subcooling

Subcooling refers to the process of cooling a liquid below its saturation temperature at a given pressure. In simpler terms, it is cooling a liquid below the point where it would normally start to boil or condense. This is often encountered in refrigeration and air conditioning systems. When a refrigerant condenses, it releases heat and becomes a saturated liquid. Further cooling of this saturated liquid below its condensation temperature is known as subcooling.

The amount of subcooling is measured by the difference between the saturation temperature and the actual temperature of the liquid. For example, if a refrigerant condenses at 100 degrees Fahrenheit but is then cooled to 90 degrees Fahrenheit before entering the expansion valve, it is said to be subcooled by 10 degrees Fahrenheit.

Subcooling is a desirable condition in many thermodynamic cycles. In refrigeration, it increases the efficiency of the system by allowing more heat to be absorbed in the evaporator. This is because the subcooled liquid has a greater capacity to absorb heat before it starts to boil. In power generation cycles, subcooling of the steam after condensation can also lead to increased overall efficiency. It prevents cavitation in pumps and can improve the performance of feedwater heaters.