| 摘要 |
PROBLEM TO BE SOLVED: To provide a refrigerating device having a high pressure in a refrigerating cycle exceeding the critical pressure of a cooling medium, improving its reliability while properly setting the high pressure in the refrigerating cycle. SOLUTION: An expansion machine 22 and an electric operated expansion valve 23 are arranged in series in a refrigerating circuit 10. The refrigerating circuit 10 is provided with a bypass pipeline 35 bypassing the expansion machine 22 and the electric operated expansion valve 23. The bypass pipeline 35 is provided with a bypass valve 36. A high pressure estimation part 73 of a controller 70 estimates the pressure of a cooling medium discharged from a compressor 21 in accordance with values for a cooling medium temperature at the outlet of a heat radiator, a rotating speed of a motor 24, a cooling medium evaporation temperature in an evaporator and a current flowing in the motor 24. A control part 74 of the controller 70 controls the openings of the electric operated expansion valve 23 and the bypass valve 36 depending on a value for pressure estimated by the high pressure estimation part 73. COPYRIGHT: (C)2004,JPO
|
