To always assure a stable heating operation regardless of the change in an indoor load, the fresh air, or the like, by controlling the amount of bypass refrigerant according to a characteristic value equivalent to an indoor temperature in an air-conditioner, where the discharge refrigerant of a compressor is bypassed to the suction side of the compressor and the low-pressure-side refrigerant is heated by a heating device.
In heating operation, high-temperature and high-pressure refrigeration gas being compressed by a compressor 1 reaches an indoor heat exchanger 6 through a four-way valve 5 and exchanges heat with the indoor air here, thus heating the inside of a room. In this case, a bypass circuit 15 for connecting the discharge and suction sides of the compressor 1 is provided and a bypass refrigerant adjustment means (solenoid valve) 16 is included in the middle. Also, a heat exchanger 9 for heating refrigerant with incineration equipment 10 as a heat source for heating a refrigerant from the indoor beat exchanger 6 is provided. Also, for commonly using the indoor heat exchanger 6 even if the amount of circulated refrigerant changes in cooling and heating, the valve travel of a solenoid valve 16 is controlled, thus making equal the amount of refrigerant flowing to the indoor heat exchanger 6 in cooling and heating.
ISHIKAWA NORIKAZU
KOSAKAI TAKESHI
FUSE TOSHIYA
TAKAGI MASAHIKO
JIYOUJIMA KAZUNOBU
