In a shell and tube type evaporator, where is the refrigerant contained?

In a shell and tube type evaporator, the refrigerant is contained in the shell. This design consists of a series of tubes housed within a larger shell. In this configuration, the refrigerant flows through the shell, while another fluid, typically water or a brine solution, circulates through the tubes. The heat transfer occurs as the refrigerant absorbs heat from the fluid inside the tubes, causing it to evaporate and thus change from liquid to gas.

Understanding the roles of the other components helps clarify why they do not contain the refrigerant in this type of evaporator. The tubes are where the secondary fluid (not the refrigerant) flows, while the compressor's role is to circulate the refrigerant through the system by compressing it from a low to a high pressure. The expansion valve is responsible for regulating the flow of refrigerant into the evaporator and reducing its pressure, but it does not store or contain refrigerant itself. Therefore, it is clear that the shell is the correct location for the refrigerant in a shell and tube type evaporator.