(Last Updated On: July 16, 2023)
How Refrigerator works?
Have you ever wondered how your refrigerator works? Below, you will learn the basics of cooling technology familiarize yourself with the main components of a refrigerator and learn which phases the refrigerant goes through in the refrigerator.
For food to stay fresh for a long time, it must be kept in an environment with a low temperature, in which harmful bacteria can hardly multiply.
A refrigerator dissipates the heat of the food from the inside to the outside, so the back of the refrigerator near the metal pipes also feels warm to the touch.
Almost every home has a refrigerator. Moreover, almost everyone will think that they somehow produce the cold inside – wrong! Because the refrigerator does not cool (actively); neither can it produce cold. Rather, it conducts heat from the inside to the outside.
To understand how a refrigerator works, you need to know:
Liquids in the process of evaporation absorb heat.
When the steam changes back to a liquid, the heat is given off again.
Today we are often not even aware of the convenience we have from owning a refrigerator. In the past, food spoiled relatively quickly – especially in summer.
Owning a refrigerator with large ice sticks was pure luxury, and it was extremely cumbersome to operate.
When operating a compressor refrigerator, two physical phenomena are used:
Energy is required to vaporize a liquid.
The condensation or boiling temperature of liquid increases with the pressure.
In the pipe system of a refrigerator, a coolant has a boiling point of approx. -30 °C at normal pressure.
Furthermore, the coolant get in the refrigerator in 100% liquid form at one bar (approx.). Since it is warmer than -30 ° C in the refrigerator, the coolant evaporates in the so-called evaporator.
If there is the requirement of maintaining pressure around 1 bar, then we have to keep the temperature of the outer condenser lower than -30° C. At this point, the gaseous coolant will become liquid again after condensation. However, usually, the outer condensers are at room temperature, so we use a trick. The condensation temperature of a gas increases when the gas is under increased pressure (cf., for example, the increase in the boiling point in the steam pot).
Compressor expands the pressure of the gaseous coolant to eight-bar (approx.), which increases the boiling or condensation temperature of the coolant to room temperature.
Under high pressure, the gaseous coolant, discharges energy into the surrounding air in the condenser pipe system, and the coolant becomes liquid.
The heat of condensation that is released is also given off to the environment. A reducing valve (throttle) now reduces the pressure of the liquid coolant to such an extent (to approx. one bar) that the boiling temperature is -30 ° C again. The coolant is now fed back into the refrigerator and the entire procedure is repeated. That’s how refrigerator works and keeps our food fresh, cold and healthy.
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