Equipment used in refrigeration operations. Different refrigeration methods use different equipment. At present, the most widely used is the vapor compression refrigeration. The main equipment includes a compressor, a condenser, an evaporator, and a throttle valve. Compressors are used for the compression and delivery of refrigerant vapors, with piston and centrifugal applications being the most widely used. Refrigeration equipment is a combination of a refrigerator and a facility that uses refrigeration. The design and construction of refrigeration equipment is to effectively use refrigeration to refrigerate food or other items; to perform product performance tests and scientific tests at low temperatures; to achieve certain cooling processes in industrial production, or to perform air conditioning. When the article is cooled or frozen, a certain amount of heat is released, and the enclosure structure of the refrigerating device will also introduce a certain amount of heat when it is used. Therefore, in order to maintain the low temperature condition in the refrigeration apparatus, it is necessary to install a refrigerator so as to continuously remove the heat, or to utilize the melting of ice or the sublimation of dry ice to absorb the heat.