JP2023085785A - Heat exchanger and water heater - Google Patents

Abstract

To provide a heat exchanger and a water heater capable of efficiently recovering heat, in the heat exchanger provided with meander-shaped heat transfer tubes arranged inside.SOLUTION: A heat exchanger includes: a casing into which combustion exhaust is supplied; and a plurality of heat transfer tubes housed inside of the casing. The casing includes: a side wall portion disposed at one end portion in a second direction orthogonal to a first direction in which the combustion exhaust is supplied; and an opposed wall portion opposed to the side wall portion in the second direction. The plurality of heat transfer tubes are formed into a meander shape as a whole, and have: a plurality of straight tube portions 62A arranged in the first direction with an attitude facing the second direction; and a plurality of folding tube portions 62B connecting one end portions and the other end portions in the second direction of the plurality of straight tube portions 62A. Both end portions of the heat transfer tubes are inserted and fixed to the side wall portion at intervals in the first direction, and the opposed wall portion of the casing is provided with a deflection guide 69 for deflecting the combustion exhaust flowing along the opposed wall portion to a side wall portion side.SELECTED DRAWING: Figure 12

Description

The present invention relates to heat exchangers and water heaters.

As a heat exchanger used in a water heater, for example, a secondary heat exchanger described in Japanese Patent Application Laid-Open No. 2020-186884 (Patent Document 1 below) is known. The secondary heat exchanger has a case and a heat transfer tube portion, and the case includes a peripheral wall portion surrounding a passage space for the exhaust gas, a bottom wall portion provided on the lower end side of the peripheral wall portion, and an upper portion of the peripheral wall portion. and a lid that closes the opening provided at the end of the side. The peripheral wall portion has a front wall portion provided with an exhaust gas outlet, a rear wall portion provided with an exhaust gas inlet, and both ends of the front wall portion and both ends of the rear wall portion. a pair of directionally opposed sidewalls. The heat transfer tube section includes a plurality of heat transfer tubes housed in the case.

The heat transfer tubes have a serpentine shape as a whole, and connect a plurality of linear tube portions arranged side by side in the front-rear direction facing the left-right direction, and one end portion and the other end portion of the straight tube portions in the left-right direction. and a plurality of folded portions. Both ends of the heat transfer tube are directed to one side in the left-right direction, and are inserted and fixed to the side wall portion located on the one side of the pair of side wall portions of the housing with a gap in the front-rear direction. .

JP 2020-186884 A

By the way, in this type of secondary heat exchanger, considering the dimensional tolerance and assembly tolerance of each part, the folded portion located on the other side in the left and right direction and the opposing wall portion (a pair of side walls) facing this It is designed to secure a certain amount of clearance between the side wall portion and the partition located on the other side of the portion. In addition, since the folded portion is formed by bending with a predetermined curvature, the area where the folded portion is arranged has a larger gap than the area where the straight pipe portion is arranged, and the exhaust resistance is increased accordingly. becomes smaller. As a result, part of the exhaust gas introduced into the case from the inflow port and directed to the discharge port is deflected toward the folded portion located on the other side, flows along the opposing wall portion, and is not sufficiently heat-exchanged to the outside. will be discharged to

SUMMARY OF THE INVENTION It is an object of the present invention to provide a heat exchanger and a hot water heater in which meandering heat transfer tubes are arranged therein, and which are capable of efficiently recovering heat.

A heat exchanger of the present disclosure includes a casing into which combustion exhaust gas is supplied, and a plurality of heat transfer tubes housed inside the casing, wherein the casing includes the combustion exhaust gas a side wall portion disposed at one end in a second direction perpendicular to the first direction in which heat is supplied; and a facing wall portion facing the side wall portion in the second direction; a plurality of straight tube portions formed in a meandering shape as a whole and arranged side by side in the first direction in a posture facing the second direction; and one end portions of the plurality of straight tube portions in the second direction. and a plurality of folded tube portions that connect the other end portions, and both ends of the heat transfer tube are inserted and fixed to the side wall portion at intervals in the first direction, and the casing In the heat exchanger, the opposing wall portion is provided with a drift guide for deflecting the combustion exhaust flowing along the opposing wall portion toward the side wall portion.

According to the present invention, efficient heat recovery can be performed.

FIG. 1 is a front view of the water heater with the front cover removed in Embodiment 1. FIG. 2 is a front view of the inner barrel of FIG. 1; FIG. 3 is a left side view of the inner barrel of FIG. 1. FIG. 4 is a right side view of the inner barrel of FIG. 1. FIG. 5 is a rear view of the inner barrel of FIG. 1. FIG. 6 is a plan view of the inner barrel of FIG. 1. FIG. FIG. 7 is a plan view of the partition plate viewed from above with the ceiling wall portion of the secondary casing of FIG. 6 removed. FIG. 8 is a perspective view of the inside of the secondary casing shown in FIG. 7 with the partition plate removed and viewed obliquely from the upper left. FIG. 9 is a perspective view of the inside of the secondary casing shown in FIG. 7 with the partition plate removed and viewed obliquely from above on the right. 10 is a plan view of the inside of the secondary casing of FIG. 7 with the partition plate removed and viewed from above. FIG. 11 is a cross-sectional view taken along line AA of FIG. FIG. 12 is a top view of combustion exhaust flowing inside the secondary casing in the first embodiment. FIG. 13 is a left side view of combustion exhaust flowing inside the secondary casing in the first embodiment. FIG. 14 is a top view of combustion exhaust flowing inside the secondary casing in the second embodiment.

Hereinafter, embodiments of the present disclosure will be listed and exemplified.
(1) A heat exchanger according to the present disclosure includes a casing into which combustion exhaust gas is supplied, and a plurality of heat transfer tubes housed inside the casing, wherein the casing includes: a side wall portion disposed at one end portion in a second direction orthogonal to the first direction in which the combustion exhaust gas is supplied; and a facing wall portion facing the side wall portion in the second direction; The heat transfer tubes are formed in a meandering shape as a whole, and include a plurality of straight tube portions arranged side by side in the first direction while facing the second direction, and a plurality of straight tube portions arranged side by side in the second direction. and a plurality of folded tube portions that connect one end portion and the other end portion, and both ends of the heat transfer tube are inserted and fixed to the side wall portion at intervals in the first direction, In the heat exchanger, the opposing wall portion of the casing is provided with a drift guide for deflecting the combustion exhaust flowing along the opposing wall portion toward the side wall portion.
Since the drift guide can divert the combustion exhaust gas flowing along the opposing wall portion toward the side wall portion, it is possible to prevent the combustion exhaust gas from being discharged without being heat-exchanged.

(2) The drift guide has a protruding plate that protrudes toward the side wall.
Combustion exhaust can be guided with a simple configuration of a projecting plate.

(3) The protruding plate of the drift guide is provided on the upstream side of the folded pipe portion located on the opposing wall portion side.
There are more gaps around the folded pipe portion than around the straight pipe portion. On the other hand, since the protruding plate is arranged on the upstream side of each folded pipe portion, it is possible to effectively suppress combustion exhaust gas from flowing into the opposing wall side through the gap around the folded pipe portion.

(4) At least three folded pipe portions are provided on the side of the opposing wall portion, and the drift guide includes a pair of projecting plates spaced apart in the first direction; and a fixing plate that connects the protruding plates and is fixed to the opposing wall portion, and the drift guide is formed in a gate shape in plan view, and the deviation guide is formed by folding the pair of protruding plates into the three folds. When viewed from the upstream side in the first direction of the pipe portions, the odd-numbered opposing wall portion side is arranged so as not to face the folded pipe portions, and the folded pipe portions are arranged on both sides in the first direction. provided in an arrangement surrounding from
Due to the uneven flow guide of the same shape, the protruding plate can be arranged on the upstream side of all the folded pipe portions located on the opposing wall side, so that the number of parts can be prevented from increasing and erroneous assembly can be prevented.

(5) The ceiling wall portion of the casing is provided with an exhaust pipe for discharging the combustion exhaust gas in the casing upward, and the inside of the casing is provided with an area where the heat transfer tubes are arranged and the ceiling wall portion. A partition plate is provided to vertically partition the area from the lower area. A communication section is provided for shortcutting to the lower region of the wall.
By providing the communication portion, the combustion exhaust gas can flow more easily toward the side wall portion, so that the synergistic effect with the drift guide can better guide the combustion exhaust gas flowing along the opposing wall portion side to the side wall portion.

(6) A pair of the side wall portions are provided at both ends of the casing in the second direction, and the casing has a partition wall that separates and partitions an internal space of the casing in the second direction. and the facing wall portion is the partition wall.
For example, the hot water supply heat exchanger and the bath heat exchanger may be configured as a single heat exchanger by separating and partitioning the internal space of the casing with a partition wall. In such a heat exchanger as well, the drift guide can deflect the combustion exhaust flowing along the partition wall toward the side wall portion.

(7) The water heater of the present disclosure includes a combustion device, a primary heat exchanger provided in series with the combustion device and through which combustion exhaust gas from the combustion device passes, and the primary heat exchanger provided in series, and a secondary heat exchanger, which is a heat exchanger through which combustion exhaust gas from the primary heat exchanger passes.
It is possible to provide a heat exchanger and a water heater capable of efficiently recovering heat in a heat exchanger in which meandering heat transfer tubes are arranged.

<Embodiment 1>
Embodiment 1 of the present disclosure will be described below with reference to FIGS. 1 to 13. FIG. In the following description, the front-back direction, the up-down direction, and the left-right direction are based on the directions indicated by the four-directional arrows in each drawing.

[Overall structure of water heater]
FIG. 1 is a front view of the water heater 1 viewed from the front, showing a state in which the front front cover is removed. The water heater 1 has a square box-shaped housing 2 with an open front, and a combustion device 4, a primary heat exchanger 5, and a secondary heat exchanger (an example of a heat exchanger) 6 arranged in order from the bottom. It is configured to accommodate the provided inner barrel 3 . A gas supply unit 7 for distributing and supplying fuel gas to the burner units in the combustion device 4 is mounted on the front face of the combustion device 4 . An intake fan 8 for supplying combustion air is attached to the lower surface of the combustion device 4 . A controller 9 containing an electrical board is installed on the lower right side of the inner barrel 3 . A path member 10 is arranged between the primary heat exchanger 5 and the secondary heat exchanger 6 .

The water heater 1 has a drain hose 14 . The drain hose 14 has an upstream end connected to the drain outlet 68 of the secondary heat exchanger 6 and a downstream end connected to the neutralizer. The drain generated by latent heat recovery in the secondary heat exchanger 6 is discharged to the outside of the secondary heat exchanger 6 through the drain outlet 68 and sent to the neutralizer through the drain hose 14 .

The water heater 1 includes a controller 9 as a control device. The controller 9 is configured, for example, as a known microcomputer or the like, is configured to be able to acquire signals from various sensors provided in the water heater 1, and operates various actuators provided in the water heater 1. It has a controllable configuration. For example, the water heater 1 operates the combustion device 4 to generate hot water when the water flow sensor detects water flow in the water inlet pipe 11 .

[Combustion device]
Combustion device 4 is connected to the lower portion of primary heat exchanger 5 . The combustion device 4 has an inner case 41 in the shape of a square box that fits inside the housing 2 . The combustion device 4 mixes the combustion gas and air supplied to each burner unit within the burner unit, and jets and burns the mixed gas upward from flame holes formed at the downstream end. generate exhaust.

[Path member]
The path member 10 is a member that connects the primary heat exchanger 5 and the secondary heat exchanger 6 . The path member 10 opens downward at its lower end and communicates with the space inside the primary heat exchanger 5 . Further, the path member 10 is open forward at its upper portion and communicates with the space inside the secondary heat exchanger 6 .

The water heater 1 circulates combustion exhaust gas generated by each rich and lean burner of the combustion device 4 to the primary heat exchanger 5 above the combustion device 4 . In the primary heat exchanger 5, heat is exchanged between the water passing through the primary heat exchanger 5 and the combustion exhaust gas. The water heater 1 recovers the sensible heat of the combustion exhaust with the primary heat exchanger 5 .

In water heater 1 , combustion exhaust gas from combustion device 4 is led from primary heat exchanger 5 to secondary heat exchanger 6 via path member 10 . The combustion exhaust that has passed through the primary heat exchanger 5 enters the secondary heat exchanger 6 from behind via the path member 10 . That is, the secondary heat exchanger 6 is arranged downstream of the primary heat exchanger 5 in the combustion exhaust path. In the secondary heat exchanger 6, heat is exchanged between the water passing through the secondary heat exchanger 6 and the combustion exhaust gas. Water heater 1 recovers the latent heat of the combustion exhaust gas by means of secondary heat exchanger 6 .

[Primary heat exchanger]
The primary heat exchanger 5 is a sensible heat recovery type heat exchanger. The primary heat exchanger 5 has a lower end connected to the combustion device 4 and an upper end connected to the secondary heat exchanger 6 . The primary heat exchanger 5 includes a primary casing 51 through which the combustion exhaust gas from the combustion device 4 passes, and a plurality of transmission conductors disposed inside the primary casing 51 and arranged side by side at predetermined intervals in the thickness direction. It is provided with heat fins and primary heat transfer tubes 52 formed in a meandering shape so as to pass through the heat transfer fins in the front-rear direction. The primary casing 51 has a rectangular tubular shape penetrating vertically. The hot water discharge pipe 13 is connected to the downstream end of the primary heat transfer pipe 52 .

[Secondary heat exchanger]
The secondary heat exchanger 6 is a latent heat recovery type heat exchanger. Combustion exhaust from the primary heat exchanger 5 is introduced into the secondary heat exchanger 6 through the path member 10 . As shown in FIG. 11, the secondary heat exchanger 6 includes a secondary casing 61 through which combustion exhaust gas from the primary heat exchanger 5 passes, and a plurality of secondary heat transfer tubes ( An example of a heat transfer tube) 62 is provided. The secondary heat exchanger 6 can be made of stainless steel, which has excellent corrosion resistance.

As shown in FIGS. 8 and 9, the secondary casing 61 includes a front wall portion 61A and a rear wall portion 61B disposed at both ends in the front-rear direction to which the combustion exhaust gas is supplied, and a left-right direction orthogonal to the front-rear direction. and a bottom wall portion 61E and a ceiling wall portion 61F disposed at both ends in the vertical direction orthogonal to the front-rear direction and the left-right direction. .

Of the pair of side walls 61C and 61D, the left side wall (an example of the side wall) 61C is positioned on the left side when viewed from the rear, and the right side wall (an example of the opposite wall) is positioned on the right side. One example) is 61D. The left side wall portion 61C and the right side wall portion 61D are arranged to face each other in the left-right direction.

A ceiling wall portion 61</b>F of the secondary casing 61 is provided with an exhaust pipe 66 that discharges combustion exhaust gas in the secondary casing 61 upward. An exhaust pipe (not shown) installed indoors is connected to the exhaust pipe 66, and combustion exhaust is discharged to the outside through this exhaust pipe. Inside the secondary casing 61, a partition plate 63 is provided that vertically partitions an arrangement region R1 of the secondary heat transfer tubes 62 and a lower region R2 of the ceiling wall portion 61F.

The rear wall portion 61B is provided with an inlet 64 penetrating in the front-rear direction. The inlet 64 is an opening for introducing combustion exhaust into the secondary casing 61 . On the other hand, an outflow port 65 is provided between the front edge of the partition plate 63 and the front end portion of the ceiling wall portion 61F. The outflow port 65 is an opening for discharging the combustion exhaust from the arrangement region R1 of the secondary heat transfer pipes 62 to the lower region R2 of the ceiling wall portion 61F. In the secondary heat exchanger 6, the combustion exhaust flows through the inflow port 64 into the installation region R1 of the secondary heat transfer tubes 62, flows forward through the installation region R1, and flows along the front wall portion 61A. , and then flows rearward through the outflow port 65 to the lower region R2 of the ceiling wall portion 61F, and is discharged to the outside of the secondary casing 61 through the exhaust pipe 66. That is, the combustion exhaust after the latent heat is recovered by the secondary heat exchanger 6 is discharged to the outside of the water heater 1 through the exhaust pipe 66 of the secondary casing 61, and is discharged to the outside through the exhaust pipe. .

The plurality of secondary heat transfer tubes 62 are formed in a meandering shape as a whole, and as shown in FIG. It has a plurality of folded pipe portions 62B that connect one end portions and the other end portions of the pipe portions 62A in the left-right direction. A plurality of secondary heat transfer tubes 62 are stacked vertically and housed in the secondary casing 61 . Both ends of the secondary heat transfer tube 62 are inserted and fixed to the left side wall portion 61C with a space therebetween in the front-rear direction.

Three folded pipe portions 62B are provided on the right side wall portion 61D side, and two folded pipe portions 62B are provided on the left side wall portion 61C side. In the left side wall portion 61C, since there are many pipes that cross the left side wall portion 61C, such as the portions of the straight pipe portion 62A that are connected to the headers 67A and 67B, the exhaust resistance is higher than that on the right side wall portion 61D side.

A pair of headers 67A and 67B are provided on the left side wall portion 61C. Of the pair of headers 67A and 67B, the front header is a front header 67A, and the rear header is a rear header 67B. The front header 67A is a portion that connects the upstream end of the secondary heat transfer pipe 62 and the downstream end of the water inlet pipe 11 . The rear header 67B is a portion that connects the downstream end of the secondary heat transfer pipe 62 and the upstream end of the relay pipe 12 . The relay pipe 12 is a pipe that relays and connects the upstream end of the primary heat transfer pipe 52 of the primary heat exchanger 5 and the downstream end of the secondary heat transfer pipe 62 of the secondary heat exchanger 6 .

[Diffusion guide]
Inside the secondary casing 61 of the secondary heat exchanger 6, as shown in FIG. 8, a pair of front and rear drift guides 69 are provided. The pair of drift guides 69 are fixed to the right side wall portion 61D by brazing or the like. The pair of drift guides 69 are of the same shape and size.

The drift guide 69 includes a pair of protruding plates 69A spaced apart in the front-rear direction, and a fixing plate 69B connecting the pair of protruding plates 69A and fixed to the right side wall portion 61D. It is formed in a visual gate shape. The protruding plate 69A of the first embodiment protrudes toward the left wall portion 61C in an arrangement orthogonal to the right side wall portion 61D. good.

The protruding plate 69A of each drift guide 69 is located upstream of the corresponding folded pipe portion 62B. The corresponding folded pipe portion 62B is the folded pipe portion 62B located on the right side wall portion 61D side, and of the pair of folded pipe portions 62B closest to the protruding plate 69A, the folded pipe portion located downstream of the protruding plate 69A. 62B. Therefore, each projecting plate 69A of the drift guide 69 is provided upstream of the corresponding folded pipe portion 62B. The drift guide 69 is arranged such that the pair of projecting plates 69A does not face the folded pipe portion 62B on the side of the odd-numbered right side wall portion 61D when viewed from the upstream side in the front-rear direction, and does not face the folded pipe portion 62B in the front-rear direction. provided in an arrangement surrounding from both sides of the The fixed plate 69B of the drift guide 69 faces the odd-numbered folded pipe portions 62B, and the left side wall portion is arranged such that the pair of projecting plates 69A sandwich the odd-numbered folded pipe portions 62B from upstream and downstream sides. It is fixed to the inner surface of 61C. As a result, the projecting plate 69A is positioned upstream of the odd-numbered and even-numbered folded pipe portions 62B.

[Communication part]
As shown in FIG. 7, at a position of the partition plate 63 excluding at least the end portion on the right side wall portion 61D side, the combustion exhaust flowing through the installation region R1 of the secondary heat transfer tubes 62 is directed to a lower region R2 of the ceiling wall portion 61F. A plurality of communicating portions 63A are provided for shortcutting to . The communication portion 63A is provided at the front end portion of the partition plate 63. As shown in FIG. 63 A of communicating parts are comprised by the circular through-hole. A plurality of communicating portions 63A are arranged side by side at equal intervals in the left-right direction, and formed in two front and rear rows. A two-dot chain line in FIG. 12 indicates the position of the communicating portion 63A. The front-row communicating portion 63A is provided at a position corresponding to the straight tube portion 62A in the first row from the front of the secondary heat transfer tube 62 positioned at the top in the front-rear direction, and the rear-row communicating portion 63A is provided in the second row from the front. It is provided at a position corresponding to the straight tube portion 62A of the eye.

[Airflow of combustion exhaust]
Next, the airflow of the combustion exhaust will be described with reference to FIGS. 12 and 13. FIG. The combustion exhaust that has flowed into the secondary casing 61 through the inlet 64 collides with the straight tube portion 62A of the secondary heat transfer tube 62 from behind, as indicated by the arrow in FIG. will be The combustion exhaust circulates from the rear to the front of the region R1 where the secondary heat transfer tubes 62 are arranged, during which time the combustion exhaust moves forward while colliding with the plurality of straight tube portions 62A, and after colliding with the front wall portion 61A, It turns upward and goes to the outflow port 65 . Combustion exhaust flows through the outlet 65 into the lower region R2 of the ceiling wall portion 61F and flows out of the secondary casing 61 through the exhaust pipe 66 .

However, since the combustion exhaust tends to flow toward a location where the exhaust resistance is small, as indicated by the arrow F1 in FIG. It tries to flow forward through the gap S1 formed between it and the next heat transfer tube 62 . Here, if the drift guide 69 were not provided, the combustion exhaust would flow forward through the gap S1 as it is, resulting in a decrease in heat exchange efficiency.

Therefore, in the first embodiment, since the right side wall portion 61D is provided with the drift guide 69, the combustion exhaust flowing along the right side wall portion 61D collides with the projecting plate 69A as indicated by the arrow F2 in FIG. Therefore, the amount of exhaust gas flowing through the gap S1 is reduced, and the amount of exhaust gas flowing between the straight pipe portions 62A is increased, thereby improving the heat exchange efficiency.

In addition, a plurality of communication portions 63A are provided at the front end portion of the partition plate 63, and these communication portions 63A are arranged closer to the left side wall portion 61C than the gap S1. Easier to drift. That is, the synergistic effect of the drift guide 69 and the communicating portion 63A can guide the airflow of the combustion exhaust indicated by the arrow F2 toward the left side wall portion 61C.

Furthermore, as indicated by the arrow F3 in FIG. 12, part of the combustion exhaust that flows straight forward from the inlet 64 passes through the communicating portion 63A, as indicated by the arrow F4 in FIG. Since the combustion exhaust gas is discharged to the outside of the secondary casing 61, the exhaust resistance of the combustion exhaust gas can be reduced. Therefore, it is possible to prevent the combustion exhaust gas from becoming difficult to flow in the secondary casing 61 and to ensure the combustion performance of the combustion device 4 .

[Effects of Embodiment 1]
The secondary heat exchanger 6 of Embodiment 1 includes a secondary casing 61 into which combustion exhaust gas is supplied, and a plurality of secondary heat transfer tubes 62 housed inside the secondary casing 61. In the heat exchanger 6, the secondary casing 61 has a left side wall portion 61C disposed at one end portion in the left-right direction perpendicular to the front-rear direction in which the combustion exhaust gas is supplied, and the left side wall portion 61C faces the left side wall portion 61C in the left-right direction. The plurality of secondary heat transfer tubes 62 are formed in a meandering shape as a whole, and are provided with a plurality of straight tube portions 62A arranged side by side in the front-rear direction with a posture facing the left-right direction, and a plurality of straight tube portions 62A. and a plurality of folded tube portions 62B that connect one end portion and the other end portion of the straight tube portion 62A in the left-right direction. The right side wall portion 61D of the secondary casing 61 is provided with a drift guide 69 that deflects the combustion exhaust flowing along the right side wall portion 61D toward the left side wall portion 61C. A secondary heat exchanger 6 .
The drift guide 69 can deflect the combustion exhaust gas flowing along the right side wall portion 61D toward the left side wall portion 61C, so that the combustion exhaust gas can be prevented from being discharged without undergoing heat exchange.

The drift guide 69 has a projecting plate 69A projecting toward the left side wall portion 61C.
Combustion exhaust can be guided with a simple configuration of the projecting plate 69A.

The protruding plate 69A of the drift guide 69 is provided upstream of the folded pipe portion 62B located on the right side wall portion 61D side.
There are more gaps around the folded tube portion 62B than around the straight tube portion 62A. On the other hand, since the protruding plate 69A is arranged on the upstream side of each folded pipe portion 62B, it is possible to effectively suppress combustion exhaust from flowing into the right side wall portion 61D side through the gap S1 around the folded pipe portion 62B.

The folded pipe portion 62B on the right side wall portion 61D side is provided with at least three rows, and the drift guide 69 includes a pair of protruding plates 69A spaced apart in the front-rear direction, and the pair of protruding plates 69A. and a fixing plate 69B that connects and is fixed to the right side wall portion 61D. No. 2, when viewed from the upstream side in the front-rear direction, it does not face the folded pipe portion 62B on the side of the odd-numbered right side wall portion 61D, and surrounds the folded pipe portion 62B from both sides in the front-rear direction.
Due to the uneven flow guide 69 having the same shape, the protruding plate 69A can be arranged upstream of all the folded pipe portions 62B located on the right side wall portion 61D side. can be prevented.

A ceiling wall portion 61</b>F of the secondary casing 61 is provided with an exhaust pipe 66 that discharges combustion exhaust gas in the secondary casing 61 upward. The exhaust pipe 66 is arranged at a position near the left side of the right side wall portion 61D of the secondary heat exchanger 6 or at a position near the center in the left-right direction. Inside the secondary casing 61, a partition plate 63 is provided that vertically partitions the arrangement region R1 of the secondary heat transfer tubes 62 and the lower region R2 of the ceiling wall portion 61F. A communicating portion 63A is provided at a position excluding at least the end portion on the side of 61D to shortcut the combustion exhaust gas flowing through the installation region R1 of the secondary heat transfer pipe 62 to the lower region R2 of the ceiling wall portion 61F.
By providing the communicating portion 63A and arranging the exhaust pipe 66 on the downstream side further to the left side, the combustion exhaust gas can flow more easily toward the left side wall portion 61C. The combustion exhaust flowing through the portion 61D side can be better guided to the left side wall portion 61C side.

<Embodiment 2>
Next, Embodiment 2 of the present disclosure will be described with reference to FIG. A water heater 201 of the second embodiment includes a secondary heat exchanger 206 having a form different from that of the water heater 1 of the first embodiment. Since the configuration other than the secondary heat exchanger 206 is the same as that of the first embodiment, the description thereof will be omitted, and the same reference numerals as those of the first embodiment will be used for the same configurations as those of the first embodiment.

The secondary heat exchanger 206 includes a secondary casing 230 , a hot water supply secondary heat exchanger 210 , and a bath secondary heat exchanger 220 . The secondary casing 230, the hot water supply secondary heat exchanger 210, and the bath secondary heat exchanger 220 can be made of stainless steel with excellent corrosion resistance.

A partition wall 231 is provided inside the secondary casing 230 to separate and partition the internal space of the secondary casing 230 in the left-right direction. The hot water supply secondary heat exchanger 210 and the bath secondary heat exchanger 220 are arranged side by side in the horizontal direction in the secondary casing 230 via the partition wall 231 . The secondary heat exchanger 206 is divided by a partition wall 231 into a hot water supply secondary heat exchanger 210 on the left side of the partition wall 231 and a bath secondary heat exchanger 220 on the right side of the partition wall 231. ing. The partition wall 231 is arranged between the left side wall portion 261C and the right side wall portion 261D, and is arranged to face the side wall portions 261C and 261D in the left-right direction.

Hot water supply secondary heat exchanger 210 includes a plurality of hot water supply secondary heat transfer tubes 211 . The hot water supply secondary heat transfer tube 211 is formed in a meandering shape as a whole, and includes a plurality of straight tube portions 211A arranged side by side in the front-rear direction facing the left-right direction, and a plurality of straight tube portions 211A arranged side by side in the left-right direction. It has a plurality of folded pipe portions 211B that connect the one ends and the other ends. A plurality of hot water supply secondary heat transfer tubes 211 are stacked vertically and housed in a secondary casing 230 . Each of hot water supply secondary heat transfer tubes 211 has one end and the other end that are open to the left. Both ends of the hot water supply secondary heat transfer tube 211 are inserted and fixed to the left side wall portion 261C with a space therebetween in the front-rear direction. Hot water supply secondary heat exchanger 210 performs heat exchange by passing water in parallel to each hot water supply secondary heat transfer pipe 211 .

The secondary heat exchanger for bath 220 is configured to have a plurality of secondary heat transfer tubes 221 for bath similarly to the secondary heat exchanger for hot water supply 210 . The bath secondary heat transfer tube 221 is formed in a meandering shape as a whole, and includes a plurality of straight tube portions 221A that are arranged side by side in the front-rear direction while facing in the left-right direction. It has a plurality of folded pipe portions 221B connecting one end portions and the other end portions together. A plurality of bath secondary heat transfer tubes 221 are stacked vertically and housed in a secondary casing 230 . Each of the bath secondary heat transfer tubes 221 has one end and the other end that are open to the right. Both ends of the bath secondary heat transfer tube 221 are inserted and fixed to the right side wall portion 261D with a space therebetween in the front-rear direction. The bath secondary heat exchanger 220 exchanges heat by passing water through the bath secondary heat transfer tubes 221 in parallel.

A partition wall 231 divides the installation area of the secondary heat transfer tubes 211 and 221 into an installation area R3 for the hot water supply secondary heat transfer tube 211 and an installation area R4 for the bath secondary heat transfer tube 221 . A pair of front and rear drift guides 69 are provided in the arrangement region R3 of the hot water supply secondary heat transfer pipes 211 . A pair of drift guides 69 are fixed to the left side surface of the partition wall 231 by spot welding, brazing, or the like.

At a position of the partition plate 63 excluding at least the end portion on the partition wall 231 side, a communication portion 263A for shortcutting the combustion exhaust gas flowing through the installation region R3 of the hot water supply secondary heat transfer pipe 211 to the lower region R2 of the ceiling wall portion 61F. is provided. In the second embodiment, since the drift guide 69 is provided on the left side surface of the partition wall 231, the combustion exhaust that has flowed into the secondary casing 230 from the inflow port 264 flows toward the left side surface of the partition wall 231, and then moves toward the left side surface of the partition wall 231. As shown by the arrow F5, the gap S2 formed between the partition wall 231 and the hot water supply secondary heat transfer tube 211 collides with the projecting plate 69A and moves toward the left side wall portion 261C. Heat exchange efficiency can be improved by reducing the amount of combustion exhaust flowing through the

As described above, in Embodiment 2, a pair of side wall portions 261C and 261D are provided at both ends of the secondary casing 230 in the left-right direction, and the secondary casing 230 extends the internal space of the secondary casing 230 in the left-right direction. The partition wall 231 separates and partitions the left side wall 261</b>C.

By separating and partitioning the internal space of the secondary casing 230 with the partition wall 231, even when the hot water supply secondary heat exchanger 210 and the bath secondary heat exchanger 220 are configured as one heat exchanger. , the drift guide 69 can deflect the combustion exhaust gas flowing along the partition wall 231 toward the left side wall portion 261C.

<Other embodiments>
The present disclosure is not limited to the embodiments illustrated by the above description and drawings. For example, the features of the embodiments described above or below can be combined in any consistent manner. Also, any feature of the embodiments described above or below may be omitted if not explicitly indicated as essential. Furthermore, the embodiments described above may be modified as follows.

(1) In Embodiments 1 and 2, the fixed plate 69B of the drift guide 69 is configured to connect the pair of projecting plates 69A. The drift guide may be constructed so as to form an L-shape in plan view as a whole.

(2) In Embodiments 1 and 2, the protruding plate 69A is arranged so as not to face the folded pipe portion 62B, but the protruding plate may be arranged to face the folded pipe portion 62B.

(3) In Embodiments 1 and 2, the drift guide 69 is configured separately from the left side wall portion 61C or the partition wall 231, but the drift guide is integrated with the left side wall portion 61C or the partition wall 231. may be configured.

Reference Signs List 1, 201: water heater 2: housing 3: inner shell 4: combustion device 5: primary heat exchanger 6, 206: secondary heat exchanger 7: gas supply unit 8: intake fan 9: controller 10: path member 11 : Water inlet pipe 12: Relay pipe 13: Hot water outlet pipe 14: Drain hose 41: Inner case 51: Primary casing 52: Primary heat transfer pipe 61: Secondary casing 61A: Front wall 61B: Rear wall 61C: Left wall (side wall Part) 61D: Right side wall portion (opposing wall portion) 61E: Bottom wall portion 61F: Ceiling wall portion 62: Secondary heat transfer tube 62A: Straight tube portion 62B: Turned tube portion 63: Partition plate 63A: Communicating portion 64: Flow Inlet 65: Outflow port 66: Exhaust pipe 67A: Front side header 67B: Rear side header 68: Drain outlet 69: Non-uniform flow guide 69A: Protruding plate 69B: Fixed plate 210: Secondary heat exchanger for hot water supply 211: Secondary for hot water supply Heat transfer tube 211A: straight tube portion 211B: folded tube portion 220: secondary heat exchanger for bath 221: secondary heat transfer tube for bath 221A: straight tube portion 221B: folded tube portion 230: secondary casing 231: partition wall 261C: Left side wall portion 261D: Right side wall portion 263A: Communicating portion 264: Inflow port R1: Arrangement area of secondary heat transfer pipes 62 R2: Lower area of ceiling wall portion 61F R3: Distribution of secondary heat transfer pipes 211 for hot water supply Installation area R4: Installation area of secondary heat transfer tube 221 for bath S1: Gap S2: Gap

Claims (7)

A heat exchanger comprising a casing into which combustion exhaust gas is supplied, and a plurality of heat transfer tubes housed inside the casing,
The casing includes a side wall portion disposed at one end portion in a second direction orthogonal to the first direction in which the combustion exhaust gas is supplied, and a facing wall portion facing the side wall portion in the second direction. ,
The plurality of heat transfer tubes are formed in a meandering shape as a whole. and a plurality of folded tube portions that connect one end portions and the other end portions in two directions, and both ends of the heat transfer tubes are inserted and fixed to the side wall portions at intervals in the first direction. and
A heat exchanger, wherein the opposing wall portion of the casing is provided with a drift guide that deflects the combustion exhaust flowing along the opposing wall portion toward the side wall portion. 2. The heat exchanger according to claim 1, wherein said drift guide has a protruding plate protruding toward said side wall. 3. The heat exchanger according to claim 2, wherein said protruding plate of said drift guide is provided upstream of said folded pipe portion positioned on said opposing wall portion side. At least three folded pipe portions are provided on the facing wall side,
The drift guide includes a pair of projecting plates spaced apart in the first direction, and a fixing plate connecting the pair of projecting plates and fixed to the opposing wall, It is formed in a plan view gate shape,
In the drift guide, the pair of protruding plates is the folded pipe portion on the odd-numbered facing wall side when viewed from the upstream side in the first direction among the three folded pipe portions. 4 . The heat exchanger according to claim 2 , wherein the heat exchanger is arranged so as not to face each other and so as to surround the folded pipe portion from both sides in the first direction. The ceiling wall portion of the casing is provided with an exhaust pipe for discharging the combustion exhaust gas in the casing upward. A partition plate is provided to divide the
A communication portion is provided at a position of the partition plate excluding at least an end portion on the side of the opposing wall portion to short-cut the combustion exhaust gas flowing through the area where the heat transfer tubes are provided to a lower area of the ceiling wall portion. A heat exchanger according to any one of claims 1 to 4. A pair of the side wall portions are arranged at both ends of the casing in the second direction, the casing has a partition wall that separates and partitions an internal space of the casing in the second direction, and the The heat exchanger according to any one of claims 1 to 5, wherein the opposing wall portion is the partition wall. a combustion device;
a primary heat exchanger connected to the combustion device and through which combustion exhaust gas from the combustion device passes;
A secondary heat exchanger, which is the heat exchanger according to any one of claims 1 to 6, provided in series with the primary heat exchanger and through which combustion exhaust gas from the primary heat exchanger passes; Including water heater.

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