Changhong Refrigerator CHR-DD238D

Refrigerators work by causing the refrigerant circulating inside them to change from a liquid into a gas. This evaporation process cools the surrounding area and produces the desired effect. You can test this process for yourself by taking some alcohol and putting a drop or two on your skin. As it evaporates, you should feel a chilling sensation – the same basic principle gives us safe food storage.

To start the evaporation process and change the refrigerant from liquid to gas, the pressure on the refrigerant needs to be reduced through an outlet called the capillary tube. The effect is similar to using an aerosol product such as hair spray. The contents of an aerosol can are the pressure/liquid side, the outlet is the capillary tube, and the open space is the evaporator. When you release the contents into the lower pressure open space, it turns liquid into a gas.

To keep a refrigerator running, you need to be able to get the gaseous refrigerant back to its liquid state, so the gas needs to be compressed to a higher pressure and temperature again. This is where the compressor comes in. As mentioned earlier, the compressor provides a similar effect to a bike pump. You can sense the heat increase in the pump while you pump and compress the air.

Once the compressor has done its work, the gas should be under high pressure and hot. It needs to be cooled in the condenser, which is mounted on the back of the refrigerator so that the ambient air can cool its contents. When the gas cools off inside the condenser (still under high pressure), it changes back into a liquid.

Then, the liquid refrigerant circulates back to the evaporator, where the process starts again.