SU932184A2 - Tube-in-tube type heat exchanging element - Google Patents

Description

c5) HEAT EXCHANGE ELEMENT TYPE TUBE V. TRUBE

one

The invention relates to heat engineering, can be used in the design of heat exchangers in various industries.

By bus. St. No. 821897 are known heat exchange elements of the pipe-in-pipe type, mainly Field's tpy, the inside of which has a step-changing section along the medium, the outside pipe also has a living section, step-varying along the medium, and its steps are offset from the steps of the inner pipe, the latter are provided at the output end of the slots iZ.

A disadvantage of the known element is that, when making a construction of thin-walled pipes, the effects of a step change in the cross section are insignificant due to the small difference in diameters; in addition, the improvement of heat transfer occurs only in places of a stepped transition. If

each element of the outer or inner pipe has a significant length, then, despite the presence of steps, a boundary layer is formed on its surface that prevents heat transfer due to the fact that each pipe element has a constant cross section, a pressure gradient that enhances the turbulization and intensifying heat exchange arises only in places of transition from one section to another.

The disadvantages include the fact that the grooves for the passage of the coolant are brushed in the inner

IS tube and form a minor fluid cross section for recirculation of the coolant. .

The purpose of the invention is to intensify heat transfer.

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The goal is achieved by the fact that in a known heat exchanger element such as a tube and tube, preferably a Field tube,

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of which has a stepwise change in cross section along the medium, the outer and inner tubes are made in the form of bellows; and grooves - in the form of bumps.

Fig, 1 shows the proposed heat exchange element, section; in fig. 2 is a section A-A in FIG. one.

The element contains the outer tube 1, the inner tube 2, made in the form of bellows. The pipe 2 is provided with slots 3.

Each of the pipes is composed of separate sections interconnected. The turbulatory grooves 3 are filled at the lower ends of the inner tubes in the direction of the medium movement.

The item works as follows.

The flow of the coolant enters the inner coarse 2 and, turning, passes through the annular space. The flow area for the coolant increases evenly in the direction of travel, which creates a pressure gradient. four

nor, enhancing the turbulization of the flow of the medium, and intensifying heat exchange.

The use of the proposed heat exchanging element in heat exchangers due to the higher intensity of the heat transfer process reduces the required heat exchange surface, reduces the size and cost of the heat exchanger,

where they will be installed.

Claims (1)

Invention Formula Heat exchange element of the type of pipe in the pipe on the author. St. f 821897, characterized in that, in order to intensify heat exchange, the outer and inner tubes are made in the form of bellows, and the grooves are in the form of corrugations. Information sources, taken into account during the examination 1. Authorship certificate of the USSR W 821897 according to application number 2786649, cl. F 28 D 7/10, 1979.