| 摘要 |
PROBLEM TO BE SOLVED: To prevent abnormally high pressure on the exit side of a compressor in a vapor compression refrigerating cycle, employing refrigerant which operates in a supercritical region. SOLUTION: The vapor compression refrigerating cycle comprises a variable displacement compressor 10 which is able to vary compression capacity, and a capacitive control valve 20 for controlling the pressure, which starts varying the compression capacity by varying a set value of the differential pressure between a discharge pressure Pd and a crankcase pressure Pc of the compressor 10 using a solenoid current. The pressure Pd of the compressor 10 is detected by a pressure sensor 40. When the pressure Pd becomes close to a given pressure which is higher than the pressure in a normal operation, the set value of the differential pressure of the valve 20 is made small to reduce the compression capacity, thereby controlling the pressure Pd to not to exceed the given pressure.
|
