Basic knowledge of chiller system
Small chiller: is a water cooling equipment, a small chiller is a constant temperature, constant current, constant pressure cooling water equipment. Small chiller works is to first put a certain amount of water into the tank, through a small chiller cooling system will be water cooling, and then by the pump will be low-temperature cooling water into the equipment to be cooled, small chillers chilled water After the temperature rise and then back to the tank, to achieve the role of cooling. Cooling water temperature can be adjusted automatically according to the requirements, long-term use can save water. Therefore, the small chiller is a standard energy-saving equipment.
First, the cooling principle of a small chiller:
The operation of the small chiller system is through three interrelated systems: the refrigerant circulation system, the water circulation system, the electrical control system.
Second, a small chiller refrigerant circulation system:
The liquid refrigerant in the evaporator absorbs the heat in the water and begins to evaporate. Finally, a certain temperature difference is formed between the refrigerant and the water, and the liquid refrigerant is completely evaporated into a gaseous state and sucked and compressed by the compressor (pressure and temperature increase) , Gaseous refrigerant through the condenser (air-cooled / water-cooled) to absorb heat, condensed into a liquid, through the thermal expansion valve (or capillary) throttling into low-temperature low-pressure refrigerant into the evaporator to complete the refrigerant cycle process.
Small chillers refrigeration system basic components:
1, the condenser: in the cooling process, the condenser plays the role of heat output and the role of condensation of the refrigerant. After the high pressure superheated steam discharged from the refrigeration compressor enters the condenser, it absorbs all the heat absorbed during the working process, including the heat absorbed from the evaporator and the refrigeration compressor and in the pipe, to the surrounding medium (water or Air) away; the refrigerant high-pressure superheated steam is re-condensed into a liquid. (Depending on the cooling medium and the cooling method, the condenser can be divided into three categories: water-cooled condenser, air-cooled condenser, evaporative condenser.)
2, the compressor: the compressor is the core components of the entire refrigeration system, but also the source of refrigerant compression power. Its role is to convert the input power into mechanical energy, the refrigerant compression.
3, thermal expansion valve: thermal expansion valve in a small chiller cooling system is the flow of the control valve, but also refrigeration equipment in the throttle valve, which is installed in the cooling equipment in the dry filter and evaporator between its The temperature wrap is wrapped at the exit of the evaporator. Its main role is to make high-pressure refrigerant at room temperature in the flow through the thermostatic expansion valve when the throttle, into low-temperature low-pressure refrigerant wet steam (most of the liquid, a small part of the steam) into the evaporator, vaporization in the evaporator Endothermic, and to achieve the purpose of cooling cooling.
4, the evaporator: the evaporator is to rely on the evaporation of refrigerant liquid (in fact boiling) to absorb the heat of the heat medium heat transfer equipment. Its function in the refrigeration system is to absorb heat (or output cooling). In order to ensure that the evaporation process can be stable and lasting, must continue to use the refrigeration compressor to extract the gas away to maintain a certain evaporation pressure.
5, the reservoir: storage device installed in the condenser, and the condenser of the drainage tube is in direct communication. The refrigerant in the condenser should flow unimpeded into the reservoir so that the cooling area of the condenser can be fully utilized. On the other hand, when the heat load of the evaporator is changed, the amount of the refrigerant liquid is also changed, and the reservoir functions to adjust and store the refrigerant. For small and small chiller cooling system, often do not install the reservoir, but the use of condenser to adjust and store the refrigerant.
6, dry filter: In a small chiller refrigeration cycle must be to prevent moisture and dirt (oil, iron, copper) and other entry, the main source of water is newly added refrigerant and lubricants contained trace moisture , Or due to the maintenance of the system when the air into the water. If the water in the system is not removed, when the refrigerant through the throttle (thermal expansion valve or capillary), due to pressure and temperature drop sometimes water will freeze into ice, so that the channel block, affecting the normal operation of the refrigeration device. Therefore, a dry filter must be installed in a small chiller refrigeration system.
7, Refrigerants: Most of the small industrial chillers used in modern industry use R22 or R12 as refrigerant. Refrigerant is a refrigerant in the refrigeration system, its main role is to carry heat, and in the state changes to achieve endothermic and exothermic.