In a heat pump system, how is a compressor protected from liquid slugging?

In a heat pump system, a compressor is protected from liquid slugging primarily by a suction line accumulator. Liquid slugging occurs when liquid refrigerant enters the compressor, which is designed to compress vapor and not liquid. If liquid enters the compressor, it can cause significant damage due to hydraulic shock.

The suction line accumulator works by temporarily storing excess liquid refrigerant that may be present in the suction line. This device allows vapor to pass through while holding back the liquid refrigerant, ensuring that only vapor enters the compressor. It maintains proper operation of the compressor by preventing liquid refrigerant from causing potential mechanical failure, thus enhancing the reliability and longevity of the heat pump system.

Other components listed, such as a thermal expansion valve, liquid line filter, or digital thermostat, have different functions in the system. For example, a thermal expansion valve regulates the flow of refrigerant into the evaporator but does not directly prevent liquid slugging. Similarly, a liquid line filter is used to remove contaminants from the refrigerant but does not address the issue of liquid refrigerant reaching the compressor. A digital thermostat controls the temperature settings but has no impact on the physical state of the refrigerant in the suction line. Therefore, the suction line accumulator is the crucial component in protecting