Why might a refrigeration system require a receiver?

A refrigeration system requires a receiver primarily to store excess refrigerant. The receiver acts as a reservoir for the refrigerant after it has been condensed from a gas to a liquid state in the condenser. During various operating conditions, particularly when the system is running at low loads or when it is first started, not all of the refrigerant that transitions to liquid needs to be in the evaporator immediately. The receiver alleviates this excess refrigerant by storing it until it is needed in the system, ensuring a steady and adequate flow to the expansion device. This function helps prevent flooding of the evaporator and allows for efficient functioning.

Moreover, the receiver helps maintain a balanced refrigerant charge in the system, particularly in larger systems where variations in the refrigerant load can occur. The ability to buffer and store the refrigerant helps in achieving stable pressure levels and efficient system operation over changing load conditions.