Heat exchangers and water heaters

Abstract

To provide a heat exchanger capable of suppressing damage of a duct due to heat.SOLUTION: A heat exchanger is equipped with a case, a first heat exchanging portion and a second heat exchanging portion which are disposed in the case, a partition member disposed in the case, and a duct. The case has a first side wall and a second side wall which oppose to each other at an interval in a first direction, a third side wall and a fourth side wall which oppose to each other at an interval in a second direction orthogonal to the first direction, and a bottom wall. On the first side wall, a gas outlet communicating to the inside of the case is formed. The first heat exchanging portion separates from the bottom wall than the second heat exchanging portion in a third direction orthogonal to the first direction and the second direction. The second heat exchanging portion has a plurality of meandering heat transfer pipes meandering in a surface orthogonal to the first direction and piled in the first direction.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a heat exchanger and a water heating device. [Background technology]

[0002] Japanese Patent Laid-Open Publication No. 2021-101131 (Patent Document 1) describes a heat exchanger. The heat exchanger described in Patent Document 1 has a housing, a plurality of serpentine heat transfer tubes, a partition member, and a duct.

[0003] The housing has a first side wall, a second side wall, a third side wall, a fourth side wall, and a bottom wall. The first side wall and the second side wall face each other with a gap in a first direction. The third side wall and the fourth side wall face each other with a gap in a second direction. The second direction is a direction perpendicular to the first direction. The bottom wall is continuous with the lower end of the first side wall, the lower end of the second side wall, the lower end of the third side wall, and the lower end of the fourth side wall. A gas outlet is formed in the first side wall. The gas outlet is connected to the interior of the housing. The gas inlet is defined by the upper end of the first side wall, the upper end of the second side wall, the upper end of the third side wall, and the upper end of the fourth side wall.

[0004] A plurality of serpentine heat transfer tubes are disposed within the housing. The serpentine heat transfer tubes are serpentine in a plane perpendicular to a first direction. The plurality of serpentine heat transfer tubes are stacked along the first direction. The plurality of serpentine heat transfer tubes are divided into a first group and a second group. The serpentine heat transfer tubes belonging to the first group are closer to the first side wall than the serpentine heat transfer tubes belonging to the second group.

[0005] The partition member is disposed within the housing. The partition member has a first portion and a second portion. The second portion extends in a plane perpendicular to the first direction. The second portion is disposed between the first group and the second group. The lower end of the second portion is spaced apart from the bottom wall. The upper end of the second portion is farther from the bottom wall than the serpentine heat transfer tube. The first portion extends from the upper end of the second portion toward the first side wall and is attached to the second side wall. A portion of the gas inlet is blocked by the first portion.

[0006] The duct is attached to the first side wall so as to be connected to the gas outlet. The combustion gas introduced from the gas inlet flows downward while exchanging heat with the hot water flowing through the serpentine heat transfer tubes belonging to the second group. When the combustion gas reaches the bottom wall, it passes between the lower end of the second section and the bottom wall, then turns back upward and exchanges heat with the hot water flowing through the serpentine heat transfer tubes belonging to the first group. The combustion gas is then discharged through the gas outlet and the duct. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent Publication No. 2021-101131 Summary of the Invention [Problem to be solved by the invention]

[0008] The heat exchanger described in Patent Document 1 is a secondary heat exchanger, with a primary heat exchanger placed above it. Furthermore, in the heat exchanger described in Patent Document 1, the end of the duct on the first side wall side is located higher than the end of the first part on the first side wall side. Therefore, in the heat exchanger described in Patent Document 1, the end of the duct on the first side wall side may be damaged by heat.

[0009] The present invention has been made in view of the above-mentioned problems of the conventional art. More specifically, the present invention provides a heat exchanger and a hot water device that can suppress damage to ducts due to heat. [Means for solving the problem]

[0010] A heat exchanger according to one aspect of the present invention includes a case, first and second heat exchange units disposed within the case, a partition member disposed within the case, and a duct. The case has a first side wall and a second side wall facing each other with a gap in a first direction, a third side wall and a fourth side wall facing each other with a gap in a second direction perpendicular to the first direction, and a bottom wall. The first side wall has a gas outlet communicating with the interior of the case. The first heat exchange unit is farther from the bottom wall than the second heat exchange unit in a third direction perpendicular to the first and second directions. The second heat exchange unit has a plurality of serpentine heat transfer tubes that meander in a plane perpendicular to the first direction and are stacked along the first direction. The plurality of serpentine heat transfer tubes are divided into a first group located on the first side wall side and a second group located closer to the second side wall than the first group. The partition member has a first portion and a second portion. The first portion is disposed between the first and second groups. The first portion includes a first end that is an end on the bottom wall side in the third direction and a second end that is an end opposite the first end. The first end is spaced apart from the bottom wall. The second portion includes a third end that is continuous with the second end in the first direction and a fourth end that is an end opposite the third end and attached to the first side wall. The duct is attached to the first side wall so as to be connected to the gas outlet. The portion of the first side wall side end of the duct that is farthest from the bottom wall in the third direction is closer to the bottom wall than the fourth end in the third direction.

[0011] In the heat exchanger, the first heat exchange section may have a plurality of straight heat transfer tubes extending along the second direction. The plurality of straight heat transfer tubes may be arranged in a plurality of rows along the first direction. The fourth end may be farther from the bottom wall in the third direction than one of the plurality of rows closest to the bottom wall.

[0012] In the heat exchanger, the second portion may include a third portion on the third end side and a fourth portion on the fourth end side. In a cross-sectional view perpendicular to the second direction, the angle between the extension direction of the fourth portion and the first direction may be larger than the angle between the extension direction of the third portion and the first direction.

[0013] In the heat exchanger, in a cross-sectional view perpendicular to the second direction, the angle formed between the extending direction of the second portion and the first direction may increase from the third end side toward the fourth end side.

[0014] In the heat exchanger described above, the first heat exchange section may include a plurality of straight heat transfer tubes extending along the second direction and fins attached to the plurality of straight heat transfer tubes. The plurality of straight heat transfer tubes may be arranged in a plurality of rows along the first direction. The fin may include a main body portion extending in a plane perpendicular to the second direction and a wall portion located at an end of the main body portion facing the first sidewall in the first direction and rising from the main body portion along the second direction. The distance in the third direction between a lower end of the wall portion and the second portion may be smaller than the distance in the third direction between one of the plurality of straight heat transfer tubes that belongs to one of the rows closest to the bottom wall and is closest to the first sidewall and the second portion.

[0015] In the heat exchanger, each of the plurality of serpentine heat transfer tubes may extend along the second direction and include a plurality of straight pipe sections arranged in a row along the third direction, a plurality of first connecting sections, and a plurality of second connecting sections. Each of the plurality of straight pipe sections may have a fifth end that is an end on the third sidewall side in the second direction and a sixth end that is an end opposite to the fifth end. The plurality of straight pipe sections may include a first straight pipe section farthest from the bottom wall, a second straight pipe section closest to the bottom wall, and a plurality of third straight pipe sections located between the first and second straight pipe sections. Each of the plurality of first connecting sections may connect two adjacent sixth ends of the plurality of straight pipe sections. The fifth end side of the first straight pipe section and the fifth end side of the second straight pipe section may be supported by the third sidewall. Each of the plurality of second connecting sections may connect two adjacent fifth ends of the plurality of third straight pipe sections. The position of the gas outlet in the third direction may be at a position where the first straight pipe section of one of the plurality of serpentine heat transfer tubes closest to the first side wall and one of the plurality of third straight pipe sections furthest from the bottom wall are visible from the gas outlet, or may be farther from the bottom wall than the positions where the first straight pipe section of one of the plurality of serpentine heat transfer tubes closest to the first side wall and one of the plurality of third straight pipe sections furthest from the bottom wall are visible from the gas outlet.

[0016] The heat exchanger may further include a support plate disposed within the case. Each of the plurality of serpentine heat transfer tubes may extend along the second direction and include a plurality of straight pipe sections arranged in a row along the third direction, a plurality of first connecting sections, and a plurality of second connecting sections. Each of the plurality of straight pipe sections may have a fifth end that is an end on the third sidewall side in the second direction and a sixth end that is an end opposite to the fifth end. The plurality of straight pipe sections may include a first straight pipe section farthest from the bottom wall, a second straight pipe section closest to the bottom wall, and a plurality of third straight pipe sections located between the first and second straight pipe sections. Each of the plurality of first connecting sections may connect two adjacent sixth ends of the plurality of straight pipe sections. The fifth end side of the first straight pipe section and the fifth end side of the second straight pipe section may be supported by the third sidewall. Each of the plurality of second connecting sections may connect two adjacent fifth ends of the plurality of third straight pipe sections. The support plate may support an end portion of each of the plurality of serpentine heat transfer tubes on the fourth side wall side. At least one of the first portion and the support plate may have a notch formed therein so that the first portion and the support plate can intersect.

[0017] A water heating device according to one aspect of the present invention includes the heat exchanger described above and a burner that supplies combustion gas to the heat exchanger. [Effects of the Invention]

[0018] Advantageous Effects of Invention According to the heat exchanger and the hot water apparatus of an aspect of the present invention, damage to the duct due to heat can be suppressed. [Brief explanation of the drawings]

[0019] [Figure 1] 1 is a schematic diagram of a water heating device 100. FIG. [Figure 2] FIG. 2 is a plan view of the heat exchanger 20. [Figure 3] FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2. [Figure 4] FIG. 2 is a first perspective view of the heat exchanger 20. [Figure 5] FIG. 2 is a second perspective view of the heat exchanger 20. [Figure 6] FIG. 4 is an enlarged view of VI in FIG. [Figure 7] FIG. 2 is a side view of the heat exchanger 20. [Figure 8] FIG. [Figure 9] FIG. 2 is a side view of a serpentine heat transfer tube 41. [Figure 10] FIG. 4 is a cross-sectional view taken along line XX in FIG. [Figure 11] 10 is a perspective view showing the positional relationship between a support member 27 and a partition member 45. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0020] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the embodiments of the present invention will be described with reference to the drawings. In the following drawings, the same or corresponding parts are designated by the same reference numerals, and redundant description will not be repeated.

[0021] (First embodiment) A description will be given of a water heating device according to a first embodiment. The water heating device according to the first embodiment is designated as a water heating device 100.

[0022] <Configuration of the water heating device 100> The configuration of the water heating device 100 will be described below.

[0023] FIG. 1 is a schematic diagram of a water heating device 100. As shown in FIG. 1, the water heating device 100 includes a gas valve 10, an orifice 11, a venturi 12, a blower 13, a chamber 14, a burner 15, an ignition plug 16, a heat exchanger 20, a pipe 60, a pipe 70, a pipe 80, and a bypass pipe 90. The heat exchanger 20 includes a first heat exchange section 30, a second heat exchange section 40, and a duct 50. The first heat exchange section 30 is a primary heat exchanger. The second heat exchange section 40 is a secondary heat exchanger. The detailed configuration of the heat exchanger 20 will be described later.

[0024] By opening the gas valve 10, the fuel gas is supplied to the venturi 12 through the orifice 11. The fuel gas supplied to the venturi 12 is mixed with air in the venturi 12 (hereinafter, the fuel gas mixed with air will be referred to as the mixed gas). The mixed gas is supplied to the burner 15 by the blower 13 through the chamber 14. The mixed gas supplied to the burner 15 is ignited by sparking the spark plug 16 and burns. As a result, combustion gas is generated in the burner 15.

[0025] One end of the piping 60 is connected to a water supply system. The other end of the piping 60 is connected to the water inlet 40a of the second heat exchange section 40. The other end of the piping 70 is connected to the water outlet 40b of the second heat exchange section 40. The other end of the piping 70 is connected to the water inlet 30a of the first heat exchange section 30. The other end of the piping 80 is connected to the water outlet 30b of the first heat exchange section 30. The other end of the piping 80 is connected to a hot water tap (not shown). The bypass piping 90 is connected to the piping 60 at one end and to the piping 80 at the other end. The bypass piping 90 and the piping 80 are connected by a three-way valve 81. The duct 50 is connected to the second heat exchange section 40.

[0026] <Detailed configuration of heat exchanger 20> The detailed configuration of the heat exchanger 20 will be described below.

[0027] FIG. 2 is a plan view of the heat exchanger 20. The duct 50 is not shown in FIG. 2. FIG. 3 is a cross-sectional view taken along line III-III in FIG. 2. FIG. 4 is a first perspective view of the heat exchanger 20. FIG. 5 is a second perspective view of the heat exchanger 20. FIG. 6 is an enlarged view of line VI in FIG. 3. FIG. 7 is a side view of the heat exchanger 20. The duct 50 is not shown in FIG. 7. FIG. 8 is a perspective view of the fins 33. FIG. 9 is a side view of the serpentine heat transfer tube 41. FIG. 10 is a cross-sectional view taken along line XX in FIG. 3. As shown in FIGS. 2 to 10, the heat exchanger 20 has a case 21. The first heat exchange section 30 and the second heat exchange section 40 are disposed in the case 21. The case 21 has a first side wall 21a, a second side wall 21b, a third side wall 21c, a fourth side wall 21d, and a bottom wall 21e.

[0028] The first side wall 21a and the second side wall 21b face each other at a distance in the first direction DR1. The third side wall 21c and the fourth side wall 21d face each other at a distance in the second direction DR2. The second direction DR2 is perpendicular to the first direction DR1. The bottom wall 21e is continuous with the lower end of the first side wall 21a, the lower end of the second side wall 21b, the lower end of the third side wall 21c, and the lower end of the fourth side wall 21d. The first heat exchanger 30 is farther from the bottom wall 21e in the third direction DR3 than the second heat exchanger 40. The third direction DR3 is perpendicular to the first direction DR1 and the second direction DR2. Although not shown, a burner 15 is attached to an opening in the case 21 defined by the upper end of the first side wall 21a, the upper end of the second side wall 21b, the upper end of the third side wall 21c, and the upper end of the fourth side wall 21d. Combustion gas is ejected from the burner 15 toward the bottom wall 21e.

[0029] The first heat exchange section 30 has a plurality of body pipes 31 , a plurality of straight heat transfer tubes 32 , and a plurality of fins 33 .

[0030] The body pipe 31 has an end 31a and an end 31b. The ends 31a and 31b are supported by the third side wall 21c. The body pipe 31 extends from the end 31a toward the end 31b along the inner wall surface of the first side wall 21a, the inner wall surface of the fourth side wall 21d, and the inner wall surface of the second side wall 21b. In other words, the body pipe 31 is U-shaped. The multiple body pipes 31 are stacked and spaced apart in the third direction DR3. The multiple body pipes 31 are farther from the bottom wall 21e than the multiple straight heat transfer tubes 32.

[0031] The end 31a of the body pipe 31 farthest from the bottom wall 21e is a water inlet 30a connected to the piping 70. The end 31b of one body pipe 31 is connected to the end 31a of another body pipe 31 adjacent to that one body pipe 31 by a flow path 22 provided on the outer wall surface of the third side wall 21c. However, the end 31b of the body pipe 31 closest to the bottom wall 21e is connected to the end 32a of the straight heat transfer tube 35 closest to the second side wall 21b by a header 23 attached to the outer wall surface of the third side wall 21c.

[0032] The straight heat transfer tubes 32 extend along the second direction DR2. The straight heat transfer tubes 32 have ends 32a and 32b in the second direction DR2. The end 32b is the end opposite the end 32a. The ends 32a and 32b of the straight heat transfer tube 32 are supported by the third side wall 21c and the fourth side wall 21d, respectively. The straight heat transfer tubes 32 are arranged in multiple rows along the first direction DR1. In the example shown in FIGS. 2 to 10, the straight heat transfer tubes 32 are arranged in two rows along the first direction DR1. The straight heat transfer tubes 32 belonging to the row closest to the bottom wall 21e of the two rows are referred to as straight heat transfer tubes 34. The straight heat transfer tubes 32 belonging to the row farthest from the bottom wall 21e of the two rows are referred to as straight heat transfer tubes 35.

[0033] The ends 32a of two adjacent straight heat transfer tubes 32 in the first direction DR1 are connected by a header 24a attached to the outer wall surface of the third side wall 21c. The ends 32b of two adjacent straight heat transfer tubes 32 in the first direction DR1 are connected by a header 24b attached to the outer wall surface of the fourth side wall 21d. However, the end 32b of the straight heat transfer tube 35 closest to the first side wall 21a is connected to the end 32b of the straight heat transfer tube 34 closest to the first side wall 21a by a header 24c attached to the outer wall surface of the fourth side wall 21d. The end 32b of the straight heat transfer tube 34 closest to the second side wall 21b is connected to a header 24d attached to the outer wall surface of the fourth side wall 21d. The header 24d is provided with a water outlet 30b connected to the piping 80.

[0034] The fins 33 are attached to the plurality of straight heat transfer tubes 32. The fins 33 have a main body 33a, a wall 33b, and a wall 33c. The main body 33a extends in a plane perpendicular to the second direction DR2. The fins 33 are attached to the straight heat transfer tubes 32 by inserting the straight heat transfer tubes 32 into through holes 33aa formed in the main body 33a. The wall 33b and the wall 33c are located at the end of the main body 33a on the first side wall 21a side and the end on the second side wall 21b side, respectively, in the first direction DR1. The wall 33b and the wall 33c rise from the main body 33a along the second direction DR2.

[0035] The second heat exchange section 40 has a plurality of serpentine heat transfer tubes 41. The serpentine heat transfer tubes 41 meander in a plane perpendicular to the first direction DR1. More specifically, the serpentine heat transfer tubes 41 have a plurality of straight pipe sections 42, a plurality of first connection sections 43, and a plurality of second connection sections 44. The straight pipe sections 42 extend along the second direction DR2. The straight pipe sections 42 are arranged at intervals in a row along the third direction DR3. The straight pipe sections 42 include a first straight pipe section 42a, a second straight pipe section 42b, and a plurality of third straight pipe sections 42c. The first straight pipe section 42a is the straight pipe section 42 farthest from the bottom wall 21e. The second straight pipe section 42b is the straight pipe section 42 that is closest to the bottom wall 21e, and the third straight pipe section 42c is the straight pipe section 42 that is located between the first straight pipe section 42a and the second straight pipe section 42b.

[0036] The straight pipe section 42 has a fifth end 42d and a sixth end 42e in the second direction DR2. The fifth end 42d is the end on the third side wall 21c side. The sixth end 42e is the end opposite the fifth end 42d. That is, the sixth end 42e is the end on the fourth side wall 21d side. The fifth end 42d side of the first straight pipe section 42a is supported by the third side wall 21c. The fifth end 42d side of the second straight pipe section 42b is supported by the third side wall 21c. The first connecting section 43 connects the sixth ends 42e of two adjacent straight pipe sections 42. The second connecting section 44 connects the fifth ends 42d of two adjacent third straight pipe sections 42c.

[0037] The plurality of serpentine heat transfer tubes 41 are stacked along the first direction DR1. A straight pipe portion 42 of one serpentine heat transfer tube 41 is located in the third direction DR3 between two adjacent straight pipe portions 42 of another serpentine heat transfer tube 41 that is adjacent to the one serpentine heat transfer tube 41 in the first direction DR1.

[0038] A fifth end 42d of the second straight pipe portion 42b is connected to a header 25 attached to the outer wall surface of the third side wall 21c. The header 25 is provided with a water inlet 40a connected to the piping 60. A fifth end 42d of the first straight pipe portion 42a is connected to a header 26 attached to the outer wall surface of the third side wall 21c. The header 26 is provided with a water outlet 40b connected to the piping 70.

[0039] The heat exchanger 20 further includes a partition member 45. The partition member 45 is disposed within the case 21. The partition member 45 includes a first portion 45a and a second portion 45b. The plurality of serpentine heat transfer tubes 41 are divided into a first group and a second group. The first group is a group of serpentine heat transfer tubes 41 located closer to the first side wall 21a. The second group is a group of serpentine heat transfer tubes 41 located closer to the second side wall 21b than the first group. The first portion 45a is disposed between the first group and the second group. The first portion 45a extends, for example, in a plane perpendicular to the first direction DR1. The number of serpentine heat transfer tubes 41 belonging to the first group is preferably smaller than the number of serpentine heat transfer tubes 41 belonging to the second group. From another perspective, the distance between the first portion 45a and the first side wall 21a is smaller than the distance between the first portion 45a and the second side wall 21b.

[0040] The first portion 45a has a first end 45aa and a second end 45ab in the third direction DR3. The first end 45aa is the end on the bottom wall 21e side. The first end 45aa is spaced apart from the bottom wall 21e. The second end 45ab is the end opposite the first end 45aa. The second end 45ab is farther from the bottom wall 21e than the serpentine heat transfer tube 41 (first straight pipe portion 42a). The second portion 45b has a third end 45ba and a fourth end 45bb in the first direction DR1. The third end 45ba is continuous with the second end 45ab. The fourth end 45bb is the end opposite the third end 45ba. The second portion 45b is attached to the inner wall surface of the first side wall 21a at the fourth end 45bb.

[0041] The second portion 45b is inclined with respect to the first direction DR1. More specifically, the position of the fourth end 45bb is farther from the bottom wall 21e than the position of the third end 45ba. The position of the fourth end 45bb is preferably farther from the bottom wall 21e than the straight heat transfer tube 34 in the third direction DR3. Note that, because the position of the fourth end 45bb is farther from the bottom wall 21e than the position of the third end 45ba, condensed water dripping from the fin 33 onto the second portion 45b is less likely to flow toward the duct 50 (the first side wall 21a).

[0042] The second portion 45b may have a third portion 45c and a fourth portion 45d. The third portion 45c is located closer to the third end 45ba. The fourth portion 45d is located closer to the fourth end 45bb than the third portion 45c. The angle between the extension direction of the third portion 45c and the first direction DR1 is defined as angle θ1, and the angle between the extension direction of the fourth portion 45d and the first direction DR1 is defined as angle θ2. The angle θ2 is larger than the angle θ1. The angle θ1 is equal to or greater than 0°. That is, the extension direction of the third portion 45c may be parallel to the first direction DR1.

[0043] The distance in the third direction DR3 between the lower end of the wall 33b (the end of the wall 33b on the bottom wall 21e side) and the second portion 45b is defined as a distance DIS1. The distance in the third direction DR3 between the straight heat transfer tube 34 closest to the first side wall 21a and the second portion 45b is defined as a distance DIS2. It is preferable that the distance DIS1 is smaller than the distance DIS2.

[0044] A gas outlet 21aa is formed in the first side wall 21a. The gas outlet 21aa penetrates the first side wall 21a in the thickness direction and communicates with the interior of the case 21. When viewed from the side along the first direction DR1, the gas outlet 21aa has a rectangular shape with its longitudinal direction aligned with the second direction DR2. When viewed from the side along the first direction DR1, the gas outlet 21aa is preferably located farther from the bottom wall 21e than the positions at which the first straight pipe portion 42a of the serpentine heat transfer tube 41 closest to the first side wall 21a and the third straight pipe portion 42c farthest from the bottom wall 21e are visible from the gas outlet 21aa. When viewed from the side along the first direction DR1, the gas outlet 21aa may be located at a position at which the first straight pipe portion 42a of the serpentine heat transfer tube 41 closest to the first side wall 21a and the third straight pipe portion 42c farthest from the bottom wall 21e are visible from the gas outlet 21aa. However, the upper end of the gas outlet 21aa is closer to the bottom wall 21e than the fourth end 45bb.

[0045] The duct 50 is attached to the outer wall surface of the first side wall 21a so as to be connected to the gas outlet 21aa. An end of the duct 50 on the first side wall 21a side is, for example, a flange portion 51. The duct 50 is attached to the outer wall surface of the first side wall 21a at the flange portion 51. A seal member 52 is disposed between the outer wall surface of the first side wall 21a and the flange portion 51. The flange portion 51 is closer to the bottom wall 21e in the third direction DR3 than the fourth end 45bb. More specifically, the upper end of the flange portion 51 (i.e., the portion of the flange portion 51 farthest from the bottom wall 21e in the third direction DR3) is closer to the bottom wall 21e in the third direction DR3 than the fourth end 45bb. The duct 50 is formed of, for example, a resin material.

[0046] The heat exchanger 20 may further include a support member 27. The support member 27 is disposed within the case 21. The support member 27 extends in a plane perpendicular to the second direction DR2. A plurality of through holes 27a are formed in the support member 27. The plurality of through holes 27a are aligned along the third direction DR3. The end of the serpentine heat transfer tube 41 on the side of the fourth side wall 21d is disposed within the through holes 27a, and is thereby supported by a portion of the support member 27 located between two adjacent through holes 27a (referred to as support portion 27b).

[0047] FIG. 11 is a perspective view showing the positional relationship between the support member 27 and the partition member 45. As shown in FIG. 11, the support member 27 intersects with the first portion 45a. More specifically, the end of the first portion 45a (partition member 45) on the fourth side wall 21d side protrudes toward the fourth side wall 21d beyond the support member 27 (see FIG. 10). The end of the first portion 45a on the fourth side wall 21d side preferably contacts the inner wall surface of the fourth side wall 21d. A notch 45ac is formed in the first portion 45a to allow intersection with the support member 27. The notch 45ac extends from the end of the first portion 45a on the fourth side wall 21d side along the second direction DR2. The support portion 27b passes through the notch 45ac. In this example, the case where the notch 45ac is formed in the first portion 45a is described, but the notch may be formed in the support member 27 (more specifically, the support portion 27b) to enable the first portion 45a and the support member 27 to intersect.

[0048] <Operation of heat exchanger 20> The combustion gas ejected from the burner 15 toward the bottom wall 21e side undergoes heat exchange in the first heat exchange section 30. More specifically, the combustion gas exchanges heat with hot water flowing through a plurality of straight heat transfer tubes 32.

[0049] The combustion gas that has passed through the first heat exchange unit 30 undergoes heat exchange in the second heat exchange unit 40. More specifically, first, the combustion gas passes between the first portion 45a and the second side wall 21b and exchanges heat with the hot water flowing through the serpentine heat transfer tubes 41 belonging to the second group. Second, the combustion gas that has reached the bottom wall 21e passes between the first end 45aa and the bottom wall 21e, turns back upward, and exchanges heat with the serpentine heat transfer tubes 41 belonging to the first group. The flow velocity of the combustion gas increases when passing between the first end 45aa and the bottom wall 21e, improving the heat exchange efficiency of the second heat exchange unit 40. Third, the combustion gas that has exchanged heat with the serpentine heat transfer tubes 41 belonging to the first group is discharged to the outside of the heat exchanger 20 through the gas outlet 21aa and the duct 50.

[0050] <Effects of Heat Exchanger 20> The effects of the heat exchanger 20 will be described below.

[0051] The combustion gas from the burner 15 passes through the first heat exchange section 30 before reaching the second heat exchange section 40. Therefore, the temperature in the portion of the first side wall 21a above the partition member 45 (away from the bottom wall 21e) becomes higher than the temperature in the portion of the first side wall 21a below the partition member 45 (close to the bottom wall 21e).

[0052] In the heat exchanger 20, the flange portion 51 is closer to the bottom wall 21e than the fourth end 45bb. That is, in the heat exchanger 20, the flange portion 51 is located below the partition member 45 and is less likely to receive heat from the portion of the first side wall 21a that is at a higher temperature. Therefore, in the heat exchanger 20, it is possible to prevent the flange portion 51 from being damaged by heat.

[0053] In the heat exchanger 20, when the fourth end 45bb is farther from the bottom wall 21e than the straight heat transfer tube 34, it is possible to ensure a distance between the flange portion 51 and a portion of the first side wall 21a that is located above the partition member 45 and has a higher temperature. Therefore, in this case, it is possible to further prevent the flange portion 51 from being damaged by heat.

[0054] When the distance DIS1 is greater than the distance DIS2, the combustion gas is more likely to enter between the lower end of the wall portion 33b and the second portion 45b. As a result, the temperature is more likely to rise in the portion of the first side wall 21a near the portion where the flange portion 51 is attached. On the other hand, when the distance DIS1 is smaller than the distance DIS2, the combustion gas is more likely to pass between the straight heat transfer tube 34 closest to the first side wall 21a and the second portion 45b than between the lower end of the wall portion 33b and the second portion 45b. Therefore, by making the distance DIS1 smaller than the distance DIS1, it is possible to further prevent the flange portion 51 from being damaged by heat.

[0055] When the position of the gas outlet 21aa is farther from the bottom wall 21e than the positions at which the first straight pipe section 42a of the serpentine heat transfer tube 41 closest to the first side wall 21a and the third straight pipe section 42c farthest from the bottom wall 21e can be seen in a side view along the first direction DR1, the combustion gas flows around the serpentine heat transfer tubes 41 belonging to the first group even at a position farther from the bottom wall 21e before being discharged from the gas outlet 21aa. Therefore, in this case, the heat exchange efficiency of the heat exchanger 20 (second heat exchange section 40) can be further improved.

[0056] When the end of the serpentine heat transfer tube 41 on the fourth side wall 21d side is supported by the support member 27, the serpentine heat transfer tube 41 is supported not only on the third side wall 21c side but also on the fourth side wall 21d side. Furthermore, because a notch is formed in either the first portion 45a or the support member 27 so that the first portion 45a and the support member 27 can intersect, the end of the partition member 45 on the fourth side wall 21d side can be positioned close to the fourth side wall 21d even when the support member 27 is disposed inside the case 21. As a result, combustion gas is less likely to take a shortcut by passing between the partition member 45 and the fourth side wall 21d without passing around the serpentine heat transfer tubes 41 belonging to the second group. Thus, when the heat exchanger 20 includes the support member 27, deformation of the serpentine heat transfer tube 41 can be suppressed by supporting the serpentine heat transfer tube 41 from both the third side wall 21c side and the fourth side wall 21d side, while improving heat transfer efficiency.

[0057] <Modification> The second portion 45b may not include the third portion 45c and the fourth portion 45d. From another perspective, the angle formed between the extension direction of the second portion 45b and the first direction DR1 may be constant. The angle formed between the extension direction of the second portion 45b and the first direction DR1 may increase from the third end 45ba side toward the fourth end 45bb side.

[0058] Although the embodiments of the present invention have been described above, the above-described embodiments can be modified in various ways. Furthermore, the scope of the present invention is not limited to the above-described embodiments. The scope of the present invention is defined by the claims, and is intended to include all modifications within the meaning and scope of the claims. [Industrial Applicability]

[0059] The above-described embodiment can be particularly advantageously applied to a heat exchanger and a water heating device having a heat exchanger. [Explanation of symbols]

[0060] 10 gas valve, 11 orifice, 12 venturi, 13 blower, 14 chamber, 15 burner, 16 spark plug, 20 heat exchanger, 21 case, 21a first side wall, 21aa gas outlet, 21b second side wall, 21c third side wall, 21d fourth side wall, 21e bottom wall, 22 flow path, 23, 24a, 24b, 24c, 24d, 25, 26 header, 27 support member, 27a through hole, 27b support portion, 30 first heat exchange portion, 30a water inlet, 30b water outlet, 31 body pipe, 31a, 31b end, 32 straight heat transfer tube, 32a, 32b end, 33 fin, 33a main body portion, 33aa through hole, 33b, 33c Wall portion, 34, 35 straight heat transfer tube, 40 second heat exchange section, 40a water inlet, 40b water outlet, 41 serpentine heat transfer tube, 42 straight pipe section, 42a first straight pipe section, 42b second straight pipe section, 42c third straight pipe section, 42d fifth end, 42e sixth end, 43 first connecting section, 44 second connecting section, 45 partition member, 45a first section, 45aa first end, 45ab second end, 45ac notch, 45b second section, 45ba third end, 45bb fourth end, 45c third section, 45d fourth section, 50 duct, 51 flange portion, 52 sealing member, 60, 70 piping, 80 piping, 81 three-way valve, 90 bypass piping, 100 water heating device, DIS1, DIS2 distance, DR1 1st direction, DR2 2nd direction, DR3 3rd direction.

Claims

1. Case and a first heat exchange unit and a second heat exchange unit disposed in the case; a partition member disposed within the case; a duct; the case has a first side wall and a second side wall facing each other with a gap in a first direction, a third side wall and a fourth side wall facing each other with a gap in a second direction perpendicular to the first direction, and a bottom wall; a gas outlet communicating with the interior of the case is formed in the first side wall; the first heat exchange unit is farther from the bottom wall than the second heat exchange unit in a third direction perpendicular to the first direction and the second direction; the second heat exchange section has a plurality of serpentine heat transfer tubes that are serpentine in a plane perpendicular to the first direction and that are stacked along the first direction, the plurality of serpentine heat transfer tubes are divided into a first group located on the first side wall side and a second group located on the second side wall side of the first group, The partition member has a first portion and a second portion, the first portion is disposed between the first group and the second group; the first portion includes a first end that is an end on the bottom wall side in the third direction and a second end that is an end opposite to the first end, the first end is spaced from the bottom wall; the second portion includes a third end connected to the second end in the first direction, and a fourth end opposite the third end and attached to the first side wall, the duct is attached to the first side wall so as to be connected to the gas outlet; A heat exchanger, wherein a portion of the end of the duct on the first side wall side that is farthest from the bottom wall in the third direction is closer to the bottom wall in the third direction than the fourth end.

2. the first heat exchange section has a plurality of straight heat transfer tubes extending along the second direction, the plurality of straight heat transfer tubes are arranged in a plurality of rows along the first direction, The heat exchanger according to claim 1 , wherein the fourth end is farther from the bottom wall in the third direction than one of the plurality of rows closest to the bottom wall.

3. the second portion includes a third portion on the third end side and a fourth portion on the fourth end side, 3. The heat exchanger according to claim 1, wherein, in a cross-sectional view perpendicular to the second direction, an angle formed between the extension direction of the fourth portion and the first direction is larger than an angle formed between the extension direction of the third portion and the first direction.

4. 3. The heat exchanger according to claim 1, wherein, in a cross-sectional view perpendicular to the second direction, the angle between the extension direction of the second portion and the first direction increases from the third end side toward the fourth end side.

5. the first heat exchange unit includes a plurality of straight heat transfer tubes extending along the second direction and fins attached to the plurality of straight heat transfer tubes, the plurality of straight heat transfer tubes are arranged in a plurality of rows along the first direction, the fin has a main body portion extending in a plane perpendicular to the second direction, and a wall portion located at an end of the main body portion on the first sidewall side in the first direction and rising from the main body portion along the second direction, 2. The heat exchanger according to claim 1, wherein the distance in the third direction between the lower end of the wall portion and the second portion is smaller than the distance in the third direction between one of the plurality of straight heat transfer tubes that belongs to one of the plurality of rows closest to the bottom wall and is closest to the first side wall and the second portion.

6. Each of the plurality of serpentine heat transfer tubes extends along the second direction and includes a plurality of straight pipe portions arranged in a row along the third direction, a plurality of first connection portions, and a plurality of second connection portions, each of the plurality of straight pipe portions has, in the second direction, a fifth end that is an end on the third sidewall side and a sixth end that is an end opposite to the fifth end; the plurality of straight pipe sections include a first straight pipe section that is farthest from the bottom wall, a second straight pipe section that is closest to the bottom wall, and a plurality of third straight pipe sections that are located between the first straight pipe section and the second straight pipe section, each of the plurality of first connection portions connects two adjacent sixth ends of the plurality of straight pipe portions; the fifth end side of the first straight pipe portion and the fifth end side of the second straight pipe portion are supported by the third side wall, each of the second connection portions connects two adjacent fifth ends of the third straight pipe portions; 6. The heat exchanger according to claim 1, wherein the position of the gas outlet in the third direction is at a position where the first straight pipe section of one of the plurality of serpentine heat transfer tubes closest to the first side wall and one of the plurality of third straight pipe sections farthest from the bottom wall are visible from the gas outlet, or is farther from the bottom wall than a position where the first straight pipe section of one of the plurality of serpentine heat transfer tubes closest to the first side wall and one of the plurality of third straight pipe sections farthest from the bottom wall are visible from the gas outlet.

7. a support plate disposed within the case; Each of the plurality of serpentine heat transfer tubes extends along the second direction and includes a plurality of straight pipe portions arranged in a row along the third direction, a plurality of first connection portions, and a plurality of second connection portions, each of the plurality of straight pipe portions has, in the second direction, a fifth end that is an end on the third sidewall side and a sixth end that is an end opposite to the fifth end; the plurality of straight pipe sections include a first straight pipe section that is farthest from the bottom wall, a second straight pipe section that is closest to the bottom wall, and a plurality of third straight pipe sections that are located between the first straight pipe section and the second straight pipe section, each of the plurality of first connection portions connects two adjacent sixth ends of the plurality of straight pipe portions; the fifth end side of the first straight pipe portion and the fifth end side of the second straight pipe portion are supported by the third side wall, each of the second connection portions connects two adjacent fifth ends of the third straight pipe portions; the support plate supports an end portion of each of the plurality of serpentine heat transfer tubes on the fourth side wall side, A heat exchanger according to any one of claims 1 to 5, wherein a notch is formed in at least one of the first portion and the support plate so that the first portion and the support plate can intersect.

8. The heat exchanger according to any one of claims 1 to 7; a burner that supplies combustion gas to the heat exchanger.

Images