| 摘要 |
PROBLEM TO BE SOLVED: To enable a cooling capability to be adjusted within a range of about 0 to 100% in respect to the maximum cooling capability and realize an energy saving. SOLUTION: A bypass passage 9 having a specific pressure expansion valve 8 is connected at its one end with an outlet side passage of a condenser 3 and at the other end with a suction side passage of a compressor 2. When a refrigerant pressure at the suction side passage of the compressor 2 become a negative pressure, the specific pressure expansion valve 8 is opened. A downstream side passage of the specific pressure expansion valve 8 in the bypass passage 9 is provided with a heat exchanger 7 for performing a heat exchanging operation between refrigerant flowing at the downstream side passage and refrigerant flowing at a discharging passage of the compressor 2. When a degree of opening of an electronic expansion valve 4 becomes 0% and a pressure within the suction side passage of the compressor 2 is apt to become a negative pressure, the specific pressure expansion valve 8 is opened, the refrigerant flows through the bypass passage 9 and it may be adjusted to prevent the pressure in the suction side passage of the compressor 2 from becoming a negative pressure. |
