| 摘要 |
In external unit 19, three-way valve 25 provided downstream of CPR 23 enables a switching connection between CPR 23 and branch line 21 A of first bypass line 21 with respect to liquid line 18 A. In internal unit 20, second bypass line 27 connects inlet side of receiver 13 and inlet side of evaporator 16, and open/close valve 28 is provided along second bypass line 27. At de-icing, three-way valve 25 switches to first bypass line 21 side and open/close valve 28 opens. There upon, hot gas from compressor 11 circulates from first bypass line 21 to liquid line 18 A to enter evaporator 16 through second bypass line 27 while squeezing out liquid refrigerant. Evaporator 16 is heated by manifest heat of introduced hot gas, and when the internal pressure of vaporator 16 rises to a condensation temperature over 0° C., de-icing is performed efficiently by manifest heat plus latent heat.
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