Super low temperature transcritical cascade refrigeration system and refrigeration method

The invention provides a super low temperature transcritical cascade refrigeration system and a refrigeration method. Because of limitation, single working medium multi-stage compression is generallyused for producing low temperature above -60 DEG C. In recent years, the demand of a super low temperature refrigerant technology is increased gradually, for the temperature range below -80 DEG C, thethree-stage cascade refrigeration system is adopted in a traditional refrigeration method. The super low temperature transcritical cascade refrigeration system comprises a high temperature stage circulating system with R404A as a circulating working medium and a low temperature stage circulating system with R14 as a circulating working medium. The super low temperature transcritical cascade refrigeration system and the refrigeration method are used for super low temperature transcritical cascade refrigeration. 超低温跨临界复叠制冷系统及制冷方法。单工质多级压缩由于其局限性，一般用来制取-60℃以上的低温。近年来超低温制冷剂技术的需求量逐渐增加，对于-80℃以下的温度范围，传统的制冷方式是采用三级复叠制冷系统。本发明组成包括：