JP2014109395A - Heat exchanger - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat exchanger capable of facilitating manufacturing and cutting manufacturing cost while keeping high durability.SOLUTION: A heat exchanger HE1 includes: a case 2 accommodating therein a plurality of heat transfer pipes 1 in a state of fixedly positioning a main pipe body portion 11 of each heat transfer pipe 1; first and second protruding portions 22 provided on a side plate portion 21 of this case 2, distanced from each other across a central line La of the side plate portion 21 in a z direction, and provided with a plurality of through-holes 28 aligned in a y direction for inserting and coupling pipe body portions 10a and 10b of the heat transfer pipes 1; and headers 3 attached to the side plate portion 21 for forming a chamber 36 communicating with interiors of the heat transfer pipes 1 using wall portions of these respective protruding portions 22. The first and second protruding portions 22 are arranged so that central lines Lc of the first and second protruding portions 22 in the z direction are offset to the central line La of the side plate portion 21 rather than central lines Ld of the pipe body portions 10a and 10b.

Description

  The present invention relates to a heat exchanger of a type in which a plurality of heat transfer tubes having a so-called spiral or meandering main tube body portion are accommodated in a case.

The present applicant has previously proposed a heat exchanger A as shown in FIG. 7 as a heat exchanger suitable for a hot water supply apparatus (see, for example, Patent Document 1).
This heat exchanger A accommodates a plurality of heat transfer tubes 9 in a case 8 in which an intake port 80 and an exhaust port 81 for combustion gas as a heating medium are formed. Each heat transfer tube 9 has a configuration in which a pair of straight tubular extending tube portions 91 are connected to upper and lower ends of a spiral main tube body portion 90. The main tube body portion 90 is a case using a spacer or the like (not shown). 8 is fixed. On the other hand, each extended pipe part 91 is inserted and joined to a through hole 83 provided in the side plate part 82 of the case 8, and a header 7 for entering and discharging water is attached to the tip part. . According to such a configuration, it is possible to recover heat from the combustion gas supplied into the case 8 using each heat transfer tube 9 and suitably heat the hot water flowing through each heat transfer tube 9. .

  In the heat exchanger A described above, since the header 7 is connected to the tip end portions of the plurality of heat transfer tubes 9, a plurality of fitting locations between the header 7 and the plurality of heat transfer tubes 9 can have a good water sealing property. And the operation | work which joins with high intensity | strength is complicated. In order to reduce the manufacturing cost, it is desired to eliminate such a situation.

As means for responding to such a request, a plurality of heat transfer tubes 9 and headers 7 are connected by forming a bulging portion on the side plate portion 82 of the case 8 and joining the header to the formation portion of the bulging portion. It may be possible to eliminate the need for direct joining.
However, when adopting the above-described means, it has been found by the inventor's test that it is necessary to pay attention to the following points.
This point will be described with reference to FIG. 8. In the heat exchanger A described above, when a water hammer is generated in the piping path connected to the heat exchanger A and the pressure in the heat transfer tube 9 becomes considerably high, the arrow As shown at N20, the extended tube portion 91 is deformed so as to swell. The force generated along with this deformation is a tensile force F <b> 1 that causes the side plate portion 82 of the case 8 to bend in the inner direction of the case 8. Then, a large tensile stress σ1 is generated in a portion n10 of the side plate portion 82 on the outer peripheral side of the side plate portion 82 with respect to the extended tube portion 91. This tensile stress σ1 also acts as a force for separating the joint portion between the extended tubular body portion 91 and the side plate portion 82, but it is preferable that such a stress σ1 is intensively generated in a wide range. is not.
In FIG. 8, the case where the bulging portion is not provided in the side plate portion 82 has been described. However, after the bulging portion is provided in the side plate portion 82, the extended tube portion 91 is joined to the bulging portion. In some cases, the stress can be more easily concentrated on a specific portion of the bulging portion. Therefore, it is necessary to fully consider such points.

JP 2008-151473 A

The present invention has been conceived under the circumstances as described above, and when a water hammer or the like occurs, it is appropriate that undue stress is concentrated on a specific wide region of the side plate portion of the case. An object of the present invention is to provide a heat exchanger capable of suppressing manufacturing and improving durability while facilitating manufacturing and reducing manufacturing costs.

  In order to solve the above problems, the present invention takes the following technical means.

  The heat exchanger provided by the present invention is connected to a spiral or meandering main tube portion, extends in a predetermined x direction, and is separated from the z direction intersecting the x direction. A plurality of heat transfer tubes each having a tubular body portion, a case that accommodates the plurality of heat transfer tubes in a state where the main tube body portion is positioned and fixed, and a side plate portion of the case that is provided in the x direction. And a plurality of the first and second extending tubular body portions that are inserted in the z-direction with the center line in the z-direction of the side plate portion interposed therebetween, and are joined to each other. The first and second bulging portions provided with the through holes arranged in the y direction intersecting the x and z directions, and the wall portions of the first and second bulging portions are used. Attached to the side plate so as to form a chamber communicating with the inside of the heat transfer tube. A heat exchanger, wherein the first and second bulging portions have center lines in the z direction of the first and second extending tube portions. It is characterized by being provided in an arrangement that is biased closer to the center line in the z direction of the side plate part than the center.

According to such a configuration, the following effects can be obtained.
That is, when a water hammer occurs in the piping path connected to the heat transfer tube of the heat exchanger, the bulging portion provided in the side plate portion is caused by deformation of the first and second extending tube portions. Although a large stress is generated, this stress is concentrated in the region on the edge side of the side plate portion (on the side opposite to the center in the z direction of the side plate portion) with respect to the first and second extending tube portions. (For details, see the embodiment described below with reference to FIG. 5). On the other hand, in the present invention, since the bulging portion is arranged so as to be biased toward the center in the z direction of the side plate portion, a region where stress is concentrated is reduced by that amount. Can do. This can increase the durability of the bulging portion. This also leads to a reduction in the thickness of the bulging portion, and consequently the side plate portion, and contributes to weight reduction and reduction in manufacturing cost.
On the other hand, according to the present invention, since the header is directly attached to the side plate of the case, the complexity of joining a plurality of heat transfer tubes and the header can be eliminated, and the manufacturing cost of the heat exchanger is further reduced. Is possible.

  In the present invention, preferably, the first and second bulge portions bulge outward from the side wall portion of the case, and the header is fitted on the first and second bulge portions. Have been joined.

  According to such a structure, the assembly | attachment operation | work of a header becomes easier.

  In the present invention, preferably, each of the heat transfer tubes has a spiral main tube portion whose axial length direction is the vertical direction, and the first and second extending tube portions are lateral widths of the case. The first and second bulging portions are vertically spaced apart from each other with the vertical center line of the side plate portion interposed therebetween, and the plurality of through-holes Are arranged side by side in the front-back width direction of the case, and the center line in the vertical direction of the first bulging portion is from the center of the first extending tube portion. And the center line in the vertical direction of the second bulging portion is above the center of the second extending tube portion.

According to such a configuration, when the water hammer is generated, stress is concentrated in the upper region of the first extending tube portion in the first bulge portion, and the second bulge portion is in the second bulge portion. While a large stress is concentrated on the lower side of the extending tube portion, the size of the stress concentration region can be reduced. Therefore, the effects as described above for the present invention can be appropriately obtained.

  In the present invention, preferably, in the plurality of heat transfer tubes, a plurality of main tube portions meandering substantially horizontally are arranged at intervals in the vertical direction, and the first and second extending tube portions are the case. The first and second bulges are spaced forward and backward across a center line in the longitudinal width direction of the case, and extend in the lateral width direction and spaced apart in the longitudinal width direction. Through-holes are arranged side by side in the up-down direction, and the center line in the front-rear width direction of the first bulging portion is from the center of the first extending tube portion. Is the rear side, and the center line in the front-rear width direction of the second bulging portion is the front side of the center of the second extending tubular body portion.

  According to such a configuration, when the water hammer is generated, the stress is concentrated in the front region of the first extending tube portion in the first bulge portion, and the second bulge portion has the second bulge portion. While stress concentrates in the rear region of the extended tube portion, the size of the stress concentration region can be reduced. Therefore, the effects as described above for the present invention can be appropriately obtained.

  In the present invention, preferably, the joining of the first and second extending tube portions and the peripheral portions of the plurality of through holes is one-side welding performed from the outside of the side plate portion, On the inner surface side, a back bead portion integrated with the heat transfer tube so as to cover the outer peripheral surfaces of the first and second extending tube portions is formed so as to protrude inward of the case. ing.

  According to such a configuration, since welding can be performed from the outside of the side plate portion of the case, unlike the case where welding is performed inside the side plate portion, the welding torch is connected to the central portion of the heat transfer tube and the case. There is no interference, and the welding operation can be performed easily and appropriately. Therefore, the productivity of the heat exchanger can be increased and the manufacturing cost can be further reduced. In addition, since the back bead portion is formed, the welding strength can be considerably increased, and the durability performance can be further improved.

  Other features and advantages of the present invention will become more apparent from the following description of embodiments of the present invention with reference to the accompanying drawings.

It is an external appearance perspective view which shows an example of the heat exchanger which concerns on this invention. (A) is IIa-IIa sectional drawing of FIG. 1, (b) is IIb-IIb sectional drawing of (a), (c) is IIc-IIc sectional drawing of (b). (A) is the principal part expanded sectional view of FIG.2 (b), (b) is the IIIb-IIIb expanded sectional view of (a). (A) is sectional drawing which shows a part of Fig.3 (a), (b) is sectional drawing which shows the welding process for obtaining the structure shown to (a), (c) is ( It is IVc-IVc sectional drawing of b). (A), (b) is explanatory drawing which shows typically the effect | action of the heat exchanger shown in FIG. The other example of the heat exchanger which concerns on this invention is shown, (a) is a plane sectional view, (b) is VIb-VIb sectional drawing of (a), (c) is (b) It is VIc-VIc sectional drawing of. A prior art example is shown, (a) is a plane sectional view, and (b) is a front sectional view thereof. It is action | operation explanatory drawing of the heat exchanger shown in FIG.

  Hereinafter, preferred embodiments of the present invention will be specifically described with reference to the drawings.

A heat exchanger HE1 shown in FIGS. 1 and 2 is suitable for a purpose of performing hot water heating by recovering heat from a combustion gas generated by a burner (not shown) such as a gas burner. Used as a heat exchanger for latent heat recovery.
The heat exchanger HE1 includes a case 2, a plurality of heat transfer tubes 1 accommodated in the case 2, and a pair of headers for incoming and outgoing water connected to the lower end and the upper end of the plurality of heat transfer tubes 1. 3 (3A, 3B).
In the present embodiment, the lateral width direction of the case 2 is the “x direction” in the present invention, the longitudinal width direction of the case 2 is the “y direction” in the present invention, and the vertical direction is the “z direction” in the present invention. And is shown appropriately in the drawings.

  The plurality of heat transfer tubes 1 are a plurality of spiral tubes whose main tube portions 11 are oblong in plan view, and the axial length direction of the spiral tubes is the vertical direction. The plurality of spiral tubular bodies have different sizes from each other, and are arranged in a substantially concentric wrapping shape. The main pipe body portion 11 is positioned and fixed in the case 2 using a spacer (not shown) or the like. First and second extending tube portions 10a and 10b extending substantially horizontally are integrally connected to an upper portion and a lower portion of the main tube portion 11. In order to efficiently recover heat from the combustion gas to the heat transfer tubes 1, the gaps above and below the heat transfer tubes 1 should be as small as the gaps between the heat transfer tubes 1 as shown in FIG. Is desirable. As a means for reducing the gap, a means for forming step portions 20 ′ and 20 ″ projecting toward the heat transfer tube 1 on the upper wall portion 20a and the lower wall portion 20b can be used. It may be appropriately increased in accordance with the degree of the passage resistance of the combustion gas, the discharge performance of the drain generated by the latent heat recovery, and the like.

  The case 2 has a substantially rectangular parallelepiped shape, and includes a pair of side plate portions 21 and 22 in addition to the main body portion 20 (rectangular cylindrical body portion) of the case 2. Each of the main body portion 20 and the side plate portions 21 and 22 is configured using a metal plate such as stainless steel, for example. The rear wall portion 20c and the front wall portion 20d of the case 2 are provided with an intake port 25 and an exhaust port 26 for combustion gas. The combustion gas flowing into the case 2 from the air supply port 25 reaches the exhaust port 26 after passing through the gaps between the plurality of heat transfer tubes 1. In this process, heat is recovered from the combustion gas by the heat transfer tubes 1. Hot water flowing through each heat transfer tube 1 is heated.

  First and second bulging portions 22 (22A, 22B) are integrally formed on the side plate portion 21 of the case 2 by pressing. The first and second bulging portions 22 are portions to be attached to the header 3 and are portions to be connected to the plurality of heat transfer tubes 1. The first and second bulging portions 22 are spaced apart from each other with the vertical center line La of the side plate portion 21 therebetween. A plurality of through holes 28 are provided in the respective front end wall portions 22b of the first and second bulged portions 22 in a substantially horizontal direction at predetermined intervals, and the heat transfer tubes are provided in these through holes 28. 1 end portions (end portions of the first and second extending tube portions 10a and 10b) are inserted and welded.

  The first and second bulging portions 22 are offset in the vertical direction in the relationship between the end portion of the heat transfer tube 1 and the through hole 28. Specifically, the first bulging portion 22A is arranged such that the vertical center line Lc is biased downward (center line La side) from the center line Ld of the first extending tube portion 10a. It is said that. The second bulging portion 22B is arranged such that its center line Le is biased to the upper side (center line La side) than the center line Lf of the second extending tube portion 10b. The significance of this will be described later.

The end portion of the heat transfer tube 1 and the peripheral portion of the through hole 28 are welded from the outside of the side plate portion 21, and a back bead portion 29 is formed on the inner surface side of the side plate portion 21. The back bead portion 29 is integrated with the heat transfer tube 1 so as to cover the outer periphery of the heat transfer tube 1, and protrudes from the inner surface of the side plate portion 21 toward the inner side of the case 2. The distal end portion of the back bead portion 29 and the vicinity thereof have a form in which the radial thickness of the heat transfer tube 1 gradually decreases toward the distal end side of the back bead portion 29 (the heat transfer tube 1 shown in FIG. 3A). The angle α formed by the outer surface and the surface of the back bead portion 29 exceeds 90 °).

  Specifically, the welding described above is performed by inserting the end of the heat transfer tube 1 into each through hole 28 of the side plate portion 21 of the case 2 as shown in FIGS. This is performed in a state in which the portion is protruded (a state in which the protrusion 13 is provided). The projecting dimension is about 0.5 to 2 mm, but this dimension can be appropriately changed according to the thickness and material of the heat transfer tube 1 and the side plate part 21. The welding is, for example, TIG welding, and one-side welding is performed from the outside of the side plate portion 21. In this welding, the TIG welding torch 9 is opposed to the peripheral edge of the through hole 28 and is not directly opposed to the heat transfer tube 1. When TIG welding is started in such a setting state, the protrusion 13 of the heat transfer tube 1 can be melted together with the peripheral edge of the through hole 28. Since the protrusion 13 is closer to the TIG welding torch 9 than the peripheral edge of the through hole 28, it is possible to cause the arc heat to act appropriately on the protrusion 13, and after the welding, the heat is transmitted. The end portion of the heat tube 1 is substantially flush with the outer surface of the side plate portion 21. The TIG welding torch 9 is moved so as to weld the entire circumference of the end of the heat transfer tube 1 and the entire circumference of the peripheral edge of each through hole 28.

  Specifically, the TIG welding torch 9 is moved along a circular locus along the outer periphery of the heat transfer tube 1 as indicated by virtual lines L1 and L2 in FIG. In this case, when welding the area | region between the some heat exchanger tubes 1, heat input is reduced rather than when welding another area | region (area | region of the upper side or the lower side of the heat exchanger tube 1). The region between the plurality of heat transfer tubes 1 is for preventing the heat input to this region from being excessive because welding is performed in an overlapping manner.

  Preferably, of the upper and lower two bulging portions 22A and 22B, the end point P1 when welding the first extending tube portion 10a in the upper bulging portion 22A is the first extending tube portion. The lower side of 10a (the side approaching the center line La). In the lower bulging portion 22B, the end point P2 when welding the second extending tube portion 10b is the upper side (side approaching the center line La) of the second extending tube portion 10b. The

  By performing the welding described above, it is possible to perform welding in which the back bead portion 29 shown in FIGS. 3 and 4A is appropriately formed. Since the protruding portion 13 of the heat transfer tube 1 serves as a filler rod, the volume of the back bead portion 29 is increased, and the protruding dimension from the inner surface of the side plate portion 21 to the inside of the case 2 is increased. It is possible. Moreover, it is possible to prevent poor welding even in a portion where the base material in the region between the heat transfer tubes 1 is small.

  As shown in FIG. 3, the header 3 is formed separately from the side plate portion 21, and has an internal hollow body portion 30 having an opening edge portion 33 that forms an opening portion 32 corresponding to the bulging portion 22. And a joint tube portion 31 connected to the rear surface side of the main body portion 30. The header 3 is fixed to the bulging portion 22 by the opening edge 33 being externally fitted to the peripheral wall portion 22a of the bulging portion 22 and being welded at the outer fitting portion. . In the header 3, a region on the outer side of the case 2 with respect to the tip wall portion 22 b is a hot water distribution chamber 36 communicating with the inside of each heat transfer tube 1.

  According to this embodiment, the following operation is obtained.

First, the case where a water hammer occurs in a pipe path connected to the heat transfer pipe 1 will be described with reference to FIG. 5. When the water hammer is not generated, the water hammer is in the state shown in FIG. On the other hand, when a water hammer is generated and the pressure in the heat transfer tube 1 is considerably increased, the first and second extending tube portions 10a and 10b are deformed so as to swell in the vertical direction, and the side plate portion 21. A force F <b> 2 is generated that bends the inside of the case 2. At that time, the tip wall portion 22b of the bulging portion 22 is also bent and deformed. As a result, a tensile stress σ is generated in the upper region of the first extending tubular portion 10a in the tip wall portion 22b of the first bulging portion 22A. In the tip wall portion 22b of the second bulging portion 22B, a tensile stress σ is generated in the lower region of the second extending tubular body portion 10b. The locations where the tensile stress σ is generated in the welded portion between the end portion of the heat transfer tube 1 and the tip wall portion 22b are in the vicinity of locations indicated by reference numerals n1 and n2 in FIG.

  On the other hand, in the heat exchanger HE1 of the present embodiment, the first and second bulging portions 22A and 22B are side plate portions 21 with respect to the first and second extending tube portions 10a and 10b. The tip wall portion 22b is provided with a bias toward the center line La, and the region where the tensile stress σ is concentrated is reduced in the tip wall portion 22b. As a result, the strength and durability of the first and second bulging portions 22A and 22B can be increased. This is suitable for reducing the thickness of the side plate portion 21 and contributes to weight reduction and manufacturing cost reduction.

  When the first and second bulging portions 22A and 22 are displaced toward the center, the distance between the first bulging portion 22A and the upper wall portion 20a of the case 2 and the second bulging portion 22B and the bottom The distance from the wall portion 20b can be increased. This prevents the welding torch from interfering with the upper wall portion 20a and the lower wall portion 20b when the header 3 is welded to the first and second bulging portions 2A and 2B, and the degree of freedom of the welding torch is increased. It is preferable in terms of enhancement. In addition, it is not necessary to change the position of the first and second extending tube portions 10a and 10b in the vertical direction, and can be set to an appropriate height.

  Since the welding end points P1 and P2, which are most likely to cause welding defects, are located at positions that avoid the above-described locations where stress concentration occurs, the above-described stress σ is prevented from acting on the end points P1 and P2, and water hammer resistance performance is improved. Can be increased. Moreover, since the end points P1 and P2 are positions that avoid the region between the heat transfer tubes 1, the end points P1 and P2 are also preferable in improving the uniformity of welding.

  Since the welding between the heat transfer tube 1 and the side plate portion 21 is one-side welding from the outside of the side plate portion 21, unlike the case of welding inside the side plate portion 21, the TIG welding torch 9 is a spiral of the heat transfer tube 1. Interfering with the portion of the tubular tube is avoided. Even after the side plate portion 21 is assembled to the main body portion 20 of the case 2, the welding operation can be easily performed. Therefore, the productivity of the heat exchanger HE1 can be increased and its manufacturing cost can be reduced.

  The back bead portion 29 formed on the inner surface side of the side plate portion 21 is integrated with the heat transfer tube 1 so as to cover the outer periphery of the heat transfer tube 1 and protrudes inward of the case 2. Compared with meat welding or the like, the welding strength can be increased and the durability can be improved. Moreover, since the radial direction thickness of the heat exchanger tube 1 is gradually decreasing toward the front end side of the front end portion of the back bead portion 29 and the vicinity thereof, there is no cross-sectional sudden change portion at which stress concentration easily occurs. As a result, the strength of the joint portion between the heat transfer tube 1 and the side plate portion 21 is further increased.

  Since the end of the heat transfer tube 1 does not protrude into the chamber 36 in the header 3, the volume of the chamber 36 can be prevented from being reduced by the presence of the heat transfer tube 1. In addition, an effect of reducing resistance when hot water flows between the chamber 36 and the heat transfer tube 1 can be obtained.

  Furthermore, according to this embodiment, the attachment of the header 3 to the side plate portion 21 can be easily performed outside the side plate portion 21. Since the header 3 is directly attached to the side plate portion 21, it is preferable to reduce the total number of parts, reduce the manufacturing cost of the heat exchanger HE1, and further to reduce the overall size. It becomes.

  FIG. 6 shows another embodiment of the present invention. In the figure, the same or similar elements as those in the above embodiment are given the same reference numerals as in the above embodiment.

In FIG. 6, unlike the above embodiment, the lateral width direction of the case 2 corresponds to the “x direction” in the present invention, but the vertical direction is the “y direction”, and the longitudinal width direction of the case 2 is “Z direction”.
In the heat exchanger HE2 of the present embodiment, the main tube portion 11 of each heat transfer tube 1 is a meandering tube portion having a substantially horizontal posture, and the plurality of heat transfer tubes 1 are arranged in the vertical height direction. Yes. The first and second extending tube portions 10 a and 10 b extend in the left-right width direction of the case 2, but they are spaced apart in the front-rear width direction of the case 2. Therefore, the first and second bulging portions 22 (22A, 22B) provided on the side plate portion 21 of the case 2 are arranged in the front-rear width direction of the case 2 with the center line Lb in the front-rear width direction of the case 2 interposed therebetween. The arrangement is separated. The arrangement direction of the plurality of through holes 28 and the ends of the heat transfer tubes 1 (first and second extending tube portions 10a and 10b) in the first and second bulging portions is the vertical direction.

  The first bulging portion 22A is provided such that the center line Lg in the front-rear width direction is on the rear side (center line Lb side) with respect to the center line Lh of the first extending tubular body portion 10a. . Preferably, the welding end point P1 in the first bulging portion 22A is set to the rear side of the first extending tube portion 10a. The second bulging portion 22B is provided such that the center line Li in the front-rear width direction is on the front side (center line Lb side) with respect to the center line Lj of the second extending tube portion 10b. Preferably, the welding end point P2 in the second bulging portion 22B is set to the front side of the second extending tube portion 10b.

  In the heat exchanger HE2 of the present embodiment, when the water hammer is generated, the first and second extending tube portions 10a and 10b swell and pull the side plate portion 21 inward as in the case of the heat exchanger HE1. The tip wall portion 22b of the first and second bulging portions 22 is also bent. As a result, tensile stress is generated in the tip wall portion 22b, but the direction in which the first and second extending tube portions 10a and 10b swell is the front-rear width direction of the case 2, which is different from the above-described embodiment. Tensile stress concentrates on the front region of the first extending tube portion 10a and the rear region of the second extending tube portion 10b. On the other hand, in this embodiment, since such a stress concentration area | region is narrowed, it is possible to improve durability. In addition, since the welding end points P1 and P2 are provided on the side opposite to the stress concentration region, tensile stress is not concentrated on the end points P1 and P2, and durability can be further enhanced. is there.

  The present invention is not limited to the contents of the above-described embodiment. The specific configuration of each part of the heat exchanger according to the present invention can be variously modified within the range intended by the present invention.

  In the above-described embodiment, the first and second bulging portions 22 are bulged toward the outside of the side plate portion 21 of the case 2, but unlike the first and second bulging portions. The part may be configured to bulge in the inner direction of the side plate part 21. Even in such a case, it is possible to attach a header to the side plate portion to form a hot water distribution chamber using the bulging portion, and to narrow the stress concentration area when water hammer occurs. The intended effect of the present invention to increase durability can be obtained. The joining means between the heat transfer tube and the side plate of the case is not limited to welding, and brazing can also be employed. In addition, when employ | adopting welding, the welding is not limited to TIG welding, For example, other arc welding can also be used and the specific kind is not ask | required.

  The heat exchange target medium flowing into the case may be a fluid other than the combustion gas. The heat exchanger according to the present invention can be used not only for recovering latent heat but also for various uses other than hot water heating.

HE1, HE2 Heat exchangers P1, P2 End point 1 of welding Heat transfer tubes 10a, 10b Extended tube portion 11 Main tube portion (of heat transfer tube)
2 Case 3 (3A, 3B) Header 21 Side plate (case)
22 (22A, 22B) 1st and 2nd bulging part 28 Through-hole 29 Back bead part 36 Chamber (header)

Claims (5)

A plurality of heat transfer tubes each having first and second extending tube portions that are connected to the spiral or meandering main tube portion, extend in a predetermined x direction, and are separated in the z direction intersecting the x direction. When,
A case for accommodating the plurality of heat transfer tubes in a state in which the main tube body portion is positioned and fixed;
Provided on the side plate portion of the case and bulging in the x direction, the side plate portion is spaced apart in the z direction across the center line in the z direction, and the first and second extending tubes A plurality of through-holes for inserting body parts and joining the first and second bulging parts provided side by side in the y direction intersecting the x and z directions;
A header attached to the side plate so as to form a chamber communicating with the inside of the heat transfer tube by utilizing the wall portions of the first and second bulging portions;
A heat exchanger comprising:
The first and second bulging portions have their z-direction center lines biased closer to the z-direction center line of the side plate portion than the centers of the first and second extending tube portions. A heat exchanger, characterized in that it is provided in an arrangement. The heat exchanger according to claim 1,
The first and second bulge portions bulge outward from the side wall portion of the case, and the header is externally fitted and joined to the first and second bulge portions; Heat exchanger. The heat exchanger according to claim 1 or 2,
Each of the heat transfer tubes has a spiral main tube portion whose longitudinal direction is the vertical direction, and the first and second extending tube portions extend in the lateral width direction of the case and in the vertical direction. It is configured with an interval,
The first and second bulging portions are vertically spaced with a vertical center line of the side plate portion interposed therebetween, and the plurality of through-holes are arranged side by side in the front-rear width direction of the case. It is assumed that
The vertical center line of the first bulging portion is below the center of the first extending tube portion, and the vertical center line of the second bulging portion is the first bulging portion. A heat exchanger that is above the center of the two extending tube portions. The heat exchanger according to claim 1 or 2,
The plurality of heat transfer tubes are arranged such that a plurality of main tube portions meandering substantially horizontally are arranged at intervals in the vertical direction, and the first and second extending tube portions extend in the lateral width direction of the case. It is configured with an interval in the width direction,
The first and second bulging portions are spaced forward and backward across a center line in the front-rear width direction of the case, and the plurality of through holes are provided side by side with a space in the vertical direction. Has been
The center line in the front-rear width direction of the first bulge part is the rear side of the center of the first extending tube part, and the center line in the front-rear width direction of the second bulge part is A heat exchanger that is on the front side of the center of the second extending tube portion. The heat exchanger according to any one of claims 1 to 4,
The first and second extending tube portions and the peripheral portions of the plurality of through-holes are joined by one-side welding performed from the outside of the side plate portion. A heat exchanger in which a back bead portion integrated with the heat transfer tube so as to cover the outer peripheral surfaces of the first and second extending tube portions is formed so as to protrude inward of the case.

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