| 摘要 |
A pressure regulating valve ( 71 ) is connected to the discharge side of a low stage compressor ( 55 ) to make the pressure in the suction side of high stage compressors ( 11, 12 ) lower than the pressure in a dome of the low stage compressor ( 55 ). Further, an oil return path ( 72 ) is connected to the dome of the low stage compressor ( 55 ) at one end and to the suction side of the high stage compressors ( 11, 12 ) by bypassing the pressure regulating valve ( 71 ) at the other end. With this configuration, refrigeration oil accumulated in the dome of the low stage compressor ( 55 ) is returned to the high stage compressors ( 11, 12 ).
|
