To put it simply there are 3 steps to using a refrigerator or refrigerator:

The cooler refrigerator is transferred around food items stored inside the refrigerator.
The refrigerator absorbs heat from food items.
The refrigerator transfers the absorbed heat to a cooler place outside.

Most people would not know what to do without refrigerators, as there are a few things that can soothe your dry throat in the same way as a glass of cold water.

Although there were ancient methods of obtaining cold water, it was certainly not as simple as opening a door at home and pulling out a cold water bottle. Even if they could get cold water to drink, they certainly had nothing to keep their food fresh for days or weeks.

Luckily, we have a little something for all these things – the fridge!

In this article, we will look at the science of refrigeration, especially the various components of a refrigerator and how they work together to store our food for a long time.

Refrigerator working principle

The operating principle of a refrigerator (and refrigerator, usually) is very simple: it involves the removal of heat from one region and its placement in another. When you pass a low-temperature liquid near the cooling point, the heat from that substance is transferred to that liquid, which evaporates to remove excess heat.

You probably already know that gases are heated when you press them and cool down when they are allowed to expand. This is why the bicycle pump feels warm when you use it to pump air inside the tire, while the spray scent feels cold.

The aerosol air freshener feels cold when it touches because the gas is allowed to rise abruptly, which lowers the temperature. (Photo Credit: Pixabay)

The tendency of hot gases when pressed and cold when expanded, along with the help of a few fine devices, helps the refrigerator to cool its contents.

Parts of a refrigerator

The refrigerator has a few key features that play an important role in the refrigeration process:

Expansion valve

Also known as a flow control device, the expansion valve controls the flow of a liquid refrigerator (also known as a ‘coolant’) into the evaporator. It is actually a very small tool that is sensitive to temperature changes in the refrigerator.

Compressor

The compressor contains a car that ‘sucks’ the refrigerator from the evaporator and presses it into the cylinder to produce hot, high-pressure gas.

This is what the compressor of a standard refrigerator looks like. (Photo Credit : Wikipedia Commons)

Evaporator

This is the cooler component that actually stores items stored inside the refrigerator. It consists of engraved tubes (made of high-temperature steel to increase heat transfer) that capture the heat coated by the fan. The evaporator traps heat in internal storage, and as a result of this heat, the liquid refrigerator turns to vapor.

Condenser

The condenser consists of an integrated set of tubes with external wings and the back of the refrigerator. It helps to dissolve the gas refrigerator by absorbing its heat and releasing it into the environment.

Condenser coils

As heat from the refrigerator is removed, its temperature drops to a constant temperature, and it turns its vapor into a liquid.

Refrigerant

And often referred to as a coolant, it is the fluid that keeps the refrigerator cycle going. It is actually a specially designed chemical that can exchange between hot gas and cooling liquids.

In the 20th century, fluorocarbons, especially CFCs, were generally preferred as a refrigerator. However, they are being replaced by more environmentally friendly refrigerators, such as ammonia, R-290, R-600A etc.

Refrigerator function: How does a refrigerator work?

The refrigerator, now in liquid form, passes through the expansion valve and turns into a cool gas due to a sudden drop in pressure.

As the cooling gas of the refrigerator flows into the cold cupboard, it absorbs heat from the food items inside the refrigerator. The refrigerator, now gas, enters the compressor, which absorbs it and presses the molecules together to form a hot, high-pressure gas.

Now, the gas transfers to the condenser coils (small radiator pipes) located behind the refrigerator, where the coils help to dissipate their heat to cool enough to thicken and return to its liquid phase. Because the heat collected from the food is given around the condenser, it feels hot when touched.

After the condenser, the liquid refrigerator returns to the expansion valve, where it encounters a pressure drop and re-cools the gas. Then it absorbs the heat of the contents of the refrigerator and the whole cycle repeats itself.