What is the function of a receiver in a refrigeration system?

The function of a receiver in a refrigeration system is to act as a temporary storage tank for liquid refrigerant. It is located in the liquid line after the condenser and before the expansion valve. The receiver provides several important functions. First, it ensures that a steady supply of liquid refrigerant is available to the expansion valve, regardless of variations in the condensing pressure or the cooling load. Second, it accommodates changes in the refrigerant charge due to variations in operating conditions. Third, it allows for the complete condensation of the refrigerant vapor leaving the condenser, preventing vapor from entering the expansion valve, which would reduce the system's cooling capacity. Fourth, it can also act as a surge tank to handle excess refrigerant during periods of low load or during pump-down cycles. The receiver is typically sized to hold the entire refrigerant charge of the system. By ensuring a consistent supply of liquid refrigerant to the expansion valve, the receiver contributes to the stable and efficient operation of the refrigeration system. For example, if the cooling load suddenly decreases, excess refrigerant can be stored in the receiver, preventing overfeeding of the evaporator. Conversely, if the cooling load suddenly increases, the receiver can supply additional refrigerant to meet the increased demand.