What is the main purpose of the expansion valve in a refrigeration system?

The expansion valve serves a critical function in a refrigeration system by allowing the refrigerant to expand and thereby reducing its pressure. When the refrigerant passes through the expansion valve, its pressure drops significantly, which leads to a decrease in its temperature. This process is essential for the refrigeration cycle, as it prepares the refrigerant to absorb heat within the evaporator coil.

As the refrigerant evaporates at low pressure, it can effectively absorb heat from the surrounding environment, cooling the space that the system is designed to condition. Without this expansion process, the refrigerant would not be able to transition from liquid to gas effectively, and the overall efficiency of the refrigeration cycle would be compromised. Thus, the expansion valve is vital for allowing the refrigerant to undergo a change in state that is necessary for heat absorption.