Readers will seem ridiculously simple device of the refrigerator, when the review will be read to the end. Inside is the heart - the compressor - freon that drives around in a circle. The veins of steel or copper transfer the refrigerant to the desired point, the capillary tube creates the desired pressure distribution. The result: freon expands in the freezer evaporator, goes into a gaseous state, taking a large amount of heat, rushes to the compressor for compression and condensation on the coil located on the back wall of the refrigerator. This is not the only method, but the main one. Adsorption refrigerators are created, where the movement of the refrigerant is caused by periodic heating and cooling of the working substance. Able to work on the wood, if the designer provides such a possibility. As a rule, blue fuel is used.
The basis of operation of the compressor refrigerator
The principle of operation of the refrigerator is based on the ability of freon to give and take up a lot of heat when it switches to a different phase state. In particular, condensation is accompanied by the release of energy, and evaporation by absorption. To increase the rate of heat exchange, a change in the phase state occurs in the coils:
- evaporator;
- condenser.
The latter is noticeable if you bother to look behind the kitchen refrigerator. There you can see a curved tube, equipped with a steel mesh radiator to accelerate heat dissipation. The ideal lens is made of copper, in the case of refrigerators, a step would lead to excessive fragility of the structure. The condenser tube is thin, it is not by chance. In order for a gas to become a liquid, the pressure generated by the compressor will help it. Freon is injected into the condenser; due to this fact, the gas temperature rises, becoming higher than the environment.
The refrigerant enters a different phase state. Energy is released, in addition to raising the temperature. As a result, the temperature of the condenser passes over 60 ºС, which is comparable with radiators. Heat begins to actively dissipate, which contributes to the rugged shape of the radiator. The greater the difference between the temperatures of the condenser and the kitchen, the stronger the heat exchange takes place. Energy leakage is proportional to the difference. Therefore, in the coolness of the device works easier. Hence, the compressor carries a smaller load.
As a result, the operating conditions in the case of refrigerators play a crucial role, prolonging or shortening the life of a vehicle.
The power consumption of refrigerators is growing - with increasing ambient temperature. The more we spend on heating, the higher the bills for freezing food. Of course, the refrigerator has a lower threshold of performance, for which you should not cross. The restriction is mainly due to the compressor oil thickening with decreasing temperature. The fact is obvious to motorists. The difference is that the compressor oil is located directly in the freon circuit. In the video, which shows how to make a pump for the wheels from the refrigerator, grease flies out of the pipes, this is not a malfunction. The compressor is bathed in an oil bath for longer life.
After the condenser comes a capillary tube, creating a pressure difference. Before the compressor, a vacuum is obtained, and after the gas is compressed in tension, under the action of a piston. Without a capillary tube, the motor would give out an incomparably greater number of revolutions, so that only at the expense of the transfer speed would create the necessary conditions for the operation of the equipment. The internal diameter of the capillary tube is small, the cooled freon hardly flows through the meters of narrow space on the way to the evaporator.
A factor that strongly influences the performance of the equipment is detected: If there is water in the freon circuit, the cooled freon at the exit from the capillary tube freezes through. Ice is formed due to dilution and low temperatures, which accumulates gradually, blocking the passage. The refrigerator stops freezing, the compressor creates unfavorable working conditions.
The compressor of the refrigerator is capable of accumulating pressure of 25 atm, 8 times more than the piped one. Can you imagine what is going on inside if the ice block clogs the capillary tube? The device of the refrigerator will not sustain such a turnover. As a result, the parts will break. Therefore, to exclude water, which certainly falls inside when making or refilling a refrigerator, a special element of the freon circuit is created - a filter drier that removes any moisture. Inside is an adsorbent that does not affect freon, but absorbs water vapor( recall that the refrigerant in front of the condenser shows a high temperature, and the liquid is in a gaseous aggregate state).
This important element must be replaced when refilling the system with freon. Pre-refrigerator is flushed with nitrogen or evacuated to remove moisture and air. It happens that the operations are done sequentially. Nitrogen is inert, there is no chance that an explosion of combustible freon will occur( similar are known).So, the liquid freon flows in after the capillary tube into the evaporator and detects a reduced pressure. This helps the substance to move to a different state of aggregation, absorbing a lot of heat.
The interior of the refrigerator
The design described is typical for compressor refrigerators. Things you need to know:
- The principle of operation of the refrigerator with the NoFrost system is based on the forced blowing of the evaporator with air drawn from the chambers. Accordingly, the cooled stream returns to its place. Systems with a single evaporator in both compartments and with two are known. The latter are more expensive, allow you to turn on the camera separately and with great accuracy to regulate the temperature, prevent the smell of the freezer and the food part of the device from mixing. No among cheap models NoFrost. However, refrigerators with forced convection have already been created at a price of 16,000 rubles, which fits into the pocket of a typical Russian consumer.
- In the refrigerator NoFrost there is trouble, which the standard models lack. Ice does not form inside these, although the instruments dry the products. But it is forgotten that moisture in the form of frost precipitates on the evaporator. NoFrost refrigerators have their own defrosting system from a heating element that periodically heats up the coil. The liquid usually flows along the way in which air passes into the lower compartment. If frost is detected in the refrigerator or the bottom is not cooled, it is recommended to check whether the frosty air is blowing. Go paper, which is initially applied to the exhaust opening of the camera( sticks), then to vtyazhmny( fluctuates).
- In refrigerators, a freezer door anti-sticking system is noted. Most clumsily made in Belarusian models. Try to put a finger between the sections. It feels distinctly warm, the heat almost burns. We believe that after the compressor freon makes an honorary circle in the specified place. For the simple reason that putting an electric heater seems impractical.
- Filter drier, a good part of the tubes of the freon path are hidden under sprayed insulation. If the Soviet refrigerators did not do without glass wool, it is now customary to use polyurethane foam. Consequently, after the repair will have to spray a little. We do not recommend using consoles( you will need a gas mask and protective clothing); instead, look for liquid insulation in cans. Shake, listening to the balls, direct the bell, push the button. The chance to inhale bad things when working is quite small.
- Refrigeration performance is included in the technical characteristics of refrigerators. Measured on special containers and physical load for the consumer does not carry. However, it is easy to compare models by this parameter. In refrigerators( as in air conditioners), the performance is capable of exceeding the power consumed from the network, because cooling is indirect. Heat is simply pumped from the inside to the kitchen. This applies, for example, heat pumps, using which significantly save on bills. Do not try to compare the performance of the refrigerator with the power consumption, because the parameters are not directly related. Refrigerator parameters are optimized by manufacturers of various methods to improve efficiency, but the relationship of input and output characteristics is not directly observed.
We add that the compressor is usually supplied with a start-up relay; the thermostat, which in the simplest case is equipped with a pressure sensor to measure the temperature, fills the operation.
