Heat exchangers, the types of devices and the principle of operation of which will be described in the article, are special devices for transferring thermal energy from a heated coolant to cold. The last can be a gaseous or liquid substance.
Area of use
The heat transfer process is important in many industries, namely in the chemical, food, metallurgical and energy fields. Heat exchange equipment promotes the transfer of energy between carriers through a separation wall between them. The process can be called very complex, it is divided according to generally accepted canons into thermal conductivity, thermal radiation and convection. In practice, these processes simultaneously occur in predetermined proportions. For heat transfer, the most important is the convective process, which is the combined effect of heat conduction and convection.
Types of heat exchangers
Heat exchangers, the type of device and the principle of operation of which should be known to the consumer before purchasing the device, can be of different types depending on the design. If you classify the units according to the method of heat transfer, they can be divided into mixing and surface, as well as regenerative and regenerative. The first type involves the transfer of heat by mixing between themselves two working environments. Such devices have a simpler design when compared with surface heat exchangers. In them, thermal energy is used more fully. However, one can highlight the disadvantage, which is expressed in the possibility of using the device only when mixing coolants.
Heat exchangers, the types of devices and the principle of operation of which are described in the article, can be superficial, in them the working coolant exchanges energy through the walls of the separator. Such aggregates can be regenerative and regenerative.
Varieties of surface heat exchangers
Considering the characteristics of the regenerative heat exchangers , you will notice that their work is based on the transfer of heat through the dividing wall. At the same time, water rushes in one direction at each of the points on the wall. The second type of surface heat exchanger is a regenerative unit, it has a distinctive feature, which is expressed in the fact that water, touching a certain heating surface, changes the flow direction from time to time.
The device and principle of operation of shell-and-tube heat exchangers
The most popular in the industry today are recuperative heat exchangers. If we divide them by design features, then we can distinguish shell-and-tube units. These devices are represented by bundles of pipes that are welded to the casing. Pipes, in turn, are fixed to the tube sheets, closed with caps on bolts or gaskets. The first coolant, overcoming the fitting located on the body, flows through the pipe space. Another coolant runs through the pipes.
Such a shell-and-tube heat exchanger has many strokes; partitions are located on the lid and its body. To increase heat transfer, pipes are made with fins by winding the tape or knurled. The shell-and-tube heat exchanger can have a fairly simple design, while the device is called elemental and does not have partitions. Such units can tolerate high pressure, but their design will be heavier and cumbersome.
The principle of operation and the device plate heat exchanger for boiler equipment
Plate heat exchangers, the types, arrangement and principle of operation of which are described in this article, belong to the class of recuperative devices. These devices have a heat exchange surface, which is formed by a whole set of stamped thin steel plates with a corrugated base. These heat exchangers for boilers include elements that are assembled in a single package that forms channels between themselves, and the heat transfer medium that exchanges thermal energy passes through the latter.
The principle of operation of such devices cannot be called the simplest, in it the plates are installed in relation to each other with a rotation of 180 degrees. This allows you to assemble 4 elements, of which two will relate to the collector circuit of the outlet, while the others - to the flow of coolant.
Two extreme elements will not participate in the process of heat energy exchange. Such heat exchangers for boilers can have a different principle of operation depending on the layout, which can be multi-pass or single-pass. In the latter case, the coolant is divided into parallel flows, it passes through all channels and rushes for output to the port. The multi-way arrangement involves the use of a more complex scheme, since the heat exchanger in this case moves along the same number of channels. This is achieved in a slightly different way, which is expressed in the presence of additional plates. They include deaf ports. Among other things, servicing this kind of plate heat exchanger is somewhat more difficult.
Characteristics of oil heat exchangers
An oil heat exchanger is used to prevent the temperature of the coolant from rising to a critical limit in powerful engines. If the engine oil is overheated, this can cause serious problems that can be expressed in a change in the viscosity of the fuel, as well as an increase in the rate of burnout. If the substance turns out to be overheated, then the lubrication of the rubbing parts is not provided sufficiently, this may complicate the cooling of the engine.
The advantages of oil heat exchangers
Using such a device allows you to get many advantages. Firstly, this eliminates the likelihood that the oil temperature will be lower than the temperature of the coolant. This indicates that less stress will occur in engine parts that come into contact with the oil. Secondly, the installation of the heat exchanger can be carried out in any convenient place on the engine, while you can easily abandon many connections and long pipelines.
Heat exchangers for a bath: characteristics
The heat exchanger for the bath can be classified depending on the location in relation to the heater. Thus, the device can be located directly in the body of the furnace, near the chimney pipe or near the heater body. Such units are designed to perform the same functions. By contacting the hot surface of the chimney or furnace, they heat the liquid in a tank of an impressive size, using the principle of convection. Their use allows the owners to place the water tank not in the steam room itself, but in the next room. You can make such a device yourself by using steel sheets, as well as pipes. Only to carry out the work will fail if you do not have a welding machine, and also do not have the skills to work with it.