Small industrial chiller is a kind of water cooling e […]
Small industrial chiller is a kind of water cooling equipment. Small chiller is a kind of cooling water equipment that can provide constant temperature, constant current and constant pressure. The working principle of the small water chiller is to inject a certain amount of water into the water tank, cool the water through the cooling system of the small water chiller, and then send the low-temperature cooling water to the equipment to be cooled. The cold water of the small chiller takes away the heat, then raises the temperature and returns to the water tank to achieve the cooling effect. The temperature of the cooling water can be automatically adjusted according to needs, and long-term use can save water. Therefore, small chillers are standard energy-saving equipment.
(1) The cooling principle of small chillers:
The operation of the small chiller system is through three interrelated systems: refrigerant circulation system, water circulation system and electrical automatic control system.
(2) Refrigerant circulation system of small chiller:
The liquid refrigerant in the evaporator absorbs the heat in the water and starts to evaporate. There is a certain temperature difference between the final refrigerant and the water. The liquid refrigerant is also completely evaporated and compressed by the compressor (pressure and temperature increase). The gas refrigerant absorbs heat through the condenser (air cooling/water cooling), condenses into liquid, and passes through the thermal expansion valve (or capillary) part. After flowing into the evaporator, the low-temperature and low-pressure refrigerant is converted to complete the refrigerant cycle process.
The basic composition of the cooling system of a small chiller is as follows:
1. Condenser: In the freezing process, the condenser plays a role in outputting heat energy and condensing refrigerant. After the high-pressure superheated steam discharged from the refrigeration compressor enters the condenser, all the heat absorbed in the working process, including the heat absorbed from the evaporator and refrigeration compressor and the heat in the pipeline, is transferred to the surrounding medium (water or air). ), the high-pressure superheated vapor of the refrigerant condenses into liquid again. According to different cooling media and cooling methods, condensers can be divided into three categories: water-cooled condensers, air-cooled condensers and evaporative condensers.
2. Compressor: The compressor is the core component of the refrigeration system and the power source for refrigerant compression. Its function is to convert the input electrical energy into mechanical energy and compress the refrigerant.
3. Thermal expansion valve: Thermal expansion valve is not only a flow regulating valve, but also a throttle valve in refrigeration equipment. It is installed between the filter drier and the evaporator in the refrigeration equipment. Its temperature-sensitive packaging is wrapped around the exit of the evaporator. Its main function is to throttle and decompress the refrigerant liquid when it flows through the thermal expansion valve at high pressure and normal temperature, and convert it into low-temperature and low-pressure refrigerant wet vapor (mostly liquid, a small part of vapor) into the evaporator, which evaporates And absorb heat, so as to achieve the purpose of refrigeration and cooling.
4. Evaporator: The evaporator is a kind of heat exchanger that absorbs the heat of the cooling medium by evaporating the refrigerant liquid (actually boiling). Its function in the refrigeration system is to absorb heat (or output cooling). In order to ensure a stable and long-lasting evaporation process, the refrigeration compressor must be used continuously to extract the evaporated gas to maintain a certain evaporation pressure.
5. Liquid storage: After the liquid storage device is installed in the condenser, it is directly connected to the condenser discharge pipe. The refrigerant liquid of the condenser should flow into the accumulator without obstruction, 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 reservoir will play a role in regulating and storing refrigerant. For small refrigerator refrigeration systems, condensers are usually used to regulate and store refrigerant rather than liquid storage.
6. Filter drier: It is necessary to prevent water and dirt (oil, iron and copper) from entering the refrigeration cycle of the small cooler. The main source of water is trace water contained in newly added refrigerants and lubricants, or water brought by air entering the maintenance system. If the water in the system is not eliminated, when the refrigerant passes through the throttle valve (thermal expansion valve or capillary tube), the water will sometimes freeze into ice due to the drop in pressure and temperature, which will block the passage and affect the normal operation of the refrigeration device . Therefore, the filter drier must be installed in the refrigeration system of the small cooler.