HEAT EXCHANGE APPARATUS

[0001]This application claims priority under 35 U.S.C. §119 to Japanese Patent Application No. 2024-197103, November 12, 2024, which is incorporated by reference.

TECHNICAL FIELD

[0002] The invention relates to a heat exchange apparatus provided with a sensible heat exchanger and a latent heat exchanger, in which the latent heat exchanger is disposed above the sensible heat exchanger via an exhaust hood member that covers an upper surface of the sensible heat exchanger.

BACKGOUND ART

[0003] Conventionally, in the heat exchange apparatus of this kind, an inflow hole is generally formed in a bottom surface of a box-shaped case of the latent heat exchanger, in which a plurality of heat absorbing pipes are arranged, the inflow hole being positioned below a portion on a rear side in a depth direction from a region where the heat absorbing pipes are arranged. In addition, a connecting hole facing the inflow hole is formed in the exhaust hood member. Thus, a combustion exhaust gas passing through the sensible heat exchanger flows into the case of the latent heat exchanger through the connecting hole and the inflow hole (for example, referring to Patent Document 1).

[0004] Here, the reason that the inflow hole is formed below the portion on the rear side in the depth direction from the region where the heat absorbing pipe are arranged is to prevent drains from dropping into the sensible heat exchanger through the inflow hole and the connecting hole, the drains being generated by condensation of moisture components in the combustion exhaust gas on an outer surface of each heat absorbing pipe and being strongly acidic. However, in the conventional heat exchange apparatus, it is necessary to expand the case of the latent heat exchanger largely toward the rear side in the depth direction (equal to or greater than a depth size of the inflow hole) from the region where the heat absorbing pipes are arranged. Therefore, there is a defect in that the latent heat exchanger becomes oversized.

PRIOR ART PATENT DOCUMENT

[0005] Patent Document 1: JP2009-243725A

SUMMARY OF INVENTION

PROBLEM THAT THE INVENTION IS TO BE SOLVED

[0006] The invention has been made in view of the point mentioned above, and addresses a problem of providing a heat exchange apparatus in which the drains do not drop into the sensible heat exchanger and in which the latent heat exchanger can be downsized.

MEANS FOR SOLVING THE PROBLEM

[0007] In order to solve the problem mentioned above, the invention provides a heat exchange apparatus provided with a sensible heat exchanger and a latent heat exchanger, in which the latent heat exchanger is disposed above the sensible heat exchanger via an exhaust hood member that covers an upper surface of the sensible heat exchanger, and the latent heat exchanger is provided with a plurality of heat absorbing pipes arranged in a box-shaped case, the apparatus comprising: an inflow hole formed in a bottom surface of the case of the latent heat exchanger and positioned below a region where the heat absorbing pipes are arranged; a connecting hole facing the inflow hole and formed in the exhaust hood member; a covering member covering the connecting hole from above and protruding within the case of the latent heat exchanger; and an opening part opened in a direction crossing a vertical direction and formed in a portion of the covering member protruding within the case of the latent heat exchanger, wherein a combustion exhaust gas is configured to flow from the connecting hole into the case of the latent heat exchanger through the opening portion of the covering member.

[0008] According to the invention, since the inflow hole in the bottom surface of the case of the latent heat exchanger is positioned below the region where the heat absorbing pipes are arranged, it is unnecessary to expand the case largely toward a rear side in the depth direction from the region where the absorbing pipes are arranged, as in the conventional apparatus. Accordingly, the latent heat exchanger can be downsized. In addition, while the inflow hole is positioned below the region where the heat absorbing pipes are arranged, drains dropping from each outer surface of the heat absorbing pipes are received by the covering member, thereby preventing the drains from falling into the sensible heat exchanger.

[0009] In addition, in the invention, it is desirable that the inflow hole opens larger than the connecting hole, that a circumferential part of the inflow hole in the bottom surface of the case of the latent heat exchanger is configured to rest on a circumferential part of the connecting hole of the exhaust hood member, that an opening edge part of the connecting hole is formed as a first bent edge part bent upward, and that a lower edge part of the covering member is positioned between the first bent edge part and the opening edge part of the inflow hole. According to this, the lower edge part is positioned between the first bent edge part and the opening edge part of the inflow hole, thereby being capable of properly securing a positional relationship among the exhaust hood member, the covering member, and the case of the latent heat exchanger.

[0010] In this case, it is desirable that the exhaust hood member, the covering member, and the case of the latent heat exchanger are configured to be brazed between the first bent edge part and the opening edge part of the inflow hole. According to this, the exhaust hood member, the covering member, and the case of the latent heat exchanger are fixed in the proper positional relationship, thereby improving assembly accuracy.

[0011] Meanwhile, it is desirable that the opening edge part of the inflow hole is formed as a second bent edge part bent upward so that the lower edge part of the covering member does not ride over the opening edge part of the inflow hole and is not displaced.

[0012] Furthermore, in the invention, it is desirable that an upper surface of the covering member is configured to contact from below each heat absorbing pipe positioned at the lowest part among the heat absorbing pipes. According to this, each heat absorbing pipe positioned at the lowest part is supported by the covering member from below, thereby reducing the number of members required for fixing each heat absorbing pipe.

[0013] In this case, it is desirable that the case of the latent heat exchanger is formed by a case main body with an opened upper surface and a lid body closing the upper surface of the case main body, and that a lower surface of the lid body is configured to contact from above each heat absorbing pipe positioned at the highest part among the heat absorbing pipes. According to this, each heat absorbing pipe is pinched both from above and below by the lid body and the covering member, thereby further reducing the number of members required for fixing each heat absorbing pipe.

BRIEF DESCRIRTION OF THE DRAWINGS

[0014] [FIG. 1] FIG. 1 is a perspective view showing a heat exchange apparatus according to an embodiment of the invention.

[0015] [FIG. 2] FIG. 2 is a cut cross-sectional view of the heat exchange apparatus according to the embodiment.

[0016] [FIG. 3] FIG. 3 is a perspective view showing a disassembled state of a main part of the eat exchange apparatus according to the embodiment.

MODES FOR CARRYING OUT THE INVENTION

[0017] A heat exchange apparatus according to an embodiment of the invention, shown in FIGS. 1, 2, is an apparatus for supplying hot water, which is mounted on a combustion box (not shown) in which a burner is built. This heat exchange apparatus is provided with a sensible heat exchanger 1 and a latent heat exchanger 3, wherein the latent heat exchanger 3 is disposed above the sensible heat exchanger 1 via an exhaust hood member 2 that covers an upper surface of the sensible heat exchanger 1. Hereinafter, descriptions will be made on the premise that a depth direction is defined as a front-rear direction, and a width direction is defined as a lateral direction.

[0018] The sensible heat exchanger 1 is formed by a fin-tube type heat exchanger in which a plurality of heat absorbing fins 12 stacked in the front-rear direction are disposed in a shell body 11 having both upper and lower surfaces opened, and a plurality of pipes 13 piercing these heat absorbing fins 12 are arranged at intervals in the lateral direction. These pipes 13 are connected in series on each outer side in the front-rear direction of the shell body 11. In addition, a water inlet pipe 15 is connected to the pipe 14 positioned at an upstream end (a right-hand side in FIG. 1) among the pipes 13, while a hot-water outlet pipe (not shown) is connected to the pipe 13 positioned at a downstream end (a left-hand end in FIG. 1).

[0019] The exhaust hood member 2 has a outer circumferential flange part 21 overlapping a flange part 111 positioned at an upper end of the shell body 11 of the sensible heat exchanger 1, and a main body part 22 which is surrounded by the flange part 21 and bulges upward.

[0020] The latent heat exchanger 3 is constructed by arranging, within a box-shaped case 31, a plurality of heat absorbing pipes 32 that extend in the front-rear direction while meandering in a lateral direction, the pipes 32 being stacked in the vertical direction. The case 31 is composed of a case main body 31a having an open upper surface and a lid body 31b that closes the open upper surface of the case main body 31a. The lid body 31b is secured to the case main body 31a by hemming the upper edge of the case main body 31a.

[0021] An exhaust hole 33 having a laterally elongated double-walled cylindrical shape is formed in a front surface of the case 31. A bottom surface 311 of the case 31 is inclined downward as a whole toward a front. A cylindrical drain port 24 for discharging drains is installed vertically at a central portion in the lateral direction of a front end part of the bottom surface 311. In addition, an inlet-side header 35, connected to a front end defined as the upstream end of the heat absorbing pipes 32, and an outlet-side header 36, connected to the rear end defined as the downstream end of the heat absorbing pipes 32, are provided on an outer surface of one side in the lateral direction of the case 31. An inlet port 351, provided with the inlet-side header 35, is connected to a water supply pipe (not shown), and an outlet port 361, provided with the outlet-side header 36, is connected to a connecting pipe (not shown) communicating with the water inlet pipe 15.

[0022] With reference also to FIG. 3, an inflow hole 37, positioned below a region where the heat absorbing pipes 32 are disposed, is formed on the bottom surface 311 of the case 31. In addition, a connecting hole 23 facing the inflow hole 37 is formed in the exhaust hood member 2. Furthermore, a covering member 38, covering the connecting hole 23 from above, is provided so as to protrude within the case 31. An opening part 381, opened in a direction crossing the vertical direction, is formed in a portion of the covering member 38 that protrudes within the case 31. Thus, a combustion exhaust gas passing through the sensible heat exchanger 1 flows from the connecting hole 23 into the case 31 through the opening part 381 of the covering member 38. It should be noted that FIG. 3 illustrates a state in which the latent heat exchanger 3 is viewed diagonally downward, while the exhaust hood member 2 and the covering member 38 are viewed diagonally upward.

[0023] Specifically describing the covering member 38, the covering member 38 includes an upper plate part 382, facing upward toward the connecting hole 23, and three side plate parts 383. One side plate part 383 is bent and extends downward from a front edge of the upper plate part 382, and the other two side plate parts 383 are bent and extend downward from both side edges in the lateral direction of the upper plate part 382. On the other hand, no side plate part extending downward from a rear edge of the upper plate part 382 is provided so that the opening part 381, opened rearward, is formed. The combustion exhaust gas passes through the opening part 381 and flows within the case 31 from a rear side to a front side, then is exhausted from the exhaust hole 33. In addition, the upper plate part 382 extends more rearward than the rear edge of the connecting hole 23.

[0024] As mentioned above, as long as the inflow hole 37 in the bottom surface 311 of the case 31 of the latent heat exchanger 3 is positioned below the region where the heat absorbing pipes 32 are arranged, it is unnecessary to extend the case 31 largely toward the rear from the region where the heat absorbing pipes 32 are arranged. Accordingly, the latent heat exchanger 3 can be downsized. In addition, while the inflow hole 37 is positioned below the region where the heat absorbing pipes 32 are arranged, the drains dropping from each outer surface of the heat absorbing pipes 32 are received by the covering member 38, thereby preventing the drains from falling into the sensible heat exchanger 1.

[0025] In addition, in the embodiment, the inflow hole 37 opens larger than the connecting hole 23, and a circumferential part of the inflow hole 37 in the bottom surface 311 of the case 31 rests on a circumferential part of the connecting hole 23 of the exhaust hood member 2. Furthermore, an opening edge part of the connecting hole 23 is formed as a first bent edge part 23a bent upward, and similarly, an opening edge part of the inflow hole 37 is formed as a second bent edge part 37a bent upward. Each lower edge part of the side plate parts 383, constituting a lower edge part of the covering member 38 is positioned between the first bent edge part 23a and the second bent edge part 37a which is the opening edge of the inflow hole 37.

[0026] Here, when assembling the latent heat exchanger 3, after mounting the case main body 31a on the exhaust hood member 2, and with a brazing material placed between the first and the second bent edge parts 13a, 37, the covering member 38 is positioned so that a lower edge part thereof is inserted between the first and the second bent edge parts 23a, 37a. Next, a plurality of the heat absorbing pipes 32 are set within the case main body 31a so that those end parts on both the upstream side and the downstream side are inserted into the side plate parts on the one side in the lateral direction of the case main body 31a, and a brazing material paste is applied to each inserted portion where the heat absorbing pipes 32 are inserted into the side plate parts on the one side in the lateral direction of the case main body 31a. Subsequently, the inlet-side and outlet-side headers 35, 36 are attached to the outer surfaces of the side plate parts on the one side in the lateral direction of the case main body 31a, and in this attached state, brazing is performed in a furnace. Finally, the lid body 31b is positioned on the upper surface of the case main body 31a, and the exhaust hole 33 is attached to the front surface of the case 31, while the lid body 31b is fixed to the case main body 31a by hemming.

[0027] As mentioned above, as long as the lower edge part of the covering member 38 is positioned between the first and the second bent edge parts 23a, 37a, a positional relationship among the exhaust hood member 2, the covering member 38, and the case 31 can be properly secured. Furthermore, the exhaust hood member 2, the covering member 38, and the case 31 are brazed between the first and the second bent edge parts 23a, 37a. According to this, the exhaust hood member 2, the covering member 38, and the case 31 are fixed in the proper positional relationship, thereby improving assembly accuracy.

[0028] In addition, in the embodiment, the upper surface of the covering member 38, i.e., the upper surface of the upper plate part 382, is configured to contact from below each heat absorbing pipe 32 positioned at the lowest position among the heat absorbing pipes 32. Furthermore, the lower surface of the lid body 31b is configured to contact from above each heat absorbing pipe 32 positioned at the highest part among the heat absorbing pipes 32 by mounting the lid body 31b on the case main body 31a. According to these configurations, the heat absorbing pipes 32 are pinched from above and below by the lid body 31b and the covering member 38, thereby reducing the number of members required for fixing each heat absorbing pipe 32. It should be noted that, insofar as the covering member 38 contacts the heat absorbing pipe 32 positioned at the lowest part, the number of members required for fixing each heat absorbing pipe 32 can be reduced to some extent, even if the lid body 31b does not contact the heat absorbing pipe 32 located at the highest position.

[0029] In the above, the embodiment of the invention has been described with reference to the figures, the invention is not limited to this embodiment. For example, in the embodiment mentioned above, the opening part 381 of the covering member 38 is opened toward the rear side. However, in a case where the heat absorbing pipes 32 extend in the lateral direction while meandering in the front-rear direction and the combustion exhaust gas is made to flow from the one side to the other side in the lateral direction within the case 3, the opening part 381 of the covering member 38 may instead be opened to the one side in the lateral direction.

[0030] In addition, the opening edge part of the inflow hole 37 may be a normal edge part that does not bend upward. However, in order to prevent the lower edge part of the covering member 38 from riding over the opening edge part of the inflow hole 37 and being displaced, it is desirable that the opening edge part of the inflow hole 37 is formed as the second bent edge part 37a bent upward, as described above. Although the embodiment applies the invention to the heat exchange apparatus for the hot-water supply, the invention may alternatively be applied to a heat exchange apparatus for heating, for example.

EXPLANATION OF MARKS

[0031]1 Sensible heat exchanger

[0032]2 Exhaust hood member

[0033]23 Connecting hole

[0034]23a First bent edge part

[0035]3 Latent heat exchanger

[0036]31 Case

[0037]31a Case main body

[0038]31b Lid body

[0039]311 Bottom surface of case

[0040]32 Heat absorbing pipe

[0041]37 Inflow hole

[0042] 37a Second bent edge part

[0043]38 Covering member