Why TopChiller Can Be Your Reliable Chiller Manufacturer and Supplier ?
TopChiller: Your Premier Choice
Of All Types of Chillers
TopChiller® is a leading chiller, chiller system, chiller unit supplier, and company in China since 1999 with over 20-years of experience in the chiller field.
Chillers can be divided into air chiller and water chiller in terms of cooling methods. Chillers can also be divided into scroll compressor chiller and screw compressor chiller depending on different compressor types.
In terms of chilled water temperature, chillers can be divided into room temperature chiller and glycol low-temperature chiller.
A chiller is also named a water chiller, coolant chiller, or chiller system, it is a mechanical device that can produce chilled water(-35℃ to +30℃) for various industrial and commercial applications.
Chillers manufactured by TopChiller® using USA Copeland, France Danfoss, and Japan Sanyo scroll compressors, all the chiller spare parts are from the world-famous refrigeration brand.
All chillers manufactured by TopChiller® are a compact design with a full protection device and portable wheels that can move easily.
Chillers can provide constant cooling water, are becoming the necessary machines for modern industries including food&beverage industries, medical machines such as CT scan and MRI machines, chemical processing, and all industrial process cooling.
TopChiller is supplying a full product range of various chillers’ cooling capacity from 0.5ton to 200Ton.
All chillers including air chiller and water chiller, scroll compressor, and screw chiller manufactured by TopChiller win a high reputation in the market, because of their steady quality and full-time service.
Since 2003, TopChiller exported thousands of high-quality chillers, chiller units, chiller systems throughout the world.
If you are looking for a good quality chiller for your plant? If you have any requirements for the chiller unit or chiller system?
please contact TopChiller sales to get your chiller design and a price quotation.
TopChiller: Your Leading Chiller, Chiller System, and Chiller Unit Manufacturer
If you are looking for a good quality chiller for your business?
If you want to know more information about the chiller system?
If you have any questions about the chiller?
You are coming to the right place. On this page, you will get a clear idea about all chillers’ concerning information.
Chiller: Your Complete Buying Guide from TopChiller
Chapter 1: What is a chiller?
Chapter 2: What are the main components of a chiller?
Chapter 3: What’s the chiller working principle?
Chapter 4: What are the different types of chillers?
Chapter 5: Which refrigerant is used in chillers?
Chapter 6: What is a chiller used for?
Chapter 7: How to size a correct chiller for your business?
Chapter 8: How do you maintain a chiller system?
Chapter 9: Why TopChiller can be your reliable chiller supplier?
Chapter 1: What is a chiller?
A chiller is a mechanical device that can remove heat from a liquid via a vapor-compression or absorption refrigeration cycle.
This water, oil, or glycol liquid then will be circulated through a heat exchanger to cool equipment, or another process stream (such as air or process water).
As a necessary auxiliary machine, refrigeration creates waste heat that must be exhausted to the ambiance, or for greater efficiency, recovered for heating purposes.
Chilled water from the chiller is used to cool and dehumidify air in small size to mid-to-large-sized commercial, industrial, and institutional facilities.
Chillers can be divided into water-cooled, air-cooled, or evaporatively cooled. Water-cooled systems can provide efficiency and environmental impact advantages over air-cooled systems.
Chapter 2: What are the main components of a chiller?
For a chiller, the main components are the Compressor, Condenser, Evaporator, Expansion Valve, Temperature Controller, and Dry Filter.
The compressor is the most important part of a chiller. We call the compressor is the refrigeration heart for a chiller.
When the compressor working, it creates a pressure difference to move the refrigerant around the system.
There are various designs of refrigerant compressors in a chiller, the most common being the centrifugal, screw, scroll, and reciprocating type compressors.
Each type of compressor has its advantages and disadvantages.
Chiller compressors are always located between the evaporators and the condensers.
It’s usually partly insulated and will have an electrical motor attached as the driving force, this will be either mounted internally or externally.
Compressors can be extremely noisy, usually a constant deep droning sound with an overlaying high pitch, hearing protection should be worn when near the chiller.
Some inner protections for chiller compressors:
When the compressor is running, some abnormal conditions may occur, such as the exhaust pressure being too high, the suction pressure being too low, the oil pressurizing being sufficient, the not being is overheated, and excess liquid entering the cylinder.
In the event of an abnormal condition, the compressor will be damaged if there is no protective measure.
- Suction and discharge pressure control
- When the compressor is running, due to the system or the compressor itself, the exhaust pressure may be too high or the suction pressure may be too low. For this purpose, the suction and exhaust pressures must be controlled.
- Safety valve
To prevent refrigerant from leaking into the atmosphere, a closed safety valve is used. The upper side of the valve disc is subjected to the exhaust pressure, and the lower side is subjected to the suction pressure and the spring force of the spring.
When the exhaust pressure is too high, the valve disc moves downward, opening the lateral hole in the lower part of the valve seat, and the high-pressure gas flows into the suction chamber through the side hole and the lateral hole on the valve body.
When the exhaust pressure is lower than the specified value, the valve disc is turned upward by the suction pressure and the spring force, and the exhaust pipe is closed. The opening pressure of the safety valve is adjusted with bolts.
- Overheat protection of built-in motor
- Motors that are well designed and operate under specified conditions, the internal temperature does not exceed the allowable value, but when the motor is operated at a voltage that is too high or too low, or when operating in a high-temperature environment, the internal temperature of the motor exceeds the allowable value and is frequently started. At the same time, the temperature is too high due to excessive starting current.
To not heat the motor, in addition to proper use, pay attention to maintenance, you can also install a thermal relay.
The overheating relay can be mounted inside the winding, called the built-in temperature relay, or external to the motor called an external temperature-current relay.
When the internal temperature of the motor exceeds the specified value, the bimetal of the built-in temperature relay is deformed to cause the contact to trip and the motor to stop running. When the temperature inside the motor drops below the specified value, the contact is reset and the circuit is turned back on.
- Missing phase protection
A phase loss of the three-phase motor will result in the motor not starting or overloading. To protect the motor from phase loss, an overload relay is used, which consists of a mechanical moving part and an electromagnetic switch part. The mechanical motion section has four terminals, two on the top and two on the bottom. A heater is installed between the upper and lower terminals.
- In the absence of phase, the winding overload current of other phases passes through the heater, and the bimetal disc is thermally deformed, pushing the pressure plate, thereby causing the overload relay contact on the electromagnetic switch to jump, no current in the excitation coil, and the magnetic contactor is no longer closed. The motor stops rotating. The overload relay is also used for normal three-phase motors to protect the motor when the current is too high.
The condenser for a chiller is one kind of certain heat exchanger.
It is located after the compressor and before the expansion valve.
The purpose of the condenser is to remove heat from the refrigerant which was picked up in the evaporator.
There are two main types of condensers, Air-cooled condenser, and Water-cooled condenser.
Water-cooled condensers will repetitively cycle “condensing water” between the cooling tower and the condenser, the hot refrigerant which enters the condenser from the compressor will transfer its heat into this water which is transported up to the cooling tower and rejected from the building.
The refrigerant and the water do not mix they are kept separated by a pipe wall, the water flows inside the pipe and the refrigerant flows on the outside.
But air-cooled condensers work slightly differently, they do not use a cooling tower but instead blow air across the exposed condenser pipes with the refrigerant flowing this time on the inside of the tube.
But what’s the difference between an air-cooled condenser and a water-cooled condenser?
Please have a look at the below video to get a clear idea.
The evaporator is located between the expansion valve and the compressor, the evaporator is also another type of heat exchanger.
The purpose of the evaporator is to collect the unwanted heat from the building and move this into the refrigerant so that it can be sent to the cooling tower and rejected.
The water cools as the heat is extracted by the refrigerant, this “chilled water” is then pumped around the building to provide air conditioning.
This “Chilled water” then returns to the evaporator bringing with it any unwanted heat from the building.
There is also two kinds of evaporators commonly, the shell and tube evaporator and plate heat exchanger evaporator.
For shell and tube evaporator:
For plate heat exchanger evaporator:
The expansion valve is a very important refrigeration component in a chiller.
It is located between the condenser and the evaporator. Its purpose is to expand the refrigerant reducing its pressure and increasing its volume which will allow it to pick up the unwanted heat in the evaporator.
There are many different types of expansion valves for a chiller unit, the most common at the thermal expansion valve, the electronic expansion valve.
The most popular expansion valve brand in the world is Danfoss.
In the chiller refrigeration system, the dry filter is an essential refrigeration component to improve and improve the working conditions of the chiller, or to improve the economics and safety of the chiller system.
Especially for the Freon refrigeration system, the refrigerant moisture must be strictly controlled, even if only a small amount of moisture is enough to freeze the expansion valve and cause system ice blockage.
The dry filter works very well in the chiller. It not only removes moisture from liquids or gases but also removes solid impurities.
Since the dryer and filter are assembled, we call it a dry filter.
It is a combination of a desiccant and a filter element in a housing. In the chiller refrigeration system, the desiccant filter is a safety protection device.
In our common Freon refrigeration system, the desiccant filter is usually installed in the pipeline between the condenser and the thermal expansion valve (or capillary) to remove moisture and solid impurities in the refrigerant liquid to ensure the chiller refrigeration system.
Its structure is also the right angle and straight-through, etc., a commonly used desiccant is silica gel and molecular sieve.
Molecular sieves are highly hygroscopic and can be close to their saturation level after exposure to air for 24 hours, so they should be installed within 20 minutes once unpacked.
When the chiller refrigeration system has ice blockage, dirty plugging fault, or normal maintenance of the chiller.
We should replace the dry filter to ensure its hygroscopicity, as well as the safe and stable operation of the chiller to meet the normal use needs of users.
Therefore, to prevent moisture from entering the refrigeration system, a dry filter must be provided to absorb the moisture that has entered the system.
High pressure and low-pressure protector
These controllers are for high voltage and low voltage protectors of the chiller system.
When the high pressure is too high and the low pressure is too low, an alarm signal is generated
The function of the oil separator is for separating the refrigerant and the freezing oil in the exhaust pipe, the refrigerant continues to enter the condenser along the pipeline, and the separated refrigerant oil is returned to the compressor through the oil return pipe
Liquid Reservoir or liquid receiver
The liquid reservoir is for the storage of excess refrigerant in the refrigeration system.
Some chiller end users will ask?
Since there are more refrigerants in a chiller, it is not enough to let go directly. Is it necessary to set up a special reservoir for storage?
Answer: The load of the refrigeration system is not constant. For example, in low-temperature conditions, the refrigerant circulating inside the chiller will be much lower than the refrigerant under normal temperature conditions.
If there is no liquid storage device at this time, then the excess refrigerant will be there will be a condenser that occupies most of the heat exchange area.
A manually opened and closed ball valve that can cut off the refrigerant circuit;
Many people think that this ball valve is useless.
It is a redundant valve. I will briefly mention several functions here:
01), when it is used to replace the filter or the thermal expansion valve, the refrigerant is closed in the condenser or the accumulator, so that it is not necessary to discharge the refrigerant of the entire system;
02) Add refrigerant to the system: When the new machine is commissioned, the refrigerant in the shutdown state cannot be added all at all.
At this time, the compressor needs to be turned on, and the refrigerant is sucked into the system through the suction pipe of the compressor.
but many At normal temperature conditions, the pressure of the evaporator is not lower or even higher than the pressure of the refrigerant tank, and the refrigerant can not be added.
Then at this time we can close the ball valve, switch the refrigerant from the condensation side, and the compressor can suck the refrigerant into the system;
03), add refrigeration oil to the system: Many colleagues in the group will consult how to add frozen oil, some of the peers said that using a grease gun to inject the frozen oil into the system is completely unnecessary.
When the compressor is turned on, the ball valve is closed, and the low pressure will gradually decrease.
When the pressure is near atmospheric pressure, the fluorinated tube is placed in the freezing oil bottle.
When the pressure is lowered, the temperature is lower than the atmospheric pressure. The oil is sucked into the refrigeration system by the suction of the compressor.
04), Ball valve can also be used for recycling refrigerant
The solenoid valve of a chiller is another important component.
A component of an electric motor that can cut the refrigeration pipeline manually or automatically.
The solenoid valve also has a great effect on the refrigeration system. You can refer to the role of the ball valve.
Chapter 3: What’s the chiller working principle?
We must know something about the chiller working diagram.
In most process chiller cooling applications, a pumping system circulates cool water or a water/glycol solution from the chiller to the process.
This cool fluid removes heat from the process and the warm fluid returns to the chiller.
The process water is how heat transfers from the process to the chiller.
Process chillers contain a chemical compound, called a refrigerant. There are many types of refrigerants and applications depending on the temperatures required but they all work on the basic principle of compression and phase-change of the refrigerant from a liquid to a gas and back to a liquid.
This process of heating and cooling the refrigerant and changing it from a gas to a liquid and back again is the refrigeration cycle.
The refrigeration cycle starts with a low-pressure liquid/gas mix entering the evaporator.
In the evaporator, heat from the process water or water/glycol solution boils the refrigerant, which changes it from a low-pressure liquid to a low-pressure gas.
The low-pressure gas enters the compressor where it is compressed to high-pressure gas.
The high-pressure gas enters the condenser where ambient air or condenser water removes heat to cool it to a high-pressure liquid.
The high-pressure liquid travels to the expansion valve, which controls how much liquid refrigerant enters the evaporator, thereby beginning the refrigeration cycle again.
There are two types of condensers used in chillers: the air-cooled condenser and the water-cooled condenser.
An air-cooled condenser uses ambient air to cool and condense the hot refrigerant gas back down to a liquid.
It can be located inside the chiller or can be remotely located outside, but ultimately it rejects the heat from the chiller to the air.
In a water-cooled condenser, water from a cooling tower cools and condenses the refrigerant.
Chapter 4: What are the different types of chillers?
There are different types of chillers in different terms:
But generally, a chiller is rated between 1ton to 1200 tons of cooling capacity.
There are three different types of chillers:
(1) air chiller
(2) water chiller
(3) evaporative condensed chiller
There are four subcategories in each of the above categories for industrial chillers:
(1) reciprocating chiller
(2) centrifugal chiller
(3) screw-driven chiller
(4) absorption chillers.
There are many types of the chiller in terms of industrial processes:
(1) plastic chiller
(2) laser chiller
(3) MRI chiller
(4) glycol chiller
(5) coolant chiller
(6) recirculating chiller.
The first three types are mechanical chillers which are powered by electric motors, steam, or gas turbines.
An absorption chiller is powered by a heat source such as steam and uses no moving parts.
Chapter 5: Which refrigerant is used in chillers?
Refrigerant is a significant part of a chiller.
The chiller uses a refrigerant internally as its working fluid.
There are many refrigerant types are available. when selecting a chiller, the application cooling temperature requirements and refrigerant’s cooling characteristics need to be matched. Important parameters to consider are the operating temperatures and pressures.
Several environmental factors concern refrigerants and also affect the future availability of chiller applications.
This is a key consideration in intermittent applications where a large chiller may last for 25 years or more.
Ozone depletion potential (ODP) and global warming potential (GWP) of the refrigerant need to be considered.
ODP and GWP data for some of the more common vapor-compression refrigerants (noting that many of these refrigerants are highly flammable and/or toxic)
Please refer to below chat of kinds of refrigerants used in a chiller:
In addition, more and more chillers required environment-friendly refrigerants.
R22 refrigerant, However, due to its destruction of the ozone layer and high greenhouse effect, China has decided to phase out its use by 2030 according to relevant international agreements.
Therefore, more and more chilled refrigeration equipment is using the R204 alternative R404a.
Although R404A and R22 have similar refrigeration performance, there are still many differences in practical use.
Replacing R22 with refrigerant R404a requires consideration of the following issues.
1. The biggest problem with using R404A instead of R22 is the problem of lubricating oil.
It is necessary to use PVE ester oil instead of mineral oil for R22. Ester lubricating oil has a high affinity with water and poor dehydration. Therefore, it should avoid contact with outside air during use.
After the container is opened, it should be used as soon as possible. It should be sealed and stored after use. Keep away from oxidant, strong alkali, and strong acid.
Store in a well-ventilated place; avoid contact with skin and eyes when in use, and avoid inhalation of vapors and sprays.
2. The exhaust pressure of R404A refrigerant is about 1.2 times that of R22, and the mass flow rate is about 1.5 times that of R22.
The exhaust flow rate increases and the resistance increases. In general, the heat transfer capacity of the condenser is increased by 20% to 30% compared to R22.
3. The saturation pressure of R404A and R22 is different at the same temperature, so the action mechanism of the R404A thermal expansion valve is different from that of R22.
At the same time, because the R404A refrigerant and lubricating oil have different compatibility with the sealing material, the expansion valve sealing material should also be changed accordingly.
Therefore, the R404A special expansion valve should be selected in the selection of the thermal expansion valve.
4. Since the saturation pressure of R404A is higher than R22, the design pressure of the pressure vessel in the system should be changed to ensure safety.
Such as liquid storage and gas-liquid separators. At the same time, the safety valve and fusible plug setting values installed on the system components will also change.
Since the gas density of R404A is about 50% larger than that of R22 under the same exhaust gas amount, the pipe diameter selected is larger than R22 when piping design using R404A refrigerant.
5. For the same compressor, the current using R404A is greater than R22, so the wire diameter of the AC contactor, thermal relay, and cable of the compressor should be adjusted.
In terms of system protection, the high-pressure switch setting is adjusted from the original 2.45 MPa to 2.7 MPa.
6. Since the saturation pressure of 404A is different from that of R22, the airtightness test pressure is greater than R22.
At the same time, the vacuum degree of the system is higher than R22, and the water content is lower than R22.
The refrigerant should be charged in liquid form during charging to prevent changes in the R404A configuration.
7. R404A is a non-azeotropic mixture. The concentration of the non-azeotropic mixture changes with temperature and pressure.
This brings certain difficulties to the production, debugging, and maintenance of the refrigeration system.
The effect, especially when the refrigerant leaks, the system refrigerant needs to be completely emptied and replaced, to ensure the proportion of each mixed component, and also achieve the design cooling effect, otherwise it will get worse.
8. Because R404A refrigerant and lubricating oil have good compatibility with water, the system’s requirements for moisture, residue, and cleanliness are improved compared with R22 refrigerant.
R404A system moisture control and impurity control It is a more important indicator, and the corresponding filtering devices in the system should be changed.
Chapter 6: What is a chiller used for?
Chillers served a wide range of applications both in industrial fields and commercial fields.
Chiller used in air conditioning:
In air conditioning systems, chilled water from the chiller is typically distributed to heat exchangers, or coils, in air handlers, or other types of terminal devices that cool the air in their respective space.
The water is then recirculated to the chiller to be cooled again.
These cooling coils transfer sensible heat and latent heat from the air to the chilled water, thus cooling and usually dehumidifying the air stream.
A typical chiller for air conditioning applications is rated between 15 and 2000 tons, and at least one manufacturer can produce chillers capable of up to 5,200 tons of cooling.
Chilled water temperatures can range from 35 to 45 °F (2 to 7 °C), depending upon application requirements.
When chillers for air conditioning systems are not operable or they require repair or replacement, emergency chillers may be used to supply chilled water.
Rental chillers are mounted on a trailer so that they can be quickly deployed to the site. Large chilled water hoses are used to connect between rental chillers and air conditioning systems.
In this video, we learn how chillers, cooling towers, air handling units, AHU, Rooftop units, RTU, fan coil units, FCU, and ductwork together form central plant HVAC systems.
This is a chiller for air conditioning applications.
Chiller used for industrial process
Chillers are also widely used for various industrial applications.
In industrial applications, chilled water or other liquid from a chiller is pumped through process or laboratory equipment.
Industrial chillers are used for controlled cooling of products, mechanisms, and factory machinery in a wide range of industries.
Chillers are often used in the plastic industries, injection and blow molding, metalworking cutting oils, welding equipment, die-casting and machine tooling, chemical processing, pharmaceutical formulation, food and beverage processing, paper, and cement processing, vacuum systems, X-ray diffraction, power supplies, and power generation stations, analytical equipment, semiconductors, compressed air, and gas cooling.
Chillers are also used to cool high-heat specialized items such as MRI machines and lasers, and in hospitals, hotels and campuses.
Chillers for industrial applications can be centralized, where a single chiller serves multiple cooling needs or decentralized where each application or machine has its chiller.
Each chiller system approach has its advantages. It is also possible to have a combination of both centralized and decentralized chillers, especially if the cooling requirements are the same for some applications or points of use, but not all.
Decentralized chillers are usually small in size and cooling capacity, usually from 0.2 to 10 short tons (0.179 to 8.929 long tons; 0.181 to 9.072 t). Centralized chillers generally have capacities ranging from ten tons to hundreds or thousands of tons.
Chilled water is used to cool and dehumidify air in mid-to large-size commercial, industrial, and institutional (CII) facilities.
Chillers can be water-cooled, air-cooled, or evaporatively cooled. Water-cooled chillers incorporate the use of cooling towers which improve the chillers’ thermodynamic effectiveness as compared to air-cooled chillers.
This is due to heat rejection at or near the air’s wet-bulb temperature rather than the higher, sometimes much higher, dry-bulb temperature.
Evaporatively cooled chillers offer higher efficiencies than air-cooled chillers but lower than water-cooled chillers.
Water-cooled chillers are typically intended for indoor installation and operation and are cooled by a separate condenser water loop and connected to outdoor cooling towers to expel heat to the atmosphere.
Air-cooled and evaporative cooled chillers are intended for outdoor installation and operation.
Air-cooled machines are directly cooled by ambient air being mechanically circulated directly through the machine’s condenser coil to expel heat to the atmosphere.
Evaporative cooled machines are similar, except they implement a mist of water over the condenser coil to aid in condenser cooling, making the machine more efficient than a traditional air-cooled machine.
No remote cooling tower is typically required with either of these types of packaged air-cooled or evaporatively cooled chillers.
Chapter 7: How to size a correct chiller for your business?
Chillers are ideal refrigeration systems not only for air conditioning also for industrial applications.
But how to select the correct chiller for your business? This comes to the first important point.
With rich experience of sizing chiller cooling capacity, TopChiller has below formula for your reference:
There is an easy way to follow a formula for determining the size of the chiller you require. However, there are a few factors you must know before you take action:
A.The incoming water temperature
B. The water temperature you required
C.The chilled water flow rate
General chiller sizing formula:
Calculate Temperature Differential (ΔT°F) ΔT°F = Incoming Water Temperature (°F) – Required Chill Water Temperature
Calculate BTU/hr. BTU/hr. = Gallons per hr x 8.33 x ΔT°F
Calculate tons of cooling capacity Tons = BTU/hr. ÷ 12,000
Oversize the chiller by 20% Ideal Size in Tons = Tons x 1.2
You have the ideal size for your needs
For example, what size chiller is required to cool 10 GPM from 72°F to 48°F?
ΔT°F = 72°F – 48°F = 24°F
BTU/hr. = 10 gpm x 60 x 8.33 x 24°F = 119,952 BTU/hr.
Ton Capacity = 119,952 BTU/hr. ÷ 12,000 = 9.996 Tons
Oversize the chiller = 9.996 x 1.2 = 11.9952
A 11.9952 or 12-Ton chiller is required.
In the refrigeration industry, we must know there are different units as Ton, Kcal/H, Btu/H, KW, HP…, but how to convert these units between?
Chapter 8: How do you maintain a chiller system?
To buy a good quality chiller is important but how to maintain a chiller is another important thing.
There are some tips for you on how to maintain your chiller:
A. Chiller compressor
The compressor acts as the pump for the chiller’s refrigerant around the system by using differences in pressure to move the liquid through the system. The key things to discuss with your engineer or check yourself are:
The compressor suction temperature and pressure
The compressor discharge temperature and pressure
Compressor refrigeration oil level and pressure
Current-voltage and current levels
B. Chiller evaporator
The next component to check is the evaporator, which has the function of taking the heat absorbed from your process.
Depending on the type of chiller, either air-cooled chiller or water-cooled chiller, these checks will be slightly different.
Again, the main points to cover are:
Evaporator fluid or air Inlet temperature and pressure
Evaporator fluid or air Outlet temperature and pressure
Evaporator refrigeration inlet and outlet temperature
Evaporator insulation Condition
C. Chiller condenser
The final of the three components should be the condenser, which functions to remove the heat transferred into the refrigerant by the compressor as described above.
Again, as with the evaporator, there are two types of condenser, air-cooled and water-cooled, which will slightly alter your checks, which will include:
Air intake and exhaust temperature
Refrigeration inlet and outlet temperature
Condensing fan motor currents, noise, and vibration
Condenser coil condition
Chilled water systems from your chiller can remove heat from buildings by transferring heat from the air into chilled water forced through piping, which circulates through chilled water loops, returning the heated water to the chiller, where refrigerant removes heat from the water.
Rarely seen in residential applications, chilled water systems are common in commercial and industrial process settings.
Chiller design and operation offer specialized challenges to maintenance staff, especially as the system can weigh several hundred tons and include miles of piping and heat transfer tubing.
Chillers also place high demands on electrical load, and even a small problem can reduce system efficiency and increase operating costs.
Remote Monitoring and Daily Logs
Remote monitoring technology allows maintenance staff to monitor large equipment daily, instead of manually checking systems every week or month.
Records from remote monitoring allow you to track chiller temperature, pressure, fluid levels, and flow rates consistently.
Comparing this daily log to the manufacturer’s chilled water system design guide allows for the early detection and correction of equipment issues.
Contaminants such as minerals, scale, algae, and mud can build up in chilled water system tubing, reducing heat transfer efficiency.
Approach temperatures may indicate contaminated tubing, as higher approach temperatures indicate a drop in heat transfer efficiency.
Tubes should be cleaned every three years in closed chiller systems. For open systems, periodic inspection is required.
Follow the guidelines in the chilled water system design and operation manufacturer’s guide.
Tube cleaning includes mechanical and chemical cleaning processes. Mechanical cleaning requires physically brushing the interior of the tubing to remove mud, sludge, and algae, and then flushing the tubes.
Chemical cleaning removes scale and must be tailored to match your local water conditions. Mechanical cleaning is necessary after chemical cleaning to remove loosened scales.
Newer chiller models have taken much of the work out of cleaning tubing. Such systems include automatic tub brushing, where small, nylon brushes flow through the tubes.
Older systems can be retrofitted to include integrated cleaning systems, a cost that typically pays for itself within two years.
Condenser Water Issues
Condenser water loops transfer water to open cooling towers or similar systems, allowing heat to escape into the atmosphere.
Exposure to open air increases the risk of contaminants capable of causing scale, corrosion, and biological growth.
All such contaminants can impair heat transfer and decrease system efficiency.
Loops should be inspected regularly for water quality issues and evidence of corrosion and condenser water should be treated as needed to prevent the accumulation of contaminants.
Air and moisture can leak into chillers, causing a decrease in system efficiency and the risk of corrosion and rust.
As little as 1 psi of air in a condenser reduces system efficiency by three percent. Moisture can create corrosive acids that damage motor windings and rust the inside of the chilled shell.
Regular purging controls non-condensate contamination, and all system strainers should be cleaned every three months to maximize their ability to maintain clean water.
Once a year, maintenance staff should take a sample of the system’s lubrication oil while the chiller is operating.
This sample should be sent to the lab for spectrometric analysis. Low-pressure systems will require more frequent sampling.
Compressor oil should only be replaced if the lab results indicate the need. Oil filters should be checked for pressure drop and replaced if the oil is replaced.
New magnetic-bearing frictionless chillers have eliminated oil from their systems.
Maintaining Proper Refrigerant Charge
A water chilling system’s ability to cool its surrounding environment depends on how much refrigerant moves through the compressor, so maintaining the level of refrigerant charge recommended by the manufacturer is important.
When levels drop, the compressor works harder to compensate.
Leaks, air, moisture, and oil can all adversely affect refrigerants. It’s not unheard of for refrigerant to contain ten percent oil in old model chillers, resulting in a twenty percent decrease in inefficiency.
Water Temperature and Flow Rate
The temperature of entering condenser water affects your chiller efficiency, with lower temperatures improving system operations. Chilled water flow rates are also an issue.
Most of the chiller’s design and operation manuals recommend a flow rate of three to twelve feet per second.
No less, and system efficiency drops. Any higher, and you increase noise, vibrations, and erosion risks.
Starter and Motor Maintenance
All starters and motors associated with the system should be checked regularly for the following:
– Inaccurate safety and sensor calibrations on microprocessor controls
– Hot spots and worn contacts on electrical connections, wiring, and switchgear
– Inadequate ground and wiring-to-wiring insulation resistance on electrical motor wiring
– Refrigerant leaks around open drive motor shafts
– Dirty or clogged motor cooling air vents.
Chiller failure phenomenon and solution
Chiller uses a coolant (usually a coolant for water, a common synthetic coolant at a low temperature, such as an aqueous solution of ethylene glycol, etc.,
hereinafter referred to as a coolant or simply “water”) as a heat transfer medium to produce other instruments or equipment that require cooling.
The heat is transferred out and the heat is dissipated to the outside of the device through the refrigeration system to ensure that the device operates within the normal temperature range.
Between the device and the instrument and equipment, the pressure of the pump in the device is used to form a closed medium circulation, and the temperature of the medium is detected by the temperature sensor to control the chiller unit.
When there are some faults in the chiller unit, we can often solve the problem according to some specific phenomena.
1. When the chiller power is turned on for the first time, the power switch indicator does not light and the pump does not turn.
Possible causes and solutions:
1. The air switch (circuit total gate) above the power supply terminal is in the “OFF” state.
2. Set the air switch to the “ON” state to solve the problem.
2. After the initial start-up or after a long time without starting the machine, the pump will not turn or block, the “Pump Normal” indicator will be on, and the buzzer will alarm.
Possible causes and solutions:
There is a lot of air or scale inside the pump, or the pump does not need to cause the rotor lubrication to drop for a long time, which makes the pump start difficult.
Need to unplug the power supply, open the device cover, and pull out the rubber disc directly behind the rotor of the motor.
Use a flat-blade screwdriver to hold the motor rotor to the left and right, and the motor can be restarted.
Note The type of pump used in different chiller units. The above method of disassembling and adjusting the pump may not be applicable.
Phenomenon: The water level alarm indicator flashes and the buzzer alarms.
Third, the possible causes and solutions:
1. There is a water shortage in the water tank and the water level is too low. Add water to the liquid level switch;
2. The level switch is shorted or damaged. Replace the level switch.
4. The water flows alarm indicator flashes and the buzzer alarms.
Possible causes and solutions:
1. The pump is not turned on. Press the button to turn on the pump;
2. The water flow circuit is open. Check the circuit;
3. The pump is damaged. Replace the pump.
Chiller application range
1. Laboratory equipment: rotary evaporator, electron microscope, distiller, condenser, welding machine.
2, laser equipment: high-performance pump laser, medical laser, laser marking machine.
3, vacuum equipment: such as molecular pumps, small vacuum coating machines.
4. Analytical instruments: atomic absorption, ICP spectrometer, X-ray instrument, fermentation device, reaction kettle, electrophoresis instrument, mass spectrometer, polarimeter, etc.
Chiller application in industrial production
Chillers are widely used in various applications and industrial production.
Nowadays, in the production process of products, manufacturers often overlook a subtle and important factor.
That is, in the production process, because the machinery, mold, and industrial reaction continuously generate heat, when the temperature exceeds the tolerance of the material, the quality of the product will be disordered.
For example, plastic products and electroplating production: the cooling time of plastic products accounts for more than 80% of the whole cycle.
The importance of cooling time is reduced. It can be seen that chilled water can absorb heat in time so that the cavity temperature is rapidly reduced, and the product is accelerated, shortening the opening.
During electroplating, chilled water from your chiller can lower the temperature of the plating solution and keep the temperature constant within a certain range, so that the metal molecules can be quickly attached to the surface of the plated material with a steady current, so that the product is smooth and the density is increased.
The chiller (temperature range: -25 ° C – 20 ° C adjustable) is widely used in a variety of industries
- chemical (scholar) industry
- plastic products, plastic containers, film, steel profiles, pipes, wires, cable sheathing, the tire industry
- electroplating and machine tool cutting fluid cooling industry
- pharmaceutical industry
- electronics industry
- hardware industry
- food and beverage industry
- footwear industry
- medical equipment
- optical instruments, etc.
A chemical industry
Chiller is mainly used for cooling and cooling of chemical reactors (chemical heat exchangers) and takes away the huge heat generated by chemical reactions in time to achieve the purpose of cooling (cooling) to improve product quality.
B Manufacturing industry for plastic products, plastic containers, food packaging films, medical packaging films, etc.
In the injection molding process of plastic products (television, computer, washing machine, mobile phone, refrigerator, air conditioner, plastic toy, automobile plastic parts, etc.), we need to use a chiller.
whether the product can be cooled and cooled in a timely and effective manner will directly affect the appearance and shape of the product.
The rate, which affects production efficiency, affects the production cost and corporate profits.
The production of plastic containers (blowing bottles) and packaging films is even more inseparable from chillers (ice water machines).
If the plastic container cannot be cooled and shaped in the production process, the container produced will not be full, the wall thickness will be uneven, the brilliance will not be bright, and even the molding will not be possible, resulting in low product quality.
If the cooling film is formed without cold water (wind) in the production of the packaging film, the qualified product cannot be produced.
If the cold water (wind) provided by the chiller (ice water machine) is used for cooling, not only can the product quality be greatly improved, but also the production efficiency can be improved. Cooling water machine
C Cooling of the plating solution, hydraulic oil, and machine tool cutting tool coolant
In electroplating production, the electroplating solution generates heat in the electroplating reaction without any part, so that the temperature of the electroplating solution is gradually increased.
When the temperature of the electroplating solution is higher than the requirements of the process, the surface plating of the electroplated product is firm and average. Degree, flatness, and surface finish have a large impact.
The freezing provided by the chiller (ice water machine) is required to keep or cool the components at a specific temperature during the production process of the electronic components, and the functional parameters of the electronic components can be controlled in the designed state.
Water to cool and maintain the constant temperature of the plating solution will greatly improve the electroplating production process and production efficiency.
The coolant of the chiller will go through the machine tool cutting tool and the control of the tool blade temperature will directly affect the tool life and product quality.
D Pharmaceutical industry
Chillers for the pharmaceutical industry are mainly used for the control of temperature and humidity in the production workshop and the heat of reaction during the production of APIs.
E Electronics Industry
Chillers can also be used in the electronics industry.
In the production process of electronic components, the components need to be kept or cooled at a specific temperature, and the functional parameters of the electronic components can be controlled in the designed state.
Chiller’s Guide to Buying
The chiller is now available in a wide range of models, and the manufacturers are mixed. The price is very different. Some high and low prices are 1-2 times. Let the users who use it have no way to start.
1. It is not recommended to choose products with low prices.
First of all, the price of the product is the cost plus profit. If the price is too low, it will make a fuss about the cost of the machine.
The first is the compressor. The cost of the compressor accounts for a large part of the cost of the chiller. The compressor is also the core component of a chiller.
Some chiller manufacturers to reduce costs, do not hesitate to use refurbished compressors as new compressors, the average user can not distinguish, such as the purchase of a chiller with refurbished compressors, will cause a lower energy consumption ratio, performance is unstable, and even the compressor will be very fast Scrap, affecting production, causing greater losses.
2. Some users choose the machine to pursue the price blindly but ignore the more important mission of the chiller, which is to ensure the reliability and stability of the industrial production or experimental process.
It was true that the procurement seemed to save a part of the cost. The follow-up problems will be even greater, resulting in manpower consumption, production losses, and far greater than the savings.
3, unit configuration, some chiller configuration is also very different, take the pump, stainless steel pump must be more durable than the ordinary casting pump, reliability is higher, and will be good for water quality, thus protecting the pipeline inside the host The cleaning and host performance are better, while the low-end chiller uses threaded galvanized pipe joints for cost savings, which is inconvenient for plastic hose connections.
4, the quality of the temperature control system is directly related to the stability of the chiller and the accuracy of temperature control, the inferior temperature control system causes frequent alarms and even shutdown of the chiller.
Chapter 9: Some common questions about chiller temperature and pressure issues you should know
Q1: Evaporation temperature and evaporation pressure
The evaporation temperature is the critical temperature at which the refrigerant changes from liquid to gas.
In the chiller system, it refers to the saturation temperature of the refrigerant liquid from the liquid to the gas in the evaporator.
The evaporation temperature in the general refrigeration system cannot be measured. It can only be derived with the corresponding evaporation pressure.
The lower the evaporation pressure (low pressure), the lower the evaporation temperature;
The higher the evaporation pressure (low pressure), the higher the evaporation temperature.
It can be said that the evaporation temperature is proportional to the evaporation pressure, and the evaporation pressure and the evaporation temperature are both correspondings.
Knowing the evaporation temperature, we can look up the value of the evaporation temperature.
The evaporation temperature is lowered. When the condensation temperature is constant, the pressure ratio of the compressor is increased, and the power of the compressor is proportional to the pressure ratio, that is, the pressure ratio is increased, and the power of the compressor is also increased.
Q2: Condensing temperature and condensing pressure
The condensing temperature is the saturation temperature at which the refrigerant vapor in the condenser condenses under a certain pressure.
The condensation temperature is not equal to the temperature of the cooling medium, and there is also a heat transfer temperature difference between the two.
The condensing pressure is the pressure at which the refrigerant condenses into a liquid in the condenser.
Since the pressure inside the condenser in the refrigeration system cannot be measured, in reality, the pressure drop of the refrigerant in the exhaust pipe and the condenser is small.
Therefore, regardless of design debugging or overhaul, it is generally considered that the exhaust pressure is approximately equal to the condensing pressure.
When chillers are commissioned, we often need to know the condensing temperature, and further calculate the condensing pressure (high pressure or exhaust pressure), and then judge whether the refrigeration system has a problem according to the actual pressure.
The most common is to determine if the refrigerant is missing refrigerant.
The condensing temperature is increased. When the evaporation temperature is constant, the pressure ratio of the compressor is increased, and the power of the compressor is proportional to the pressure ratio, that is, the pressure ratio is increased, and the power of the compressor is also increased.
Q3: Overcooling and overheating
Overcooling: After the refrigerant is liquefied in the condenser and before entering the throttling mechanism, the liquid refrigerant is further cooled to a supercooled liquid.
Overcooling temperature: The temperature of the subcooled liquid that is cooled to below the saturation temperature before throttling.
Overcooling temperature difference: the difference between the supercooled temperature and the saturated liquid temperature corresponding to its pressure
Superheat temperature: The temperature of the superheated refrigerant vapor that the compressor draws above its saturation temperature.
Superheat: The difference between the temperature after steam overheating and the saturation temperature at the same pressure.
Effective overheating: Overheating absorbs heat from the cooling medium, producing a useful cooling effect.
Harmful overheating: The heat absorbed by the heat comes from the outside of the medium being cooled, and there is no cooling effect.
Definition of some special technical words
Relationship between the evaporation temperature and evaporation pressure
- Evaporation temperature and evaporation pressure
The evaporation temperature is the temperature at which the liquid refrigerant boils. The actual refrigeration system used varies in evaporation temperature, but the evaporation temperature of the refrigerant must be lower than the minimum temperature required by the cold material so that there is a certain relationship between the refrigerant and the cold material in the evaporator.
- The temperature difference is used to ensure the driving force required for heat transfer. In this way, when the refrigerant evaporates, heat can be absorbed from the cold material to achieve low-temperature heat transfer. The pressure corresponding to the evaporation temperature is the evaporation pressure.
- Evaporation temperature and evaporation pressure
The lower the evaporation pressure, the lower the evaporation temperature. If the evaporation temperature of the system is continuously reduced, the refrigeration capacity of the refrigeration compressor will be continuously reduced, the cooling speed will not be fast, and the evaporation temperature will be lower.
- In this case, the lower the cooling coefficient of the chiller system, then increasing the load of the system, resulting in ever-increasing energy consumption of the system, especially the low-temperature system.
- Application of evaporation temperature and evaporation pressure
The chiller utilizes the characteristic that the boiling point of the refrigerant changes with pressure, so that the refrigerant vaporizes and absorbs the heat of the cooling substance at low pressure, and reduces the temperature to achieve the refrigeration purpose, and the vaporized refrigerant is condensed into a liquid state under high pressure. In this cycle operation, the purpose of adjusting the room temperature is achieved using the heat absorption and heat release process of the refrigerant during the state change.
- Cause of abnormal evaporation temperature
Common reasons for the low evaporation temperature are: the expansion valve opening is small; the chiller system lacks refrigerant; the throttle mechanism is blocked; the filter is clogged; the internal air volume is insufficient; the evaporator frost is severe. Common reasons for the high evaporation temperature are an excessive expansion of the expansion valve; excessive refrigerant; air in the system; blockage of the evaporator discharge; poor condensation; low compressor efficiency or low speed; Or leak; the heat load is too large, etc.
Relationship between condensation temperature and condensing pressure
- Condensing temperature and condensing pressure
The condensing temperature refers to the temperature at which the superheated refrigerant vapor condenses into a liquid in the condenser.
- The refrigerant gas which is compressed into a high temperature and high-pressure state during the compression stroke enters the condenser where it is cooled by air or water to release the heat of condensation and become a liquid. The pressure corresponding to the condensation temperature is the condensation pressure.
- Relationship between condensation temperature and condensing pressure
During the refrigerant condensation process, if the condensation pressure is constant, the condensation temperature is also constant.
- Application of condensation temperature and condensing pressure
Factors affecting the condensing temperature are cooling water temperature, cooling water flow rate, condenser heat transfer area size, and cleanliness. The condensing temperature is mainly limited by the temperature of the cooling water.
- The condensing temperature varies depending on the area used and the season, but it must be higher than the temperature of the cooling water so that there is a refrigerant between the condenser and the cooling water. A certain temperature difference to ensure heat transfer.
- Cause of abnormal condensation temperature
The condensing temperature depends on the temperature of the cooling air or the cooling water. Under normal circumstances, the condensing temperature of the wind is 8~12 °C higher than the ambient temperature, and the condensing temperature of the water is 3~5 °C higher than the effluent temperature of the cooling water. When the condensing temperature is too high, the condensing pressure is also increased accordingly, the compression ratio is increased, the axial force is increased, the gas transmission coefficient is reduced, the actual exhaust gas volume is decelerated sharply, and the cooling capacity is also reduced; in addition, the condensing pressure is increased, which will cause the exhaust pressure to rise. High, the exhaust gas temperature also rises, and the power consumption will increase by about 3% for every 1 °C increase in the condensing temperature corresponding to the condensing pressure.
- The reason why the condensation temperature is too high:
Water cooling: the condenser is selected too small; the cooling water flow is insufficient; the cooling water temperature is too high; the condenser heat exchange area is reduced; the condenser pipe has scale; the refrigerant charge is excessive.Air-cooled: There is air in the condenser; the refrigerant charge is too much; the fins are blocked or the heat is not good.
Evaporation temperature and condensation temperature determine reference data
- Water-cooled chiller: evaporation temperature = cold water outlet temperature -5 ° C (dry evaporator) if it is a flooded evaporator, -2 ° C.
- Condensation temperature = cooling water outlet temperature + 5 ° C; air cooling: evaporation temperature = cold water outlet temperature -5 ~ 10 ° C; condensation temperature = ambient temperature + 10 ~ 15 ° C, generally take 15.
- Cold storage room: evaporation temperature = cold storage design temperature -5 ~ 10 °C.
Chapter 10: Why TopChiller can be your reliable chiller supplier?
TopChiller has been in the chiller industry since 1999. With rich experience in chiller systems, we have a complete product line of various chiller models from small cooling capacity 1Ton to middle size 200Ton then to large size 800/100Ton.
Our chillers are commonly used in air conditioning, commercial and industrial applications.
Looking for high-quality and best cooling performance chiller manufacturers? You are coming to the right place.
TopChiller will always provide a total chiller solution for your business.
If you have any chiller inquiries, please contact the TopChiller refrigeration expert to get a professional chiller solution for your industry.
TopChiller offers many chiller solutions including industrial chillers, water chillers, air chillers, oil chillers, glycol chiller, packaged chillers and screw chillers from 0.5Ton to 500Ton cooling capacity and temperature controlling range from 35℃ to -30℃
Our many different kinds of chillers are available for all of your chilling or cooling needs. While other chillers’ brand wears out, our chillers wear in. Contact TopChiller now!