One method to mitigate vibration and sound level in heat pump chiller with evi function

摘要

A heat pump system and a control method thereof. The heat pump system includes: a major heat exchange loop (100), including at least one compressor (110), a flow-path switching valve (120), a condenser (130), a first throttling element (140), an economizer (150), and an evaporator (160) that are connected sequentially to form a loop; and an air supply branch (200), which is connected from a flow path between the first throttling element and the economizer to an air supply inlet of the compressor, the air supply branch being provided with a switch valve (231) for preventing a gas-phase refrigerant from flowing back; where a pressure balance branch (300) is further included, which is connected from the air supply branch at the upstream of the switch valve to a low-pressure gas-phase refrigerant side of the major heat exchange loop.