The principle of operation of the refrigerator
a Lot of copies expected to understand how the produced cold, but we decided today to send another army. Perhaps, will not be material in vain, and pains — in vain. The principle of operation of the refrigerator is entirely based on the ability of freon easily change the aggregate state, giving and taking the heat. Not always used this class of substances. Used ammonia, and many other harsh environments. But in the 30-ies of the last century opened CFCs, which were relatively safe for humans and very effective. As a result, all else forgotten today, and refrigerants are called numerals with the prefix R. Today, the whole world goes to isobutane, because its concentration is low, and safe for the ozone layer high. However, this substance is explosive. Now let's talk about the principle of operation of the refrigerator.
How does a refrigerator
let's Start a conversation about the principles of operation of the refrigerator with a compressor. It is the heart, and the most important thing here. The motor of the refrigerator is usually asynchronous, therefore it is often required protective relays. The responsibilities of this unit include connecting the starting winding, but only at the start time. Once heated internal bimetallic plate, the capacitor is disconnected from starting winding, and operates only working. According to a similar system works and overheat protection: if the motor of the refrigerator runs too long, the thermal effect of the current extends another bimetallic plate, which breaks the contact to give windings to relax.
When removed from the refrigerator motor, the protective relay is included in the package. You can't take another relay from another engine, it likely violates the normal operation or sooner or later leads to the combustion of the windings.
the fact that different motors of refrigerators of different requirements to start. Power is also different, therefore, the type, and heating of the bimetallic plate relay does not remain constant. There are special directories where you can see what the engines refrigerators are, and what types of relays correspond to them. By the way, we on this site have already uploaded the list, I hope that he is pleased with our readers. But modern engines refrigerators not only have the inverter is running, but the crankshaft no longer contain. The motion of the shaft into linear and call them by this epithet.
what? Inside the coil, which has a core, moving progressively according to the law of the alternating current supplied to the wire. Despite the seeming absurdity (and similarities with electric shavers) such motors, as practice shows, best meet the objectives. In addition most effectively realized inverter control, which helps to reduce noise, but also prolong life. No wonder that Samsung provides 10 years warranty on their motors in refrigerators. Recall what it is:
- As you know, asynchronous motors with squirrel-cage rotor have the ability to change the frequency of rotation including from changes in the frequency of the supply voltage.
- This ability deprived collector motors, which in refrigerators are rarely used.
- a New type of engines of the coil and an oscillating core is also easily controlled by changing the pulse repetition rate.
the result is the following scheme:
- Input voltage is rectified.
- And then cut on the power key the desired duration.
- Work controls, for example, the processor clock.
This is the simplest scheme, which rather refers to the pulse power supply, but the essence still remains the same: there is a voltage of 50 Hz, which is then converted into a voltage of another frequency. In the result of changing the speed of movement of the piston, causing the freon starts to move with a different speed. It gives us all?
Freon in refrigerators
the Heart pumps the blood, and the compressor — freon. The bottom line is that we need to create a high pressure in the condenser (on the back of the fridge) and lowest in the evaporator. As a result, the ground begins to liquefied refrigerant, and from the second he actively evaporates. In the first case, the large amount of heat that goes to the kitchen, in the second case, the absorbed energy, configschema out of the refrigeration compartment. As a result, we have what we have: refrigerator cold. The faster moving blood, the more vigorous feels man, the more the difference of pressure drops in the condenser and the evaporator, and the more cold, and hence the compressor have to sweat.
so, we have shown the dependence of the production of cold from the speed of the compressor, and now consider what happens the pressure difference. You know, on YouTube you can watch the video where the person with fins running along the water. He runs far enough away from the shore, and he'd failed, no matter how quickly moved her legs, if not support. Here and in the refrigerator exactly the same thing. As quickly nor spinning rotor of the motor, freon will never give the desired pressure difference, if not for one important addition to the veins of the circulation of the refrigerant. And this capillary tube. She is very thin and is placed after the condenser. As a result, the pressure here is growing rapidly, whereby the refrigerant becomes a liquid. At this point he gives up energy. On this rests the principle of operation of the refrigerator.
additionally, do not forget that some heat accumulated on the evaporator. As it turns out? You won't believe, but in a vacuum to evaporate even water, even ice evaporates… sublimation. A similar process goes behind the rear wall of the freezer (refrigerator compartment), where a compressor suction. Liquid freon slowly flows through the capillary tube and immediately disappears. Even at the low temperature that prevails in the evaporator, he still manages to take heat from the frozen metal. In this regard, it is time mentioned about another part, without which the device of the refrigerator in no way be complete. This filter-drier (sometimes referred to as a receiver).
the result is that the compressor seems to be running at full speed, the pressure difference between condenser and evaporator incredible, but it was no use, because the freon is unable to circulate. Hence, there is no one to transfer heat from place to place.
Characteristic of the fault in this case is that it disappears if you turn off the fridge for a while. Then everything would start again. This is because the tube melts, then increases again. That's why the filter-drier and working near the condenser to pick up more of the water. Inside is usually a trivial silica gel, which is familiar to many shoes and clothes. These are the same bags with balls, which should pick up moisture. It is clear that gradually filter-drier produces its own resource, and water vapor still continue to flow in the refrigerant circuit of the refrigerator. By the way, occur at this part must be replaced.
the Filter-drier looks like thickening of the copper tube, which is impossible not to notice. However, often it is hidden under a layer of polyurethane foam. In this case, the details still need to get. It all depends on the types of refrigerators. But all of this would have been a pile of iron, if there was no thermostat, which deals with the measurement conditions in the cells, and issues a command for switching on and off of the compressor.
the Thermostat of the refrigerator
Usually the thermostat based on the pressure measurement. It is clear that cold air is heavier, therefore, it is possible to determine whether enough he presses on the membrane. Access to the sensitive element is conducted through the tube. The screw is tightened the tension of the membrane. As a result, we have such a small "pocket watch», in which instead of the chain long tube. The extra piece is placed between the walls, and the suction hole is held in the working chamber.
Modern thermostats are much more primitive. This is a common thermocouple on the magnitude of the EMF which depends, what exactly will take the electronic Board of the refrigerator in the next moment. It is clear that this scheme is in contrast to the previous requires power, which somewhat complicates the whole process. But the repair turns into a real entertainment: the main thing is to find the thermocouple with the appropriate characteristics, and do not need to tear up half the fridge to pull up. This simplifies life masters.
We finished the story, how does a refrigerator, and also mentioned and many aspects of what was in the fridge.