Working principle of water cooled industrial water chiller
A water chiller is a water cooling device that can provide constant temperature, constant flow, and constant pressure cooling water equipment. Its working principle is to first inject a certain amount of water into the water tank inside the machine, cool the water through the refrigeration system, and then send the low-temperature cooling water to the equipment that needs to be cooled by a water pump. The chilled water takes away the heat, increases in temperature, and then returns to the water tank, achieving the cooling effect. The cooling water temperature can be automatically adjusted according to requirements, and long-term use can save water. Therefore, water chillers are a standard energy-saving device.
Cooling principle of industrial water chillers
The operation of industrial water chiller systems is through three interrelated systems: refrigerant circulation system, water circulation system, and electrical automation system.
Refrigerant circulation system:
The liquid refrigerant in the evaporator absorbs heat from the water and begins to evaporate. Finally, 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 in and compressed by the compressor (pressure and temperature increase). The gaseous refrigerant absorbs heat through the condenser (air cooled/water cooled) and condenses into a liquid. After being throttled by a thermal expansion valve (or capillary tube), it becomes a low-temperature and low-pressure refrigerant that enters the evaporator, Complete the refrigerant circulation process.
Basic composition of refrigeration system
Compressor: The compressor is the core component of the entire refrigeration system, and is also the source of power for refrigerant compression. Its function is to convert the input electrical energy into mechanical energy, compressing the refrigerant.
Condenser: During the refrigeration process, the condenser serves to output heat energy and condense the refrigerant. After the high-pressure superheated steam discharged from the refrigeration compressor enters the condenser, all the heat absorbed during its working process, including the heat absorbed from the evaporator and refrigeration compressor and in the pipeline, is transferred to the surrounding medium (water or air) to take away; The refrigerant high-pressure superheated vapor recondenses into a liquid. (Depending on the cooling medium and cooling method, condensers can be divided into three categories: water cooled condensers, air cooled condensers, and evaporative condensers.)
Liquid receiver: The liquid receiver is installed behind the condenser and is directly connected to the discharge pipe of the condenser. The refrigerant liquid of the condenser should flow smoothly 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 changes, the demand for refrigerant liquid also changes. At that time, the liquid reservoir plays a role in regulating and storing refrigerant. For small refrigeration device systems, it is often not necessary to install a liquid reservoir, but rather to use a condenser to regulate and store refrigerant.
Drying filter: During the refrigeration cycle, it is necessary to prevent the entry of moisture and dirt (oil, iron, copper). The main source of moisture is the trace moisture contained in the newly added refrigerant and lubricating oil, or the moisture caused by the entry of air during maintenance of the system. If the water in the system is not completely discharged, when the refrigerant passes through the throttle valve (thermal expansion valve or capillary tube), sometimes the water will solidify into ice due to the decrease in pressure and temperature, causing channel blockage, affecting the normal operation of the refrigeration device. Therefore, a drying filter must be installed in the refrigeration system.
Thermal expansion valve: In refrigeration systems, thermal expansion valve is both a flow regulating valve and a throttle valve in refrigeration equipment. It is installed between the drying filter and the evaporator in the refrigeration equipment, and its temperature sensing bulb is wrapped at the outlet of the evaporator. Its main function is to throttle and depressurize the refrigerant liquid at high pressure and normal temperature as it flows through the thermal expansion valve, transforming it into a low temperature and low pressure refrigerant wet vapor (mostly liquid, with a small portion of vapor) that enters the evaporator, where it vaporizes and absorbs heat, achieving the purpose of refrigeration and cooling.
Evaporator: An evaporator is a heat exchange device that relies on the evaporation (actually boiling) of refrigerant liquid to absorb the heat of the cooled medium. Its function in a refrigeration system is to absorb heat (or output cold energy). In order to ensure a stable and lasting evaporation process, it is necessary to continuously use a refrigeration compressor to extract the evaporated gas to maintain a certain evaporation pressure.
Refrigerant: Most industrial water chillers used in modern industry use R22 or R12 as the refrigerant. Refrigerant is a flowing working medium in a refrigeration system. Its main function is to carry heat and achieve heat absorption and release when the state changes.