Where does low pressure liquid refrigerant enter a horizontal shell and tube type evaporator?

In a horizontal shell and tube type evaporator, low-pressure liquid refrigerant typically enters at the bottom of the shell. This design allows the liquid refrigerant to rise as it absorbs heat from the surrounding space, which is usually facilitated by the counterflow or concurrent flow arrangement in the evaporator.

Entering at the bottom ensures that the refrigerant can effectively flow up through the tubes, maximizing its exposure to the refrigerating surface and enhancing the heat exchange process. As the refrigerant absorbs heat from the system, it transitions from a liquid phase to a gas phase, which is essential for its function in the refrigeration cycle.

The placement of the refrigerant entry point is crucial for maintaining the efficiency of the evaporator, ensuring that all liquid refrigerant can enter and evaporate completely while preventing potential issues like flooding in the system. This design consideration makes the bottom entry point the appropriate choice in most horizontal shell and tube evaporator applications.