| 摘要 |
PROBLEM TO BE SOLVED: To provide a cascade-type refrigerating device that does not require high pressure needed at individual use of a carbon dioxide refrigerant, and at the same time, can prevent the risk of explosion when a propane refrigerant used individually. SOLUTION: A cascade capacitor C including a high-stage-side (the outside of the refrigerating device) evaporator 4 and a low-stage side (the inside of the device) condenser 6 is shared, and high-stage side circulation circuit A and a low-stage side circulation path B are formed, thus composing a cascade- type binary refrigerating circuit. As the refrigerant of the high-stage side circulation path A, a natural system refrigerant (a hydrocarbon system such as propane and ammonia) is used, and a carbon dioxide is used as the refrigerant of the low-stage side circulation path B. An auxiliary capacitor 9 for cooling the refrigerant by a fixed temperature is installed in front of a low-stage side condenser 6 of the cascade capacitor C.
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