HEAT PUMP SYSTEM FOR VEHICLE AIR CONDITIONING DEVICES

Provided is a vehicle air-conditioning apparatus heat pump system configured so that an excessive increase in the temperature (superheat degree) of refrigerant discharged from a compressor can be prevented in air-heating operation. The heat pump system (HP) includes a compressor (C) and an indoor heat exchanger (HXC) on a refrigerant circuit (RC). A first branched flow path (BC) on which a first expansion mechanism (EX) of which opening degree is adjustable and a first heat absorption heat exchanger (HXA) are arranged in series and a second branched flow path (BC) on which a second expansion mechanism (EX) of which opening degree is adjustable and a second heat absorption heat exchanger (HXA) are arranged in series are arranged in parallel on the refrigerant circuit extending from the indoor heat exchanger to the compressor.