JP2004037005A - Fin and tube type heat exchanger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fin and tube type heat exchanger capable of increasing the heat exchanging efficiency without increasing the area of fin plates. <P>SOLUTION: The fin and tube type heat exchanger is structured so that a pair of cut-up parts 23a and 23b are provided in a truncated shevron shape in positions downstream of pipes 17b in the downstream about the flow of a combusted exhaust gas G and also a pair of cut-up parts 24a and 24b are provided in a truncated shevron shape in upstream positions. Also a pair of cut-up parts 25a and 25b are provided in a truncated shevron shape in positions downstream of pipes 17a in the upstream positions, and the upstream region serves as a region 28 free of any cut-up part. Burring holes 26 and 27 are formed in the middle between the pipes 17a and 17b so that heat conduction to the pipes 17a and 17b is concentrated. Accordingly the heat conduction from the combusted exhaust gas is suppressed upstream while the heat conduction is promoted downstream. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a fin-and-tube heat exchanger, and more particularly to a fin-and-tube heat exchanger capable of improving the heat exchange efficiency.
[0002]
[Prior art]
Conventionally, as a fin-and-tube heat exchanger, for example, a fin-and-tube heat exchanger installed in a water heater is known. In this device, the water passed through the fin tube is heat-exchanged and heated by the combustion heat of the combustion burner.More specifically, the combustion exhaust gas is passed through the gap between the fin plates, and the heat of the combustion exhaust gas is passed through the fin plate. Heat is transferred to the fin tubes to heat the water in the fin tubes.
[0003]
More specifically, as shown in FIGS. 6 and 7, the can body of the water heater contains a fin-and-tube heat exchanger 12 (see FIG. 7) inside a barrel 11 and has a heat exchange can body. The lower portion of the heat exchange can 13 is connected to a combustion can 14 containing a combustion burner (not shown), and the upper portion is connected to an exhaust pipe 15.
[0004]
As shown in FIG. 8, the heat exchanger 12 includes a fin plate group 16 composed of a number of fin plates 161, 161,... And a pipe (fin tube) 17 penetrating the fin plate group 16. . The pipe 17 is bent a plurality of times outside the barrel 11 and penetrates the barrel 11 and the fin plate group 16 a plurality of times. As shown in FIG. Four pipes 17 are provided at the combustion burner 18 side, and three pipes 17 are provided at the upper position (the exhaust pipe 15 side) in a staggered arrangement. Then, when the high-temperature combustion exhaust gas G from the combustion burner 18 passes through the gap between the fin plates 161, the combustion heat is transferred to the fin plates 161 and water passed through the pipe 17 is formed. Is performed, and the combustion exhaust gas after the heat exchange is discharged from the exhaust stack 15 to the outside.
[0005]
[Problems to be solved by the invention]
However, the fin-and-tube heat exchanger 12 has the following various disadvantages.
[0006]
First, as shown by the dotted arrows in FIG. 9, the flow of the combustion exhaust gas G passes through the gaps between the fin plates 161 and 161 while the flow path is bent by the pipes 17 in a staggered arrangement. It comes out to the exhaust pipe 15 side. In this case, the flow velocity distribution of the combustion exhaust gas G passing through the gap between the fin plates 161 and 161 becomes the main flow having the fastest flow velocity at the center position of the gap M as shown in FIG. Then the flow velocity becomes almost zero. The temperature distribution of the combustion exhaust gas G also has the same tendency, the temperature of the main stream becomes highest, and becomes the lowest at the surface position of each fin plate 161. For this reason, a layer having a thermal resistance called a temperature boundary layer is formed on the surface of each fin plate 161, which results in a heat transfer effect from the combustion exhaust gas G to each fin plate 161, which results in a less promising result. The exchange efficiency will be reduced.
[0007]
Secondly, the pipes 17 at the lower position (upstream position when viewed from the flow of the flue gas) where the flue gas G contacts first come into contact with the flue gas G in a high temperature state to be in a high endothermic state, but the upper position ( The amount of heat absorbed by each of the pipes 17 at the downstream side of the combustion exhaust gas (the downstream side of the combustion exhaust gas) decreases as a result of the temperature of the combustion exhaust gas G decreasing due to heat transfer to each of the pipes 17 at the upstream side. As a result, exhaust gas drain easily occurs, and fin plate clogging tends to occur due to generation and accumulation of copper oxide, which is a material for forming the pipes 17 and the like. In this case, the heat exchange efficiency cannot be improved. Further, as a result of each pipe 17 at the upstream position being in a high heat absorbing state, there is a possibility that boiling abnormal noise may be caused.
[0008]
Third, the fin plates 161 at the upstream side where the lower pipes 17 are located receive the combustion heat and the combustion exhaust gas from the combustion burner 18 directly. It is necessary to prevent burnout of parts and maintain durability. For this reason, in order to increase the heat exchange efficiency, in consideration of the second inconvenience, it is necessary to suppress endothermic as much as possible in the above-mentioned upstream part and to secure as much endothermic as possible in the above-mentioned downstream part. You.
[0009]
Fourth, there is a demand for a more compact heat exchanger, and an increase in the fin plate area, that is, an increase in heat exchange efficiency due to an increase in the size of the fin plate itself cannot be adopted.
[0010]
The present invention has been made in view of such circumstances, and an object of the present invention is to provide a fin-and-tube heat exchanger capable of increasing heat exchange efficiency without increasing a fin plate area. It is in.
[0011]
[Means for Solving the Problems]
In order to achieve the above object, the present invention provides a fin plate having a plurality of fin plates serving as heat transfer paths, and a pipe through which the first fluid flows. For the fin-and-tube heat exchanger configured so that the second fluid is passed through the gap between the first fluid and heat exchange with the first fluid, the following points are considered as main parts. Things. In other words, by forming a cut-and-raised portion in a predetermined oblique direction integrally with each fin plate, the second fluid approaches the one fin plate or approaches the other fin plate in the gap between the two fin plates. This is a point that the cut-and-raised portion is not formed on each fin plate in the upstream region of the second fluid of the pipe. Further, by adding a point where a burring hole is formed in each fin plate at the downstream position, the function and effect of the present invention can be further increased. Note that the heat exchange between the first fluid and the second fluid includes any of heat exchange with cold heat and heat exchange with warm heat, and furthermore, heat exchange with the first fluid or the second fluid. Either may be a cold or hot heat source for heat exchange.
[0012]
Specifically, in the invention according to claim 1, the cut-and-raised portion that is cut and raised so as to protrude toward the other fin plate adjacent to the fin plate is integrally formed, while the second fluid is formed. The specific area of each of the fin plates upstream of the pipe with respect to the flow direction is a non-formation area of the cut-and-raised portion.
[0013]
In this case, since the second fluid flowing in the gap between the fin plates is agitated by the formation of the cut-and-raised portion, the temperature boundary layer on the surface of each fin plate is broken, and the second fluid is separated by the gap. It is possible to promote the heat transfer to each fin plate by staying longer inside. On the other hand, since the upstream region of each fin plate is a region where the cut-and-raised portion is not formed, the heat transfer in the upstream region of each fin plate is relatively suppressed, and the heat transfer is promoted on the downstream side. It becomes possible to plan. As a result, both the improvement of durability and the suppression of generation of abnormal noise by suppressing heat transfer in the upstream region of each fin plate and the promotion of heat transfer in the downstream region are achieved, and the heat exchange efficiency is increased. In addition to this, the generation of exhaust gas drain when the second fluid is the combustion exhaust gas can be surely suppressed.
[0014]
In the invention according to claim 2, a cut-and-raised portion that is cut and raised so as to protrude toward the other adjacent fin plate is integrally formed at a position near each of the fin plates surrounding the pipe. In addition, at least two cut-and-raised portions at an upstream position with respect to the flow direction of the second fluid of the pipe are arranged obliquely so as to open in a C shape toward the pipe, while at a downstream position. At least two cut-and-raised portions were arranged obliquely so as to close in an inverted C shape toward the pipe.
[0015]
In the case of the second aspect, the cut-and-raised portions at the upstream and downstream positions are obliquely arranged in the same direction on each side in the direction orthogonal to the upstream and downstream directions of the second fluid of each pipe, and each pipe is inclined with respect to the orthogonal direction. The second fluid flowing on both side positions is agitated and rotated in the same direction, and forms a longitudinal vortex in a direction approaching one of the fin plates or approaching the other fin plate in the gap between the fin plates to the downstream side. It will flow. Therefore, the temperature boundary layer on the surface of each fin plate is broken by the agitation, and the longitudinal vortex can significantly promote heat transfer to each fin plate. Thereby, the heat exchange efficiency is significantly increased.
[0016]
In the fin-and-tube heat exchanger according to claim 2, at least two pipes are arranged at predetermined intervals in a direction orthogonal to the upstream and downstream directions of the second fluid with respect to each fin plate as the pipe. A burring hole is formed by burring at an intermediate position between two adjacent pipes and at a position downstream of a line connecting the two pipes with respect to a flow direction of the second fluid. (Claim 3). In this case, due to the presence of the burring hole, the burring hole becomes a passage resistance, and the passage area of the second fluid tends to be narrowed. As a result, the linear velocity (passing speed) of the second fluid becomes higher. The heat transfer coefficient to the portion near the burring hole, that is, the portion immediately adjacent to each pipe and the cut-and-raised portion near each pipe is increased (the amount of heat transfer per unit time is increased). This makes it possible to increase the amount of heat transfer due to the presence of the burring hole, in addition to the heat transfer promotion by the cut-and-raised portion, thereby further promoting the heat exchange efficiency. In addition, since this burring hole is formed at a downstream position of each pipe, it can contribute to improvement of durability by suppressing heat transfer of each fin plate at an upstream portion.
[0017]
In the invention according to claim 4, as the pipe, a predetermined interval is provided at each position on both the upstream and downstream sides of the second fluid in the upstream and downstream directions with respect to each fin plate in a direction orthogonal to the upstream and downstream directions of the second fluid. Cut-and-raised portions that are arranged in a staggered manner with at least two fin plates spaced apart from each other and protruded toward the other fin plate side adjacent to the adjacent position of each of the fin plates surrounding the pipe. Are integrally formed. In each of the pipes at the upstream position, a region of each fin plate upstream of each pipe with respect to the flow direction of the second fluid is a non-formed region where the cut-and-raised portion is not formed, and At the position, the two cut-and-raised portions are arranged obliquely so as to be closed in an inverted C shape toward each of the pipes. In each of the pipes at the downstream position, at least two cut-and-raised portions are disposed obliquely at the upstream position with respect to the flow direction of the second fluid so as to open in a C shape toward each of the pipes. On the other hand, the two cut-and-raised portions are obliquely arranged at the downstream side so as to be closed in an inverted C shape toward each of the pipes. In addition, an intermediate position between the two adjacent pipes at the downstream position adjacent to each other and at a position downstream of the line connecting the two pipes with respect to the flow direction of the second fluid, Burring holes were formed by burring.
[0018]
In the case of the fourth aspect, it is possible to obtain all of the actions according to the first aspect, the actions according to the second aspect, and the actions according to the third aspect.
[0019]
In the fin-and-tube heat exchanger according to any one of claims 1 to 4, each cut-and-raised portion may be formed in a rectangular shape, a trapezoidal shape, a triangular shape, or a semicircular shape. 5). In particular, it is preferable that each of the cut-and-raised portions is formed in a trapezoidal shape or a triangular shape, and is formed such that the rising dimension on the downstream side with respect to the flow direction of the second fluid is larger than that on the upstream side. ). In this case, the above-described stirring and longitudinal vortex described for the operation according to claim 2 can be generated more reliably and effectively.
[0020]
【The invention's effect】
As described above, according to the fin-and-tube heat exchanger of claim 1, claim 5, or claim 6, each of the fin plates has an upstream area that is a cut-and-raised portion non-formed area. Improving durability and suppressing generation of abnormal noise by suppressing heat transfer in the upstream area of the fin plate, and promoting heat transfer by the agitating action of the cut-and-raised section in the downstream area together achieve heat exchange efficiency. In addition to being able to achieve an increase, exhaust gas drain generation when the second fluid is combustion exhaust gas can also be reliably suppressed.
[0021]
According to the fin-and-tube heat exchanger of the second, third, fifth, or sixth aspect, the second fluid is agitated in the gap between the fin plates by the cut-and-raised portions. A vertical vortex of the fluid can be generated. For this reason, the temperature boundary layer on the surface of each fin plate can be broken by the stirring, and the heat transfer to each fin plate can be greatly enhanced by the vertical vortex. Thereby, the heat exchange efficiency can be significantly increased.
[0022]
In particular, according to the third aspect, in addition to the promotion of heat transfer by the cut-and-raised portion, the amount of heat transfer due to the presence of the burring hole can be increased, and the increase in heat exchange efficiency can be further promoted. In addition, by forming a burring hole having such an effect at a downstream position of each pipe, it is possible to contribute to improvement of durability by suppressing heat transfer of each fin plate at an upstream portion.
[0023]
According to the fin-and-tube heat exchanger of the fourth, fifth or sixth aspect, all of the effects of the first to third aspects can be obtained.
[0024]
According to the fifth aspect, the shape of each of the cut-and-raised portions is specified, and according to the sixth aspect, the agitation and the vertical vortex can be generated more reliably and effectively.
[0025]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings.
[0026]
FIG. 1 shows a fin-and-tube heat exchanger 2 according to an embodiment of the present invention. This heat exchanger 2 is applied to an application installed in a water heater can in the same manner as described in the section of the prior art. That is, the heat exchanger 2 includes a fin plate group 21 composed of a number of fin plates 22, 22,... And a penetrating pipe (fin tube) 17.
[0027]
The pipe 17 has the same configuration as that described in the section of the prior art, and one pipe 17 is repeatedly bent and continuous using a U-shaped pipe portion or a U-shaped vent, and a fin plate group is formed. 21 are repeatedly penetrated, whereby four pipes 17 are arranged in a lower position (combustion burner 18 side), and three pipes 17 are arranged in an upper position (exhaust cylinder 15 side). It is installed in. When the high-temperature combustion exhaust gas G as the second fluid from the combustion burner 18 passes through the gap M between the fin plates 22, the combustion heat is transferred to the fin plates 22 and the pipes 17. The water as the first fluid that is passed through the inside is heat-exchanged and heated, and the combustion exhaust gas G after the heat exchange is discharged from the exhaust stack 15 to the outside.
[0028]
In the following description, each pipe at the lower position (upstream position with respect to the flow direction of the combustion exhaust gas G) is denoted by reference numeral 17a and is referred to as an upstream pipe 17a, and the upper position (with respect to the flow direction of the combustion exhaust gas G). Reference numeral 17b is assigned to each pipe at the (downstream position), and the two pipes are distinguished from each other by being referred to as a downstream pipe 17b. Further, the flow direction of the combustion exhaust gas G is simply expressed as “upstream side” or “downstream side”. Note that the above “three” or “four” is an example, and two or more desired numbers may be staggered.
[0029]
Each of the fin plates 22 has a pair of cut-and-raised portions 23a, 23b, 24a, 24b, 25a, 25b (hereinafter referred to as symbols 23, 24, 25 when collectively referred to) and burring holes 26, 27 are provided in a number corresponding to each of the pipes 17a and 17b.
[0030]
Each of the cut-and-raised portions 23, 24 and 25 is formed by locally cutting and raising a part of each of the fin plates 22 so as to protrude toward another adjacent fin plate 22 (see FIGS. 2 to 2). 4). Each of the cut-and-raised portions 23, 24, and 25 is formed in a trapezoid, and the short side of the trapezoid is located on the upstream side, and the long side is located on the downstream side. Thereby, the combustion exhaust gas G (see FIG. 2A and FIG. 4) hits, so that a vertical vortex described later is easily generated. In addition, each of the cut-and-raised portions 23, 24, and 25 is set to have a rising dimension that is shorter than the width dimension of the gap M between the fin plates 22 by a predetermined amount (see FIG. 2B or FIG. 4). . For example, the rising dimension is set to 1.5 mm for the width dimension of the gap M of 2.5 mm. This point also facilitates the generation of the vertical vortex.
[0031]
The burring holes 26 and 27 are formed through the burring process, and the rim portions 261 projecting to the same side as the cut-and-raised portions 23a, 23b, 24a, 24b, 25a and 25b by the burring process. , 271 (see FIG. 3) are integrally formed.
[0032]
The pair of cut-and-raised portions 23a and 23b (hereinafter, collectively referred to by reference numeral 23) is disposed at a downstream position (an upper position in FIG. 1) of each pipe 17b on the downstream side with respect to each fin plate 22. It is arranged obliquely so as to gradually close in an inverted C shape toward each of the pipes 17b (downward in FIG. 1).
[0033]
The other pair of cut-and-raised portions 24 a and 24 b (hereinafter, collectively referred to by reference numeral 24) is located at an upstream position (lower position in FIG. 1) of each pipe 17 b on the downstream side with respect to each fin plate 22. It is disposed diagonally so as to gradually open in a C-shape toward each of the pipes 17b (upward in FIG. 1).
[0034]
Still another pair of cut-and-raised portions 25a and 25b (hereinafter, collectively referred to by reference numeral 25) is disposed at a downstream position (an upper position in FIG. 1) of each pipe 17a on the upstream side with respect to each fin plate 22. It is arranged obliquely so as to gradually close in an inverted C shape toward each of the pipes 17a (downward in FIG. 1).
[0035]
The specific area of each fin plate 22 extending to the left and right sides (both sides in the direction orthogonal to the flow direction of the combustion exhaust gas G) and the upstream sides (the lower side in FIG. 1) of each of the upstream pipes 17a is completely cut. The raised portion is not formed, but is a non-formed region 28 of the cut and raised portion (see FIGS. 1 and 3). That is, the “specific region of each fin plate upstream of the pipe” in the claims refers to the upstream region of each pipe 17a or the upstream region as well as the right and left of each pipe 17a. A region that includes both regions.
[0036]
In the above description, the obliquely arranged state of the cut-and-raised portions 23, 24, and 25 has been described in terms of the letter "C" or the inverted letter "C" when viewed from each of the pipes 17a and 17b. 23, 24, and 25 are arranged in such a manner that when viewed in pairs, each of them has an inverted C shape or a V shape.
[0037]
On the other hand, the burring hole 26 is located at an intermediate position between the pipes 17b, 17b adjacent to each other on the downstream side, and is located at a position downstream of a line connecting the center positions of the pipes 17b, 17b. Respectively. The other burring holes 27 are respectively formed at the center positions of the areas of the fin plates 22 surrounded by one pipe 17a on the upstream side and two adjacent pipes 17b on the downstream side.
[0038]
In the case of the heat exchanger 2 having the above-described configuration, the flue gas G from the combustion burner 18 is cut and raised in the gap M between the fin plates 22, 22, as shown in FIG. At the same time as being agitated, it flows downstream (upward in FIG. 4) while generating a vertical vortex (see a dotted arrow in FIG. 4) that approaches one fin plate 22 or approaches the other fin plate 22. Will go on. Thereby, the heat transfer from the combustion exhaust gas G to the fin plates 22, 22 on both sides constituting the gap M can be promoted while breaking the temperature boundary layer conventionally formed on the surface layer of each fin plate 22.
[0039]
In addition, since the upstream portion of each fin plate 22 with which the high-temperature flue gas G first comes into contact is the non-formed region 28 of the cut-and-raised portion, heat transfer from the flue gas G can be suppressed. In addition, the temperature of the combustion exhaust gas G can be maintained at a relatively high temperature by the amount corresponding to the heat transfer suppression while flowing to the downstream side while avoiding the risk of occurrence of burnout.
[0040]
Further, burring holes 27 and 26 are formed in each fin plate 22 at the downstream position of each of the pipes 17a on the upstream side and each of the pipes 17b on the downstream side, and the combustion exhaust gas G flows through each of the burring holes 27 and 26. Since the fin plate 22 (the portion where the burring holes 27 and 26 are formed) is located away from the pipes 17a and 17b, heat is not absorbed by the fin plate 22 and the edge portions 271 and 261 and the cut-and-raised portions 25 are not absorbed. , 24, 23 can be further promoted. That is, the hole edge 271 and the pair of cut-and-raised portions 25a and 25b on the upstream side of the hole edge 271 are applied to the upstream pipe 17a by the hole-edge portion 271 and a pair of cut-and-raised portions on both sides of the hole edge 271. The heat is effectively transferred to the downstream pipe 17b by the holes 24a and 24b, and to the downstream pipe 17b by the hole edge 261 and the pair of cut-and-raised portions 23a and 23b on both sides of the hole edge 261. Water can be heat exchanged and heated.
[0041]
That is, as a heat exchange process of absorbing heat into water in the pipes 17 (17a, 17b) using each fin plate 22 as a heat transfer path, heat transfer is suppressed on the upstream side and heat transfer on the downstream side is promoted, It is possible to perform heat absorption closer to the same on both the downstream side, and it is possible to increase the heat exchange efficiency at the time of heat exchange heating using the combustion exhaust gas G as a heat source.
[0042]
<Other embodiments>
Note that the present invention is not limited to the above-described embodiment, but includes various other embodiments. That is, in the above-described embodiment, a trapezoidal shape is illustrated as the shape of each of the cut-and-raised portions 23, 24, and 25. However, the present invention is not limited to this. For example, a triangular cut-and-raised portion 23 'as shown in FIG. , 24 ′ and 25 ′ may be employed, and may be formed in a rectangular shape such as a rectangle, a semicircular shape, a semielliptical shape or the like.
[Brief description of the drawings]
FIG. 1 is an explanatory front view showing an embodiment of the present invention.
2 (a) is a partially enlarged view of FIG. 1, and FIG. 2 (b) is a top view of the cut and raised portion of FIG. 2 (a). FIG.
FIG. 3 is a partially enlarged perspective view of FIG. 1;
FIG. 4 is a partially omitted enlarged sectional view taken along line AA of FIG. 1;
5 is a view corresponding to FIG. 2 showing another shape of the cut-and-raised portion. FIG. 5 (a) corresponds to FIG. 2 (a), and FIG. 5 (b) corresponds to FIG. 2 (b). I have.
FIG. 6 is a side view of a can body in the water heater.
FIG. 7 is an exploded perspective view of the can body of FIG.
FIG. 8 is a partially omitted enlarged sectional view taken along line BB of FIG. 6;
9 is a diagram corresponding to FIG. 1 showing a conventional heat exchanger, and is a cross-sectional explanatory view taken along line CC in FIG. 8;
FIG. 10 is a diagram showing a flow velocity distribution of combustion exhaust gas flowing through a gap between fin plates.
[Explanation of symbols]
2 Fin-and-tube heat exchangers 17, 17a, 17b Pipe 22 Fin plates 23, 24, 25 Cut-and-raised portions 23a, 23b, 24a, 24b, 25a, 25b Cut-and-raised portions 26, 27 Burring hole 28 Non-cut / raised portion Forming area G Combustion exhaust gas (second fluid)
M gap

Claims (6)

A plurality of fin plates serving as heat transfer paths, and a pipe penetrating through the fin plates and through which the first fluid flows are provided, and a second fluid is passed through a gap between two adjacent fin plates. In a fin-and-tube heat exchanger configured to perform heat exchange with the first fluid,
Each of the fin plates is integrally formed with a cut-and-raised portion protruding toward another adjacent fin plate, while the cut-and-raised portion is located upstream of the pipe with respect to the flow direction of the second fluid. The specific region of each of the fin plates is a region where the cut-and-raised portion is not formed. A plurality of fin plates serving as heat transfer paths, and a pipe penetrating through the fin plates and through which the first fluid flows are provided, and a second fluid is passed through a gap between two adjacent fin plates. In a fin-and-tube heat exchanger configured to perform heat exchange with the first fluid,
A cut-and-raised portion that is cut and raised so as to protrude toward the other adjacent fin plate side is integrally formed at a position near the pipe of each of the fin plates,
At least two cut and raised portions of the pipe at an upstream position with respect to the flow direction of the second fluid are arranged obliquely so as to open in a C shape toward the pipe, while at least two cut and raised portions at the downstream position are arranged. A fin-and-tube heat exchanger, wherein the cut-and-raised portions are arranged obliquely so as to close in an inverted C shape toward the pipe. A fin and tube heat exchanger according to claim 2, wherein
At least two pipes are arranged at predetermined intervals in a direction orthogonal to the upstream and downstream directions of the second fluid with respect to each fin plate,
A burring hole is formed by burring at an intermediate position between two adjacent pipes and at a position downstream of a line connecting the two pipes with respect to the flow direction of the second fluid. Fin and tube heat exchanger. A plurality of fin plates serving as heat transfer paths, and a pipe penetrating through the fin plates and through which the first fluid flows are provided, and a second fluid is passed through a gap between two adjacent fin plates. In a fin-and-tube heat exchanger configured to perform heat exchange with the first fluid,
At least two pipes are disposed at respective positions on both the upstream and downstream sides of the second fluid in the upstream and downstream directions of the second fluid with respect to each fin plate at predetermined intervals in a direction orthogonal to the upstream and downstream directions of the second fluid. Are arranged in a zigzag pattern.
A cut-and-raised portion that is cut and raised so as to protrude to the adjacent other fin plate side is integrally formed at a position near each of the fin plates surrounding the pipe,
In each pipe at the upstream position, a region of each fin plate upstream of each pipe in the flow direction of the second fluid is a non-formed region where the cut-and-raised portion is not formed, while a downstream side is formed. The two cut-and-raised portions are arranged diagonally so as to be closed in an inverted C shape toward each of the pipes at the position,
In each of the pipes at the downstream position, at least two cut-and-raised portions are arranged obliquely at the upstream position with respect to the flow direction of the second fluid so as to open in a C shape toward each of the pipes. On the other hand, two cut-and-raised portions are obliquely arranged at the downstream position so as to be closed in an inverted C shape toward each of the pipes, and
A burring process is performed at an intermediate position between the two adjacent pipes at the downstream position and at a position downstream of the line connecting the two pipes with respect to the flow direction of the second fluid. A fin-and-tube heat exchanger, wherein a burring hole is formed by a fin and a tube. A fin-and-tube heat exchanger according to any one of claims 1 to 4, wherein
A fin-and-tube heat exchanger, wherein each of the cut-and-raised portions is formed in a rectangular, trapezoidal, triangular, or semicircular shape. A fin and tube heat exchanger according to claim 5, wherein
Each of the cut-and-raised portions is formed in a trapezoidal shape or a triangular shape, and is formed so that a rising dimension on the downstream side in the flow direction of the second fluid is larger than that on the upstream side. Exchanger.

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