What happens to the un-evaporated liquid in the evaporator of a flooded system during operation?

In a flooded evaporator system, the design allows for the continuous presence of liquid refrigerant in the evaporator, which aids in efficient heat exchange. During operation, any un-evaporated liquid refrigerant is typically directed back into the surge drum. The surge drum serves as a storage vessel that collects liquid refrigerant, ensuring that there is a reliable supply for the evaporator while maintaining the necessary levels to avoid flooding or starvations in the system.

This process ensures that the refrigerant cycles properly between various components of the cooling system, facilitating consistent performance and preventing issues related to liquid carryover or insufficient refrigerant. By returning the un-evaporated liquid to the surge drum, the system effectively manages refrigerant levels and allows un-evaporated liquid a chance to be reintroduced into the evaporator as conditions change, enhancing system efficiency and performance.