What is the process called when heat is removed from a saturated liquid refrigerant?

The process of removing heat from a saturated liquid refrigerant is called subcooling. In the context of refrigeration cycles, subcooling refers to the cooling of a liquid refrigerant below its saturation temperature at a given pressure. This is typically done after the refrigerant has been condensed into a liquid form and before it enters the expansion device.

Subcooling is essential because it ensures that the refrigerant is entirely liquid before it passes through the expansion valve, improving the efficiency of the refrigeration cycle and maximizing its cooling capacity. By subcooling, the refrigerant can absorb more heat when it evaporates in the evaporator, leading to more effective cooling.

In contrast, other processes mentioned do not pertain to the cooling of a saturated liquid refrigerant. Superheating involves adding heat to a vapor, condensation refers to the process of a vapor turning into a liquid, while expansion generally refers to the decrease in pressure and temperature of a refrigerant as it passes through an expansion valve. Therefore, subcooling is the correct term for this specific process.