How does a refrigerator work?

 We all have a refrigerator in our homes. It is usually used to preserve food for a long time and prevent it from spoiling. It is a strange device! I use the word 'strange' because it can freeze any object at normal temperature using only electricity.

Which is a strange phenomenon. So today we will discuss how a refrigerator or freezer works.

Fig : Refrigerator

Use of refrigerators in ancient times

Since there was no way to preserve food, fruits, etc. of the people of the primitive era, they would rot. Therefore, the demand for refrigerators from that early era is noticeable. In ancient times, the Greeks and Romans built a special type of house for storing food, called an 'ice house', where they would store food in ice all year round.

History of the invention of the refrigerator 

 Around 1740, Scottish scientist William Cullinan first brought the idea of artificial refrigeration to the fore. But he was limited to his theory. He could not invent any such device at that time. Later, in 1802, an American farmer named Thomas Moore invented a type of device called an icebox. He called it a refrigerator. In addition, the first effective vapor compression refrigeration system was created in 1834. Then in 1854, the commercial ice maker was invented. Finally, in 1913, Fred W. Wolf invented the refrigerator suitable for home use.

                       Fig : Parts of a refrigerator 

 

Main Parts of a Refrigerator

A refrigerator is an electrical appliance. Three processes (electrical, chemical, mechanical) take place in a refrigerator. To understand how a refrigerator works, it is necessary to know about the different parts of a refrigerator. For example:

Compressor: It is called the heart of the refrigerator. Its main function is to compress the gas and increase its pressure and temperature.

Condenser: The curved pipe that comes out of the compressor is called the condenser. It is located at the back of the refrigerator. The condenser's job is to transport the hot gas that is usually released from the compressor.

Evaporator: It is similar in shape to the condenser and is located inside the refrigerator. The evaporator usually cools the inside of the refrigerator.

Expansion valve: Its function is to reduce the pressure of the refrigerant.

Capillary tube: This is a type of tube that looks like a spring. It is usually used to connect the condenser and evaporator.

Refrigerant: Refrigerant is a type of liquid that carries heat or cools. R-134a is commonly used as a refrigerant in home refrigerators. It is an effective refrigerant.

Basic working principle of refrigerator

The refrigerant coming from the evaporator enters the compressor through the tube. The compressor compresses the refrigerant and turns it into a hot gas. Then this hot refrigerant enters the condenser. The heated refrigerant in the condenser gradually loses heat and turns into a liquid. While in the condenser, the temperature of the refrigerant is 55° Celsius. Then this liquid refrigerant reaches the expansion valve. 

Where the expansion valve reduces the pressure of the refrigerant, causing its temperature to drop further. Now the cold refrigerant flows towards the evaporator. As the pressure of the refrigerant decreases, its temperature also decreases, resulting in a cold refrigerant creating a cool environment inside the refrigerator. And when any type of food such as fish, meat, fruits, etc. is kept in the refrigerator. The refrigerant then absorbs heat from these foods, gradually cooling the food until it turns into ice. The last cooled refrigerant returns to the compressor through the tube and this cycle continues. This cycle is called the refrigeration cycle. This is basically how a refrigerator works.

Impact on the environment

While various scientific discoveries have played a helpful role in improving the quality of life of humans, they have also had a negative impact on the environment. Refrigerators are one of the most important food storage devices, and they are no exception. CFC gas or chlorofluorocarbons emitted from refrigerators react with the ozone layer of the earth's atmosphere, damaging it. As a result, the sun's ultraviolet rays fall directly on the earth, which is dangerous for the earth's biodiversity.