Inside a refrigerator, a liquid refrigerant circulating within becomes gaseous. Through this process of vaporization or evaporation, the surrounding area is cooled, thus achieving the desired effect. You can test this process yourself by placing one or two drops of alcohol on your skin. As the liquid evaporates, you feel a cooling sensation on your skin—our food is cooled and safely stored using this same basic principle.
To trigger the evaporation process and change the state of the refrigerant from liquid to gas, the pressure under which the refrigerant is held is reduced by a nozzle—the so-called capillary tube. A similar effect occurs when you use an aerosol product such as hairspray. Inside the spray can, there is a liquid and a propellant gas under pressure. The valve and spray head function like the capillary tube, and the open space into which the product is sprayed serves as the evaporator. As soon as the can's contents are released into the environment of lower pressure, the liquid becomes gaseous.
For a refrigerator to work, the gaseous refrigerant must be returned to its liquid form. The gas must therefore be brought back to a higher pressure and a higher temperature. This is where the compressor comes in. As previously mentioned, the compressor has an effect similar to a bicycle pump. You can feel the warming in the pump as you pump and compress the air.
Once the compressor has done its work, the gas should be under high pressure and be hot. The gas must be cooled in the condenser. Therefore, the condenser is located on the back of the refrigerator so that its contents can be cooled by the ambient air. As the gas now cools in the condenser (while still under high pressure), it becomes liquid again.
The refrigerant then circulates in its liquid state back to the evaporator, where the process begins all over again.
0 Comments