Cold storage belongs to the food circulation industry. Refrigerators are generally used in cold storage. Liquid (ammonia or freon) with extremely low gasification temperature is used as coolant, which evaporates under low pressure and mechanical control to absorb the heat in the storage room and achieve the purpose of cooling down. The most commonly used is the compression refrigerator, which is mainly composed of compressor, condenser, throttle valve and evaporation tube. According to the evaporation tube device, it can be divided into direct cooling and indirect cooling. The direct cooling evaporation pipe is installed in the cold storage. When the liquid refrigerant passes through the evaporation tube, it directly absorbs the heat in the warehouse and cools down.

Moldproof, sterilization and disinfection in cold storage: Cooking materials and food stored in cold storage contain certain fat, protein and starch. The existence of these nutrients will make molds and bacteria multiply and grow in large numbers. In order to do a good job in hygienic management of cold storage and ensure the quality of cold storage of food and cooking materials, it is necessary to carry out hygienic disinfection of cold storage regularly. For mildew prevention, sterilization and disinfection of cold storage, acid disinfectant can be used first. The bactericidal function of acid disinfectants is mainly to coagulate protein in bacteria. Common disinfectants are lactic acid, peracetic acid, bleaching powder and formalin.