| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a heat pump apparatus capable of suppressing vibration during a low speed operation by keeping a proper pressure ratio balance at a multistage compressor. <P>SOLUTION: An injection expansion valve 43 is controlled to be opened when a suction pressure and a discharge pressure of a two-stage compressor 31 come to be a predetermined pressure during a cooling operation, in other words during a cooling low pressure ratio operation, to form a bypass path which runs from a point 31d of intermediate pressure of the two-stage compressor 31 toward a connection point 43d to a main coolant circuit. As a result, the vibration during a low speed operation in the two-stage compressor 31 is suppressed. <P>COPYRIGHT: (C)2013,JPO&INPIT</p> |
