JP2005241098A - Heat exchanger for high temperature - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To reduce the inside resistance of a heat transfer pipe, to improve system efficiency, to simplify the shape of a holder of the heat transfer pipe, and to reduce the manufacturing cost. <P>SOLUTION: In this heat exchanger for high temperature 11 constituted to perform the heat exchange between the fluid circulated in a tube 12 and the other fluid circulated outside of the tube 12, the tube 12 is provided with fixed end parts 13, 14 at its both ends, and first fold-back parts 17 of large folding width and second fold-back parts of small folding width are alternately formed between the fixed end parts 13, 14. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a heat exchanger that exchanges heat between two fluids, and more particularly, to a high-temperature heat exchanger that exchanges heat between a high-temperature fluid and a low-temperature fluid.

  Conventionally, a high-temperature heat exchanger is used when recovering exhaust heat of a high-temperature gas discharged from a gas turbine or when generating hydrogen as fuel in a fuel cell.

  FIG. 7 shows an example in which this type of high temperature heat exchanger is used in a power plant. The power plant is provided in a gas turbine 1, a high temperature heat exchanger 3 for exhaust heat recovery connected to the gas turbine 1 via an exhaust pipe 2, and a high temperature heat exchanger 3. An evaporator 4 and an economizer 5 are provided. The evaporator 4 and the economizer 5 are composed of meandering heat transfer tubes 6, 7, and steam and water flow through the heat transfer tubes 6, 7, respectively. Each of the heat transfer tubes 6 and 7 is supported by a holder (not shown), and this holder is formed by drilling a large number of support holes in a flat plate or by joining members in a lattice shape. .

  In such a configuration, the high-temperature exhaust gas discharged from the gas turbine 1 is sent to the high-temperature heat exchanger 3 for exhaust heat recovery via the exhaust pipe 2, and in the high-temperature heat exchanger 3. Then, heat is exchanged with steam and water flowing through the heat transfer tubes 6 and 7, respectively, and exhaust heat of the exhaust gas is recovered (see, for example, Patent Document 1).

JP 58-203303 A

  However, in the above-described conventional high temperature heat exchanger, since the heat transfer tubes 6 and 7 are meandered, the resistance in the tubes is increased, the power source is enlarged, and it is difficult to increase the system efficiency. was there.

  In addition, since the shape of the heat transfer tube holder is complicated, there is a problem that it takes time to manufacture and it is difficult to reduce the manufacturing cost.

  The present invention has been made to solve the above-described problems, and can reduce the internal resistance of the heat transfer tube, increase the system efficiency, simplify the shape of the heat transfer tube holder, and reduce the manufacturing cost. An object of the present invention is to provide a high-temperature heat exchanger that can be made into a high temperature.

  The present invention is a high-temperature heat exchanger 11 configured to perform heat exchange between one fluid flowing in the tube 12 and the other fluid flowing outside the tube 12, 12, fixed end portions 13 and 14 are formed at both ends, and a first folded portion 17 having a large folding width and a second folding portion 18 having a small folding width are alternately formed between the fixed end portions 13 and 14. It is characterized by being.

  Preferably, two tubes 12 are provided as a set, and the second folded portion 18 ′ of the other tube 12 ′ is disposed at the first folded portion 17 of the one tube 12, and the The second folded portion 18 is configured such that the first folded portion 17 ′ of the other tube 12 ′ is disposed.

  Further, the tubes 12 are provided in a plurality of rows, holders 21 capable of supporting the rows of the tubes 12 in two rows are provided, and notches 23 on which the tubes 12 can be fitted are respectively provided on both sides of the holder 21. Is formed.

  According to the present invention, since the first folded portion having a large folded width is formed in the tube, the in-pipe resistance can be reduced, the size of the power source can be reduced, and the system efficiency can be increased. Moreover, when two tubes are combined in one set, the tubes can be efficiently and compactly arranged, and the space can be effectively used. Furthermore, when notches are provided on both sides of the holder that can support the tubes in two rows, the structure of the holder is simplified and the manufacturing cost can be reduced. The excellent effect can be obtained.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Here, FIG. 1 is a schematic explanatory view showing a high-temperature heat exchanger according to an embodiment of the present invention, FIG. 2 is a plan view showing a tube in the embodiment of the present invention, and FIG. 3 is an embodiment of the present invention. It is a side view which shows the holder in a form.

  The high temperature heat exchanger 11 is provided with a plurality of rows of tubes 12 through which a low temperature fluid can flow, and a low temperature fluid flowing through the tube 12 and a high temperature fluid flowing outside the tube 12 are connected to each other. Heat exchange is performed between them. The tube 12 is bent into a Z shape, and fixed ends 13 and 14 are formed at both ends, respectively, and are welded to the header plates 15 and 16 via the fixed ends 13 and 14, respectively. It has become.

  Further, the tube 12 is formed with a first folded portion 17 having a large folded width and a second folded portion 18 having a small folded width between the fixed end portions 13 and 14, respectively. 17 has two 90-degree bent portions 19, and the second folded portion 18 has one 180-degree bent portion 20. As a result, as shown in FIG. 2, the tubes 12 and 12 ′ can be combined in pairs, and the second tube 12 ′ of the other tube 12 ′ can be combined with the region surrounded by the first folded portion 17 of the one tube 12. The folded portion 18 ′ is arranged, and the second folded portion 18 of one tube 12 is arranged in a region surrounded by the first folded portion 17 ′ of the other tube 12 ′.

  As described above, the tube 12 is formed with the first folded portion 17 having a large folded width, and two tubes can be combined in one set, thereby reducing the number of 180-degree bent portions 20 with high pressure loss. be able to. Therefore, the in-pipe resistance can be reduced, and the power source can be downsized. Further, by bending the tube 12 into a Z shape, as shown in FIG. 6, the number of welded portions P with the header plates 15 and 16 that are required in the case of the conventional straight tube 8 is reduced to two as shown in FIG. Therefore, the assembling work can be simplified. Further, since the fixed end portion having a high pressure loss is reduced to two places, the pressure loss can be reduced.

  Further, as shown in FIG. 3, the high-temperature heat exchanger 11 is provided with holders 21 for supporting a plurality of rows of tubes 12 by two rows. The holder 21 is welded to the holder plate 22 at both ends, and a plurality of semi-oval cutouts 23 (six in FIG. 3) on which the tube 12 can be fitted are provided on both sides of the holder 21, respectively. Is formed. As shown in FIG. 3, the notch 23 is preferably formed in a staggered manner, and by doing so, both the fixed end portions 13 and 14 of the tube 12 can be concentrated in a compact manner. A tank (not shown) provided on the fixed end portions 13 and 14 side can be downsized.

  Next, the operation of the above-described high temperature heat exchanger 11 will be described.

  As shown in FIG. 1, the cryogenic fluid flows into the tube 12 from one fixed end 13 (upper right side in FIG. 1), passes through the first folded portion 17 and the second folded portion 18, and the other (shown in FIG. 1). 1 flows out of the tube 12 from the fixed end 14 at the lower left side. At this time, the tube 12 is expanded by the heat of the low-temperature fluid, but the extension of the tube 12 is absorbed by the two 90-degree bent portions 19 of the first folded portion 17 and the 180-degree bent portions 20 of the second folded portion 18. Since the thermal stress can be relaxed, no load is applied to the welded joints between the fixed ends 13 and 14 and the header plates 15 and 16 on both sides. Further, since the tube 12 is held by the holder 21, thermal deformation due to elongation can be prevented.

  On the other hand, the high-temperature fluid circulates outside the tube 12 in a direction that is generally opposite to the flow direction of the low-temperature fluid (in FIG. 1, from the bottom to the top). Heat exchange is performed with a low-temperature fluid circulating in the interior. At this time, since the low-temperature fluid and the high-temperature fluid are orthogonally opposed, the heat exchange efficiency can be increased.

  In the above embodiment, the tube 12 is provided with the first folded portion 17 and the second folded portion 18 one by one. However, the first folded portion 17 and the second folded portion 18 are alternately arranged. As long as it is formed, any number of locations may be provided. For example, as shown in FIG. 4, two first folded portions 17 and two second folded portions 18 may be provided, or alternatively, as shown in FIG. In addition, two first folded portions 17 may be provided and one second folded portion 18 may be provided.

It is a schematic explanatory drawing which shows the high temperature heat exchanger which concerns on embodiment of this invention. It is a top view which shows the tube in embodiment of this invention. It is a side view which shows the holder in embodiment of this invention. It is a top view which shows another example of the tube in embodiment of this invention. It is a top view which shows another example of the tube in embodiment of this invention. It is a schematic explanatory drawing which shows the arrangement | sequence of the tube in the past. It is a systematic diagram which shows a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 High temperature heat exchanger 12 Tube 13 Fixed end part 14 Fixed end part 17 1st return part 18 2nd return part 21 Holder 23 Notch part

Claims (3)

A high-temperature heat exchanger configured to exchange heat between one fluid flowing in the tube and the other fluid flowing outside the tube,
The tube has fixed end portions at both ends, and a first folded portion having a large folded width and a second folded portion having a small folded width are alternately formed between the fixed ends. High temperature heat exchanger. The tubes are provided as a set of two tubes, the second folded portion of the other tube is disposed at the first folded portion of one tube, and the second folded portion of the other tube is disposed at the second folded portion of the one tube. The high temperature heat exchanger according to claim 1, wherein the one folded portion is arranged. The tube is provided in a plurality of rows, a holder capable of supporting the plurality of rows of tubes in two rows is provided, and a notch portion in which the tube can be fitted is formed on both sides of the holder. The high temperature heat exchanger according to claim 1 or 2.

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