How low temperature is attained in a refrigerator?

In a refrigerator, low temperatures are achieved through a process called refrigeration. This process involves removing heat from the inside of the refrigerator and transferring it to the outside environment.

Here's a step-by-step explanation of how low temperature is attained in a refrigerator:

1. Compressor:

The refrigeration cycle begins with the compressor, which is the heart of the refrigeration system. The compressor is an electric motor that compresses a gaseous refrigerant (usually a chemical compound like hydrofluorocarbons or ammonia). This compression increases the pressure and temperature of the refrigerant.

2. Condenser:

The hot, high-pressure refrigerant gas then flows into the condenser. The condenser is a set of coils or tubes designed to dissipate heat. As the refrigerant passes through the condenser, it releases heat to the surrounding environment, causing it to condense and turn into a high-pressure liquid.

3. Expansion Valve or Capillary Tube:

The high-pressure liquid refrigerant then passes through a small opening in the expansion valve or capillary tube. This sudden drop in pressure causes the liquid refrigerant to expand rapidly and turn into a low-pressure, low-temperature mixture of liquid and vapor.

4. Evaporator:

The low-pressure refrigerant mixture enters the evaporator, which is a set of coils or tubes that line the inside of the refrigerator. As the refrigerant flows through the evaporator, it absorbs heat from the inside of the refrigerator, causing the temperature to drop. This absorbed heat is transferred to the refrigerant, causing it to evaporate and become a low-pressure gas.

5. Cycle Repeats:

The low-pressure refrigerant gas then returns to the compressor, and the refrigeration cycle repeats. This continuous process of compressing, condensing, expanding, and evaporating the refrigerant allows the refrigerator to maintain a low temperature and keep food and beverages cool.