What is the purpose of a subcooler in a vapor-cycle cooling system?

The purpose of a subcooler in a vapor-cycle cooling system is primarily to cool the refrigerant, ensuring that it remains in a liquid state before it enters the expansion valve. This subcooling process prevents premature vaporization of the refrigerant in the high-pressure side of the system, enhancing the efficiency of the cooling cycle. When the refrigerant is adequately subcooled, it absorbs more heat when it passes through the evaporator, leading to improved overall system performance. By maintaining the refrigerant in a liquid form, the subcooler helps ensure that the compressor operates more effectively, as it minimizes the risk of drawing in vaporized refrigerant, which can lead to inefficiencies or potential damage.