Principle and application of industrial chiller
The industrial chiller consists of three systems: a refrigerant circulation system, a water circulation system, and an electrical control system.
First, the refrigerant circulation system
The liquid refrigerant in the evaporator absorbs the heat in the water and begins to evaporate. The liquid refrigerant also evaporates completely into a gaseous state and is sucked and compressed by the compressor. The gaseous refrigerant absorbs heat through the condenser and condenses into a liquid, and passes through the thermal expansion valve section. After the flow, the low-temperature low-pressure refrigerant enters the evaporator to complete the refrigerant cycle.
Basic composition of the refrigeration system
Compressor: The compressor is the core component of the entire refrigeration system and the source of refrigerant compression. Its function is to convert the input electrical energy into mechanical energy, inhale, compress and transport the refrigerant vapor, and drive the cycle.
Condenser: The condenser acts to output thermal energy and condense the refrigerant during cooling. 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 the refrigeration compressor and in the pipeline, is transferred to the surrounding medium (water or The air is taken away; the refrigerant high pressure superheated vapor recondenses into a liquid.
Drying filter: In the refrigeration cycle, it is necessary to prevent the ingress of moisture and dirt. The source of moisture is mainly the amount of water contained in the newly added refrigerant and lubricating oil, or the moisture brought in by the air entering the system. If the moisture in the system is not cleaned out, when the refrigerant passes through the throttle valve (thermal expansion valve or capillary), the moisture will solidify into ice due to the pressure and temperature drop, which will block the passage and affect the normal operation of the refrigeration unit. Therefore, a dry filter must be installed in the refrigeration system.
Throttle valve: A thermal expansion valve (or capillary tube) is installed between the desiccant filter and the evaporator in the refrigeration device, and the temperature sensor package of the thermal expansion valve is wrapped at the outlet of the evaporator. Its main function is to reduce the pressure of the high-pressure normal temperature refrigerant liquid when flowing through the thermal expansion valve, and become a low-temperature low-pressure refrigerant wet steam (mostly liquid, a small part is steam) enters the evaporator and vaporizes in the evaporator. It absorbs heat and achieves the purpose of cooling and cooling.
Evaporator: An evaporator is a heat exchange device that relies on the evaporation (actually boiling) of a refrigerant liquid to absorb the heat of the cooled medium. Its function in the refrigeration system is to absorb heat. In order to ensure a stable and long-lasting evaporation process, the vaporized gas must be continuously withdrawn by a refrigeration compressor to maintain a certain evaporation pressure.
Refrigerants: Most industrial chillers used in modern industry use R22 or R407C as refrigerants. Refrigerant is a working fluid in a refrigeration system. Its main function is to carry heat and achieve heat absorption and heat release when the state changes.
Second, the water circulation system
The water circulation system is a pump that draws water from the water tank to the equipment that the user needs to cool. The chilled water takes the heat away and the temperature rises, and then returns to the chilled water tank.
Third, electrical control system
The electric appliance automatic control system includes a power supply part (main circuit) and an automatic control part (control circuit). The main circuit part is the power supply to the compressor, fan, water pump, etc. through the contactor. The control circuit part includes a combination of a temperature controller, a pressure protection, a delay device, a relay, an overload protection and the like to automatically start and stop according to the water temperature, and the like.