RU2770970C1 - Heat exchanger with coaxial arrangement of heat exchange surface - Google Patents

Abstract

FIELD: heat engineering.

SUBSTANCE: invention relates to the field of heat engineering; it can be used to create efficient small-sized heat exchangers. In a heat exchanger containing a cylindrical case with bellows for inlets and outlets of air media, a partition for separating air flows of the first and the second media, the partition is made with triangular-shaped holes for the passage of air media along an inner circular part of an end arc-shaped separating flange of a triangular shape, and a heat exchange surface is formed from a bundle of rectilinear thin-walled pipes of various diameters assembled in a coaxial type package limited by end arc-shaped separating flanges of a triangular shape with blades installed in grooves, for the passage and separation of the first and the second media through a space located inside pipes.

EFFECT: intensification of heat exchange, reduction in a dead zone (non-working zone) at the beginning and end of a heat exchanger with the possibility of creating a given power by scaling without loss of efficiency, reduction in aerodynamic drag.

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Description

The invention relates to the field of heat engineering and can be used to create efficient small-sized heat exchangers for various purposes for various industries, such as construction, chemical and other industries in the ventilation system.

An urgent task in the development of heat exchangers is to increase the efficiency of heat transfer with a simultaneous reduction in their dimensions and weight.

A patent is known (RU 2306515, F28D 7/00, publ. 20.09.2007). Shell-and-tube heat exchanger containing a distribution chamber with a cover connected to the casing, heat exchange tubes connected by baffles with segmented cutouts, and fittings for annular and tube spaces, characterized in that the distribution chamber is divided by a partition, and on the side opposite the distribution chamber, in the casing cover , a floating head is placed, while the ratio of the outer diameter D _n of the casing to the length L of the heat exchange pipes is in the optimal range of values D _n /L = 0.14 ... 0.26, the ratio of the diameter of the heat exchange pipes d to the outer diameter D _n of the casing is in the optimal range of values d/D _n =0.02…0.14, the total number of heat exchange pipes is in the optimal range of values 13…1701, the heat exchange surface with the length of the heat exchange pipes L, which lies in the range from 1 to 9 m, is in the optimal range of values 1.0…961 m ² , the cross-sectional area of the flow in the segment cutouts of the partitions is in the optimal range of values 30…1640 m ² , the cross-sectional area of the flow between the baffles is in the optimal range of 50 ... 1870 m ² , the cross-sectional area of one pass through the heat exchange pipes is in the optimal range of 40 ... 3750 m ² , the ratio of the outer diameter D _n of the casing to the nominal diameters D _y of fittings for pipe and conditional passage D _y1 fittings for the annular space, respectively, are equal to D _n /D _y =D _n /D _y1 and are in the optimal range of values 1.9 ... 4.0.

The disadvantage of this solution is the lack of an increase in the heat exchange area while maintaining the original dimensions.

A patent is known (RU 2455604, F28D 9/00, publ. 07/10/2012). The plate heat exchanger comprises a plurality of heat exchange plates. The plates are located one next to the other and are permanently connected to each other, forming a plate pack having gaps between the first plate and gaps between the second plate. Each heat transfer plate has a heat transfer area and four hole areas defined by the edge of the hole. Each of the regions with a hole contains a flat annular region located on one of the levels - primary or secondary, as well as a plurality of internal sections on a flat annular region on another of the levels - primary or secondary. Each inner section has an inner portion adjacent to the edge of the opening and an outer segment adjacent to the inner portion and having an angular extent of at least 180°. The outer segment has a continuous contour and radius R, which can vary within the range 0.8R≤R≤1.2R. EFFECT: creation of a plate heat exchanger with a high design pressure.

The disadvantages of this solution are the complexity of assembly and the difficulty of sealing a large area when assembling the model.

Closest to the claimed invention is a heat exchanger (SU 1086336 A1, F28D 7/10 F28D 9/04). A heat exchanger containing coaxial pipes fastened in pairs by means of transverse semi-annular baffles-plugs located diametrically opposite on the opposite ends of the pipes, and alternately on each of the ends of adjacent pipes, with the formation of spiral slotted channels between the pipes connected to the collector chambers, separated by a partition into cavities connected to the corresponding branch pipes for supplying and discharging media, characterized in that, in order to intensify heat transfer and facilitate assembly and dismantling, each pair of pipes is connected by transfer fittings located along the length of the pipes with a given pitch, perpendicular to their longitudinal axis, and having oblique cuts at the ends at an angle of 45° relative to the longitudinal axis of the pipes, while the cuts are directed in opposite directions both in adjacent fittings and at each individual fitting, and the collector chambers are attached to the outer pipe.

The disadvantage of this patent: the complexity of the design, increased aerodynamic resistance, the complexity of sealing between the channels of oncoming flows, in the area of installation of overflow fittings.

The problem solved by the invention - a heat exchanger with a coaxial arrangement of the heat exchange surface will be able to work with greater intensification of heat transfer processes.

EFFECT: intensification of heat transfer by reducing the dead zone (non-working zone) at the beginning and end of the heat exchanger, the possibility of scaling without loss of efficiency, reducing aerodynamic drag.

This result is achieved by the fact that the heat exchanger, placed in a cylindrical housing, with sockets for the inlets and outlets of air media, has a partition for separating the air flows of the first and second media, with triangular holes for the passage of air media around the arcuate end flange of a triangular shape and a heat exchange surface, which is formed from a bundle of straight thin-walled pipes of various diameters, assembled into a coaxial-type package, limited by end arcuate triangular-shaped separating flanges, with blades installed in the grooves, for passing and separating the first and second medium along the space located inside the pipes.

The heat exchanger can be made, for example, using 3D printing technology.

The claimed invention meets the criterion of novelty, since at the present time similar devices are not known from the prior art, characterized by the above set of essential features. The differences of the proposed solution are a new form of execution of structural elements and the relationship between them.

The proposed solution is shown in Fig. 1 and FIG. 2 heat exchange apparatus with a coaxial arrangement of the heat exchange surface, as well as a description of the process of its operation.

In the figure, positions are indicated:

1 - cylindrical body,

2 - heat exchange surface consisting of pipes of different diameters,

3 - central tube with a hairpin inside,

4 - end arcuate separating flanges of a triangular shape,

5 - partition for separating air flows of media with triangular holes,

6, 7 - socket in the wall of the housing 1 for the inlet and outlet of the first medium,

8, 9 - socket in the wall of the housing 1 for the inlet and outlet of the second medium,

10 - annular space,

11 - blades.

The direction of movement of the media is shown by the arrows: the blue line is the movement of the flows of the first medium; the red line is the movement of flows of the second medium.

The essence of the proposed solution lies in the fact that the proposed design uses a coaxial arrangement of heat exchange surfaces with triangular arcuate separating flanges and blades installed in the grooves of the arcuate separating flanges.

Due to this solution, an intensification of heat transfer is achieved, a decrease in the dead zone (non-working zone) at the beginning and end of the heat exchanger, with the possibility of creating a given power by scaling without loss of efficiency, and a decrease in aerodynamic resistance.

The specified technical effect is achieved by a new, unknown from the prior art set of essential features and, therefore, the claimed invention has an inventive step.

Making the module monolithic is the best option, since it provides the maximum possible heat transfer between all structural elements, including heat transfer between the walls of the channels for the passage of the first and second media. Monolithic execution - a guaranteed absence of thermal resistance that occurs when connecting parts due to the presence of air gaps between them with different types of connection, assembly, and the ability to work at high pressures of interacting media. The use of modern technologies for the manufacture of monolithic structures, for example, using 3D printing technology using thermal melting, makes it possible to expand the range of materials used and remove restrictions on dimensions, for example, the distances between adjacent channels associated with the technological capabilities of manufacturing and channel wall thicknesses. Such technologies allow the use of modern materials, for example, composite materials with good thermal conductivity.

The heat exchanger with a coaxial arrangement of the heat exchange surface, shown in Fig. 1 and 2, it works as follows: air is pumped into the room and removed using fans, the points of intake and removal are located at different coordinates of the room, from the side of the street, the points of intake and removal are also spaced apart in space to prevent mixing of flows. The first medium (outdoor air) is taken in through the socket 8 and fed into the body 1 of the heat exchanger. To prevent mixing and separation of air flows, there are hermetically installed partitions 5 with triangular holes inside the case. The air flow enters the arcuate end flange 4, which has a triangular shape, to reduce aerodynamic resistance from the outside. The flange also contains additional space on the inside for faster and more even distribution of the intake medium over the circular heat exchange surface. Blades 11 are installed in the grooves between the arcuate separation flanges 4 to create a vortex air movement and direct part of the air flow through the triangular holes into the inner part of the arcuate separation flanges 4 for better distribution over the heat exchange surface.

The generated vortex flow passes through the annular space 10 (between two adjacent pipes), takes heat from the oncoming air flow (passing in parallel through adjacent channels), and enters the room through the socket 9. The oncoming air flow goes simultaneously through the parallel channels of thin-walled tubes with coaxial placement . Warm air taken from the room through the socket 7, passing through the end arcuate dividing flange 4 and, having given off heat, is thrown out into the street 6. Thus, heat exchange occurs between the oncoming air flows through the walls of thin-walled pipes. Since the thin-walled tubes are assembled in a coaxial package, and in the partition 5 there are holes of a triangular shape and blades are installed in the grooves of the end arcuate dividing flange to create a vortex air movement, the air does not flow in a straight line, but twists, forming a vortex flow moving in a circle in the annular space. The central tube with a pin inside 3 is used for the structural part, that is, for fixing the heat exchanger in space, therefore it is not used for air movement.

The heat exchanger is made single-pass, in accordance with Fig. 1. and Fig. 2. Channels for the passage of the first and second medium - annular space, located in the body cavity coaxially.

The present invention can be implemented using modern 3D printing technologies. These technologies provide a wide range of design dimensions and materials, and therefore expand the scope of such heat exchange modules. Thus, the present invention is industrially applicable and can provide a solution to a wide range of problems - from household appliances to, for example, industrial ventilation.

Used sources

1. Patent RU 2306515, F28D 7/00, Shell and tube heat exchanger publ. 20.09.2007 Authors: Evenko V.I., Anisin A.K., Poroshin B.V., Evenko V.V. Kochetov O.S., Kochetova M.O., Lvov G.V.

2. Patent RU 2455604, F28D 9/00, Plate heat exchanger publ. 07/10/2012 Authors: LARSSON X.(SE), BERMHULT P. (SE), ANDREASSON F. (SE), KRISTENSEN P. (SE), SVENSSON M. (SE).

3. Patent SU 1086336 A1, F28D 7/10 F28D 9/04, Heat exchanger. 04/15/1984 Authors: Danilov M.P., Zhurkovskiy I.S., Skoropad A.G., Ivanov I.V.

Claims (1)

A heat exchanger comprising a hollow cylindrical body bounded by sockets for the passage of media through the annular space inside the body, characterized in that the heat exchange surface, formed from a bundle of straight thin-walled pipes of various diameters, assembled in a coaxial-type package, is fixed by end arcuate separating flanges made of a triangular shape , with blades installed in the grooves at the air inlet, and partitions for separating air flows have triangular holes.

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