Carbon dioxide refrigerating system and refrigerating method thereof

A refrigeration method using carbon dioxide as a medium, comprising the following steps:

• (1), compressing high-pressure carbon dioxide gas in an evaporator into a condenser by a compressor for cooling;
• (2), sucking the carbon dioxide gas mixed in carbon dioxide liquid away by a suction assembly to achieve gas-liquid separation;
• flash-evaporating part of the carbon dioxide liquid by the suction assembly, performing multi-stage cooling to cause the liquid carbon dioxide to be in a super-cooled state;
• and
• (3), introducing the super-cooled carbon dioxide liquid into a liquid reservoir for use;
• wherein in step (1), the carbon dioxide gas is completely condensed and liquefied in a flash-evaporation condenser by a flash-evaporation condensation method, wherein a heat exchange device and a liquid atomization device are arranged in a closed housing, a negative-pressure fan is arranged on the closed housing, a liquid is sprayed through the high-pressure liquid atomization device to form an atomized liquid with a large specific surface area, and is dispersed in an accommodating chamber of the housing;
• and under the radiant heat generated by the heat exchange device and the negative pressure generated by the negative-pressure fan, small particles of the atomized liquid are dispersed and suspended in a gas medium to form an aerosol, so that water molecules on a surface of the atomized liquid depart from droplet bodies, transform into vapor and take away heat;
• in step (2), the multi-stage cooling is realized by providing a plurality of float valves connected in series, the carbon dioxide liquid passes through the plurality of float valves in sequence, the plurality of float valves are respectively connected to the suction assembly, part of the liquid carbon dioxide is gasified under a suction force, so that the remaining liquid carbon dioxide is in the super-cooled state, and a liquid carbon dioxide with a lower temperature is obtained.