JP2007139344A - Heat exchange cell structure by primary surface recuperator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat exchange cell structure in a high-temperature heat exchanger, capable of improving fuel efficiency by drift prevention or the like while miniaturizing the structure and retaining high durability to temperature cycle. <P>SOLUTION: In this heat exchange cell structure, drift of low-temperature fluid is prevented using a primary heat transfer surface having a dimple-shaped distributor to raise the recovery rate of high-temperature exhaust heat, whereby fuel efficiency is improved, and durability to temperature cycle is enhanced by adapting a primary surface recuperator. Further, this heat exchange cell structure is easy to manufacture since it is constituted by alternately laminating two kinds of heat transfer plates produced while disposing a spacer bar on the primary heat transfer surface, and can be miniaturized and significantly reduced in manufacturing cost since no passage by secondary heat transfer surface is formed. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a cell structure for heat exchange of a plate heat exchanger, and more specifically, a high temperature plate heat exchanger used in a high temperature environment such as a gas turbine, a high temperature fuel cell, and a hybrid system combining these. The present invention relates to a cell structure for heat exchange by the primary transmission system.

  In recent years, much attention has been focused on the effective use of energy, and technological development for constructing an energy supply and demand system for the future is steadily proceeding. From the viewpoint of effective use of energy, a distributed energy system is regarded as promising as an energy system replacing a large power generation system.

  Distributed energy systems include a variety of distributed energy conversion technologies such as gas engines, solar cells, and wind turbines. Among them, heat engines such as gas turbines and high-temperature types that generate electricity directly from fuel through chemical processes. Fuel cells are actively being developed. Examples of the high-temperature fuel cell include SOFC (Solid Oxide Fuel Cell) and MCFC (Molten Carbonate Fuel Cell). In addition, a hybrid system in which a gas turbine and a high-temperature fuel cell are combined is intended for use as a distributed power source, and is being studied for its realization.

  In these distributed energy systems, exhaust heat recovery performance greatly affects the performance of gas turbines and high-temperature fuel cells. Therefore, when designing a gas turbine or a high-temperature fuel cell, it is essential to use a high-performance regenerative heat exchanger capable of exchanging heat efficiently and effectively.

  In addition, since gas turbines and high-temperature fuel cells are frequently started and stopped repeatedly, it is required to employ a heat exchanger having high durability against a temperature cycle. A plate fin type heat exchanger for high temperature is used as a regenerative heat exchanger capable of sufficiently exhibiting such a function.

  FIG. 1 is a perspective view showing an example of a heat exchange cell structure of a plate fin type heat exchanger for high temperature. As shown in FIG. 1, the cell structure for heat exchange of a high-temperature plate fin type heat exchanger generally has a configuration in which high-temperature fluid passages 2 and low-temperature fluid passages 3 are alternately stacked with tube plates 7 interposed therebetween. .

  FIG. 2 is a plan view showing an example of a low-temperature fluid passage in the heat exchange cell. As shown in FIG. 1 and FIG. 2, the cryogenic fluid passage 3 has a corrugated fin 4 sandwiched between two tube plates 7 and has distributor fins 5a and 5b cut into triangles, and spacer bars 6a, 6b, It is configured by closing at 6c. The above-described tube plate and distributor fin are integrated with the corrugated fin by adhesive bonding, brazing, or the like, but are basically separate members and are referred to as a secondary heat transfer surface.

  On the other hand, without arranging another member by adhesive bonding or brazing, for example, a thin alloy sheet such as stainless steel is formed into a waveform so as to have a pleating property, or bent, The constructed heat transfer surface is called a primary heat transfer surface.

  That is, in the above example, the corrugated fin itself is a primary heat transfer surface, and the tube plate and the distributor fin are secondary heat transfer surfaces arranged to add other functions such as a distribution function.

  Until now, various heat exchange cell structures have been proposed by combining the primary and secondary heat transfer surfaces, but the high temperature used in gas turbines, high-temperature fuel cells, and hybrid systems combining them has been proposed. In the plate fin type heat exchanger, from the viewpoint of high durability against the temperature cycle, instead of the secondary heat transfer surface, a heat exchange method using only the primary heat transfer surface, that is, a primary surface heat transfer method (Primary Surface Recuperator) is used. Development of a new heat exchanger that is adopted is desired.

  As a heat exchanger adopting the primary transmission system, Patent Document 1 discloses a primary surface heat exchanger used in a high-pressure specific gas turbine engine. This heat exchanger is a heat exchanger that includes a first surface and a second surface, and further includes an air chamber composed of a plurality of primary surface sheets having a heat transfer portion, a pair of end portions, and a pair of transition portions. It is possible to minimize pressure head degradation due to fluid and cryogenic fluid. However, the invention described in Patent Document 1 relates to the main passage portion of the primary heat transfer surface, and does not relate to the entire heat exchange cell structure including the distributor.

JP-T 9-503288

  In the cell structure for heat exchange that combines the primary heat transfer surface and the secondary heat transfer surface, the distributor fin is placed on the primary heat transfer surface crushed by a tube plate or press etc. by adhesive bonding, brazing, etc. Will lead to an increase. In addition, when assembling the heat exchange cell, it is difficult to position the spacer bar when multiple layers are stacked.

  In addition, various heat exchangers using a primary heat transfer surface or a heat exchanger combining a primary heat transfer surface and a secondary heat transfer surface have been proposed in the past. It had been.

  The present invention has been made in view of the above-described situation, and in designing a high-temperature heat exchanger, by adopting a primary transmission method, the stacked structure of the heat exchange cell is made compact and a temperature cycle is achieved. It is intended to provide a low-cost heat exchange cell structure for a high-temperature plate heat exchanger that can improve heat exchange efficiency by preventing drift of low-temperature fluid. .

  The present inventors have studied various structures capable of preventing the drift of the low-temperature fluid without forming a passage by the secondary heat transfer surface in the distributor section. As a result, the primary heat transfer surface is crushed with a press or the like, and at the same time, a part of the primary heat transfer surface is left as a plurality of dimples, thereby producing a dimple-shaped distributor integrated with the primary heat transfer surface. It was found that a drift prevention effect equivalent to a passage formed by a secondary heat transfer surface such as a distributor fin can be obtained.

The present invention has been completed based on the above findings, and the gist of the following (1) to (5).
(1) In a cell structure of a plate-type heat exchanger having a configuration in which passages for circulating a high-temperature fluid and a low-temperature fluid are alternately stacked in a container, and a distributor section is provided in the passage for circulating the low-temperature fluid. In the passage where the distributor part is provided, a primary heat transfer surface configured integrally with a crushed distributor instead of a secondary heat transfer surface configured by a distributor fin, a corrugated fin, and a tube plate Cell structure for heat exchange by primary transmission system using
(2) When the cell structure for heat exchange described in (1) above is assembled by alternately laminating and assembling two types of heat transfer plates in which the arrangement positions of the spacer bars provided on the primary heat transfer surface are changed This is desirable because it facilitates manufacturing.
(3) In the heat exchange cell structure according to (1) or (2) above, if one or more dimples are formed in the distributor portion formed on the primary heat transfer surface, It is desirable because the heat recovery efficiency of the heat exchanger is improved by preventing drift.
(4) In the cell structure for heat exchange as described in (3) above, if the passage is formed by the contact between the crest portion and the flat portion of the dimple in the distributor portion, the dimple positioning needs accuracy. Rather, it is easy to manufacture and desirable.
(5) The heat exchange cell structure according to any one of (1) to (4) is preferably used for a high temperature heat exchanger used in a high temperature environment of 400 ° C. or higher.

  In the present invention, since it is not necessary to attach secondary heat transfer surfaces such as distributor fins and tube plates in the distributor, the cell structure for heat exchange can be made compact and the manufacturing cost can be reduced, and the primary surface transfer method is adopted. By doing so, the cell structure for heat exchange provided with the high durability with respect to a temperature cycle can be provided.

  Moreover, since the pressure loss is increased by the dimple shape in the distributor and the drift of the low temperature fluid is prevented, the recovery rate of the high temperature exhaust heat is increased, and the fuel efficiency can be improved.

Hereinafter, the cell structure for heat exchange according to the present invention will be described in detail with reference to the drawings.
(1) Trapezoidal Heat Exchange Cell Structure FIG. 3 is a perspective view showing an example of a primary heat transfer surface used in the trapezoidal heat exchange cell structure of the present invention. As shown in the figure, the trapezoidal heat exchange cell structure has a shape suitable when the supply direction and the discharge direction of the cryogenic fluid 16 to the heat exchange cell are opposite.

  If it is a conventional method, the primary heat transfer surface is flattened by crushing the distributor part with a press or the like, and the distributor fin is arranged as a secondary heat transfer surface on the flat part. As shown in FIG. 3, the primary heat transfer surface 8 is crushed with a press or the like, and at the same time, a part of the primary heat transfer surface is left as dimples 10a and 10b. Produced in the process.

  The heat exchange cell structure of the present invention is characterized in that one or more dimples are formed in the distributor part, and FIG. 3 illustrates the case of two types of dimples.

  Here, the dimple 10a is intended to prevent the drift of low-temperature fluid due to pressure loss, and the dimple 10b is a dimple for facilitating the positioning of the spacer bar, and is intended to improve the assembly work efficiency. .

  FIG. 4 is a diagram schematically showing the flow of a low-temperature fluid when the distributor section does not have dimples. As shown in the figure, when the dimples are not provided in the distributor section 11, the flow of the low-temperature fluid in the main passage section is concentrated on the inlet / outlet side, so that a drift occurs and heat exchange cannot be performed efficiently. In the present invention, by arranging the dimple 10a in the distributor portion, such a drift can be prevented, heat exchange can be performed in the entire main passage portion of the primary heat transfer surface, and the efficiency can be improved.

  Further, in the conventional method for manufacturing a heat exchange cell, when multiple layers are stacked, the end portions of each layer are displaced from each other, and positioning of the spacer bar (side bar) becomes difficult. By placing the bar against the dimple 10b, accurate and easy positioning is possible.

  FIG. 5 is a diagram schematically showing an example of the heat transfer plate and heat exchange cell of the present invention, wherein FIG. 5 (a) is a perspective view of two types of trapezoidal heat transfer plates, and FIG. It is a perspective view of the trapezoidal heat exchange unit cell obtained by combining two types of trapezoidal heat transfer plates.

  The heat transfer plate of the present invention is manufactured by arranging a spacer bar on a primary heat transfer surface formed integrally with a dimple-shaped distributor. As shown in FIG. 5A, two types of heat transfer plates, that is, the trapezoidal upper plate 12 and the trapezoidal lower plate 13 can be easily obtained by changing the arrangement of the spacer bars 6b and 6d.

  Further, when the spacer bars 6b and 6c of the two kinds of heat transfer plates are welded to each other and positioned by applying the spacer bar 6a to the dimple 10b as described above, welding is performed as shown in FIG. As described above, the trapezoidal heat exchange unit cell 14 is assembled, and a passage through which the high temperature fluid 15 and the low temperature fluid 16 are circulated can be easily configured.

  Here, the unit cell for heat exchange refers to a cell structure configured by combining two types of heat transfer plates, that is, an upper plate and a lower plate illustrated in FIG. By arranging the heat exchange unit cells in a stacked manner, that is, by alternately arranging two types of heat transfer plates, the heat exchange cell structure of the present invention can be obtained.

  As described above, the cell structure for heat exchange according to the present invention alternately stacks two types of heat transfer plates manufactured by arranging spacer bars on the primary heat transfer surface integrated with the dimple-shaped distributor. Since it can be easily obtained by arranging, it is possible to make the heat exchange cell compact and to prevent the drift of the low temperature fluid due to the pressure loss effect of the dimple shape. In addition, the cell structure for heat exchange according to the present invention employs a so-called primary surface transmission system that does not use distributor fins and tube plates as secondary heat transmission surfaces, so it also has high durability against temperature cycles. ing.

FIG. 6 is a diagram schematically showing a cross section of the distributor part of the cell structure for heat exchange according to the present invention. In the heat exchanging cell structure of the present invention, a passage can be formed by contact between the dimple peaks in the distributor portion, and a passage formation 3 can be achieved by contact between the dimple peaks 10a and the flat portion 9 as shown in FIG. is there. If the passage is formed by the contact between the dimple crest and the flat portion, the dimple positioning does not require accuracy, and the manufacture is facilitated.
(2) Rectangular heat exchange cell structure FIG. 7 is a perspective view showing an example of a primary heat transfer surface used in the rectangular heat exchange cell structure of the present invention. As shown in the figure, the rectangular heat exchange cell structure has a shape suitable when the inlet direction and the outlet direction of the cryogenic fluid 16 with respect to the heat exchange cell are the same direction.

  The rectangular primary heat transfer surface shown in FIG. 7 has a flat surface portion 9 and dimples by crushing the distributor portion with a press or the like and simultaneously leaving a part of the primary heat transfer surface as dimples 10a. A distributor consisting of shapes is manufactured in one step. As with the trapezoidal shape, the dimple 10a is intended to prevent the drift of low temperature fluid due to pressure loss.

  FIG. 8 is a diagram schematically showing an example of the heat transfer plate and heat exchange cell of the present invention, in which (a) is a perspective view of two types of square heat transfer plates, and (b) It is a perspective view of a square type heat exchange unit cell obtained by combining two types of square type heat transfer plates.

  Similarly to the trapezoidal type, the heat transfer plate used in the square heat exchange cell structure is manufactured by arranging a spacer bar on the primary heat transfer surface formed integrally with the dimple-shaped distributor. As shown in FIG. 8A, two types of heat transfer plates, that is, the rectangular upper plate 17 and the rectangular lower plate 18 can be easily obtained by changing the arrangement of the spacer bars 6a, 6b, 6d.

  8A that the spacer bar 6a can be easily positioned by placing the spacer bar 6a (side bar) against the spacer bars 6b and 6d in the rectangular lower plate 18. FIG.

  Then, if the spacer bars 6b of the two types of heat transfer plates are welded together, as shown in FIG. 8B, the rectangular heat exchange unit cell 19 is assembled, and the high temperature fluid 15 and the low temperature fluid 16 are circulated. The passage to be made can be easily configured.

  Also in the distributor section, as in the case of the trapezoidal shape, a passage can be formed by contact between the dimple ridges, and a passage formation 3 by contact between the dimple ridge 10a and the flat portion 9 can be performed as shown in FIG. It is. If the passage is formed by the contact between the dimple crest and the flat portion, the dimple positioning does not require accuracy, and the manufacture is facilitated.

  The cell structure for heat exchange proposed in the present invention is not limited to the trapezoidal heat exchange cell and the square heat exchange cell, and can be applied to various shapes of heat exchange cell structures. And in any shape, since it is not necessary to attach a secondary heat-transfer surface, the cell structure for heat exchange can be made compact, and the manufacturing cost can be reduced. Moreover, since the arrangement of the entrance / exit can be freely configured by changing the arrangement of the spacer bar, it can be used according to the application.

  In the cell structure for heat exchange of the present invention, the constituent material is not particularly limited, but when used in a heat exchanger for high temperature used in a high temperature environment, for example, stainless steel (SUS321, SUS347, etc.) at 400 to 600 ° C. At 600 ° C. or higher, a Ni-based heat-resistant alloy (Inconel 625, Hastelloy X, etc.) can be appropriately employed.

  In the present invention, since the passage by the secondary heat transfer surface such as the distributor fin and the tube plate is not formed in the distributor section, the heat exchange cell structure can be made compact and the manufacturing cost can be reduced, and the primary surface transfer method is adopted. By doing so, the cell structure for heat exchange provided with the high durability with respect to a temperature cycle can be provided.

  Moreover, since the pressure loss is increased by the dimple shape in the distributor and the drift of the low temperature fluid is prevented, the recovery rate of the high temperature exhaust heat is increased, and the fuel efficiency can be improved.

  This makes it possible to improve the performance of high-temperature plate fin heat exchangers used in high-temperature environments such as gas turbines, high-temperature fuel cells, and hybrid systems that combine these, and this will contribute to the development of distributed energy systems. You can contribute a lot.

It is a perspective view which shows an example of the cell structure for heat exchange of the plate fin type heat exchanger for high temperature. It is a top view which shows an example of the low temperature fluid channel | path in the cell for heat exchange. It is a perspective view which shows an example of the primary heat-transfer surface used with the cell structure for trapezoid type heat exchange of this invention. It is the figure which showed typically the flow of the low temperature fluid when not having a dimple in a distributor part. It is a figure which shows typically an example of the heat-transfer plate of this invention, and the cell for heat exchange, (a) is a perspective view of two types of trapezoid type heat-transfer plates, (b) is two types of trapezoids It is a perspective view of the unit cell for trapezoid type heat exchange obtained combining a type | mold heat-transfer plate. It is the figure which showed typically the cross section of the distributor part of the cell structure for heat exchange of this invention. It is a perspective view which shows an example of the primary heat-transfer surface used with the square-shaped heat exchange cell structure of this invention. It is a figure which shows typically an example of the heat-transfer plate of this invention, and the cell for heat exchange, The same (a) is a perspective view of two types of square-shaped heat-transfer plates, The same (b) is two types of square. It is a perspective view of the unit cell for square type heat exchange obtained by combining a type heat transfer plate.

Explanation of symbols

1. 1. Heat exchange cell 2. Hot fluid passage 3. Cryogenic fluid passage Corrugated fins 5a, 5b. Distributor fins 6a, 6b, 6c, 6d. Spacer bar 7. Tube plate 8. Primary heat transfer surface 9. Planar portions 10a, 10b of the primary heat transfer surface after crushing. Dimple 11. Distributor section 12. Trapezoidal upper plate 13. Trapezoidal lower plate 14. 15. Trapezoidal heat exchange unit cell High temperature fluid 16. Cryogenic fluid 17. Square plate 18. Square-shaped lower plate 19. Unit cell for square heat exchange

Claims (5)

In the cell structure of the plate-type heat exchanger, the passages for circulating the high temperature fluid and the low temperature fluid are alternately stacked in the container, and the passage for circulating the low temperature fluid is provided with a distributor.
In the passage where the distributor part is provided, a primary heat transfer surface configured integrally with a crushed distributor instead of a secondary heat transfer surface configured by a distributor fin, a corrugated fin, and a tube plate A cell structure for heat exchange by a primary transmission system, characterized in that the use of   The heat exchange by the primary surface transfer system according to claim 1, wherein two types of heat transfer plates in which the arrangement positions of the spacer bars provided on the primary heat transfer surface are changed are alternately stacked and assembled. Cell structure.   3. The cell structure for heat exchange according to claim 1, wherein one or two or more dimples are formed in the distributor portion formed on the primary heat transfer surface.   4. The heat transfer cell structure according to claim 3, wherein a passage is formed in the distributor portion by contact between a crest portion and a flat portion of the dimple. It is used for the heat exchanger for high temperature used in a high temperature environment of 400 degreeC or more, The cell structure for heat exchange by the primary transmission system in any one of Claims 1-4 characterized by the above-mentioned.

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