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Why in the refrigerator cold?
What is the principle of a refrigerator?

It is difficult to imagine modern apartment without a refrigerator. Everyone knows that a refrigerator keeps the cold inside, so the products stored in it, do not deteriorate for a long time. How is the fridge?

In the refrigerator 4 main regions:

1. A refrigerant is a substance that goes in a circle and takes Teplov as the refrigerant gas is to be used freon.

2. The compressor - motor, which operates on the principle of the pump and drives the refrigerant in a circle.

3. The capacitor - and through him, the heat goes out into the environment. The condenser is the grille on the back of the fridge.

4. The evaporator is in heat gets it out of the fridge. Usually the evaporator serves as the inner wall of the refrigerator


The main part of the household refrigerator:
1 - evaporator, 2 - condenser 3 filter-drier, 4 - capillary, 5 - compressor

The compressor sucks the refrigerant from the evaporator. The refrigerant at this point is in the form of vapour. The compressor is under pressure pumps it into the condenser. Refrigerant under pressure is compressed, i.e. transforms from gaseous state to liquid. Thus, its temperature increases. The hot gas passing through the tubes of the condenser releases heat into the surrounding space and as a result cools to room temperature.

Then through a very narrow bore (capillary), the refrigerant enters the evaporator. Its pressure abruptly decreases, and due to this, the evaporation of the refrigerant - it boils, turning to steam. While it is cooled. As a result, it takes heat from the walls of the evaporator, and the evaporator, in turn, cools the inner space of the refrigerator and the products contained therein.

Thus, the refrigerant operates on a cycle: in the condenser under high pressure condenses and becomes a liquid, releasing heat in the evaporator under the influence of low pressure boils and turns into gas, absorbing heat.


The scheme of work of compression refrigerator
1 - condenser 2 - capillary, 3 - evaporator 4 - compressor

The refrigerator has a temperature regulator, which sets the temperature of the cooling of the refrigerating chamber. When this temperature is reached, the thermostat opens the circuit and the compressor stops.

After some time the temperature in the refrigerator starts to rise again (under the influence of the environment). Then the contacts of the thermostat are closed and the motor of the motor-compressor is started using the protective-start relay. The whole cycle is repeated again until the temperature in the refrigerator again lowered to the desired values.

That's why we hear the fridge from time to time begins to "growl", and then calms down again - it turns on and off the compressor motor.

In the scheme of circulation of the refrigerant in the first diagram you probably noticed another link - filter-drier. It is needed for cleaning and drying of the refrigerant, which passes through it. The filter-dryer is a cylinder filled with a substance that absorbs moisture (silica gel or zeolite).

Now, the fridge is arranged in such a way that it does not cool the air in the chamber, and takes from it the heat and releases it into the environment. It is provided by the difference of pressure in the condenser and the evaporator of the refrigerator. The refrigerant moves from area of high pressure, where it turns to liquid (condenses), a section of low pressure, where the pressure of the refrigerant decreases and it turns into a vapor (evaporates).

This article uses material from the site secureforms.danfoss.com and Wikipedia.

 


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Total votes: 249

Your comments:

Dasha
2013-12-29 19:49:41
interesting...
Babak...
2013-12-08 16:01:10
Do you think for a report 3rd class go? Well, or something?
AAAA
2013-11-07 20:38:32
how to build an ice rink with this system
Max
2013-11-06 13:37:53
All clearly written, and about the pressure it gives, read carefully it is necessary, but what about the freezer, probably there is a separate evaporator is
fireball10
2013-10-21 11:45:30
it is not clear if there is a freezer and refrigerated, how is the difference in their temperatures when one compressor
Buhl
2013-06-19 13:10:10
To the question about the relationship of pressure and temperature. Roughly speaking (for ideal gas) pV=NT (p - pressure, T - temperature) (p grows, and T grows). But physically, when the pressure of gas molecules stronger start to interact, thereby gaining a greater energy and more gray wall volume
bad
2013-03-13 20:59:38
Just for kids written. Simple and clear,without formulas, etc.
Anna
2012-12-05 14:57:23
I liked it, but really, do not understand the relationship between pressure and temperature, this moment lost
VARLEN Kleiner
2012-10-21 04:04:06
preferably it is better to emphasize the relationship between pressure and temperature
Bob
2012-09-24 14:04:37
Properly, not for children, for the student for the course - at the time)

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