentiates between a water cooled and air cooled screw chiller.

It transfers the heat formed by refrigerant vapor into condensing water by a tube and shell condenser of a Water Cooled Screw Chiller.

Then, condenser water gets heat-up and pumped into the cooling tower, where this heat dissipates into the atmosphere.

• An Oil Separator

When the Screw Compressor compresses the refrigerant, some oil will come out in the Water Cooled Screw Chiller.

This oil has to be removed within a specific time limit otherwise it will start flowing through other cooling components.

As a result, it will hinder the heat transfer process. It also decreases the capacity of the condenser and evaporator.

The need for an oil separator starts here; it is used to detach the oil from the refrigerant and reduce the amount of oil flowing through the Water Cooled Screw Chiller.

• An Evaporator

A Water Cooled Screw Chiller uses a shell and tube evaporator. The refrigerant gets into the shell and starts flowing through the tubes.

It absorbs the heat from high-temperature water that flows through the tubes.

At a specified water temperature, it will drive the heat back to the refrigerant to evaporate.

Usually, Water Cooled Screw Chiller’s evaporator is installed between the expansion valve and screw compressor of the system.

• Expansion Valve

An expansion valve of a Water Cooled Screw Chiller connects the condenser and evaporator to maintain the fluid pressure difference between both.

It controls the refrigerant fluid flow to the evaporator and compressor also.

If you want to reduce the temperature adjust the pressure value lower. It regulates the capacity load according to the requirements of your application.

What are the Main Features of Water Cooled Screw Chiller?

Water Cooled Screw Chiller has many features. Some of its features are given below:

• Water Cooled Screw Chiller features superior durability.
• It offers high energy efficiency.
• Its components have a longer lifespan.
• Adaptive frequency drive option is available in Water Cooled Screw Chiller.
• It provides clean Energy & Intelligent management.
• It provides an easy interface with BMS through protocols.
• Water Cooled Screw Chiller uses ozone-friendly refrigerant HFC134a, HFC407c.
• It has a highly reliable design with a top-quality cop.
• Water Cooled Screw Chiller is equipped with an advanced ‘H-smart’ microprocessor-based controller.
• Efficient lubrication, even in a power failure, is also a useful feature.
• Its body is made up of Galvanized Steel.
• Powder Coated / Polyurethane paint makes it more qualified.
• Water Cooled Screw Chiller provides anti-freeze safety and water flow switches.
• High-class safety controllers for equipment and compressors of Water Cooled Screw Chiller.
• Custom-built machine inquiries are also entertained in it.
• Equipment extended warranty options of Water Cooled Screw Chiller are available for up to 10 years.
• The site support with Amc options is also available for the whole life of the equipment.

What are the Industrial Applications for a Water Cooled Screw Chiller?

Because of the higher efficiency of Water Cooled Screw Chiller, it is widely applied in large industrial applications. Some of its main industrial applications are appended below:

• Water Cooled Screw Chiller is helpful in Comfort Air-Conditioning.
• Chemicals and pharmaceuticals are also used in various processes.
• The engineering industry employs the use of a Water Cooled Screw Chiller to provide cooling.
• It can be used in commercial & institutional applications for efficient cooling.
• The telecommunication industry also uses to cool down the equipment.
• A laser technology industry also uses it in different cooling processes.
• Water Cooled Screw Chiller is applied in Welding Engineering factories for cooling purposes after the welding process.
• It can be used in aeronautical testing facilities and defense laboratory testing facilities.
• A computer chip manufacturing industry uses a Water Cooled Screw Chiller for the cooling process.
• A medical industry applies a Water Cooled Screw Chiller for regulating temperature.
• The blow mold machine, plasma spray machine, induction hardening machine, and injection molding machine are other applications of a Water Cooled Screw Chiller.
• It is applied in plastics Processing Industries for constant temperature control.
• An electroplating industry and anodizing plants also use it for cooling effect requirements.
• Water Cooled Screw Chiller is widely used in the food process and beverage industry.
• It can apply in the dye and pigment manufacturing process.

What are the advantages of a Water Cooled Screw Chiller for your Application?

Some advantages of a Water Cooled Screw Chiller are appended below:

• A Water Cooled Screw Chiller is designed in a simple structure with less moving and wearing parts.
• It offers longer operations with an extremely low failure rate.
• It has a low search process when operating with low load, noise, and vibration.
• It offers circular stable motion.
• The EER value of its compression is higher.
• A Water Cooled Screw Chiller is not sensitive to wet strokes.
• It has small in size and it can be built as enclosed high-capacity water cooled screw refrigeration unit.
• It has very lightweight and has no issue with the intrusion of external air.
• Step-less regulation of a Water Cooled Screw Chiller is 10% to 100%.
• It provides higher efficiency operation with an incredible power-saving feature.

How Water Cooled Screw Chiller is Different from an Air cooled screw chiller?

Besides using the same compression still, there is some difference between these two chillers; Water Cooled Screw Chiller and air cooled screw chiller.

Water Cooled Screw Chiller

• A Water Cooled Screw Chiller is also used to refrigerate facilities of all kinds, cooling products, and equipment.
• A Water Cooled Screw Chiller often uses a cooling tower or an adiabatic system. This chiller is smaller than air cooled screw chiller.
• It provides water cooling condensation.
• A Water Cooled Screw Chiller is more efficient than air cooled screw chiller
• It can also be used in the high-temperature area because it is used with an external water source.
• It is mostly used indoors.
• When we talk about operating costs Water cooed Screw Chiller is cheaper than an air cooled screw chiller.
• High maintenance requirements as compared to air cooled screw chiller.
• Because of water usage surrounding are sometimes wet.
• The cooling capacity of Water Cooled Screw Chiller is comparatively higher than Air cooled screw chiller.

On the other hand, air cooled screw chiller is described below:

Air cooled screw chiller

• Air cooled screw chiller is most commonly used for commercial and industrial facilities.
• Similar to a Water Cooled Screw Chiller, air cooled screw chiller also has a compressor, condenser, evaporator, and Expansion valve. No need for a cooling tower.
• It provides an air cooled condensation.
• Air-cooled screw chiller is less efficient than Water Cooled Screw Chiller.

• Air-cooled screw chiller absorbs the heat from the water and spread it into the environment, which makes ambient temperature high; it is used in areas where heat discharge is not a serious issue.
• Air-cooled screw chiller has to throw warm air into the environment. Mostly it is installed outdoor.

When we calculate the operating costs,

• Air-cooled screw chiller requires less maintenance than Water Cooled Screw Chiller.
• It is used in areas of drought.
• It does not use water, so it has a dry environment.
• Cooling capacity is less than Water-cooled Chiller.

What are the Environmental Requirements for a Water Cooled Screw Chiller?

A Water Cooled Screw Chiller is a refrigeration system that uses a water-based condenser and a screw compressor to provide cooling in different industrial applications.

Do you want to obtain maximum output for your application? It is necessary to have proper guidance about the environmental requirements of the Water Cooled Screw Chiller.

• Indoor Area

Water Cooled Screw Chiller installed indoors. It uses water as a cooling medium to remove heat from your application.

It also exhausts the heat the unwanted heat to the ambient air by using a cooling tower. It is exclusively installed on the roof.

• Temperature Requirements

A Water Cooled Screw Chiller works efficiently in a high-temperature environment. You can install it indoor areas with extremely high mechanical temperatures or where there is minimum ventilation.

• Refrigerant

The type of refrigerant used in a Water Cooled Screw Chiller depends on its environmental requirements.

Some of the common refrigerants used in a Water Cooled Screw Chiller are water, R-I34A R-407C, R-404A, and R-410A.

You need to use a refrigerant that is environmentally friendly to prevent environmental pollution and global warming.

• Humidity Requirement

The humidity level of the room, where you want to install your Water Cooled Screw Chiller must not exceed 60 percent for a smooth operation.

The higher humidity can result in microorganisms’ growth and lower humidity can cause dryness.

• Availability of Clean Water

Water is an integral part of Water Cooled Screw Chiller; you need to make sure about the availability of the required standard of water for a Water Cooled Screw Chiller.

It is important to avoid corrosion and scaling that may block the water path. You need to use clean water free from contaminations.

• Power Consumption

When you use the term power consumption, it gives the sense of life cycle cost but here it is about environmental effects.

A Water Cooled Screw Chiller with higher power consumption emits extra carbon you need to have all the ancillary equipment or equal compression.

What are the Installation Requirements of a Water Cooled Screw Chiller?

All the CAUTIONS and WARNINGS must be followed for installation of your Water Cooled Screw Chiller. Otherwise, it can result in severe injuries or damage.

1. Site Requirements

• Choose the site away from heat and fire.
• The normal indoor temperature should be less than 46 degrees Fahrenheit.
• The availability of sufficient light is important.
• Sufficient clearance from walls and equipment for maintenance and inspection.
• The room must be high enough with sufficient entrance, for easy entry of crane or fork lifter.

2. Confirmation of Site 

• Confirm whether the site is suitable for installation or not.
• Confirm that holes made for nuts and bolts are of proper size.
• Confirm the Dimensions of rooms are according to the requirements.

3. Construct the Base

The base is to be constructed at a suitable place on the site. The base must fulfill the following requirements;

• Height must be more than the specified limit. For ease in maintenance.
• The level difference must not exceed a specified limit.
• The base must be a concrete or steel structure to bear a running load of Water Cooled Screw Chiller.
• The base should have a drainage ditch around the refrigeration unit.

4. Unpacking the Equipment

Unpack the equipment and ensure the availability of all parts as per the attached list.

In case of deficiency or any damage, report to the manufacture in texting/ on-call and request for replacement of the damaged or defective part.

5. Ensure Availability of Tool and Crain

Ensure availability of all the tools and other equipment required for installation must be available.

Crain or fork lifter is also available for the installation of your Water Cooled Screw Chiller.

6. Earthling Point

An earthling point must be made available close to your Water Cooled Screw Chiller; to ground your Water Cooled Screw Chiller. It will protect the operator or technician from electric shock.

How to Increase the lifespan of Water Cooled Screw Chiller?

The life span of your Water Cooled Screw Chiller can be increased by using proper service and maintenance procedures, as prescribed in the manufacturer manual.

Some of the steps to enhance the lifespan of Water Cooled Screw Chiller are given below.

1. Quality of Power Supply

Fluctuation in the different parameters of the power supply may affect the performance of electrical and mechanical components.

Ensure that your power panel must be equipped with calibrated, voltmeter, ampere meter, Frequency meter, and phase indicators, to observe the following parameters.

• Over and under-voltage
• Over and undercurrent
• Over or under Frequency.
• Missing phase.

It is suggested to use a heavy-duty voltage stabilizer for the provision of accurate and stable power to your Water Cooled Screw Chiller.

2. Before Startup

Before daily start-up to ensure about followings:

• Check the logbook.
• Note Elapsed time indicator reading.
• No water or other fluid is splashed around.
• Check power supply parameters.
• Check for any leakage.

After ensuring these checks you may start your Water Cooled Screw Chiller.

3. Seasonal Shutdown

Seasonal shut down ensure for.

• Record operating pressure and voltage and current.
• Leak test.
• Oil inspection.
• All the water in the system must be drained.
• Check record for any different maintenance.
• Check record for any calibration is due.

4. Seasonal Start-Up

• Check the water flow and its interlock.
• Check set point.
• Safety devises operation.
• Record operating pressure and voltage and current.
• Leak test.
• Inspect electrical cables.
• Carry out oil analysis.
• Replace all oil filters.
• Vibration analysis
• Refrigerant Analysis.

All of the above-mentioned preventive maintenance practices increase the lifespan of your Water Cooled Screw Chiller drastically.

The operator must be well trained because he is the man behind your Water Cooled Screw Chiller.

How to troubleshoot a Water Cooled Screw Chiller?

Following are some commonly occurring faults of your Water Cooled Screw Chiller, their causes, and corrective actions to fix the faults.

1. Fault: Phase reversal or phase is missing.

Probable Cause

The phase sequence can be changed due to different reasons but it will not harm the system due to the phase protection circuit.

Corrective Action

Change the connection of any of the two phases, the problem will be resolved. If the phase is missing, check for any damaged wire.

2. Fault: The low refrigerant indicator on the panel is in one position.

Probable Cause

It may be due to the temperature of the Water Cooled Screw Chiller being above 5 degrees Celsius or the pressure of the low-pressure gauge is lower than the specified value.

Corrective Action Check for any leakage of refrigerant, if any leak is detected repair it and top up the Refrigerant.

3. Fault: No or low cooling.

Probable Cause

It may be due to the condenser of your Water Cooled Screw Chiller having poor heat dissipations, compressor efficiency is low, the running current being increased and high pressure being raised to 20 kg/cm2.

Corrective Action

Check the cooling tower cycle, whether the water temperature is too high, the cooling tower valve is open d properly, Check if the condenser is dirty.

If all of the checks are ok then press the restart button for your normal operation.

4. Fault: High and low-pressure abnormal.

Probable Cause

The compressor valve is damaged or broken.

Corrective Action

Consult the engineer for expert advice.

In addition to the above-mentioned faults, your Water Cooled Screw Chiller may cause other different problems so always consult manufacturer supplied manual or an expert engineer.

Always remember to record faults and all maintenance in your logbook for future reference and fault isolation.

FAQs of Water Cooled Screw Chiller.

1. What Technology is used in Water- Cooled Screw Chiller?

Different Chiller uses different compression technologies and named after that technology they use for Compression. A Water Cooled Screw Chiller uses spiral or screw technology.

2. How much Clearance is Required Around Water Cooled Screw Chiller?

About 4 to 5 meters clearance should be available around your Water Cooled Screw Chiller for maintenance and inspection.

3. Can the Cooling Capacity of Water Cooled Screw Chiller be Controlled?

Yes, in different models of Water Cooled Screw Chillers, cooling capacity may be controllable, in steps.

• 100%
• 75%
• 50%
• 25%

In some other models of Water Cooled Screw Chiller, it is controllable, in Steps

• 100%
• 66%
• 33%

And in some models, this cooling capacity is not controllable.

4. What is the Advantage of using Two Compression StagesWater a Cooled Screw Chiller?

By using two compressor stages in Water Cooled Screw Chiller, the efficiency can be improved, low power consumption, which not only saves power but is also economical in terms of cost.

5. 5. What are Basic Practices for the Water Cooled Screw Chiller?

The Best care for your Water Cooled Screw Chiller is to carry out all the inspections and preventive maintenance well in time to avoid complications.

For smooth and efficient running, the condenser coil must be checked for proper operation. If clogging is found it must be removed.

6. Can you use an Emergency Stop Button of Water Cooled Screw Chiller in Normal Condition?

No, because during normal operation if you want to stop Water Cooled Screw Chiller, you have to use a normal stop switch.

In this way, all the systems will be shut down by following a proper sequence, but in an Emergency shutdown no sequence is followed by the system, and it may cause damage to your system.

7. What types of Protection does a Water Cooled Screw Chiller Compressor requires?

Being an essential part of the Water Cooled Screw Chiller, the Compressor is provided with the following protection circuits.

• Missing Phase protection.
• Thermal and overload protection.
• Compressors exhaust temperature protection.
• Differential Temperature protection.

The above protections ensure the smooth operation of the compressor.

8. What are the Functions of the Display Panel of Water Cooled Screw Chiller?

The display panel is used to perform the following functions.

• Display running information.
• Display system information.
• Display malfunction code.
• Setting running parameters.
• Setting the auto-start and stopping the timer.

Consult manufacturer manual for the procedure, use, and fault decoding for all of the above.

9. What is Meant by CAUTION, and WARNING in the Manual of Water Cooled Screw Chiller? 

In the manufacturer manual some time the word caution or warning is used, you need to know the meanings.

• Shows potentially hazardous situations, Failures to observe precaution may result in injury to person or damage to equipment.

• Shows potentially hazardous situations, Failure to observe may cause damage to equipment or injury or death of the person.

10. What is the Benefit of a Closed-Loop Water Cooled Screw Chiller?

The Water Cooled Screw Chiller is a Closed-loop Chiller. The advantage of a closed-loop chiller is its continuous monitoring of the environmental temperature and very precise temperature control.

So it is used in the industry where very precise temperature control is required.

11. How to Calculate the Cooling Capacity or Heat Load for a Water Cooled Screw Chiller?
12. The cooling cooling capacity(kW) for a Water Cooled Screw Chiller= [Flow Rate(m3/h)*Temp Change(T1-t2)]/0.86.

2. Heat Load for a Water Cooled Screw Chiller= C(specific heat)* M(quality output per hour)*Temp Change(T1-T2)

12. How Water Treatment Increases the Life of Water Cooled Screw Chiller?

Water treatment increases the life of your screw chiller by keeping it clean from corrosion, algae formation, and erosion.