JP2005090868A - Heat exchanger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat exchanger capable of preventing deformation of a tube due to an internal pressure, and deformation of an outer fin by considering arrangement of an uneven cross section of an inner fin. <P>SOLUTION: The heat exchanger is provided with plurally laminated tubes 110 communicating internal fluid in interiors, the inner fin 120 inserted in the tube 110 and formed so that uneven cross sections are discretely arranged, and the outer fin 130 interposed between the tubes 110, and it carries out heat exchange between the internal fluid and external fluid passing the outer fin 130. Recessed parts 121 and protruding parts 122 of the uneven cross section are arranged in positions that respectively match when looking at a projection of each inner fin 120 from a laminating direction of the tubes 110. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a heat exchanger, and is suitable for application to a heat exchanger for a hot water heater that performs heat exchange between hot water and combustion gas.

  As a conventional heat exchanger, as shown in Patent Document 1, an outer fin is interposed between a plurality of stacked tubes, and an internal fluid that flows through the tube and an external fluid that passes through the outer fin (in Patent Document 1) Those that exchange heat with the combustion gas) are known.

  Inside the tube of this heat exchanger, an inner fin is inserted that has a cross-sectional shape that is uneven, increases the heat transfer area, and improves the heat transfer rate for the internal fluid.

In general, the inner fin inserted into the tube functions as a strength member that improves the heat transfer coefficient as described above and suppresses the deformation of the tube due to the internal pressure of the tube and the deformation of the outer fin.
JP 2002-267272 A

  However, in the said patent document 1, the fine consideration with respect to a deformation | transformation of a tube is not made | formed and nothing is disclosed about arrangement | positioning of the uneven | corrugated shaped cross section of an inner fin.

  That is, as shown in FIG. 8, depending on the shape of the concave-convex cross section of the inner fin 120, the concave portion 121 and the convex portion 122 can be oriented, and the arrangement pattern of the concave portion 121 and the convex portion 122 in the tube 110. Is not always constant. Therefore, in the part (the arrow part and broken-line ellipse part in FIG. 8) where the arrangement relation is formed such that the concave parts 121 (or the hollow side of the convex part 122) of the inner fin 120 face each other, the tube 110. There is a problem that the inner pressure is received with only the plate thickness, the tube 110 is deformed as a stress concentration part, and the outer fin 130 is further deformed.

  In view of the above problems, an object of the present invention is to provide a heat exchanger that can prevent deformation of the tube due to internal pressure and further deformation of the outer fin by considering the arrangement of the concavo-convex cross section of the inner fin.

  In order to achieve the above object, the present invention employs the following technical means.

  In the first aspect of the present invention, an inner fluid is circulated therein, and a plurality of stacked tubes (110) and an inner portion that is formed so that the concavo-convex sections are arranged in a discrete manner and inserted into the tube (110). In a heat exchanger that includes a fin (120) and an outer fin (130) interposed between the tubes (110), and performs heat exchange between the internal fluid and the external fluid passing through the outer fin (130). When the inner fins (120) are projected and viewed from the stacking direction of the tube (110), the concave portions (121) and the convex portions (122) of the concave-convex cross section are arranged so as to coincide with each other. It is characterized by that.

  Thereby, in the inner fin (120) in the adjacent tube (110), the bottom of the concave portion (121) of one tube (110) is connected to the hollow side of the concave portion (121) of the other tube (110). The hollow side of the convex portion (122) is opposed to the ceiling portion of the convex portion (122) of the other tube (110). On the hollow side of the concave portion (121) and the convex portion (122), the tube (110) receives internal pressure only with its own plate thickness, but on the opposite side, the tube (110) has an inner fin ( 120), the internal pressure can be received back through the outer fin 130. Since this relationship is formed over the entire stacked tube (110), there is no portion where stress is concentrated by the internal pressure, and the tube (110) is deformed, and further the outer fin (130) is deformed. Can be prevented.

  In the invention according to claim 2, the inner fin (120) is provided with a positioning portion (123) for regulating the front and back of the inner fin (120) with respect to the tube (110), and the concave portion (121) and the convex portion are provided. The shape part (122) is characterized by being arranged so as to be point-symmetric with respect to the center of the inner fin (120).

  As a result, the front and back of the inner fin (120) are reliably regulated, and the positions of the concave portion (121) and the convex portion (122) are the same even if the inner fin (120) is inverted 180 degrees with respect to the center. Therefore, when the inner fin (120) is inserted into the plurality of tubes (110), the positions of the concave portion (121) and the convex portion (122) can be easily matched.

  The positioning portion (123) is provided on the diagonal of the inner fin (120) as in the invention described in claim 3, and the tube convex portion (111f, 111g) provided on the tube (110). If it does as a notch part (123) engaged with, it can form easily.

  Further, as the concave-convex cross section of the inner fin (120), it is assumed that the inner fin (120) is continuously offset in one direction as in the invention according to claim 4, or the concave and convex as in the invention according to claim 5. The inner fins (120) excellent in improving the heat transfer coefficient on the internal fluid side can be obtained, which are preferably offset in a zigzag manner in the direction perpendicular to the direction in which the cross-sections continue.

  Furthermore, in the invention according to claim 6, the outer fin (130) is formed so that the concavo-convex cross section is continuously or discretely arranged, and the concavo-convex shape in the inner fin (120) and the outer fin (130). The side walls (124, 132) of the cross section are characterized by being arranged so as to cross each other.

  Accordingly, the inner fin (120) and the outer fin (130) can be supported more firmly with each other, so that the deformation of the tube (110) and the outer fin (130) can be effectively performed. Can be prevented.

  In addition, the code | symbol in the bracket | parenthesis of each said means shows a corresponding relationship with the specific means of embodiment description mentioned later.

(First embodiment)
1st Embodiment of this invention is described based on drawing shown in FIGS. 1 and 2 are a plan view and a front view of the heat exchanger 100 for a hot water heater, FIG. 3 is a cross-sectional view taken along the line AA of FIG. 2, FIG. 4 is a front view of the tube 110, and FIG. FIG. 6 is an external perspective view of the inner fin 120.

  The heat exchanger of the present invention is used in a water heater and performs heat exchange between hot water (corresponding to the internal fluid of the present invention) and combustion gas (corresponding to the external fluid of the present invention). (Hereinafter referred to as a heat exchanger) 100, as shown in FIG. 1, a plurality of tubes 110 are stacked, and so-called formed by outer fins 130 interposed between the tubes 110. This is a heat exchanger 100 called a Delon cup type.

  As shown in FIG. 2, the heat exchanger 100 is used in a posture in which the longitudinal direction of the tube 110 is substantially horizontal, and the combustion gas is supplied from the upper side to the lower side. In addition, each member (described below) constituting the heat exchanger 100 is made of a stainless steel material here, and after the members are assembled into the shape of the heat exchanger 100, they are brazed together. ing.

  The tube 110 is formed by joining the tube plate 111 and the tube plate 112 shown in FIG. 1, FIG. 3, and FIG. Both tube plates 111 and 112 are formed by drawing processing having the same basic shape. A flange portion 111b is provided on the outer peripheral portion of the tube plates 111, and a projecting portion 111c that protrudes inwardly in the drawing shape and extends in the horizontal direction. Is provided. When both the tube plates 111 and 112 are aligned, the flange portion 111b and the projecting portion 111c come into contact with each other.

  Further, the projecting portions 111c that contact each other form a partition wall 113 in the tube 110, and communicate with the one end in the longitudinal direction (left side in FIG. 4) of the tube 110, that is, the upper side. A flow path 114 and a lower flow path 115 are formed. A portion where both the flow paths 114 and 115 are formed forms a flat tube portion 110 a of the tube 110. Both flow paths 114 and 115 respectively communicate with a pair of tank portions 110b formed on the other longitudinal end side (the right side in FIG. 4) of the tube 110. The tank portion 110b has a communication port 111a. Is open.

  Since both the tube plates 111 and 112 have the same throttle shape as described above, the cross-sectional shape of the peripheral portion 111e is also the same, and the stress acting on the peripheral portion 111e due to the internal pressure of the hot water supply water is Both tube plates 111 and 112 are made uniform. A plurality of claw portions 112a are provided on the outer peripheral portion of the tube plate 112. After the tube plates 111 and 112 are combined, the shape of the tube 110 is maintained by caulking the claw portions 112a. ing.

  The tank part 110b is provided with a thickness greater than that of the flat tube part 110a, and a flat part 111d is provided on the outer surface of the tube plates 111 and 112 forming the tank part 110b so as to surround the communication port 111a. . In addition, a bushing 116 having a crescent shape as a strength member is inserted into the tank portion 110b.

  As shown in FIG. 1, the plurality of tubes 110 are stacked so that the tank portions 110 b are connected to each other, and the flat portions 111 d are joined to each other. Thereby, the flow paths 114 and 115 of each tube 110 are mutually connected through the communication port 111a opened to the tank part 110b. An inner fin 120 is inserted into the tube 110 to increase the heat transfer area. In the present invention, the inner fin 120 is provided with a feature, and details will be described later.

  As shown in FIG. 1, the outer fin (hereinafter referred to as a fin) 130 is formed by bending a thin plate material into an uneven shape as an overall shape, and the side wall 132 of the uneven cross section extends in the vertical direction in FIG. 2. These are arranged so that the combustion gas flows through the uneven space, and are joined to the surface of the flat tube portion 110a of the tube 110. Note that a plurality of cut-and-raised portions 131 are provided in the concavo-convex portion of the fin 130 in the flow direction of the combustion gas so as to promote heat transfer on the combustion gas side by the turbulent flow effect.

  Further, as shown in FIG. 1 and FIG. 2, a hot water supply port 140 and a hot water outlet 150 are joined to the tank portion 110b on the tube 110 disposed on one end side in the stacking direction. Reinforcing plates 160 are joined to both ends of the tube 110 in the stacking direction.

  Next, the main part of the present invention will be described. As shown in FIGS. 4 to 6, the inner fin 120 is formed so that the concavo-convex sections are arranged in a discrete manner. Specifically, the concavo-convex sections 121, 122 are unidirectional. The offset fins are continuously offset. The segment 124 in the offset fin corresponds to the side wall of the concave-convex cross section of the inner fin 120. The concave portion 121 and the convex portion 122 are opposite to each other when viewed from the front side and the back side of the inner fin 120. Here, for convenience, the side protruding from the paper surface in FIGS. Is the convex part 122, and the concave side is the concave part 121 (in FIG. 3, the side protruding to the left is the convex part 122, and the other part is the concave part 121).

  And the concave part 121 and the convex part 122 are arrange | positioned so that it may become point-symmetrical with respect to the center of the inner fin 120 (FIG. 4).

  Further, a notch 123 is provided on the diagonal of the outer periphery of the inner fin 120. The notch 123 engages the tube 110 while avoiding interference between the corner R portion 111f on one longitudinal end side of the tube 110 and the R projecting portion 111g on the other longitudinal end side. It functions as a positioning part that regulates the front and back of the inner fin 120. Here, restricting the front and back of the inner fin 120 means that the front and back of all the inner fins 120 in each tube 110 are unidirectional if the notch portion 123 is positioned as shown in FIG. It means being unified. The corner R portion 111f and the R launch portion 111g of the tube 110 correspond to the tube convex portion of the present invention.

  The inner fin 120 is disposed so that the segment 124 faces substantially in the horizontal direction as shown in FIG. 4, and is inserted into the upper flow path 114 and the lower flow path 115 in the tube 110. The inner fin 120 inserted into the lower flow path 115 is used by inverting the front and back of the inner fin 120 inserted into the upper flow path 114, and basically the same member (common specification). Yes.

  Thus, in the present invention, the concave portion 121 and the convex portion 122 are arranged point-symmetrically with respect to the center of the inner fin 120 as described above, and positioning by the notch portion 123 is performed, as shown in FIG. As shown in FIG. 5, the concave fins 121 and the convex portions 122 are arranged so that the positions thereof coincide with each other when the inner fins 120 are projected and viewed from the stacking direction of the tubes 110 stacked in plurality.

  Next, the operation of the heat exchanger 100 based on the above configuration and the operation and effect thereof will be described. Hot water flows into the one tank part 110b of each tube 110 from the hot water supply port 140 of the heat exchanger 100, and the lower channel 115 and the upper channel formed in the flat tube part 110a from the one tank part 110b. 114 flows into the other tank part 110b and flows out from the other tank part 110b through the hot water outlet 150.

  On the other hand, as shown in FIG. 2, the combustion gas flows from the top to the bottom of the heat exchanger 100 and exchanges heat with hot water when passing through the heat exchanger 100 to heat the hot water. At this time, the combustion gas is condensed at a temperature lower than the dew point temperature (for example, 30 to 50 ° C.) at least on the outlet side of the heat exchanger 100. That is, the heat exchanger 100 can heat not only the sensible heat of the combustion gas but also the latent heat released when the combustion gas condenses to heat the hot water supply water.

  By the way, as explained in the section “Problems to be Solved by the Invention”, hot water flows through the tube 110 so that an internal pressure is applied to the tube 110, and if there is a portion with low rigidity, stress is present there. The tube 110 and the fin 130 may be deformed by concentration, but in the present invention, the positions of the concave portion 121 and the convex portion 122 of the inner fin 120 coincide with the stacking direction of the tubes 120, respectively. Therefore, the deformation can be prevented.

  That is, as shown in FIG. 3, in the inner fins 120 in the adjacent tubes 110, the bottom of the concave portion 121 of one tube 110 faces the hollow side of the concave portion 121 of the other tube 110, and The hollow side of the shape portion 122 is in a shape facing the ceiling portion of the convex portion 122 of the other tube 110. On the hollow side of the concave portion 121 and the convex portion 122, the tube 110 receives internal pressure only with its own plate thickness. On the opposite side, the tube 110 is added with the plate thickness of the inner fin 120. The internal pressure can be received back through the fins 130. And since this relationship is formed over the entire tube 110 to be laminated, it is possible to eliminate the portion where the stress is concentrated by the internal pressure and prevent the deformation of the tube 110 and further the deformation of the fin 130. is there.

  In the present invention, the inner fin 120 is provided with a positioning portion for regulating the front and back of the inner fin 120 with respect to the tube 110, and the concave portion 121 and the convex portion 122 are point-symmetric with respect to the center of the inner fin 120. So that the front and back of the inner fin 120 are reliably regulated, and the positions of the concave portion 121 and the convex portion 122 are the same even if the inner fin 120 is inverted 180 degrees with respect to the center. When the inner fin 120 is inserted into the plurality of tubes 110, the positions of the concave portion 121 and the convex portion 122 can be easily matched.

  The positioning portion 123 is provided as a notch portion 123 that is provided on the diagonal of the inner fin 120 and engages with the tube convex portion (the corner R portion 111f and the R launch portion 111g). Can be formed.

  Further, since the inner fin 120 is an offset fin in which the concavo-convex cross section is continuously offset in one direction, it is possible to prevent the deformation as described above and to improve the heat transfer rate on the hot water supply side. 120.

  Furthermore, since the side walls 124 and 132 of the concavo-convex cross sections of the inner fin 120 and the fin 130 are arranged so as to cross each other, the inner fin 120 and the fin 130 support each other more firmly. The tube 110 and the fin 130 can be effectively prevented from being deformed.

(Second Embodiment)
A second embodiment of the present invention is shown in FIG. 2nd Embodiment changes the type of the inner fin 120 arrange | positioned in the tube 110 with respect to the said 1st Embodiment.

  As shown in FIG. 7, the concavo-convex cross-sectional shape of the inner fin 120 is staggered in a direction perpendicular to the direction in which the concavo-convex cross-section continues (vertical direction in FIG. 7) (left-right direction in FIG. 7). An offset fin that is offset may be used, and the same effect as in the first embodiment can be obtained.

(Other embodiments)
In the first and second embodiments, the heat exchanger according to the present invention has been described as being applied to a heat exchanger for a hot water heater. Widely applicable.

  Further, the positioning part of the inner fin 120 is not limited to the notch part 123 but may be a marking or the like that can identify either the front or the back.

  The inner fin 120 is not limited to the offset fin described above, and may have an opening on the side wall of the straight fin.

  Moreover, although the tube 110 was demonstrated as a U-turn type tube which has the upper side flow path 114 and the lower side flow path 115, it is not restricted to this, It is good also as a straight type tube.

  Further, the flow directions of the internal fluid (hot water) and the external fluid (combustion gas) have been described as the horizontal direction and the vertical direction, respectively, but the flow directions of the two are opposite to each other (the internal fluid is the vertical direction and the external fluid is the horizontal direction). It may be.

It is a top view which shows the heat exchanger for water heaters in 1st Embodiment. It is a front view which shows the heat exchanger for water heaters in FIG. It is sectional drawing which shows the cross section in the AA part of FIG. It is a front view which shows a tube. It is a front view which shows an inner fin. It is a perspective view which shows the external appearance of an inner fin. It is a perspective view which shows the external appearance of the inner fin in 2nd Embodiment. It is sectional drawing which shows the stress concentration site | part by the internal pressure in the heat exchanger of a prior art.

Explanation of symbols

100 Heat exchanger for water heater (heat exchanger)
110 tube 111f corner R part (tube convex part)
111g R launch part (tube convex part)
120 Inner fin 121 Concave part 122 Convex part 123 Notch part (positioning part)
124 segment (side wall)
130 Outer fin 132 Side wall

Claims (6)

A tube (110) in which an internal fluid circulates and is stacked;
An inner fin (120) formed so that the concavo-convex cross-sections are discretely arranged and inserted into the tube (110);
An outer fin (130) interposed between the tubes (110),
In a heat exchanger for exchanging heat between the internal fluid and the external fluid passing through the outer fin (130),
Arranged so that the positions of the concave portion (121) and the convex portion (122) of the concavo-convex section coincide with each other when the inner fins (120) are projected and viewed from the stacking direction of the tubes (110). A heat exchanger characterized by being made. The inner fin (120) is provided with a positioning portion (123) for regulating the front and back of the inner fin (120) with respect to the tube (110),
The heat according to claim 1, wherein the concave portion (121) and the convex portion (122) are arranged so as to be point-symmetric with respect to the center of the inner fin (120). Exchanger.   The positioning portion (123) is provided on a diagonal of the inner fin (120), and is a notch portion (123) that engages with a tube convex portion (111f, 111g) provided on the tube (110). The heat exchanger according to claim 2, wherein   The heat exchanger according to any one of claims 1 to 3, wherein the uneven cross section of the inner fin (120) is continuously offset in one direction.   The heat exchanger according to any one of claims 1 to 3, wherein the concavo-convex cross section of the inner fin (120) is offset in a zigzag manner in a direction perpendicular to the continuous direction. . The outer fin (130) is formed such that the concavo-convex cross section is continuously or discretely arranged,
The side wall (124, 132) of each concavo-convex section in the inner fin (120) and the outer fin (130) is disposed so as to intersect with each other. The heat exchanger according to crab.

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