COOLING STORAGE

PROBLEM TO BE SOLVED: To prevent an auxiliary compressor from frequently repeating start/stop when compensating for shortage of freezing capacity by driving the compressor. SOLUTION: During control cooling, even if a constant speed compressor 32B of a second freezing circuit 31B is required to start as only the freezing capacity by an inverter compressor 32A of a first freezing circuit 31A is insufficient, the constant speed compressor 32B does not immediately start. The constant speed compressor 32B starts only after inside temperature TR rises to upper limit temperature TH of set temperature To. Even if the constant speed compressor 32B is required to stop during operation of both compressors 32A, 32B, it does not immediately stop. The constant speed compressor 32B stops only after the inside temperature TR is decreased to temporary lower limit temperature TLk lower than the set temperature To by a predetermined value, though the inside temperature TR is still higher than the lower limit temperature TL. COPYRIGHT: (C)2009,JPO&INPIT