In which part of the refrigeration cycle does liquid refrigerant change to gas?

The part of the refrigeration cycle where liquid refrigerant changes to gas is the evaporator. In the evaporator, the refrigerant absorbs heat from the environment (such as the air or water being cooled) and, as it absorbs this heat, it undergoes a phase change from a liquid to a vapor.

This process is essential as it allows the refrigeration system to extract heat from the space that needs to be cooled. The evaporator operates at low pressure, facilitating the absorption of heat and ensuring that the refrigerant efficiently transforms into a gas under the conditions within the system.

As a result, the evaporator is a critical component in the refrigeration cycle, enabling the cycle to continue by producing vapor that is then sent to the compressor to be pressurized and cycled back through the system. Understanding the function of the evaporator helps illustrate the importance of phase changes in refrigeration systems and the overall efficiency of heat exchange processes.