Types of heat exchangers. Principle of operation of heat exchangers

Not so long ago, almost all the heat exchangers had a shell-and-tube construction, in which the medium rushed to each other, moving along the tubes. The last elements are placed one in the other. But even today such a heat exchanger device is a thing of the past. Such devices are rather cumbersome, but they function quite efficiently. Among their shortcomings can be identified a large consumption of the heated medium. Considering the types of heat exchangers, you should note that today the new devices are being replaced by the above-described plate-type high-speed units.

The principle of operation of the plate heat exchanger

Considering the types of heat exchangers, it is necessary to pay special attention to the plate type of such devices. Structurally, these devices differ from the shell-and-tube precursor. In the latter, the surface area of the energy exchange is increased due to the impressive length of the coil, which certainly caused the more impressive dimensions of the device. If we are talking about a new heat exchanger, the goal is achieved by increasing the number of plates that have the same area. Modern types of heat exchangers have the same power, but in size they are 3 times smaller than shell-and-tube models. New devices provide an impressive flow rate of the heated medium, which is used for the needs of hot water supply. This led to the fact that the unit acquired a second name - it is called a high-speed heat exchanger. Similar devices have in the composition of the return and supply pipes, which are used to connect the heating medium, as the last acts coolant.

Device and work features

The device has an outlet and an inlet for heated media. You can see in the design of the fixed plate, which is located in front. There are holes for water in the device. The heat exchanger will also not work without a gasket, which is represented by a ring, as well as a heat exchange working plate. There is a rear movable plate and upper guides in the design. The device is equipped with a rear support, a hairpin and a gasket, which is located on the contour of the plate.

Described types of heat exchangers are used for heating a simple design with nozzles, which are located on opposite sides of the device. Between the plates that are on the two guides, a number of plates with a seal between them are clamped. On the plates, to increase the surface of the exchange, there is a relief crimping. In some models, the branch pipes are located on one side of the apparatus, they are on the front plate, which, however, does not affect the functioning of the plate device. Plate heat exchangers work according to the principle that involves filling the space between the plates with a heated medium.

Additional information about the work

The form of the gaskets determines the order of filling: in one department they open the way to water, in the other section heat is absorbed. In the process of functioning of the devices of each section, in addition to the last and the first one, one can notice a rather intensive heat exchange by means of a plate on both sides. Mediums flow through the sections, heading towards each other. The heating medium comes from above, but exits through the lower branch pipe. As for the heated, it follows the direction opposite to the heating medium.

Types of heat exchangers

On sale today you can find a cast-iron heat exchanger, but there are other devices that are made of other materials. Varieties of similar devices are presented in a wide range. Their use is not limited to one area of the industry, the units are now used everywhere: in metallurgy, chemical industry, power engineering, heat points, heating, air conditioning and ventilation systems.

Differences in the way of heat transfer

If you want to install a furnace with a heat exchanger, you should initially understand the types of devices described in the article. So, they can be distinguished also by the method of heat transfer, in this respect they can be surface and mixing. In the first case, heat exchange occurs between different media through walls made of a heat-conducting special material. In this case, the contours remain completely hermetic. If you are interested in surface-type equipment, then you should be aware that there are regenerative and recuperative devices. In the latter case, the temperature exchange between heat carriers occurs through thin walls of the contours, while the flow of the medium has the same direction. In the second case, the direction of the flow can vary. If you decide to install a gas heat exchanger, you should pay attention to the mixing versions of the devices. Heat transfer in them occurs by mixing two media, but devices of this type are used less often than those mentioned above.

Types of heat exchangers in the field of use

When the owner of a private or suburban house decides to install a furnace with a heat exchanger, he most often chooses a shell-and-tube system that has a bundle of tubes connected to each other in a grid by welding and soldering. Another type is the plate heat exchangers, which were discussed above, they have a heat exchange area, represented in the form of plates. The latter are joined together by heat-resistant seals. Concentric coils are used for mounting cast heat exchangers, the working medium in them is moved along curved pipes, as well as space between pipes.

You can not miss out on the spiral devices, which are represented by thin metal sheets. They are folded in a spiral in the manufacturing process. The presented list is not complete, among the most common one we can also highlight air, as well as water devices.

The heat exchanger, whose price can amount to 7000 rubles, is presented today in a wide variety. It is simply impossible to list all types of such aggregates, therefore only the most popular ones were presented above. The leader among them is lamellar.

Varieties of plate devices

Plate heat exchangers are offered for sale in a wide range, they can be demountable, brazed, welded and semi-welded. The first variety was discussed above, but as for the soldered version, it has corrugated metal plates made of stainless steel. These elements are connected together by soldering in vacuum conditions using nickel or copper solder.

Conclusion

The heat exchanger (the price is presented above) can also be welded. Such devices are intended for operation in conditions of high temperatures and extreme pressure. They are used in installations whose parameters do not allow the use of sealing elements.