What component do some heat pumps use to store extra liquid refrigerant during heating mode?

Some heat pumps employ a charge compensator tank to store excess liquid refrigerant during heating mode. This component is necessary because, in heating mode, heat pumps may experience changes in refrigerant flow and pressure due to varying heating demands. The charge compensator tank acts as a reservoir that accommodates the fluctuations in refrigerant volume.

When the heat pump is operating in heating mode, the demand for refrigerant can increase or decrease based on the heating load. The tank helps maintain the proper balance of refrigerant in the system, ensuring that the evaporator and condenser always have the necessary refrigerant to operate efficiently. It also helps prevent liquid refrigerant from flooding the compressor, which is crucial for maintaining the longevity and efficiency of the system.

In contrast, other components mentioned, such as the expansion valve, condenser, and receiver drier, serve different functions in the refrigeration cycle. For example, the expansion valve regulates the flow of refrigerant into the evaporator, and the condenser is where heat is expelled from the refrigerant. The receiver drier, meanwhile, is responsible for filtering moisture and contaminants from the refrigerant and providing a storage function, but it does not function in the same manner as the charge compensator tank during heating mode.