Refrigerant refrigerator to complete the thermodynamic cycle of the work. It absorbs heat from the cooled object at low temperatures and then transfers to cooling water or air at a higher temperature.
In a vapor compression chiller, a refrigerant is used at ambient temperature or at a lower temperature to liquefy the refrigerants. such as freon (saturated hydrocarbons, fluorine, chlorine, bromine derivatives), azeotropic mixture (by two kinds of freon by a certain proportion of mixed azeotropic solution), hydrocarbons (propane, ethylene, etc.), ammonia and so on; in a gas compressed refrigerator, a gas refrigerant, such as air, hydrogen, helium, etc., is always gaseous in the refrigeration cycle; In an absorbing refrigerator, The two-element solution consisting of absorbent and refrigerant is used as a working quality, such as ammonia and water, lithium bromide (molecular formula: LiBr.) White cubic crystalline or granular powder, extremely soluble in water, and water, and so on; Steam jet chillers are used as refrigerants. The main technical indicators of refrigerant are saturated vapor pressure, specific heat, viscosity, thermal conductivity, surface tension and so on. After 1960, the application of non-azeotropic mixture has been studied extensively, and it has been used for liquefied natural gas and separating. The low evaporation temperature can be obtained by using the non-azeotropic mixture single-stage compression, and the refrigeration capacity can be increased and the power dissipation is reduced. Its nature is directly related to refrigeration effect, economy, safety and operation Management, thus the understanding of refrigerant nature requirements cannot be ignored.