Hot water apparatus and heat exchanger used therefor

Abstract

To provide a water heater capable of properly preventing drain water from scattering from an exhaust flow passage to the outside when the exhaust flow passage of a heat exchanger is formed by using an auxiliary member.SOLUTION: First and second burner parts 11A and 11B which can be individually driven and burnt and are arranged side by side, a fan 10 which sends air to them, and first and second heat transfer pipes 3A and 3B which heat hot water are arranged in a case 2 to which combustion gases are supplied are provided. The 20a of the front wall part of the case 2 is provided with a heat-exchanger HE provided with an exhaust pipe part 23 for combustion gases, and auxiliary members 4, 5 arranged in the exhaust pipe part 23 to form an exhaust gas flow passage 7. In the water heater WH capable of generating a specific state in which combustion gas flows into one side of an exhaust gas flow passage 7 and air blown from a fan 10 flows into the other side of the exhaust gas flow passage 7, auxiliary members 4, 5 constitute an upper wall surface part 70 of the exhaust gas flow passage 7, and at least a part of the upper wall surface part 70 is inclined wall surface parts 70a, 70b.SELECTED DRAWING: Figure 8

Description

[Technical Field]

[0001] The present invention relates to a hot water device such as a water heater, and a heat exchanger that can be used as a component of the hot water device. [Background technology]

[0002] Specific examples of water heating devices include those described in Patent Documents 1 to 3. The hot water devices described in these documents recover heat from combustion gas generated by a burner unit using primary and secondary heat exchangers to heat water. Here, the secondary heat exchanger has a case that houses heat transfer tubes and into which combustion gas is supplied, and an exhaust pipe protrudes from the front wall of this case. After heat recovery by the heat transfer tubes, the combustion gas (exhaust gas) passes through an exhaust flow path in the exhaust pipe and is exhausted to the outside of the case. However, if the combustion gas passes through the exhaust pipe in a turbulent state, the exhaust noise increases. Therefore, in Patent Documents 1 to 3, an auxiliary member (a rectifying member) is provided inside the exhaust pipe as a means for rectifying the combustion gas and reducing the exhaust noise.

[0003] However, the above-mentioned prior art has room for improvement, as will be described below.

[0004] That is, as shown in Patent Document 3, there is a hot water system that is equipped with a so-called one-tank, two-channel type heat exchanger and is capable of supplying, for example, general hot water and hot water for heating (or bath water). In such a hot water system, two burner sections, one for supplying general hot water and one for supplying hot water for heating, are provided as burner sections that receive air from a fan, and two sets of heat transfer tubes, one for supplying general hot water and one for supplying hot water for heating, are arranged side by side within the heat exchanger case in correspondence with the two burner sections.

[0005] In such a hot water system, for example, when only the heating / hot water burner is driven and combusted, and the resulting combustion gas flows toward the area where the heating / hot water heat transfer tubes of the heat exchanger are located, the airflow from the fan flows toward the area where the general-purpose heat transfer tubes are located. This creates a specific situation in which the combustion gas (exhaust gas) that has passed through the area where the heating / hot water heat transfer tubes are located passes through one side of the exhaust pipe of the heat exchanger in the width direction, while low-temperature airflow passes through the opposite side. In this situation, the combustion gas is cooled in the exhaust passage, causing the water vapor in the combustion gas to condense, resulting in drain water (condensed water). This drain water may be blown away by the flow of the combustion gas or the blown air and splash outside. This could contaminate the front portion and the area in front of the heat exchanger. Therefore, a solution to this problem is required. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 6076290 [Patent Document 2] Patent No. 6893422 [Patent Document 3] Japanese Patent Publication No. 2020-176802 Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention was conceived under the circumstances described above, and provides a water heater that can appropriately prevent drain water from scattering to the outside from an exhaust passage of a heat exchanger formed using an auxiliary member, and a heat exchanger suitable for use in the water heater. The challenge is to provide it. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention provides the following technical solutions.

[0009] The hot water device provided by the first aspect of the present invention comprises first and second burner sections that can be driven and burned individually and are arranged in a predetermined width direction, a fan for blowing air to these first and second burner sections, a case to which the combustion gas generated by the first and second burner sections is supplied, in which first and second heat transfer tubes for heating hot water are arranged side by side corresponding to the first and second burner sections, and the front wall of the case has a heat exchanger with an exhaust pipe section for the combustion gas, and an auxiliary member arranged in the exhaust pipe section to form an exhaust flow path, and the hot water device is configured in such a way that a specific state can be created in which the combustion gas flows into one side of the exhaust flow path in the width direction, and at the same time, blown air from the fan flows into the side opposite to the one side of the exhaust flow path, and the auxiliary member forms the upper wall surface of the exhaust flow path, and at least a portion of this upper wall surface is an inclined wall surface that is inclined up and down with respect to the width direction.

[0010] This configuration provides the following effects. Specifically, when the combustion gas and blast air supplied to the heat exchanger case travel through the case, approach the front wall of the case, and enter the exhaust flow path, a sudden change in flow path causes a contraction of the flow path. Furthermore, beyond the contraction point in the exhaust flow path, a vortex that expands the flow is generated (see also the explanation of Figure 10 below). When this contraction and subsequent expansion occur, the flow direction of the combustion gas and blast air is perpendicular to the upper wall surface of the exhaust flow path at the upper part of the exhaust flow path. In contrast, in the present invention, the upper wall surface is provided with an inclined wall surface that slopes upward and downward. When the specific condition occurs and the combustion gas and blast air flow perpendicular to this inclined wall surface, the combustion gas and blast air also flow in the width direction (horizontal direction), which actively transfers heat to the upper wall surface of the exhaust flow path where the combustion gas and blast air act. This helps to equalize the temperature distribution at various locations on the upper wall surface of the exhaust flow path. Therefore, the high-temperature combustion gas is prevented from coming into contact with the upper wall surface of the exhaust pipe, which has been cooled considerably by the blown air, and causing condensation. As a result, the generation and adhesion of a large amount of drain water (condensed water) on the upper wall surface of the exhaust flow path is prevented. Furthermore, even if drain water is generated on the upper wall surface of the exhaust flow path, this drain water can be made to flow downward along the inclined wall surface and be removed. As a result, the drain water is appropriately prevented or suppressed from splashing forward and outside the exhaust flow path of the heat exchanger, thereby contaminating the front surface and front area of ​​the heat exchanger. Drain water can be generated not only on the upper side (upper wall surface) of the exhaust flow path but also on the lower side. However, drain water generated on the lower side of the exhaust flow path is less likely to be blown forward by combustion gas or blown air and is less likely to cause contamination. In contrast, when drain water is generated on the upper side (upper wall surface) of the exhaust flow path, it tends to hang down on the upper wall surface and is easily blown away over a long distance by the flow of combustion gas or blown air. In the present invention, this is rational because it prevents drain water from scattering from the upper side (upper wall surface) of the exhaust flow path.

[0011] In the present invention, the inclined wall portion preferably comprises first and second inclined wall portions having one end connected to each other at a position closer to the center of the upper wall portion in the width direction, and the first and second inclined wall portions have inclination directions opposite to each other so that the height decreases toward the ends of the upper wall portion in the width direction.

[0012] According to this configuration, when the specific state occurs, a combustion gas that generates a contraction flow and a subsequent expansion flow in the vicinity of the portion where one end of the first and second inclined wall surface portions is connected to each other is generated. The gas and the blown air can flow close to each other, allowing them to mix. This allows the temperature of the upper wall surface of the exhaust flow path to be averaged, and the generation of drain water can be more effectively suppressed.

[0013] In the present invention, preferably, both the first and second inclined wall portions are flat.

[0014] This configuration provides the following effects. That is, in the present invention, it is possible to form the inclined wall surface portions (first and second inclined wall surface portions) in a curved shape. However, in this case, when the combustion gas or the blown air undergoes a contraction flow and then a bulging flow, it becomes somewhat difficult to make the flow large and uniform in the width direction of the exhaust flow path. In contrast, with the above-described configuration, this problem can be avoided.

[0015] In the present invention, preferably, the exhaust gas turbine further comprises a sound absorbing material attached to the auxiliary member so as to face the exhaust flow path.

[0016] This configuration is advantageous in terms of reducing exhaust noise, and since auxiliary members are used to attach the sound-absorbing material, the configuration is rational.

[0017] In the present invention, the auxiliary member preferably comprises a lower member that is arranged in a lower portion of the exhaust pipe portion so as to block this portion and that constitutes a lower wall surface portion of the exhaust flow path, and an upper member that is located above the lower member at a distance in the width direction and that rises upward from the lower wall surface portion to constitute a pair of left and right side wall surface portions of the exhaust flow path, and that has an upper part connecting the upper parts of the pair of rising parts, and the upper part constitutes an upper wall surface portion of the exhaust flow path.

[0018] With this configuration, the upper wall surface portion, lower wall surface portion, and a pair of side wall surface portions of the exhaust flow path can be formed using a simple configuration that combines the lower member and the upper member, making it possible to provide the exhaust flow path with excellent effects in preventing drain water from splashing and exhaust noise.

[0019] A heat exchanger provided by a second aspect of the present invention is a heat exchanger comprising a case into which combustion gas is supplied and in which first and second heat transfer tubes for heating hot and cold water are arranged side by side, and in which an exhaust pipe section for exhausting the combustion gas is provided on the front wall section, and an auxiliary member arranged within the exhaust pipe section to form an exhaust flow path, wherein the auxiliary member forms the upper wall surface section of the exhaust flow path, and at least a portion of this upper wall surface section is an inclined wall surface section that is inclined up and down relative to the width direction of the case.

[0020] A heat exchanger having such a configuration is suitable for use as a heat exchanger in the hot water system provided by the first aspect of the present invention, and can be expected to provide the same effects as those described for the hot water system provided by the first aspect of the present invention.

[0021] Other features and advantages of the present invention will become more apparent from the following description of the preferred embodiments of the invention, which proceeds with reference to the accompanying drawings. [Brief explanation of the drawings]

[0022] [Figure 1]1 is a front cross-sectional view schematically showing an example of a hot water device according to the present invention. [Figure 2] 2 is a perspective view of a heat exchanger (secondary heat exchanger) used in the hot water system shown in FIG. [Figure 3] FIG. 3 is a front view of the heat exchanger shown in FIG. 2. [Figure 4] 4(a) is a cross-sectional view taken along line IV-IV in FIG. 2, and FIG. 4(b) is an enlarged cross-sectional view of a main part of FIG. 4(a). [Figure 5] FIG. 5 is a cross-sectional view taken along line VV of FIG. [Figure 6] FIG. 6 is an exploded cross-sectional view of a main part of FIG. 5. [Figure 7] FIG. 6 is an enlarged exploded perspective view of a main part of the heat exchanger shown in FIGS. 2 to 5. [Figure 8] 8(a) is a cross-sectional view taken along line VIII-VIII in FIG. 5, and FIG. 8(b) is an enlarged view of a main part of FIG. 8(a). [Figure 9] 9 is a cross-sectional view taken along line IX-IX in FIG. 5. [Figure 10] 10A and 10B are explanatory diagrams showing examples of the flow action of a heat exchanger and blown air. [Figure 11] FIG. 10 is a cross-sectional view of a main part showing a comparative example to the present invention. [Figure 12] 10(a) and 10(b) are cross-sectional views of the main part showing another example of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0023] Preferred embodiments of the present invention will now be described in detail with reference to the drawings.

[0024] The hot water device WH shown in Figure 1 is a water heating device that includes a heat exchanger HE, as well as a fan 10, first and second burner sections 11A and 11B arranged side by side that receive a supply (blow) of combustion air from the fan 10 and can be driven and burned individually, and a primary heat exchanger 12 that recovers sensible heat from the combustion gas generated by the first and second burner sections 11A and 11B to heat hot water. The heat exchanger HE is a secondary heat exchanger for recovering latent heat, and corresponds to a specific example of the heat exchanger of the present invention. The primary heat exchanger 12 does not correspond to a specific example of the heat exchanger of the present invention.

[0025] The primary heat exchanger 12 includes heat transfer tubes 13A and 13B corresponding to the first and second burner sections 11A and 11B, respectively, and a boiler body 18 that houses them. Hot and cold water flowing through the heat transfer tubes 13A and 13B can be heated individually by the first and second burner sections 11A and 11B. A partition plate 15 is provided between the combustion chambers of the first and second burner sections 11A and 11B, allowing the combustion gases generated by the first and second burner sections 11A and 11B to act efficiently on the heat transfer tubes 13A and 13B.

[0026] 2 to 5, the heat exchanger HE includes a case 2, a plurality of first and second heat transfer tubes 3A and 3B housed in the case 2, and auxiliary members 4 and 5 (4A, 4B, 5A, and 5B). Note that the first and second heat transfer tubes 3A and 3B are shown schematically in FIG.

[0027] The first and second heat transfer tubes 3A, 3B are arranged side by side, and are configured, for example, by stacking serpentine tubes having a serpentine shape in a plan view at intervals above and below each other. The first heat transfer tube 3A is used for general hot water heating, and the second heat transfer tube 3B is used for hot water heating (or bath reheating). A partition wall 90 is provided between the first and second heat transfer tubes 3A, 3B. The first heat transfer tube 3A is larger in overall length than the second heat transfer tube 3B. Correspondingly, the first burner section 11A has a greater combustion capacity than the second burner section 11B.

[0028] Both ends of the first and second heat transfer tubes 3A, 3B penetrate both side walls 20f of the case 2 and are connected to the water inlet and outlet headers 6a-6d provided on both side walls 20f. As the hot water entering the water inlet headers 6a, 6c passes through the first and second heat transfer tubes 3A, 3B, it is heated by the combustion gas supplied into the case 2 and then reaches the water outlet headers 6b, 6d. The hot water output from the water outlet headers 6b, 6d is sent to the heat transfer tubes 13A, 13B of the primary heat exchanger 12.

[0029] The case 2 is roughly rectangular parallelepiped and has intake ports 21A and 21B for combustion gas provided in the rear wall portion 20b, and an exhaust tube portion 23 protruding from the front wall portion 20a and having an exhaust port 22 at its tip. Air inlet 21A is wider than air inlet 21B, and has a larger opening area. Combustion gas that has passed through heat transfer tubes 13A and 13B is supplied to these air inlets 21A and 21B. The combustion gas supplied into case 2 from air inlets 21A and 21B advances within case 2 and acts on first and second heat transfer tubes 3A and 3B, respectively, to recover heat. The combustion gas then passes through exhaust flow path 7, described below, provided in exhaust tube portion 23, and is discharged as exhaust gas from exhaust port 22 to the outside of case 2.

[0030] 6 and 7, exhaust tube portion 23 has a configuration in which a substantially cylindrical base end tube portion 23a is integrally formed by deep drawing or the like with front wall portion 20a of case 2, and a substantially cylindrical tip tube portion 23b formed separately from base end tube portion 23a is fitted and connected to this. A cap 91 is attached to exhaust port 22 to prevent foreign objects, human fingers, etc. from entering exhaust tube portion 23. The exhaust tube section 23 is located approximately in the center of the front wall section 20a of the case 2 in the left-right width direction, and serves both to exhaust combustion gas that has acted on the first heat transfer tube 3A and to exhaust combustion gas that has acted on the second heat transfer tube 3B.

[0031] In this water heating apparatus WH, the following "specific state" may occur. In this state, both combustion gas (exhaust gas) and air blown from the fan 10 pass through the exhaust pipe portion 23 (exhaust flow path 7). To explain this point in more detail, first, this hot water device WH can provide either only general hot water supply or only heating hot water supply, out of both general hot water supply and heating hot water supply. When only heating hot water supply is performed, the fan 10 is operated, the first burner unit 11A is deactivated, and the second burner unit 11B is activated. Therefore, as shown by the thick black arrow in FIG. 4, combustion gas generated by the second burner unit 11B is supplied into the case 2 from the air inlet 21B, acts on the second heat transfer tube 3B, and then flows toward the exhaust tube unit 23 (exhaust flow path 7). Meanwhile, as shown by the thick white arrow in FIG. 4, a portion of the air blown from the fan 10 is supplied into the case 2 from the air inlet 21A, acts on the first heat transfer tube 3A, and then flows toward the exhaust tube unit 23 (exhaust flow path 7). In this case, combustion gas (exhaust gas) flows into one side of the exhaust flow path 7 in the width direction, while air flows into the opposite side. Such a state corresponds to a specific example of the "specific state" in the present invention. In this specific state, water vapor in the combustion gas (exhaust gas) is likely to condense in the exhaust passage 7, which may result in the generation of a large amount of drain water. However, according to this embodiment, the means described below is provided to reduce such a risk.

[0032] The auxiliary members 4 and 5 are originally rectifying members for suppressing turbulence in the combustion gas (exhaust gas) passing through the exhaust tube portion 23 and reducing exhaust noise, but in this embodiment, they are members for forming the exhaust flow path 7 within the exhaust tube portion 23, the flow path area of ​​which is smaller than the opening area of ​​the inner region of the exhaust tube portion 23. However, when drain water generated on the surfaces of the first and second heat transfer tubes 3A and 3B due to latent heat recovery by the tubes 3A and 3B is blown directly into the exhaust tube portion 23 by the combustion gas, the auxiliary members 4 and 5 also function as drain water scattering prevention members that block the blown water and prevent it from scattering forward of the exhaust port 22. The drain water generated within the case 2 flows over the bottom wall portion 20d of the case 2, for example, and reaches the drain water outlet 27, where it is discharged to the outside.

[0033] As shown in FIGS. 4, 5, 8, and 9, the exhaust flow path 7 has a pentagonal shape in a front view or a front cross-sectional view of the heat exchanger HE, and is made up of a bottom wall surface portion 72, a pair of left and right side wall surface portions 71 located above the bottom wall surface portion 72, and an upper wall surface portion 73 connecting the upper ends of the pair of side wall surface portions 71. The upper wall surface portion 70 is divided into first and second inclined wall surface portions 70a, 70b, as will be described later. In this embodiment, the lower wall surface portion 72, the pair of side wall surface portions 71, and the upper wall surface portion 70 are each flat (although they may also be curved).

[0034] In this embodiment, the auxiliary members 4, 5 include first and second lower members 5 (5A, 5B) and first and second upper members 4 (4A, 4B). These correspond to specific examples of the "lower members" and "upper members" of the present invention, and are all formed by pressing thin stainless steel plates or the like.

[0035] 6 and 7, the first lower member 5A has a main body 50 and a support piece 51 for supporting the main body 50. The main body 50 has a horizontal first base plate 50a and a front plate 50b and a rear plate 50c that protrude downward from the front and rear edges of the base plate 50a. The second lower member 5B has a second base plate 52a and a rear plate 52b that protrudes downward from the rear edge. The first and second lower members 5A and 5B are connected using screws 92 with the front plate 50b and the rear plate 52b overlapping each other.

[0036] The main body 50 of the first lower member 5A and the second lower member 5B are disposed in a lower portion of the exhaust pipe portion 23, and this lower portion is closed by the rear plate portion 50c. As shown in Figures 4 and 5, the first and second lower members 5A, 5B are fixed in the exhaust pipe portion 23 by joining the support piece portion 51 of the first lower member 5A to the back surface of the front wall portion 20a of the case 2 (and also to the rear support piece portion 43 of the first upper member 4A, which will be described later). The upper surfaces of the first and second base plate portions 50a, 52a form the lower wall surface portion 72 of the exhaust flow path 7. As shown in FIG. 4, a baffle plate 94 for blocking the blown air (or combustion gas) traveling as indicated by arrow Na may be provided on the rear surface of the front wall portion 20a of the case 2.

[0037] 6 and 7, the first upper member 4A includes a pair of first rising portions 40 that rise in the vertical height direction, a first upper side portion 41 that is curved in front view and connects the upper portions of the first rising portions 40, and a plurality of front support pieces 42 and rear support pieces 43 that are connected to the front and rear edge portions of the first rising portions 40 and the rear edge portions of the second rising portions 44. The second upper member 4B includes a pair of second rising portions 44 that rise in the vertical height direction, a second upper side portion 45 that is curved in front view and connects the upper portions of the first rising portions 40 and the rear edge portions of the second rising portions 44. The first and second rising portions 40, 44 and the first and second upper side portions 41, 45 correspond to specific examples of the "rising portions" and "upper side portions" of the upper member as defined in the present invention. The first and second upper members 4A, 4B are connected by using screw members 93 in a state in which the front support piece portions 42 and the support piece portions 46 are overlapped with each other.

[0038] The first and second upper members 4A, 4B are fixed within the exhaust pipe section 23 and disposed above the first and second base plate sections 50a, 52a by having the rear support piece sections 43 overlap and be joined to the rear surface of the front wall section 20a of the case 2. As a result, the inward surfaces of the first and second rising sections 40, 44 form a pair of left and right side wall surface sections 71 of the exhaust flow path 7. In addition, the downward surfaces of the first and second upper sections 41, 45 form an upper wall surface section 70 of the exhaust flow path 7.

[0039] The first upper member 4A is also used to attach a sound absorbing material 80 (which is appropriately indicated by a halftone dot pattern in FIGS. 4 to 6). The sound absorbing material 80 is made of, for example, foamed resin, and is in the form of a bent sheet that corresponds to the shape of the first upper member 4A. The first rising portion 40 and The upper portion 41 is provided with a plurality of claws 47 for attaching the sound-absorbing material 80, and also with a plurality of openings 48 (the openings 48 are omitted in FIG. 4). As clearly shown in FIG. 5, a portion of the sound-absorbing material 80 faces the exhaust flow path 7 through the plurality of openings 48. This action serves to further reduce exhaust noise. The portion of the sound-absorbing material 80 that faces the exhaust flow path 7 through the openings 48 corresponds to a portion of the upper wall surface portion 70 or the side wall surface portion 71 of the exhaust flow path 7.

[0040] The upper wall surface portion 70 of the exhaust flow path 7 (the downward surfaces of the first and second upper portions 41, 45) is bent in a generally V-shape and configured as first and second inclined wall surface portions 70a, 70b. The first and second inclined wall surface portions 70a, 70b are connected at one end at the center in the width direction of the upper wall surface portion 70, and are inclined so that the height decreases toward the ends in the width direction of the upper wall surface portion 70, with the inclination directions being opposite to each other.

[0041] Next, the operation of the water heating device WH equipped with the heat exchanger HE will be described.

[0042] First, when only hot water heating is used, as described above, a specific state occurs in which combustion gas flows into one side of the exhaust passage 7 in the width direction, and air blown from the fan 10 flows into the other side. At this time, a contraction flow and a subsequent expansion flow occur, as described below. That is, as shown schematically in FIG. 10 , the flow path area A2 of the exhaust flow path 7 is significantly smaller than the flow path area A1 inside the case 2. Therefore, the gas (combustion gas or blown air) flowing inside the case 2 undergoes a contraction near the inlet of the exhaust flow path 7, where the projected area A3 of the flow is temporarily smaller than the flow path area A2. This contraction occurs more significantly the less rounded and the more acute the corner C at the base end opening of the exhaust flow path 7 is (in this embodiment, the corner indicated by symbol C1 in FIG. 4( b) is designed to be less rounded, so that the contraction occurs as significantly as possible). Furthermore, after the gas that has flowed into the exhaust flow path 7 undergoes the contraction, it expands so that the gas flow reaches the flow path area A2.

[0043] When the above-described contraction and subsequent expansion occur, the flow direction of the combustion gas and blown air is perpendicular to the upper wall surface 70 of the exhaust flow path 7, as shown in FIG. 8(b). In contrast, because the upper wall surface 70 is inclined as the first and second inclined wall surface portions 70a and 70b, the combustion gas and blown air that cause the contraction and subsequent expansion also flow in the width direction (horizontal direction) by a distance ΔLa corresponding to the inclination. This actively promotes heat transfer in the upper wall surface 70 of the exhaust flow path 7, helping to average the temperature distribution throughout the upper wall surface 70. Therefore, condensation caused by high-temperature combustion gas coming into contact with portions of the upper wall surface 70 that have been significantly cooled by the blown air is suppressed.

[0044] Furthermore, near the portion where the ends of the first and second inclined wall surface portions 70a, 70b are joined, the combustion gas and the blown air, which cause a contracting flow and a subsequent expanding flow, can flow close to each other. This allows the combustion gas and the blown air to be actively mixed, averaging the temperature of the upper wall surface portion 70 and more effectively suppressing the generation of drain water.

[0045] FIG. 11 shows a comparative example of the present invention. In this comparative example, the upper wall surface portion 70e of the exhaust flow path 7e is provided horizontally without inclination over the entire width of the exhaust flow path 7e. In this comparative example, the combustion gas and blown air that flow into the exhaust flow path 7e undergo the aforementioned contraction flow and subsequent expansion flow, and even if they flow in a direction perpendicular to the upper wall surface portion 70e, the movement dimension ΔLb in the width direction is substantially zero. Therefore, the effect described with reference to FIG. 8(b) cannot be obtained. In this comparative example, the temperature distribution in the upper wall surface portion 70e is not averaged, and the upper wall A portion of the surface portion 70e is kept at a fairly low temperature by the blown air, and if this portion comes into contact with the combustion gas, there is a risk that a large amount of drain water will be generated. In contrast, in this embodiment, such a risk is eliminated and the amount of drain water generated can be reduced. Therefore, it is possible to prevent the drain water generated in the upper wall surface portion 70 from being blown out in front of the exhaust port 22 by the combustion gas or blown air, and to appropriately resolve the problem of the drain water contaminating the periphery of the front part of the water heater WH.

[0046] Furthermore, if the upper wall surface portion 70 is formed as the first and second inclined wall surface portions 70a, 70b, the drain water generated in these areas flows along these inclinations to both ends in the width direction of the upper wall surface portion 70. This also makes it possible to prevent the drain water on the upper wall surface portion 70 from being blown out in front of the exhaust port 22. Drain water can also be generated at positions such as the lower wall surface portion 72 of the exhaust flow path 7, but drain water generated in such low-lying portions is less likely to be blown forward by combustion gases or blown air, and is less likely to become a cause of contamination.

[0047] 12 shows another embodiment of the present invention. In these figures, elements that are the same as or similar to those in the previous embodiment are given the same reference numerals as in the previous embodiment, and duplicated explanations will be omitted.

[0048] In the embodiment shown in FIG. 12(a), the upper wall surface portion 70 of the exhaust flow path 7 is an inclined wall surface portion 70c that is inclined in one direction across the entire width in the lateral direction. In the embodiment shown in FIG. 1(b), a portion of the upper wall surface portion 70 of the exhaust flow path 7 in the width direction is a non-inclined wall surface portion 70f, and the remaining portion is an inclined wall surface portion 70d. In any of these embodiments, the inclined wall surface portions 70c, 70d are provided, and therefore the intended effect of the present invention can be achieved. As can be understood from these embodiments, in the present invention, it is sufficient that at least a portion of the upper wall surface portion of the exhaust flow path is an inclined wall surface portion that is inclined up and down with respect to the width direction (horizontal direction).

[0049] The present invention is not limited to the above-described embodiment, and the specific configurations of the water heating device and the heat exchanger according to the present invention can be freely modified in various ways within the intended scope of the present invention.

[0050] In the above-described embodiment, the first and second lower members 5 (5A, 5B) and the first and second upper members 4 (4A, 4B) are provided as auxiliary members, but the present invention is not limited to this. For example, it is also possible to configure the exhaust flow path 7 using only the members corresponding to the first lower member 5A and the first upper member 4A among the above members. The auxiliary members are essentially members that form the exhaust flow path, and they may constitute the upper wall surface of the exhaust flow path, and at least a portion of this upper wall surface may be configured as an inclined wall surface that is inclined upward and downward with respect to the width direction. The specific shape, size, material, and total number of parts of the entire auxiliary member are not important.

[0051] The exhaust tube portion is not limited to a circular shape when viewed from the front, and may be, for example, a rectangular shape or an elliptical shape when viewed from the front, and there are no limitations on the specific shape or size. The first and second heat transfer tubes of the heat exchanger are not limited to serpentine tubes, but may be spiral tubes having a circular, elliptical or oval shape in plan view, or straight tubes. The hot water device according to the present invention includes devices for general hot water supply, hot water supply for baths, hot water supply for heating, and also devices for melting snow. The "front wall of the heat exchanger case" in the present invention is a wall located at the front of the heat exchanger case itself, and when the heat exchanger is assembled in a hot water supply device, the front of the case is not necessarily The water heater need not be located in front of the water heater. [Explanation of symbols]

[0052] HE heat exchanger WH water heater 10 Fans 11A, 11B First and second burner sections 2 cases 20a Front wall (of the case) 23 Exhaust pipe part 3A, 3B First and second heat transfer tubes 4A, 4B First and second upper members (auxiliary members) 5A, 5B First and second lower members (auxiliary members) 7 Exhaust flow path 70 Upper wall surface (of exhaust flow path) 70a, 70b First and second inclined wall portions (inclined wall portions) 70c,70d Slanted wall section 71 Side wall surface portion (of exhaust flow path) 72 Lower wall portion (of exhaust passage)

Claims

1. First and second burner units that can be individually driven and combusted and that are arranged in a predetermined width direction; a fan for blowing air to the first and second burner units; a heat exchanger in which first and second heat transfer tubes for heating hot and cold water are provided in a case to which the combustion gases generated by the first and second burner units are supplied, the first and second heat transfer tubes being arranged side by side corresponding to the first and second burner units, and an exhaust pipe for the combustion gases is provided on a front wall of the case; an auxiliary member disposed in the exhaust tube portion to form an exhaust flow path; It is equipped with A water heating device configured to be able to generate a specific state in which the combustion gas flows into one side of the exhaust flow path in the width direction, and simultaneously, blown air from the fan flows into the opposite side of the exhaust flow path, A hot water device characterized in that the auxiliary member forms an upper wall surface portion of the exhaust flow path, and at least a portion of this upper wall surface portion is an inclined wall surface portion that is inclined up and down with respect to the width direction.

2. The hot water device according to claim 1, The inclined wall portion comprises first and second inclined wall portions whose ends are connected to each other at a position closer to the center of the width direction of the upper wall portion, and the first and second inclined wall portions have opposite inclination directions so that the height becomes lower as they approach both ends of the width direction of the upper wall portion.

3. The hot water device according to claim 2, The water heating device, wherein the first and second inclined wall portions are both flat.

4. The hot water device according to claim 1, The water heating apparatus further comprises a sound absorbing material attached to the auxiliary member so as to face the exhaust flow path.

5. The hot water device according to claim 1, As the auxiliary member, a lower member disposed in a lower portion of the exhaust tube so as to close the lower portion and constituting a lower wall surface portion of the exhaust flow path; an upper member located above the lower member and spaced apart in the width direction, the upper member having a pair of rising portions rising upward from the lower wall surface portion to form a pair of left and right side wall surface portions of the exhaust flow path, and an upper portion connecting upper portions of the pair of rising portions; It is equipped with The water heating device, wherein the upper portion constitutes an upper wall surface portion of the exhaust flow path.

6. a case into which combustion gas is supplied, in which first and second heat transfer tubes for heating hot and cold water are arranged side by side, and in which an exhaust pipe for exhausting the combustion gas is provided on a front wall; an auxiliary member disposed in the exhaust tube portion to form an exhaust flow path; A heat exchanger comprising: A heat exchanger characterized in that the auxiliary member forms an upper wall surface portion of the exhaust flow path, and at least a portion of this upper wall surface portion is an inclined wall surface portion that is inclined up and down with respect to the width direction of the case.

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