Working Principle Of Refrigerant

The working fluid that completes the thermal cycle in a refrigerator. It absorbs heat from the cooled object at low temperatures and then transfers it to cooling water or air at higher temperatures. In a vapor compression refrigeration machine, refrigerants that can liquefy at room temperature or lower temperatures are used, such as fluorocarbons (derivatives of saturated hydrocarbons such as fluorine, chlorine, and bromine), azeotropic mixtures (azeotropic solutions composed of two types of fluorocarbons mixed in a certain proportion), hydrocarbons (propane, ethylene, etc.), ammonia, etc; In a gas compression refrigeration machine, gas refrigerants such as air, hydrogen, helium, etc. are used, and these gases remain in the gaseous state throughout the refrigeration cycle; In an absorption refrigerator, a binary solution composed of an absorbent and a refrigerant is used as the working fluid, such as ammonia and water, lithium bromide (molecular formula: LiBr. White cubic crystalline or granular powder, highly soluble in water), and water; Steam jet refrigerators use water as the refrigerant. The main technical indicators of refrigerants include saturated vapor pressure, specific heat, viscosity, thermal conductivity, surface tension, etc. After 1960, a large amount of experimental research was conducted on the application of non azeotropic mixed refrigerants, and they have been used for liquefaction and separation of natural gas. The application of non azeotropic mixed refrigerant single stage compression can achieve very low evaporation temperature, increase refrigeration capacity, and reduce power consumption. Its nature directly affects the refrigeration efficiency, economy, safety, and operation management of refrigeration devices, so understanding the requirements for refrigerant properties cannot be ignored.