All flooded systems uniquely supply SAT liquid refrigerant to the bottom of the evaporator from which component?

The correct answer is the surge drum (Low Pressure Receiver or LPR) because it plays a critical role in flooded refrigeration systems. In these systems, the surge drum serves as a reservoir where the liquid refrigerant is stored before it is distributed to the evaporator. The surge drum maintains a steady supply of saturated liquid refrigerant, ensuring that the lower portion of the evaporator is adequately flooded with this refrigerant. This flooding is essential for maximizing heat transfer and achieving efficient cooling performance.

The design and function of the surge drum allow for the separation of vapor from liquid refrigerant, ensuring that only the saturated liquid enters the evaporator. This direct supply minimizes the risk of vapor entering the evaporator, which is crucial for maintaining the system's efficiency and capacity. Overall, the surge drum is integral to the operation of flooded systems, providing the necessary conditions for effective heat exchange.

In comparison, other components listed do not have the same primary function in supplying saturated liquid refrigerant to the evaporator in flooded systems. While pumps may circulate refrigerant within the system and TXVs can regulate refrigerant flow, neither directly supplies refrigerant uniquely to the bottom of the evaporator in the way that a surge drum does. Therefore, the surge drum is correctly identified