How does a mechanical expansion valve regulate refrigerant flow?

A mechanical expansion valve regulates refrigerant flow primarily by utilizing a diaphragm that responds to changes in evaporator temperature. When the evaporator temperature drops, the diaphragm moves in response to the varying pressure inside the system, thereby affecting the flow of refrigerant. This mechanism allows the valve to maintain a consistent superheat, ensuring that the refrigerant reaches optimal temperatures for effective heat exchange in the evaporator.

The diaphragm’s movement is a direct result of pressure differentials between the evaporator and the refrigerant vaporization process, enabling the valve to adapt to varying load conditions in the cooling system. This ability to adjust flow based on temperature is crucial for maximizing efficiency and ensuring the comfort of the space being cooled.