| 摘要 |
PURPOSE:To prevent a rise in a high pressure side refrigerant pressure without providing a bypass circuit when an indoor heat exchanger having low capacity is connected. CONSTITUTION:A microcomputer 22 executes a superheat degree control based on an outdoor heat exchanger outlet temperature from a thermistor 12 and a low pressure saturation temperature from a thermistor 13 at the time of heating. Further, when a maximum value of a condensing temperature from a thermistor 21 exceeds a predetermined temperature, a rotation controller 19 is controlled to stepwisely reduce a rotating frequency of a compressor 2. Moreover, when the frequency of the compressor 2 is a lower limit value, a valve controller 20 is controlled to set an opening of a first motor operated expansion valve EV0 to a predetermined opening smaller than a lower limit value under a normal heating degree control and to increase a target value of the superheat degree control. Thus, the compressing capacity of the compressor 2 and an apparent capacity of the outdoor heat exchanger are reduced thereby to prevent pressure rising of a high pressure side refrigerant, thereby making it possible to heat a room in an available range of the compressor 2.
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