What thermodynamic process describes refrigerant phase change within an evaporator at a constant pressure?

The thermodynamic process that describes refrigerant phase change within an evaporator at a constant pressure is called an isobaric process. In an isobaric process, the pressure remains constant while the state of the refrigerant changes from a liquid to a gas (vaporization) or vice-versa. This constant pressure phase change is essential for the evaporator to absorb heat effectively. For instance, when liquid refrigerant enters the evaporator, it absorbs heat from the surrounding air or fluid, causing it to boil and turn into a vapor. This phase change occurs at a constant pressure because the evaporator is designed to maintain a steady pressure level. The energy absorbed during this phase change is the latent heat of vaporization, which is used to overcome the intermolecular forces holding the refrigerant in a liquid state without changing its temperature. This process ensures efficient heat transfer and cooling within the refrigeration cycle.