What happens during the expansion phase of the refrigeration cycle?

During the expansion phase of the refrigeration cycle, the refrigerant undergoes a significant change in pressure and temperature as it moves from a high-pressure state to a low-pressure state. This phase typically occurs in the expansion valve or capillary tube, where the liquid refrigerant is allowed to expand and pressure is reduced.

As the refrigerant expands, it absorbs heat from the surroundings, leading to a decrease in its temperature. This drop in temperature is crucial for the refrigeration process, as it allows the refrigerant to extract heat from the area or substance being cooled. Thus, during the expansion phase, the refrigerant indeed experiences a decrease in temperature as it transitions from a high-pressure liquid to a low-pressure mixture of liquid and vapor, ready to enter the evaporator and effectively absorb heat.

This process is essential for the functioning of refrigeration systems, as it enables the cycle to repetitively cool the internal environment or substance. The other options focus on unrelated processes: compressing the refrigerant involves an increase in pressure and temperature, heating the refrigerant does not occur during this phase, and changing from liquid to vapor primarily takes place in the evaporator rather than during expansion.