The function of refrigerant in a refrigerator or freezer is to facilitate the heat transfer process that allows the appliance to cool its interior and maintain low temperatures. Refrigerants are substances with specific thermodynamic properties that enable them to undergo phase changes from liquid to gas and back to liquid at relatively low temperatures.
Here's how the refrigeration cycle works in a typical refrigerator or freezer:
Compression: The process begins with the refrigerant in a gaseous state at low pressure and low temperature. A compressor, which is usually located at the back or bottom of the appliance, compresses the gaseous refrigerant, raising its pressure and temperature significantly.
Condensation: The high-pressure, high-temperature gas is then sent through a set of condenser coils located at the back or bottom of the refrigerator. As the hot refrigerant comes into contact with the cooler air outside the appliance, it releases heat and condenses into a high-pressure liquid.
Expansion: The high-pressure liquid refrigerant now passes through an expansion valve or capillary tube, where its pressure is reduced suddenly. This causes the refrigerant to expand rapidly, leading to a drop in temperature.
Evaporation: The cold, low-pressure liquid refrigerant now enters the evaporator coils, which are located inside the refrigerator or freezer compartment. As the warm air from inside the fridge comes into contact with the cold evaporator coils, the refrigerant absorbs heat from the air, causing the refrigerant to evaporate into a low-pressure gas.
Absorption of Heat: The heat energy is transferred from the interior of the fridge to the refrigerant, which causes the temperature inside the fridge to decrease.
Re-compression: The cycle repeats as the low-pressure gas is drawn back into the compressor, where it is compressed again, and the entire process continues to maintain a consistently low temperature inside the appliance.
The continuous circulation of the refrigerant through this cycle allows the refrigerator or freezer to remove heat from its interior and keep the contents cold or frozen. Refrigerants play a crucial role in this process, as they are responsible for absorbing and releasing heat efficiently at the required temperature ranges, making refrigeration and freezing possible in household appliances and various cooling systems.