What is the primary role of the thermal expansion valve in a refrigeration system?

The primary role of the thermal expansion valve in a refrigeration system is to regulate the flow of liquid refrigerant into the evaporator. This component is essential for maintaining the proper refrigeration cycle efficiency. By controlling the amount of refrigerant that enters the evaporator, the thermal expansion valve ensures that the evaporator has an adequate supply of refrigerant to absorb heat effectively, which allows the refrigeration system to cool the surrounding area.

The valve operates based on the temperature and pressure of the refrigerant, responding to changes in the evaporator's conditions. This regulation is crucial because too much refrigerant can flood the evaporator, leading to inefficiencies and potential system damage, while too little can result in inadequate heat absorption.

In contrast to the other options, increasing the pressure of Freon is the function of the compressor, converting gas to liquid involves the condenser, and storing liquid Freon is generally managed by the receiver-drier or accumulator. These functions are separate from the thermal expansion valve's specific purpose of flow regulation into the evaporator.