What is the primary function of an expansion valve in a refrigeration system?

The primary function of an expansion valve in a refrigeration system is to regulate the flow of refrigerant into the evaporator. This component plays a crucial role by controlling the amount of refrigerant that enters the evaporator coil, which allows for the proper operation of the refrigeration cycle.

By modulating the refrigerant flow, the expansion valve ensures that the evaporator can absorb heat effectively from the surrounding environment. This process is essential for the system to remove heat from the space being cooled. The expansion valve allows the refrigerant to expand and drop in pressure as it moves into the evaporator, which facilitates the cooling effect as the refrigerant absorbs heat and changes phase from liquid to vapor.

This regulation is vital for maintaining system efficiency and avoiding issues such as flooding (too much refrigerant) or starving (too little refrigerant), both of which can lead to inefficiencies or damage to the system. Other options like increasing pressure or heating the refrigerant are functions performed by other components in the refrigeration cycle, not by the expansion valve.