| 摘要 |
PROBLEM TO BE SOLVED: To perform a positive adjustment for a supplying amount of refrigerant to an evaporator for an upper stage freezing operation even in the case that a compressor with a fixed capacity is employed in a refrigerant circuit at a low temperature side of double-element type freezer. SOLUTION: A low temperature side refrigerant circuit (30) is provided with a bypassing circuit (40) and a refrigerant heat exchanger (50). A first passage (51) in the refrigerant heat exchanger (50) is connected between a compressor (38) and a cascade condenser (26) in a low temperature side refrigerant circuit (30). A second passage (52) in the refrigerant heat exchanger (50) is arranged at the middle part of the bypassing circuit (40). When one freezing device (13b) is thermally turned off, a bypassing solenoid valve (41) is opened to cause a part of a liquid refrigerant to be fed into the bypassing circuit (40). The refrigerant entered the bypassing circuit (40) is decreased in its pressure with a capillary tube (42), thereafter the refrigerant is fed into a second passage (52) of the refrigerant heat exchanger (50). Then, a part of discharged refrigerant at the compressor (38) is condensed at the first passage (51) of the refrigerant heat exchanger (50).
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