Heat pump device

摘要

The device has an expansion valve (19) arranged in front of an evaporator (3) along flow direction. Oil separators (25, 26) are arranged behind respective compressors (C1, C2) along flow direction and connected with the compressors over respective oil conduits (101, 102) for returning deposited oil to the compressors. The compressors are operated independently. The compressors are bridged by a bypass line (122) or another bypass line in a non-operative state. A check valve (27) is connected upstream to one of the compressors along flow direction.