Industrial refrigeration equipment refers to the equipment mainly used for cooling food for crew members, refrigerating food for sailors, cooling various items, and providing summer air conditioning cooling. It is mainly composed of compressors, expansion valves, evaporators, condensers, accessories and pipelines. According to the working principle, it can be classified into compression refrigeration equipment, absorption refrigeration equipment, steam jet refrigeration equipment, heat pump refrigeration equipment and electric heating refrigeration devices. Currently, the most commonly used on ships is compression refrigeration equipment. The equipment works by releasing the heat of objects and their surroundings, thereby maintaining a certain low-temperature state. The refrigerants used are mainly Freon and ammonia, with Freon being the most commonly used. However, due to the damage to the ozone layer caused by Freon, it has begun to be restricted by environmental protection regulations. Ammonia and other new refrigerants are being re-employed and tested. 

           Before the development of artificial refrigeration, humans had already known how to maintain low temperatures using natural ice and snow in simple devices, that is, using natural cold sources. In China, natural ice was used to preserve food about 3,000 years ago. Even in modern times, people still use ice, snow and groundwater as natural cold sources. Refrigeration equipment cooled by natural ice or artificial ice can only achieve limited low temperatures, and the technology and hygiene conditions are poor, making it difficult to meet various requirements. Modern refrigeration equipment all uses refrigerators for cooling. 

In 1834, the United States successfully developed a type of refrigeration machine. This refrigeration device used ether as the working fluid and could operate continuously. In 1844, the United States developed a refrigeration device for use in hospitals. This device used air as the working fluid to produce ice and cool the air. From 1872 to 1874, with the advent of advanced technologies, the ammonia compressor was invented and ammonia vapor compression refrigerators were manufactured, marking the beginning of modern compression refrigeration machines. In the 1850s, the Carré brothers from France successfully developed an absorption refrigeration machine and an ammonia absorption refrigeration device, which used sulfuric acid and water as the working fluid. In 1910, steam jet refrigeration equipment appeared. The Freon refrigerant was introduced in 1930, promoting the rapid development of compression refrigeration machines. In 1945, the United States successfully developed a silver bromide absorption refrigeration machine.