Compared with liquid nitrogen refrigeration, dry ice has two major cost advantages. First, the price of dry ice per liter is 1 ~ 1 8 yuan, while the price of liquid nitrogen is around 2 yuan. Secondly, the structure of dry ice refrigeration is simpler. Before use, it converts high-pressure liquid carbon dioxide into snowflake-like dry ice under normal pressure through an external decompression device, and fills it into the cold source storage room of the container. There is no decompression device in the container itself, and there is one less spraying device than the liquid nitrogen refrigerated container, which further improves its operation reliability.