The refrigeration process and principle of refrigerators, the working principle of refrigerator refr

Hello! The refrigerant is sucked in by the compressor in the form of gaseous, compressed into a high-temperature and high-pressure vapor into the condenser through the exhaust pipe, and the refrigerant dissipates heat into the outside air, condenses into a high-pressure liquid, enters the capillary through the filter, and is intercepted and depressurized into the evaporator for vaporization. The refrigerant liquid absorbs external heat and vaporizes into dry saturated steam to cool down the refrigerator, and the refrigerant becomes low-pressure superheated vapor and is sucked back by the compressor, and so on.

Purpose of the experiment]:

Master how refrigerator compressors work.

Experimental Principle]:

There are three states of matter in the world: gaseous, solid and liquid, and the three states can be converted into each other under certain conditions. When the liquid changes from liquid to gaseous, it will absorb a lot of heat, referred to as "liquid vaporization and heat absorption", the refrigerator is made by using liquid vaporization heat absorption to refrigerate, the refrigerator is made by the principle of mechanical energy provided by the electric motor, and the refrigeration system works on the refrigeration system through the compressor, and the refrigeration system uses the refrigerant with low boiling point to absorb the heat of vaporization when evaporating.

The throat of the refrigerator is filled with a refrigerant called freon: freon, commonly known as refrigerant. The commonly used one is difluorodichloromethane (CCL2F2), which is a colorless, odorless and non-toxic gas with a boiling point of 29.

When the freon is in a gaseous state, it is pressurized by a compressor, and after being pressurized, it flows through the throat to the condenser on the back of the refrigerator, and then condenses into a liquid after dissipating heat with a heat sink (the temperature rises when the substance is compressed). When the liquid Freon enters the valve of the evaporator, it immediately turns into steam due to the pressure of the compressor, causing the inside of the refrigerator to cool. After vaporization, Freon is pressed back to the condenser outside the box by the compressor to dissipate heat, and then turns into liquid, and so on, pumping the heat energy in the refrigerator to the outside of the box.

The cycle schematic diagram of the refrigeration system of the vapor compression refrigerator is shown in the figure. It consists of compressors, condensers, filter driers, capillaries, evaporators, and other components. It is powered by a compressor, a filter drier is used to filter swag and dry moisture, a capillary is used to throttle and depressurize, and a heat exchanger is a condenser and an evaporator.

The refrigeration compressor sucks in the low-temperature and low-pressure gas refrigerant from the evaporator, which becomes a high-temperature and high-pressure superheated vapor after compression, and is discharged into the condenser, and dissipates heat to the surrounding air to become a high-pressure supercooled liquid, and the high-pressure supercooled liquid flows into the capillary throttle through the drier filter to reduce the pressure, and becomes a low-temperature and low-pressure liquid state, enters the evaporator for vaporization, absorbs the heat of the surrounding cooled items, and reduces the temperature to the required value. The continuous operation of the compressor cold cycle ensures the continuity of the refrigeration process.

When a liquid evaporates into a gas, it has the ability to absorb heat from surrounding objects"Evaporative endothermy"nature, the principle of refrigeration is the application of this property. The specific process is as follows:

1. The compressor feeds the Freon gas into the condenser;

2. The gas entering the condenser is cooled and turned into liquid Freon;

3. The liquid Freon passes through the capillary tube and is depressurized into a liquid that is easy to evaporate and enters the evaporator;

4. The low-temperature and low-pressure liquid that enters the evaporator absorbs the heat in the room and turns it into gas, and then enters the compressor.

The principle of refrigerator refrigeration is through the working substance (i.e. freon.

gas) brings the heat inside the box to the outside of the box, which lowers the temperature inside the box. So how does this work? Combined with the first law of thermodynamics.

Ignoring the secondary factors, let's analyze the principle. When the working substance reaches the pipe in the box, the volume of the gas expands to do work externally, ignoring the role of heat transfer, which is formulated by the first law of thermodynamics.

It can be known that the temperature in the gas can be reduced, and the temperature of the working substance in the pipeline is lower than the temperature in the box at this time, so the heat in the box is transferred to the working substance in the pipeline. When the working substance that absorbs heat reaches the pipeline outside the box, the compressor compresses the gas volume, and the outside does work on the gas, ignoring the role of heat transfer, which is formulated by the first law of thermodynamics.

It can be seen that the temperature of the gas can increase in temperature, and the temperature of the working material in the pipeline is higher than the temperature of the external environment, so the working material in the pipeline transfers heat to the external environment.

From the above analysis, it can be seen that when the working substance reaches the pipe in the box, it absorbs the heat in the refrigerator, and when the working substance reaches the pipe outside the box, it releases heat to the external environment, so that the heat is brought from the inside of the refrigerator to the outside of the refrigerator, that is, the refrigerator refrigeration is realized. Here, the working substance acts as a carrier of heat.

The refrigerant liquid is heat exchanged with the cooled object at a low temperature in the evaporator, absorbs the heat of the cooled object and vaporizes, and the low-pressure steam generated is sucked in by the compressor and discharged at high pressure after compression. The high-pressure gaseous refrigerant discharged from the compressor enters the condenser and condenses into a high-pressure liquid. When the high-pressure liquid flows through the expansion valve, it throttles and becomes a low-pressure and low-temperature gas-liquid two-phase mixture, which is evaporated and refrigerated in the evaporator, and the low-pressure steam produced is sucked in by the compressor again and circulates continuously.

The refrigerant liquid is heat exchanged with the cooled object at a low temperature in the evaporator, absorbs the heat of the cooled object and vaporizes, and the low-pressure steam generated is sucked in by the compressor and discharged at high pressure after compression. The high-pressure gaseous refrigerant discharged from the compressor enters the condenser and condenses into a high-pressure liquid. When the high-pressure liquid flows through the expansion valve, it throttles and becomes a low-pressure and low-temperature gas-liquid two-phase mixture, which is evaporated and refrigerated in the evaporator, and the low-pressure steam produced is sucked in by the compressor again and circulates continuously.

The refrigerator is very important in our daily life, for example, we buy fresh vegetables or fruits, and we can't finish eating them in one meal, at this time we can put them in the refrigerator freezer to keep them fresh, so that we can eat them very fresh the next day, so what is the refrigeration principle of such a magical refrigerator? Let's find out.

Refrigeration principle: first of all, the refrigerant absorbs heat and evaporates into gas, when the temperature in the compressor is lower than the critical temperature of the refrigerant to reach the required pressure, the refrigerant will be liquefied, and a large amount of heat is emitted into the air during the liquefaction process, at this time, the temperature of the liquefied refrigerant is reduced, and the buffer is returned to the evaporation chamber again, and the evaporation continues, and a large amount of heat is reabsorbed, and the temperature around the evaporator is reduced. To put it simply, the refrigerant evaporates and absorbs heat, and then liquefies**, and then evaporates and absorbs heat again.

What should I do if my fridge doesn't refrigerate?

First, the first case.

1. Reason: The compressor of the refrigerator works for a long time, which causes the internal temperature of the compressor to rise, and if the heat is not dissipated in time, the fuse will break, resulting in the refrigerator not being refrigerated.

2. Solution: If the fuse of our compressor is blown out because the temperature is too high, we need to replace the fuse in the refrigerator and cool down the compressor.

Second, the second case.

1. Reason: The refrigerator stores a lot of food, and some food is leaning against the inner wall of the refrigerator, which leads to the freezing of the refrigerator and the phenomenon of non-refrigeration.

2. Solution: First of all, take out the food in the refrigerator and melt the ice in the refrigerator, after that, we reduce the amount of food in the refrigerator, and pay attention to the food not to be close to the inner wall of the refrigerator when placing it in the later stage.

3. The third case.

1. Reason: The defroster in the refrigerator is damaged, and the ice in the refrigerator is not cleaned up in time, at this time, the ice of the refrigerator will block the refrigerator, resulting in its non-refrigeration.

2. Solution: First of all, if the defroster is broken, we need to replace it with a new defroster, and the ice in the refrigerator should also be cleaned up, and the refrigerator drainage pipe should be dredged.

Fourth, the fourth case.

1. Reason: The fan in the refrigerator is faulty, which causes the refrigerator to fail to dissipate heat in time, or even blocks the air outlet because there is more food in the refrigerator.

2. Solution: First of all, we need to repair our exhaust fan, and in addition, we need to dredge the air outlet to increase the heat dissipation of the refrigerator, so as to reduce the temperature of the refrigerator.

The above is a few days of sharing, I hope it can help everyone.

Tip: If you can't handle it yourself, get a professional to inspect and repair it to avoid more damage.

Types of refrigerators and corresponding refrigerator refrigeration principles:

1.Compression refrigerator:

This type of refrigerator uses an electric motor to provide mechanical energy, which works on the refrigeration system through a compressor. The refrigeration system is made by using the principle that the refrigerant with a low boiling point absorbs the heat of vaporization when it evaporates. Its advantage is that it has a long life and is easy to use, and 91 95 refrigerators in the world currently belong to this category.

2.Absorption refrigerator:

This type of refrigerator can use heat sources (such as gas, kerosene, electricity, etc.) as power. The ammonia and hydrogen mixed solution are used to achieve the purpose of refrigeration in the process of continuous absorption and diffusion. Its disadvantage is low efficiency and slow cooling, and it has been gradually phased out.

3.Semiconductor refrigerators:

It is a refrigerator that uses the principle of direct current to produce the Peltier effect on the junction of the PN-type semiconductor.

4.Chemical Refrigerator:

It is a refrigerator that uses certain chemicals to absorb heat strongly when dissolved in water to obtain a cooling effect.

5.Electromagnetic vibrating refrigerator:

It is a refrigerator that uses an electromagnetic vibrator as the main power to drive the compressor. Its principle and structure are basically the same as those of compression refrigerators.

6.Solar Refrigerator:

It is a refrigerator that uses solar energy as a cooling energy source.

7.Adiabatic demagnetization refrigeration refrigerators, radiant refrigeration refrigerators, solid refrigeration refrigerators. Detailed explanation of the principle of refrigerator refrigeration.

1.The compressor compresses the refrigerant gas. This increases the pressure and temperature of the refrigerant (orange), while the heat exchange coils on the outside of the refrigerator help the refrigerant dissipate the heat generated by pressurization.

2.When the refrigerant cools, the refrigerant liquefies into a liquid form (purple) and flows through the safety valve.

3.As the refrigerant flows through the safety valve, the liquid refrigerant flows from the high-pressure area to the low-pressure area, so it expands and evaporates (light blue).

4.During the evaporation process, it absorbs heat and exerts a cooling effect.

5.The coils inside the refrigerator help the refrigerant absorb the heat and keep the inside of the refrigerator cold. Then, repeat the cycle.

Different types of refrigerators have different refrigeration principles. The gas compression type electric pulse refrigerator uses a refrigerant with a low boiling point to absorb heat during evaporation and vaporization to achieve the purpose of refrigeration, and then evaporates and compresses it with a compressor to release heat and liquefy, so as to complete the refrigeration cycle. The gas-absorbing refrigerator uses a mixed solution of ammonia-water-hydrogen to achieve refrigeration in a continuous "absorption-diffusion" process.

Chemical refrigerators use certain chemicals when they are dissolved in water to absorb heat strongly and achieve a refrigeration effect.

Semiconductor refrigerators use semiconductor materials to generate the Pearl-dominant effect to work, that is, p-type semiconductors and n-type semiconductors are used to make galvanic couples, and after direct current is turned on, heat release and heat absorption are generated at the nodes, so as to achieve the purpose of refrigeration.

In general, the refrigeration principle of the refrigerator is that the evaporator absorbs the refrigerant and then sends the compressed refrigerant into the condenser, and the condenser sends the liquefied refrigerant into the evaporator through the capillary for evaporation and heat absorption, which achieves the purpose of refrigerator refrigeration.

A refrigerator is a refrigeration device that maintains a constant low temperature, and it is also a civilian product that keeps food or other items in a constant low temperature and cold state. The refrigerator box contains a compressor, an ice machine, and a cabinet or box for freezing, as well as a storage box for the refrigeration unit. Whether it is a home, a restaurant, a store, etc., it will be seen, and the volume of household refrigerators is usually 20-500 liters.

The refrigerator should be placed in a position that is free from direct sunlight and conducive to ventilation, and at the same time keep a distance from the wall to facilitate heat dissipation during the operation of the refrigerator.

Precautions for refrigerator maintenance

1. The refrigerator should be cleaned regularly (at least twice a year). When cleaning the refrigerator, first cut off the power, use a soft cloth dipped in water or dish soap, scrub gently, and then dip it in water to wipe off the dish soap.

2. In order to prevent damage to the outer coating of the box and the plastic parts inside the box, do not use washing powder, detergent, alkaline detergent, Tianna water, boiling water, oil, brushes, etc. to clean the refrigerator.

3. When the refrigerator is not used for a long time, the power plug should be unplugged, the inside of the box should be wiped clean, and the door of the box should be closed after the box is fully dried.