Gaseous ammonia precooler for producing food-grade carbon dioxide

The utility model discloses a gaseous ammonia precooler for producing food-grade carbon dioxide. The device comprises a carbon dioxide storage tank, a compressor, an ammonia liquefier, a pressurizingtank and an air buffer tank, the air buffer tank is connected with the compressor; the pressurizing tank is positioned below the ammonia liquefier; the bottom of the carbon dioxide storage tank is connected with an air pressure pump; an air inlet pipeline penetrating through the ammonia liquefier is arranged on the air pressure pump; wherein a gas outlet end of the gas inlet pipeline is communicated with the pressurizing tank, the gas inlet pipeline in the ammonia liquefier is vertically arranged in the ammonia liquefier in an S shape, a heat exchange pipeline wound on the gas inlet pipeline is arranged in the ammonia liquefier, one end of the heat exchange pipeline is connected with the compressor, and the other end of the heat exchange pipeline penetrates through the pressurizing tank and then is connected with