The device of the refrigerator compressor

Who are familiar with the principle of operation of the internal combustion engine can easily imagine what is happening inside the compressor. There is also a piston and valve system. The vaporized freon enters and immediately heated by compression, and then emitted to the side of the condenser pressure. Due to this, it easily becomes a liquid and gives energy to the premises, to then go for a new cycle through the capillary expander. The trick to freon all the time to circulate the blood through the vessels. That is why the compressor is often called the heart of the modern refrigerator. But they come in different types, simple and inverter, in General list for a long time – the entry is not enough. Let's talk about the device, compressor refrigerators in more detail.

Classification of compressors

I would Like to thank Bykov A.V. for a good reference for refrigeration compressors 1992 release. Without him (and reference book, and the author's) all in Runet and would read along that one site overwrites the other, and calls it informative.

of course, You heard that in a typical domestic refrigerator compressors piston, and still think that Koreans, opening in 1981, the principle of operation of the twin screw extractor, really created something new? Oh, it's a big mistake! Screw compressors have been known since 1878, and it was there that used rotors, rotating towards each other to create pressure. Think it's some archaic? It is in vain. Screw compressors before the piston has a number of advantages: 

  1. Constant speed of rotation of the shaft regardless of the pressure in the system. It gives all the parameters of the twin-rotor screw compressor high stability in all conditions.
  2. High compression ratio, which is determined mainly by the build quality, surface treatment of parts, the exposure of specified tolerances, landings and sizes. In other words, it requires high technology.
  3. design Features are such that there are no parts that carry a high load, due to this, the device is very durable. In the steam chamber (the space between the two – we almost said augers – rotors) is injected oil.
  4. continuous adjustment performance by simply changing the speed of rotation of the rotors. It is very convenient to the inverter control circuits.

in Addition regarding industry there and some key advantages of the twin-rotor screw compressors before piston:

  1. Small level of vibration. As a consequence, does not require a heavy and solid Foundation.
  2. Relatively little noise, avoiding, in some cases, problems with equipment placement.
  3. Smaller size of the compressor.

the Disadvantage is actually only one:

  • Small efficiency in case of transfer of refrigerant from one state to another right inside. This is due to the constant speed rotation of the shafts and different compression ratio. The piston then moves until you have enough forces, screws and grind and grind, not paying any attention. Of course, if the capacity is sufficient.

this is the kind of simple facts. But how does all of this, and what compressors are available? Consider the class of equipment can be divided as follows into types and subtypes:

the Kingdom of compressors:

  • dynamic Subclass:
  1. Class centrifugal,
  2. Class axis.
  • Subclass volume:

1. The piston class:

is a Subclass of progressive.

the Subclass to the crankshaft.

2. Class rotary.

is a Subclass of rotary:

A) a Family double.

B) single-Family.

is a Subclass of a rolling rotor.

is a Subclass of the spiral.

is a Subclass of the plate.

is a Subclass of the rotary piston (trochoidea).

Let the readers will excuse our poor knowledge of biology, but for the classification of compressors with their grief in half enough. So we see how it happens in the world of devices, and most of them find their application. Thus, the spiral is often included in heat pumps.

Dynamic compressors

In contrast to surround these compressors use ‘live’ power blades. If the piston and the like, the entire burden falls on a rigid structure, the work is done by the fan. Who is familiar with the systems of ventilation and air conditioning already noted the similarity in names. And it is not accidental, but a deliberate and fully informed: inside dynamic compressors are in fact fans are of two types:

  • axial;
  • centrifugal.

Many readers already understood the essence, for the rest explains that:

  1. Axial fans this is what we used to abbatissa in the heat. Only such a device put inside the pipe (working chamber)to create pressure in the right direction. Due to this, the environment moves under the action of rotating blades.
  2. Centrifugal work due to the fact that every body moving in a circle, tends to fly straight from its orbit. So satellites (including geostationary) are held only by the gravitation of the earth, that's why all Eutelsat hang over the equator at the same height. Speed is the same.

Disadvantages of dynamic compressors are obvious: it is impossible to obtain a high compression ratio, and therefore, problematic and create high pressure. For example, refrigeration units pump the freon to 15 – 25 atmospheres, and some argue that this is not the limit. This is a very high performance. But the design of dynamic compressors is relatively simple, and it's great. The requirements for it, on the contrary, low, and it is also good.

Reciprocating compressors

the Principle of operation of the refrigerator compressor is very similar to the internal combustion engine with one cylinder. There inside of the compressor such as the crankshaft, which is driven by an electric motor. However, there is another construction which is more economical and easier managed by inverting the pulse forming network. In this case, there is a rod with a piston at one end, which is inside a coil of wire. Passing alternating current causes the system to perform the translational motion, and has a fridge. These technologies are currently considered the best, and Koreans actively implement them in their products, and provide excellent instructive videos.

In the working chamber has two valve – intake and expenditure. They are usually located on the walls. If the compressor flow, the sign may be placed on the cylinder. But this construction is not very common. The valve in the piston increases the mass of the moving parts, it is also difficult to provide the desired flow areas. Today, therefore, are used in the technique nepamatania reciprocating compressors. 

Rotary compressors

twin-Rotor compressors are fully analogous twin screw extractor. Here are just a generally helical spiral uneven. Leading the rotor has four lobes with slightly rounded tops, under which the slave cut six furrows corresponding profile. Both shafts are placed in a dual cylindrical housing and in contact along the entire length. The rotation is forward.

the intake and output openings for freon usually located diagonally:

  • refrigerant enters at the beginning of the rotors above;
  • compressed gas to be released in late spirals from the bottom.

the Design designed in such a way that the spiral rotors are tight to the body. The rotation is carried out so that from the intake chamber portion of the air is dispersed sideways (in different directions), zahvatyvali moving shafts. On one rotor such portions of four, the other six. Turning around in a circle, in the end, at the bottom of the spiral is encountered. Further rotation causes shock compression of refrigerant under high pressure it is thrown away.

to understand all the charm of a design, remember that the twin screw juicers the maximum rate of spin, and they can grind even the bones, if made of steel without much damage. Such an arrangement of refrigerator compressor allows you to create shock pressure, which is difficult to achieve in other cases.

Recall that the space between the shafts (steam chamber) is injected oil to reduce friction. But this is not the only reason. It is obvious that the efficiency of the device depends on how tight cavity rotors. The oil due to the surface tension creates a tube in between the spirals and the housing. This increases the pressure without any effort. Hence, it is possible to reduce the rotational speed to achieve a given performance, reduce power consumption, lower technological requirements for Assembly and quality details.

the Principle of operation of the refrigerator compressor far away from the screw, and may be in vain. But do not think that reign everywhere pistons. We have already mentioned that many heat pumps have scroll compressors. It has a stator and a rotor. Both of them – spiral threaded into each other. When the circular movement of the rotor, the freon is compressed more and thrown out.