In the refrigeration system, the refrigerant is in warm liquid at which of the following stages?

• A. Expansion valve
• B. Evaporator
• C. Liquid line
• D. Compressor

Answer: (C)

The refrigerant is in warm liquid form in the liquid line stage of a refrigeration system. In this stage, the refrigerant has already been condensed from a vapor into a liquid by the condenser. Although it is still warm, it is under high pressure and is moving through the liquid line towards the expansion device. The temperature of the refrigerant at this point is higher than at the point where it enters the evaporator because it hasn't yet undergone the pressure drop and phase change that occurs when it passes through the expansion valve.

This component's primary role is to promote the flow of the refrigerant toward the evaporator while allowing it to maintain a liquid state until it reaches the appropriate point for expansion into a low-pressure vapor. Once the refrigerant passes through the expansion valve, it will enter the evaporator, where it will absorb heat and begin the cycle again as it transitions to a gas phase.