Cooler is a machine that achieves refrigeration effect through steam compression or absorption cycle. These liquids can flow through the heat exchanger to achieve the purpose of cooling the air or equipment. The steam compression chiller contains four main components of the steam compression refrigeration cycle (compressor, evaporator, condenser, and partial metering equipment). These The machine can handle different refrigerants. The refrigerant used in absorption refrigerators and benign silica gel used in city water are used as desiccants. The absorption refrigerator uses water as the refrigerant and relies on the strong affinity between water and lithium bromide solution to achieve a strong refrigeration effect.

Cooling principle

The operation of the chiller system is through three interrelated systems: refrigerant circulation system, water circulation system, and electrical automatic control system. Super air knife

Compressor: The compressor is the core component of the entire refrigeration system and the source of power for refrigerant compression. Its function is to convert the input electrical energy into mechanical energy and compress the refrigerant.

Chiller refrigerant circulation system:

The liquid refrigerant in the evaporator absorbs the heat in the water and begins to evaporate. Eventually, a certain temperature difference is formed between the refrigerant and the water. The liquid refrigerant also completely evaporates into a gaseous state and is sucked into the compressor and compressed (the pressure and temperature increase). ), the gaseous refrigerant absorbs heat through the condenser (air-cooled/water-cooled) and condenses into a liquid. After being saved through the thermal expansion valve (or capillary tube), it becomes low-temperature and low-pressure refrigerant and enters the evaporator to complete the refrigerant cycle process.

The basic components of the chiller refrigeration system are:

Condenser: During the refrigeration process, the condenser plays the role of outputting heat energy and condensing the refrigerant. After the high-pressure superheated steam discharged from the refrigeration compressor enters the condenser, all the heat absorbed during the operation, including the heat absorbed from the evaporator and refrigeration compressor and in the pipeline, is transferred to the surrounding medium (water or air) is taken away; the high-pressure superheated vapor of the refrigerant condenses back into liquid. (Based on different cooling media and cooling methods, condensers can be divided into three categories: water-cooled condensers, air-cooled condensers, and evaporative condensers.)

Liquid receiver: The liquid receiver is installed after the condenser and is directly connected to the drain pipe of the condenser. The refrigerant liquid of the condenser should flow into the liquid receiver in all directions, so that the cooling area of the condenser can be fully utilized. On the other hand, when the heat load of the evaporator changes, the demand for refrigerant liquid also changes. At that time, the liquid receiver plays the role of adjusting and storing refrigerant. For small chiller refrigeration equipment systems, liquid receivers are often not installed, but condensers are used to adjust and store refrigerant.

Drying filter: In the refrigeration cycle of the chiller, moisture and dirt (oil, iron filings, copper filings) must be prevented from entering. The source of moisture is mainly the trace moisture contained in the newly added refrigerant and lubricating oil, or due to Moisture brought by air entering during maintenance of the system. If the water in the system is not removed, when the refrigerant passes through the saver valve (thermal expansion valve or capillary tube), the water will sometimes solidify into ice due to the drop in pressure and temperature, blocking the passage and affecting the normal operation of the refrigeration equipment. Therefore, a drying filter must be installed in the chiller refrigeration system.

Evaporator: The evaporator is a heat exchange device that relies on the transpiration (actually boiling) of the refrigerant liquid to absorb the heat of the cooled medium. Its function in the refrigeration system is to absorb heat (or output cold energy). In order to ensure that the transpiration process can proceed stably and for a long time, the transpiration gas must be continuously pumped away by a refrigeration compressor to maintain a certain transpiration pressure.

Thermal expansion valve: The thermal expansion valve is not only a flow regulating valve in the chiller refrigeration system, but also a throttle valve in the refrigeration equipment. It is installed between the drying filter and the evaporator in the refrigeration equipment. Its temperature sensing package is Wrap it around the outlet of the evaporator. Its primary effect is to make the high-pressure and normal-temperature refrigerant liquid save pressure when flowing through the thermal expansion valve, and turn it into low-temperature and low-pressure refrigerant wet vapor (mostly liquid, a small part is steam) into the evaporator, and vaporizes in the evaporator. Absorb heat and achieve the purpose of cooling.

Refrigerant: Most industrial chillers used in modern industry use R22 or R12 as the refrigerant. Refrigerant is a fluid working fluid in a refrigeration system. Its main function is to carry heat and absorb and release heat when conditions change.