What is a Chiller? Chiller is a new term, but it is an indispensable important system in the refrigeration industry. Currently, chiller are becoming popular and widely used in many manufacturing plants, including fields such as pharmaceutical, medical, and electronics. In this article Tan Long will explain the system What is a chiller? and advantages and disadvantages of this system.
Learn about what is Chiller?
What is a chiller? Chiller is a type of cold water machine used to supply cold water to cooling systems. Usually installed in factories, workshops or commercial centers.
Chiller System, also known as central air conditioning system, creates cold source to cool food, goods and produce chilled water for central air conditioning system. Water is used as coolant and is cooled through evaporator, usually from 12℃ to 7℃.
What are the structural details of a Chiller?
In addition to the concept and structure of What is a chiller system? is also a question that many people wonder. Chiller includes main parts: compressor, condenser, evaporator, expansion valve, power supply, controller and water box.
Compressor
Compressor The compressor is the main engine located between the evaporator and condenser, creating a pressure difference to move the refrigerant through the system. Compressors come in a variety of designs, including centrifugal, screw, scroll, rotary, and piston, each with their own unique characteristics. Compressors can be loud and continuous, so hearing protection is required when working near a chiller.
Condenser
Condenser Located after the compressor and before the expansion valve, it is responsible for removing heat from the refrigerant after it has absorbed heat at the evaporator. Condensers come in two main types: air-cooled and water-cooled.
With water-cooled condensers, the “condensate” cycle takes place between the cooling tower and the condenser. Refrigerant from the compressor to the condenser, transferring heat to the cooling water, which then carries this heat to a cooling tower for removal from the building. Refrigerant and the water is separated by the tube wall: the water flows inside the tube, and the refrigerant flows outside.
Meanwhile, air-cooled condensers work differently, without the use of a cooling tower. Instead, a fan blows air through exposed condenser tubes, while the refrigerant flows inside the tubes, effectively dissipating heat.
Throttle valve
Throttle valve located between the condenser and the evaporator, has the role of expansion refrigerant when passing through the valve. This process not only reduces pressure but also helps optimize heat absorption at the evaporator, improving the cooling efficiency of the system.
Evaporator
Evaporator, also known as Chiller, is a heat exchange device between a refrigerant boiling at low pressure and temperature and the space to be cooled.
Between expansion valve and compressor, the evaporator is responsible for absorbing heat from the building, then transferring this heat to the refrigerant to be sent to the cooling tower or air-cooled, depending on the type of chiller. When the heat is absorbed by the refrigerant, the water will be cooled, creating "cold water" to supply the air conditioning system in the building. The cooled water will circulate back to the evaporator with the newly absorbed heat from the building.
Power supply
Power supply can be mounted directly to the chiller or separately, installed on a wall at another location and connected to the chiller via an electrical cable. The power supply is responsible for controlling the electrical current supplied to the chiller, and typically includes components such as starters, circuit breakers, speed controllers, and power monitoring devices to ensure the system operates safely and efficiently.
Controller
Controller Often mounted directly on the chiller, the controller monitors and regulates the performance of the system. By monitoring operating parameters, the controller can alert the engineering team when problems arise and automatically shut down the system to protect the equipment. In addition, the controller is often connected to the building management system (BMS), allowing remote monitoring and control, improving operational flexibility and efficiency.
Water box
Water boxes are installed on the evaporator and condenser of water-cooled cooling systems, helping to guide and distribute water flow effectively during operation.
Water Chiller
What does a Chiller system consist of?
The structure of a central Chiller air conditioning system consists of 5 basic parts:
Water Chiller Central Cluster
Water Cooled Chiller is the center of the Chiller system, is the most expensive device and consumes the most electricity in the system. This device is manufactured with preset power levels.
Calculation and selection of Water Cooled Chiller cluster is based on cooling efficiency requirements and factors such as compressor type, working efficiency, gas type used, or other options such as heat pump.
Popular brands that offer Water Cooled Chiller units include York, Trane, Carrier, and Hitachi.
Pump and water piping system
Pump system:
The pump system is responsible for pumping cold water from the Chiller to the direct-use loads. Cooling efficiency will be optimized if each Chiller has its own pump, suitable for high-rise buildings with low noise and low pressure head (due to the closed circulation system between the outgoing and returning pressure heads).
The amount of water pumped into the system needs to be maintained stable, not increasing or decreasing erratically, and the capacity can be adjusted by inverter if the overall system is not optimized.
When choosing the pump capacity, it is necessary to base on the water flow and water pressure. Calculating the pump pressure is relatively complicated because it involves many parameters, so using calculation software will give more accurate results.
Water pipes:
Water pipes are usually made of black steel, which has good insulation against cold water and leads to the cooling tower. Recently, PPR plastic pipes have gradually replaced steel pipes, bringing good efficiency and positive feedback.
Piping selection depends on the amount of water flow required. Piping that is too small will cause large pressure losses and have to withstand high pressures, while piping that is too large will significantly increase system costs.
Direct load system: AHU, FCU, PAU,…
AHU (Air Handling Unit): AHU is a device that exchanges and processes temperature and humidity in the Chiller system, while improving air quality. This device is equipped with many auxiliary air ducts, helping to distribute air to the air-conditioned areas. AHU has many copper coils and customized dust filters to handle air for large spaces.
FCU (Fan Coil Unit): FCU is often used for small rooms or areas where the AHU duct system cannot reach. FCU can also be installed in places with different temperature and humidity requirements than AHU systems. However, FCU does not have the ability to handle heat as efficiently as AHU. Therefore, for more demanding requirements, it is possible to combine an external PAU system and connect the duct to the FCU to improve the cooling efficiency.
PAU (Pre-Conditioned Air Unit): PAU systems provide drier air than the air in the air conditioner, i.e. control dryness rather than relative humidity. PAUs typically provide low temperature air, which reduces the size of the Indoor Unit or FCU where possible, resulting in higher air conditioning efficiency.
Indirect load system
The duct system is designed to blow air through the rooms that need air conditioning, combined with control valves and air vents such as VAV, Damper, etc.
Return air and fresh air are mixed and fed into the AHU or FCU for treatment, ensuring that the temperature and humidity requirements of the air-conditioned space are met.
There are many calculation methods for duct systems, of which the most common is the homogeneous friction calculation method. The calculation process is quite simple, as the number of air outlets and the size of each branch can be easily determined. Important factors such as air flow and required noise level can be easily looked up, making the calculation convenient.
However, the exact representation of the above parameters 2D/3D drawing Giving investors the right metrics is the most challenging part.
In addition, the system also includes other types of air ducts such as return air ducts, exhaust air ducts, stair pressurization air ducts, etc.
Pumping and water circulation system through Cooling Tower (if any) for water-cooled chiller
All devices such as AHU, FCU, PAU, Chiller,… all operate independently and are controlled via DDC controllerThis controller is capable of receiving signals from temperature, humidity, air flow, water, etc. sensors and is programmed to automatically adjust via a computer with an integrated communication port.
DDC Connect to the server via standard protocol, helping the server identify and monitor the operating status of each system. Thereby, the manager can monitor and adjust the devices based on actual requirements.
The installation of the control system requires the ability to communicate between devices and connect the computer to the specialized BMS software. Usually, this is done by a company specializing in providing control equipment, using specific control product lines, such as Delta equipment, etc.
Overview of central air conditioning system model What is Chiller?
Below is the operating model of a water-cooled Chiller air conditioning system with four circulation loops:
- Red circle: This is the hot water loop, pumped into the cooling tower to cool and radiate heat to the surrounding environment.
- Green Cycle: The cold gas ring in the water chiller cluster helps the cooling process take place effectively.
- Light purple cycle: The cold water loop is pumped to devices such as AHU, FCU, PAU, PHE, etc. to cool the air-conditioned space.
- The Golden Cycle: This is the circulation of the duct system, blowing conditioned air into the rooms that need cooling.
Describe the role of Chiller in Water Chiller system
In the system Water Chiller, Chiller acts as the center and divides the entire system into two main phases as follows:
- Cooling phase: Including the Chiller's evaporator and equipment such as AHU, FCU, performing the function of cooling air or water in the space that needs air conditioning.
- Cooling phase: Consists of a condenser and a Cooling Tower, where heat is removed from the system and released to the environment.
Chiller Classification
Chillers are divided into two main types: Air cooled chiller and Water cooled chiller, with different characteristics and applications.
- Water cooled chiller: This is the more popular type, has large capacity, suitable for large or very large scale projects.
- Air cooled chiller: With small operating capacity, this type is suitable for projects requiring small capacity and areas using water contaminated with iron.
Besides, there are many other classifications based on factors such as:
- By compressor type: Piston, screw, helical, centrifugal, etc.
- According to condenser: Water-cooled.
- According to the heat recovery device: Chiller has heat recovery function.
- According to the flow through the evaporator: The traffic type is constant or variable.
- Absorption chiller: This type uses a heat absorption process for cooling instead of using refrigerant gas.
Each type of Chiller has its own advantages and applications suitable for each specific project requirement.
What is the operating principle of the Chiller system?
Beyond Concept What is a chiller?, the operating principle of this system is to convert water from gas to liquid and vice versa. The Chiller system operates based on the principle of thermodynamics, in which the refrigerant undergoes a change in state of matter to absorb and release heat. Specifically, water from the gaseous state will condense into liquid, and then from liquid will freeze into solid.
When the refrigerant changes from solid to liquid and then to gas, it absorbs heat from the surrounding environment, reducing the temperature of the surrounding space. During the operation of the Chiller, the liquid refrigerant gas will evaporate, absorbing heat from the water, causing the water to decrease in temperature and become colder.
In the reverse phase, the gas in the low pressure state will be compressed by the refrigerant compressor. The copper pipe or cooling water system will help dissipate heat, causing the gas to change from gas to liquid. This whole process takes place in a closed cycle, and is regulated through the throttle valve to ensure stable cooling efficiency.
Advantages and disadvantages of air conditioning chiller system
What are the advantages of Chiller?
- Flexible capacity: Chiller capacity can range from 5 tons to thousands of tons, especially with water cooling systems, suitable for many different types of projects.
- Compact design: The cold water pipe system has a compact design, easy to install for high-rise buildings or limited space, helping to save installation area.
- Stable and durable operation: Chiller has long life and stable operation, minimizing problems and maintenance.
- Flexible adjustment capabilities: The system has many levels of load reduction, helping to flexibly adjust capacity depending on actual needs and loads. A machine can have from 3 to 5 levels of load reduction, with large systems being able to use multiple machine clusters to increase the number of load reduction levels.
- Suitable for all projects: Chiller systems can be applied to projects from small to large or very large, meeting diverse requirements.
- Cost savings: Saves energy and operating costs, bringing high economic efficiency to users.
- Stable temperature: Ensures stable temperature is maintained throughout operation.
- Custom capacity on demand: Chiller can adjust capacity according to customer's specific requirements, ensuring optimal response to cooling needs.
What are the disadvantages of Chiller?
- Complex installation and operation: The installation and operation process requires high technical expertise, therefore requires skilled and experienced staff.
- Installation space requirements: Some systems require large spaces, especially in basements, which affects the usable area.
- Need computer room and specialized staff: The system requires a separate machine room and specialized staff to manage and operate.
- Complex repair and maintenance: Repair and maintenance are not simple, requiring technical knowledge and specialized tools.
- High power consumption: Power consumption per unit of cooling capacity is quite large, especially when the load does not reach maximum, leading to high operating costs.
What is the application of Chiller?
Chiller, one cooling system Advanced, widely applied in many different industries:
Plastic production
In the plastics manufacturing industry, the Chiller system plays an important role in cooling hot plastic after injection, blowing, extrusion or stamping. At the same time, it also helps cool machinery and equipment used in production, such as the hydraulic system of the molding machine, gearbox, and other parts. The use of Chiller not only helps to cool down effectively but also contributes to saving energy and reducing wear and tear of equipment, ensuring stable and long-term operation of machinery during the production process.
Milk, beer, beverage production
Chiller in milk production
In the dairy industry, after the milk is collected, it is put into a cold tank with temperature below 40℃ thanks to Chiller systemAfter going through the processing stages, The temperature of milk is raised from 40-90℃. However, when entering the canning process, milk needs to be cooled for a certain period of time to ensure product quality. This cooling process is very important because it determines the output quality of the product. The Chiller will cool the water, helping reduce the temperature of milk from 90℃ to 30℃, ensuring milk is cooled quickly and efficiently.
In addition, the Chiller system also plays an important role in the packaging and creation of milk cartons. Specifically, the air compressor system helps blow the plastic glue and press it tightly to form the mold for the milk cup.
Chiller cooling system:
- Helps cool plastic molds, preventing molds from overheating due to heat transferred from the product.
- Providing cold water helps cool the mold quickly, minimizes waiting time and prevents mold sticking, thereby increasing production efficiency and finished product quality.
Chiller in beer and beverage production
In the production of beer and fermented beverages, the processing requires strict temperature control to ensure the quality of the final product. Therefore, water cooling chiller systems are indispensable in beer factories, especially at important stages in the fermentation and processing process.
Chiller System participate in the following stages:
- Cooling the sugar solution: After cooking, the sugar solution is usually around 80℃, it needs to be cooled down to 6-8℃ for the fermentation process to take place quickly. If the fermentation time is prolonged, microorganisms may grow and affect the quality of the beer.
- Beer fermentation: Chiller helps reduce the temperature released during the fermentation process, thereby supporting the conversion of Houblon sugar into beer through the action of yeast.
- Preserving yeast: The Chiller system maintains low temperatures in special containers to preserve the yeast strain in the best conditions.
In addition, this system also plays an important role in cooling water, cooling fermentation tunnels and helping to effectively regulate temperature throughout the production process.
HVAC and printing industry
HVAC: System HVAC (Heating, Ventilation, and Air Conditioning) is a large-scale air conditioning system, used to cool buildings and industrial applications. This system is easy to replace and maintain, with a long life (from 10 to 20 years). HVAC System Operates at a reasonable and efficient energy cost, suitable for large projects.
Printing: In the printing industry, the chiller not only helps to remove the heat generated during the impact of the rollers, but also plays an important role in cooling the paper after being processed through the ink drying oven. This cooling process ensures that the paper does not deform and helps to improve the quality of printed products.
Industrial Medicine – MRI Imaging Systems
The role of What is a chiller? in medicine? Magnetic resonance imaging (MRI) is a diagnostic imaging method that helps to observe the internal organs of the human body. This device is especially useful in distinguishing pathological tissues, such as brain tumors, from normal tissues. During operation, the MRI machine generates heat, and to maintain stable performance, the Chiller system is used to remove this heat. The excess heat is transferred through a cooling system, which can be ambient air or a water source such as a cooling tower, to ensure that the MRI machine operates efficiently and does not overheat.
How to calculate capacity to install a cooling chiller
Normally, factories use two methods to calculate the installed capacity of water chillers as follows:
Calculated based on available parameters
In the Chiller's manual (catalogue), the following parameters are usually provided:
- Required cooling capacity of the machine: Qll (kW cooling)
- Cold water flow: m³/h, liter/min
- Cold water temperature to be maintained: ℃ and °F
The formula for calculating cooling capacity is:
Q = 4.186 * At * Qll / 3.6 (kW cooling)
In there:
- At is the temperature difference between the plastic in its molten state and after it has been cooled.
When converting from a cooling tower system to a Chiller, the capacity can be calculated as follows:
For example:
If the cooling tower has a capacity of 20 Tons, with the inlet water temperature of 30℃ and the outlet water temperature of 35℃, then to reduce 5℃, 20 Tons of cold is needed. To lower the water temperature from 20℃ to 25℃, the Chiller system needs a capacity of 40 Tons of cold.
Calculated by cooling capacity for the machine
To calculate the cooling capacity of the machine, we use the following formula:
Q = Cp * At * M / 3600 (kW cooling)
In there:
- At: The temperature difference between the plastic when it is still molten and after it has been cooled. Typically, At is taken as 200°C (with an ideal difference of 230°C to 30°C).
- Cp: Specific heat of plastic.
- M: Product yield in one hour (unit: Kg).
Some notes when calculating Chiller capacity:
- Calculate surplus capacity: Because over time, the machine will gradually lose performance, it is necessary to calculate surplus capacity to ensure that the machine can still operate effectively.
- Backup machine: Backup machines are needed to ensure continuous production, even if the main machine fails. Backup machines also help coordinate operations between machines, allowing them to rest, thereby increasing the life of the machine and electrical system.
Some notes when installing Chiller system
Chiller is the solution chosen by many industrial parks, factories, and hotels thanks to its ability to help machines operate efficiently, minimizing problems caused by high temperatures. However, for the system to operate optimally, it is necessary to pay attention to some important factors when installing:
- Select installation location: It is necessary to choose a suitable, well-ventilated location to ensure the cooling performance of the system.
- Water pipe connection: Make sure the plumbing system is properly connected, free of leaks and the water flow is properly adjusted.
- Electrical installation: Check and ensure the electrical system has sufficient capacity, is safe and stable.
In addition, the quality of the Chiller system is also an important factor to note. Choosing high-quality Chiller equipment helps ensure productivity, operating efficiency, long-term durability and easy maintenance during use.
What are the criteria to help you choose to buy a Chiller?
Below are the criteria and experiences to help you choose the right Chiller:
Find a reputable supplier
Choosing a reputable supplier brings many benefits, the most prominent of which is professional and dedicated advice from a team of staff with solid expertise. This makes it easy for you to choose a Chiller system that is suitable for your production process and factory operating requirements. In addition, reputable suppliers regularly check and maintain the Chiller system periodically, ensuring stable performance and prolonging the life of the equipment.
Determine operating capacity
To meet production requirements, the minimum capacity of the Chiller is usually from 100HP or more. However, depending on the nature and scale of each factory, some small production facilities can choose air-cooled Chiller lines with a capacity of about 30HP, which is more suitable for their operating needs.
Compare prices
The price of a Chiller will vary depending on the supplier and different product lines. In the current market, the price of a Chiller cooling system usually ranges from 20 to 30 million VND.
Because of the variety of prices from different suppliers, businesses need to be cautious and consider carefully before deciding to buy. This is a large-sized device, with a high investment cost and a long-term usage time.
Above are detailed answers to the question. What is a chiller? but Tan Long want to share with you. Hope you will have more information to buy the right Chiller machine. If you still have questions about this type of machine, you can call us for answers.
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