| 摘要 |
PURPOSE:To surely prevent liquid refrigerant from returning a compressor by a method wherein proportional control valves are controlled so that the degree of superheat of the refrigerant flowing through an indoor heat exchanger operated under large capacity is kept at constant while the degree of superheat of the refrigerant flowing through an indoor heat exchanger operated under small capacity does not fall down below the certain fixed value. CONSTITUTION:A controller 12 controls the valve openings of proportional control valves 13A and 13B so as to reduce the pressure of refrigerant provided on branch pipes 14A and 14B, through which the high pressure liquid refrigerant flows into the respective indoor heat exchangers 11A and 11B. At means 36A and 36B, the controller 12 controls the valve opening on the side of one indoor unit, in which the deviation value between the room temperature and the set temperature is larger than that in the other indoor unit, so as to bring the degree of superheat of refrigerant at the outlet side of the indoor heat exchanger belonging to the former indoor unit. Further, in means 37A and 37B, the controller 12 controls the valve opening of the other or the latter indoor unit so as to be proportional to the difference between the respective deviation values between the room temperature and the room set temperature of the respective indoor units. At the same time, in means 38A and 38B, the controller 12 controls said valve opening of the other indoor unit so as not to fall down the degree of superheat of refrigerant at the outlet side of the indoor heat exchanger belonging to the other indoor unit below the certain fixed value.
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