Which part of the system is responsible for changing high-pressure liquid to low-pressure liquid?

The correct answer is that the metering device is responsible for changing high-pressure liquid to low-pressure liquid in a refrigeration system. The metering device, which can be a thermal expansion valve (TXV), capillary tube, or other types of expansion devices, works by controlling the flow of refrigerant into the evaporator.

When the high-pressure liquid refrigerant passes through the metering device, it experiences a significant drop in pressure. This pressure drop is essential because it converts the refrigerant from a high-pressure liquid state to a low-pressure liquid or a refrigerant vapor mixture, preparing it to absorb heat in the evaporator.

This process is critical for the overall operation of the refrigeration cycle, as the low-pressure liquid entering the evaporator is where the refrigerant absorbs heat from the environment, leading to the cooling effect. Understanding the function of the metering device is key for anyone looking to work with refrigeration systems, as it plays a vital role in the efficiency and effectiveness of the cooling process.