Indirect cooling
Indirect cooling relies on the evaporation of the refrigerant in the evaporator of the refrigerator, so that the refrigerant (such as brine) is cooled, and then the refrigerant is input into the cabinet or building of the refrigeration device, and the air in it is cooled by a heat exchanger. This cooling method has a slow cooling speed, a large total heat transfer temperature difference, and a more complicated system, so it is only used in fewer occasions, such as salt water ice making and cold storage with constant temperature requirements.