What is an industrial chiller?
Bently industrial chiller is a type of compression chiller that is used in industries and industrial processes to provide cooling. Industrial chiller medium is generally distilled water or distilled water with ethylene glycol or ethylene propylene as antifreeze. As specified in the definition of industrial chiller, this chiller is also a type of compression chiller on top of the vapor compression refrigeration cycle. Industrial chiller has 4 basic parts: compressor, condenser, evaporator and expansion valve. Industrial chillers that are usually used in industries are of compression type and depending on the required conditions, they can be water-cooled or air-cooled.
What is an industrial chiller?
From the cooling produced by the industrial chiller in the cooling of industrial equipment and molds such as chemical processes, plastic injection molds, dehumidification from compressed air, data center cooling, clean room temperature control, oil cooling of grinding machines and process cooling. Wide face is used for high zero applications.
A type of industrial chiller is designed and manufactured, which is called a sub-zero industrial chiller and produces water and antifreeze at a temperature below zero degrees Celsius. The most important difference between the Bently industrial chiller and the air conditioning chiller and the building chiller is that the industrial chillers are generally designed to work continuously so that they can be used throughout the year, while the air conditioning and building chillers are used only during the seasons. It is used year round.
It should be considered that the absorption chiller is rarely used in industrial applications. Because if absorption chillers are used in industrial processes, the cost of supply, operation and depreciation is very high for the users. On the other hand, absorption chillers are designed and produced with high refrigerating capacities, and generally, due to the structure and mechanism of the absorption refrigeration cycle, they lack continuous cooling capacity control. Therefore, considering these cases, employers and operators of industrial equipment should show less luck for using absorption chillers for industrial cooling.
It should be kept in mind that some kind of absorption chillers are used in the CCHP industrial process of simultaneous production of heat, cold and power. This process is known as the simultaneous production of cold, heat and electricity, and in gas, heating and combined cycle power plants, generally in hot and tropical regions, it is possible to produce cooling and Cooling is paid and in this condition, absorption chiller can only be used. The main application of absorption chiller is where there is waste heat such as power plants and geothermal or solar. But unfortunately in Iran it is used in the building along with the boiler.
The main components of Bently industrial chiller
Bently industrial chiller evaporator
Bently industrial chiller evaporator is designed to absorb heat from water and convert it into cold water or chiller water. This part or piece of industrial chiller is made in three types. These three types are:
- Plate or plate evaporator
- Shell&Tube evaporator or tube shell
- Tank evaporator or ice bank
Considering that there are wide temperature fluctuations in many industrial processes, the cooling water returned from the industrial equipment and processes to the evaporator of the industrial chiller is constantly fluctuating in temperature. In order to avoid the effect of this temperature fluctuation on the chiller and the dangers caused by the heating of the compressors, in the air conditioning and cooling engineering frameworks, it is suggested to use a buffer tank or an intermediate water and antifreeze tank.
Therefore, all manufacturers of industrial chillers, including Bently, design and produce evaporators in the Ice Bank style based on the intended use. For example, in plastic and polymer injection industries, tank evaporators or ice banks are used. This type of chillers are known as mold chillers .
Bently Industrial Chiller Condenser:
Condenser is the high pressure part of the industrial chiller refrigeration cycle, which is responsible for discharging the heat of the refrigerant to the outside environment and reducing the temperature of the refrigerant.
Considering that industrial chillers are a type of permanent chillers that must work in winter and in very cold weather conditions, the design of condenser tube fin plate coils and condenser fan performance control should be in such a way that, in any condition, the parameters and meet the pressure and temperature design requirements of the vapor compression refrigeration cycle of the industrial chiller.
Of course, in some situations, it is possible to install free cooling to take advantage of the cool temperature of the outside air. This type of chiller is known as industrial free cooling chiller.
In industrial chillers, along with condenser heat exchangers, water heat exchangers are used, which can cool the water circulating in them by passing air over it and directly transfer this cool water to industrial processes. It is known as Free Cooling Chiller. The high initial cost of purchasing this device is the most important obstacle in its widespread use in industries.
Industrial chiller compressor:
One of the main components of the refrigeration cycle of industrial chillers is the industrial chiller compressor. Usually, piston and screw compressors are used in industrial chillers due to the performance conditions. Because piston and screw compressors have higher reliability in enduring harsh industrial conditions such as liquid return or high pressure of the refrigeration cycle due to environmental pollution.
Another feature of piston compressors in industrial chillers is that they are repairable, and usually after a few years of operation, a complete service is performed on them so that they are again in proper working conditions. Also, in climates that have hot and humid weather, it is more common to use piston compressors. Because they have high tolerance in high pressures and suffer less damage and fatigue due to thermal stress and high discharge pressure.
Industrial chiller expansion valve:
The expansion valve is a part of the refrigeration cycle that is placed in the liquid line at the outlet of the condenser and before the evaporator.
Its task is to control the amount of refrigerant entering the evaporator. In the operation valve, refrigerant volume increases and phase change occurs. The amount of volume increase and its quality play a fundamental role in system cooling.
This part has two basic and special tasks in the refrigeration cycle of an industrial chiller:
- Controlling the refrigerant flow rate entering the evaporator
- Maintaining the pressure difference between the industrial chiller condenser (high pressure area) and the evaporator (low pressure area)
As a result of using the expansion valve, the high-pressure refrigerant liquid coming out of the condenser of the industrial chiller turns into a two-phase mixture of liquid and low-pressure gas with a very low temperature, which can enter the evaporator of the industrial chiller and add water and antifreeze to provide cooling and cooling. Cool industrial processes. Generally, in industrial chillers with refrigeration tonnage or high refrigerating capacity, an electronic expansion valve is used, and in industrial chillers with low tonnage, a thermostatic expansion valve is used. Of course, in sub-zero industrial chillers, it is better to use an electronic expansion valve, even at low refrigeration tonnages.
Types of expansion valves (refrigerant flow control mechanism)
In total, all refrigerant flow control mechanisms that may be used in air conditioning systems or refrigeration devices are:
- Thermal expansion valve
- manual valve
- Capillary tube
- Automatic valve
- Electronic expansion valve
- Low-pressure float valve
- Low-pressure float valve
