| 摘要 |
PROBLEM TO BE SOLVED: To excellently determine frost formation, and attain reduction in power consumption.SOLUTION: The cooling device comprises: a coolant circuit 20 that is composed of a vaporizer 24 arranged inside a commercial product storage chamber 3, a compressor 21 sucking coolant from the vaporizer 24 and compressing the coolant, a radiator 22 dissipating heat from the coolant compressed by the compressor 21, and an expansion mechanism 23 for adiabatically expanding the coolant having the heat dissipated by the radiator 22 and sending out the adiabatically-expanded coolant to the vaporizer 24, which are sequentially connected by coolant piping 25, and causes the vaporizer 24 to evaporate the coolant, thereby cooling air inside the commercial product storage chamber 3; an in-chamber temperature sensor S1 that detects an interior temperature of the commercial product storage chamber 3; and a vaporizer temperature sensor S2 that detects a temperature of the vaporizer 24. During a cooling operation, when the vaporizer temperature is equal to or lower than a cooling temperature T1 and an in-chamber temperature difference &Dgr;T after a determination time has elapsed is equal to or smaller than a threshold value t0, a control part 30 stops a drive of the compressor 21 and the like and performs a defrost operation of the vaporizer 24. |
