| 摘要 |
PROBLEM TO BE SOLVED: To reduce energy consumption under the most suitable environment by providing a controller for switching the operation from compression cycle to refrigerant pump cycle when the outdoor temperature is equal to or lower than a set level. SOLUTION: In the compression cycle, gas refrigerant is pressurized by a compressor 5 and fed to a condenser 8 where the refrigerant is liquefied through heat exchange with outdoor air. The refrigerant is then reduced in pressure through an expansion valve 9 and used for cooling indoor air at an evaporator 4 before being returned back to the compressor 5 while being gasified. In the refrigerant pump cycle, gas refrigerant is delivered from the evaporator 4 to the condenser 8 where it is cooled with low temperature outdoor air and liquefied before being fed to a refrigerant pump 1. Liquid refrigerant is pressurized by the refrigerant pump 1 and introduced to the evaporator 4 where it is used for cooling the indoor air and liquefied refrigerant is returned back to the condenser 8. Outdoor temperature is detected by means of a sensor 15 and when it is lower than a set level, operation is switched from compression cycle to refrigerant pump cycle. A controller 16 makes a decision concerning to the set level of outdoor temperature. |
