JP2013130348A - Latent heat heat-exchanger and water heating apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a latent heat heat-exchanger where noise and deformation are difficult to be generated, and to provide a water heating apparatus.SOLUTION: A casing 2 includes: a case body 10 having a roughly rectangular box shape; and a top board 40 attached to the case body 10 to cover the opening 16 of its upper surface. A heat absorbing pipe 50 has a pipe structure where a straight pipe part 51 extending toward both sidewalls 14 and 15 of the case body 10 and a folded part 52 bent to be a roughly semicircular arc shape are repeatedly continued. Both pipe ends 53 and 54 on the upstream side and the downstream side are supported and fixed on one sidewall 14, and at least folded parts 52 of the respective heat absorbing pipes 50 disposed to vertically overlap each other in a contacted state. In the bottom wall 13 of the case body 10, there are provided support projected parts 131 and 132 for abutting and supporting, from below, the folded part 52 of the heat absorbing pipe 50 disposed undermost. In the top board 40, there are provided elastic pressing members 181 and 182 brought, respectively from above, into press contact with the folded part 52 of the heat absorbing pipe 50 disposed at the top thereof.

Description

  The present invention relates to a latent heat exchanger that condenses water vapor in combustion exhaust and recovers latent heat, and a hot water supply device that includes the latent heat exchanger.

  Conventionally, a so-called condensing type hot water supply apparatus having a sensible heat exchanger and a latent heat exchanger in an apparatus main body is known. In this type of hot water supply apparatus, after the sensible heat of the combustion exhaust is recovered by the sensible heat exchanger, the latent heat of the combustion exhaust is further recovered by the latent heat exchanger.

  As a latent heat exchanger incorporated in the hot water supply device, in order to realize downsizing and high thermal efficiency, the heat absorption of a piping structure in which a straight pipe portion extending toward the side wall of the casing and an arcuate folded portion are continuously repeated. There is known a structure in which a plurality of pipes are arranged in a stacked manner, and each of the heat absorption pipes is collectively connected to an external pipe via a header provided on one side surface of the casing.

  However, in this case, since the endothermic tube is supported in a cantilevered manner on one side wall of the casing, when the load is applied due to the flow of combustion exhaust gas introduced into the casing during operation or the water hammer phenomenon, etc. Each endothermic tube tends to vibrate and may cause problems such as noise and deformation.

  Therefore, in a conventional latent heat exchanger, a plurality of overlapping heat absorption tubes are fixed by being clamped together from above and below by a U-shaped clamp member, or meanderingly bent between these heat absorption tubes. The thing which aimed at suppression of the said vibration by pinching the wire was proposed (for example, refer patent documents 1 and 2).

JP 2006-343090 A JP 2008-151474 A

  However, in the above-described conventional latent heat exchanger, when assembling, it is necessary to first attach a fixing member such as a clamp member or a wire to the heat absorption tube, and perform brazing processing between the heat absorption tube and the casing in this state. The fixing member may be deformed by being exposed to high-temperature heat during brazing. If the fixing member is thermally deformed, unnecessary gaps are formed in the overlapping portions between the endothermic tubes or between the endothermic tube and the fixing member, resulting in a problem that vibration of each endothermic tube during operation cannot be sufficiently suppressed. .

  The present invention has been made to solve the above-described problems, and an object of the present invention is a latent heat heat exchanger that is less likely to cause noise, deformation, and the like in a latent heat heat exchanger that is required to be downsized and have high thermal efficiency. And a hot water supply apparatus including the latent heat exchanger.

The present invention provides a casing whose inside is a passage for combustion exhaust, a plurality of heat absorption tubes accommodated in the casing, an inflow header for introducing a fluid to be heated into the heat absorption tube, and a fluid to be heated from the heat absorption tube. A latent heat exchanger with a leading outflow header,
The casing has a substantially rectangular box-shaped case body having an upper surface opened, and a top plate attached to the case body so as to cover the opening on the upper surface.
The heat absorption pipe has a piping structure in which a straight pipe portion extending toward both side walls of the case main body and a folded portion bent in a substantially semicircular arc shape are repeatedly connected, both on the upstream side and the downstream side. A tube end is supported and fixed to the one side wall, and at least the folded portion of each heat absorption tube is arranged so as to overlap vertically with each other in contact with each other,
On the bottom wall of the case body, a support convex portion is provided that abuts and supports the folded portion of the heat absorption pipe disposed at the lowest position in the casing from below,
The top plate is provided with an elastic pressing member that presses and comes into contact with the folded portion of the endothermic tube disposed at the uppermost position in the casing from above.

  In this case, a plurality of heat absorption tubes supported on one side wall of the case body are fixed by being sandwiched from above and below by a support convex portion provided on the bottom wall of the case body and an elastic pressing member provided on the top plate. Since it is comprised so that each endothermic tube may be fixed stably. In addition, when assembling, the heat absorbing tubes and the case main body are brazed first, and then the heat absorbing tubes are fixed by attaching the top plate to the upper surface of the case main body. There is no risk of deformation due to the heat of the brazing process.

  Therefore, in the stage before attaching the top plate to the case body, it is unnecessary for the overlapping portions between the heat absorption tubes and between the heat absorption tubes and the support convex portions due to variations in assembly accuracy and thermal deformation of each component after brazing. Even if there is a gap, since the folded portion of the heat absorption tube is pushed down to the support convex portion side by the elastic pressing member when the top plate is attached to the case body, each heat absorption tube is stably fixed. As a result, unnecessary gaps are hardly generated in the overlapping portions between the heat absorption tubes, between the heat absorption tubes and the support convex portions, or between the heat absorption tubes and the elastic pressing members, and vibration of the heat absorption tubes during operation can be reliably prevented. .

  Moreover, in this thing, since the folding | returning part of each heat absorption tube which overlaps in a contact state is fixed so that it may be pinched | interposed by an elastic pressing member and a support convex part, each heat absorption tube is fixed more stably. As a result, the unnecessary gap is less likely to occur, and vibration of the heat absorption tube can be more reliably prevented.

  Further, in this case, each folded portion of the heat absorption tube is fixed by the elastic pressing member so as to be individually pushed down to the support convex portion side, so that variations in assembly accuracy, variations in the dimensions of the heat absorption tube itself, brazing processing Each endothermic tube is stably fixed even when the variation in thermal deformation of each component is large. As a result, the unnecessary gap is less likely to occur, and vibration of the heat absorption tube can be more reliably prevented.

  In the latent heat exchanger, the elastic pressing member has an upper portion fixed to the lower surface of the top plate and a lower portion having elasticity from above with respect to the folded portion of the heat absorption pipe disposed at the uppermost position in the casing. It is desirable that the leaf spring is formed so as to abut.

  In this case, the folded portions of the heat sink tubes that overlap in the contact state are pressed against each other in the overlapping direction by the appropriate elastic force of the leaf spring, so that variations in assembly accuracy, dimensional variations in the heat sink tubes themselves, Regardless of the variation in the thermal deformation of each part, each heat absorption tube is fixed more stably. As a result, the unnecessary gap is less likely to occur, and vibration of the heat absorption tube can be more reliably prevented.

  As described above, according to the present invention, it is possible to reliably prevent vibration of the heat absorption tube during operation, and thus it is possible to provide a latent heat exchanger and a hot water supply device that are less likely to generate noise and deformation.

FIG. 1 is a perspective view of a latent heat exchanger according to an embodiment of the present invention. FIG. 2 is an exploded perspective view of the latent heat exchanger according to the embodiment of the present invention. FIG. 3 is a perspective view of the heat absorption tube of the latent heat exchanger according to the embodiment of the present invention. FIG. 4 is a vertical cross-sectional view of the folded portion of the latent heat exchanger according to the embodiment of the present invention. FIG. 5 is a side view longitudinal sectional view of a first pipe presser (elastic presser member) portion of the latent heat exchanger according to the embodiment of the present invention. FIG. 6 is a longitudinal sectional view in rear view of the second pipe presser (elastic presser member) portion of the latent heat exchanger according to the embodiment of the present invention. FIG. 7 is a perspective view of the vicinity of the first pipe presser (elastic presser member) of the latent heat exchanger according to the embodiment of the present invention. FIG. 8 is a perspective view of the vicinity of the second pipe presser (elastic presser member) of the latent heat exchanger according to the embodiment of the present invention. FIG. 9 is a schematic configuration diagram of a hot water supply apparatus including a latent heat exchanger according to an embodiment of the present invention.

  Next, a latent heat exchanger according to an embodiment of the present invention and a hot water supply apparatus provided with the latent heat exchanger will be specifically described with reference to the accompanying drawings.

  As shown in FIGS. 1 and 2, the casing 2 of the latent heat exchanger 1 according to the embodiment of the present invention covers a substantially rectangular box-shaped case main body 10 having an upper surface opened and an opening 16 on the upper surface. In the internal space of the casing 2 surrounded by the case main body 10 and the top plate 40, a plurality of (in this case, eight) meandering bends are provided. The endothermic tube 50 is accommodated in a state where it is overlapped vertically.

  The case body 10 is integrally formed by drawing a thin metal plate having corrosion resistance such as stainless steel, and includes a back wall 11, a front wall 12, a bottom wall 13, one side wall 14, and the other side. A side wall 15 is provided. More specifically, the rear wall 11 and the front wall 12 stand up from the front and rear side edges of the flat bottom wall 13 extending in a certain direction, and the front and rear walls 11 and 12 are integrated with the bottom wall 13 through the corner. It is connected. Moreover, the one side wall 14 and the other side wall 15 stand up from the left and right side edge portions of the bottom wall 13, and the left and right side walls 14 and 15 are integrally connected to the bottom wall 13 through a corner portion. Furthermore, the left and right side edge portions of the back wall 11 and the front wall 12 are integrally connected to the one side wall 14 and the other side wall 15 via corner portions, respectively. Thus, an internal space having a substantially rectangular opening 16 surrounded by the back wall 11, the front wall 12, the bottom wall 13, the one side wall 14 and the other side wall 15 is formed in the case body 10.

  The upper end edge of the peripheral walls 11, 12, 14, 15 consisting of the back wall 11, the front wall 12, the one side wall 14, and the other side wall 15, that is, the peripheral edge of the opening 16, extends further outward from the peripheral edge A top plate mounting portion 101 that is bent horizontally is formed. The top plate placing portion 101 is integrally formed over the entire upper surface of the case body 10, and the top plate 40 is placed on the top surface and is screwed and joined.

  For the sake of convenience, in this specification, the direction in which the back wall 11 and the front wall 12 face each other is the front-rear direction, the direction in which the one side wall 14 and the other side wall 15 face each other in the left-right direction, and the bottom wall 13 and the top plate 40 are Although the opposing directions are referred to as the up and down directions, these directions may differ from the actual directions depending on how the latent heat exchanger 1 is attached to the hot water supply apparatus.

  As described above, if the case main body 10 is integrally formed by drawing, it is not necessary to perform a welding operation or a brazing operation when manufacturing the case main body 10. In addition, if the case body 10 has a joint portion such as welding or brazing, strong acid drain generated when the latent heat is recovered by the latent heat exchanger 1 enters the gap between the joint portions, and the metal plate Although there is a problem that corrosion of a case body 10 is likely to proceed, there is no joint by welding or brazing in the lower part of the case body 10 in the present embodiment, so that strongly acidic drain is generated in the casing 2. Even so, the drain does not easily stay in the lower portion, and corrosion of the case body 10 is suppressed. Further, since the peripheral walls 11, 12, 14, 15 and the top plate mounting portion 101 are integrally formed by drawing, the casing 2 can be easily manufactured with a small number of parts. The case main body 10 does not need to be integrally formed by drawing, but may be formed by joining different members together by welding or brazing.

  On the other hand, both end portions in the front-rear direction of the side wall 14 (end portions on the back wall 11 side and the front wall 12 side) respectively include an upstream end insertion hole 141 through which the upstream pipe end portion 53 of the heat absorption tube 50 is inserted, and heat absorption. Downstream end insertion holes 142 through which the tube end portion 54 on the downstream side of the tube 50 is inserted are drilled by the number of the endothermic tubes 50 (eight in each case) by burring. The upstream end insertion holes 141 and the downstream end insertion holes 142 are arranged in two vertical rows and in a staggered manner. Note that the number and arrangement of the upstream end insertion holes 141 and the downstream end insertion holes 142 are appropriately set according to the number of the heat absorption tubes 50.

  Both pipe end portions 53 and 54 of the heat absorption pipe 50 are led out of the case body 10 through the corresponding insertion holes 141 and 142, and are brazed and fixed to the peripheral edges of the insertion holes 141 and 142 in this state. . Furthermore, an upstream pipe end 53 and a downstream pipe end 54 led out of the case body 10 from the insertion holes 141 and 142 are respectively provided with an inflow header 60 disposed outside the one side wall 11 and Connected to the outflow header 70. In this manner, the inflow header 60 and the outflow header 70 are connected to the plurality of heat absorption tubes 50 in parallel, thereby reducing the water flow resistance as compared with the case where the heat absorption tubes 50 are connected in series. .

  The inflow header 60 and the outflow header 70 have vessel-shaped header bodies 61 and 71 and vessel-like header lid bodies 64 and 74 fitted into the header bodies 61 and 71, respectively. The header bodies 61 and 71 and the header lid bodies 64 and 74 are brazed and joined in such a manner that the surfaces on the opening side are overlapped with each other. Further, the bottom plate portions 62 and 72 of the header main bodies 61 and 71 are provided with endothermic tube connection holes 160 and 170 through which the pipe end portions 53 and 54 of the endothermic tube 50 are inserted. ) Is only drilled.

  Furthermore, an inflow port 164 that connects the inside and outside of the inflow header 60 is formed by burring in the bottom plate portion 65 of the header lid body 64 on the inflow header 60 side, and the bottom plate portion of the header lid body 74 on the outflow header 70 side. In 75, an outlet 174 connecting the inside and outside of the outflow header 70 is formed by burring. The inlet 164 and the outlet 174 are connected to a joint tube 68 for connecting a water supply pipe connected to a water supply source such as a water pipe and a connection pipe connected to a water inlet side connection port of the sensible heat exchanger, respectively. The joint cylinder 78 is attached. As a result, the fluid to be heated supplied to the inflow header 60 side flows to the outflow header 70 side via the plurality of heat absorption tubes 50, and the latent heat is recovered when water vapor in the combustion exhaust is condensed on the surface of the heat absorption tubes 50. Is done.

  As shown in FIG. 2 and FIG. 3, the endothermic tube 50 is a corrugated tube having a circular cross section made of a metal having corrosion resistance such as stainless steel (valleys and peaks are alternately continuous in the axial direction). A straight pipe portion 51 that extends in the left-right direction of the case body 10 (between the one side wall 14 and the other side wall 15), and a folded portion that bends in a semicircular arc from one end of the straight pipe portion 51. The portion 52 has a meandering piping structure that is continuously repeated in the same plane (however, in FIGS. 1 and 2, etc., only a part of the straight pipe portion 51 is shown in a bellows shape).

  A plurality of straight pipe portions 51 are arranged in parallel at equal intervals in the front-rear direction of the case body 10 (here, six), and each straight pipe portion 51 arranged in the last row (the back wall 11 side) in the casing 2 is arranged. The pipe end 51 (the pipe end on the upstream side of the endothermic pipe 50) 53 of the pipe 51 is inserted into and supported by the upstream end insertion hole 141 of the case body 10, and the foremost row (front wall in the casing 2). The pipe end part (the pipe end part on the downstream side of the heat absorption pipe 50) 54 on the one side wall 14 side of each straight pipe part 51 disposed on the (12 side) is inserted and supported in the downstream end insertion hole 142 of the case body 10. The

  The folded portion 52 is provided in a plurality (here, five locations) so as to connect the ends of the adjacent straight pipe portions 51, and is compressed and deformed up and down to have a flat cross section (see FIG. 4). .

  As shown in FIGS. 2 and 5, the folded portions 52 of the heat absorption tubes 50 are in contact with each other in a manner in which they are alternately shifted by a half pitch in the front-rear direction of the case body 10. That is, the endothermic pipes 50 are overlapped with the odd-numbered endothermic pipes 50 at the positions where the even-numbered endothermic pipes 50 are shifted by a half pitch toward the exhaust outlet 121 side (the exhaust direction of the combustion exhaust). Thereby, the distance between the heat absorption tubes 50 adjacent to each other in the overlapping direction becomes narrow, and the heat absorption tubes 50 can be densely arranged in the casing 2. As a result, the latent heat exchanger 1 can be reduced in size, and the combustion exhaust can be efficiently brought into contact with the heat absorption pipe 50. It should be noted that a plurality of heat absorption tubes 50 in which the straight tube portion 51 and the arcuate folded portion 52 bent in one direction are continuous may be used, and these heat absorption tubes 50 may be spirally arranged in the casing 2. good.

  As shown in FIG. 2, the first side wall 14 bulges toward the outside of the case body 10 at the center portion in the front-rear direction (between the upstream end insertion hole 141 and the downstream end insertion hole 142). The bulging portion 145 is formed by drawing. The first bulging portion 145 includes a step portion formed at a certain distance from each corner portion in the front-rear direction and a curved surface portion connecting the step portions, and includes an upstream end insertion hole 141 and a downstream end insertion hole. The one side wall 14 where the 142 is formed bulges outward from both end portions in the front-rear direction. Accordingly, the inner volume of the casing 2 is increased by the amount of the bulge, and the length of the heat absorption pipe 50 accommodated in the casing 2 can be increased accordingly. Further, since the first bulging portion 145 is integrally formed at the central portion of the one side wall 14, it contributes to the improvement of the strength of the casing 2 as a whole.

  A second bulging portion 155 that bulges outward from the case main body 10 is formed in the central portion of the other side wall 15 in the front-rear direction by drawing. The second bulging portion 155 includes a step portion formed at a certain distance from each corner portion in the front-rear direction and a curved surface portion connecting the step portions, and both side end portions of the other side wall 15 in the front-rear direction. It bulges outward. Thus, the strength of the casing 2 as a whole is further improved by integrally forming the second bulging portion 155 at the center portion of the other side wall 15.

  By the way, in this embodiment, since the case main body 10 is integrally formed by drawing processing, when the heat absorption pipe 50 is attached to the case main body 10, both pipe end portions 53 and 54 of the heat absorption pipe 50 are connected to the case main body 10. It is necessary to insert into the insertion holes 141 and 142 from the inside and connect to the inflow header 60 and the outflow header 70. Therefore, in a state where the endothermic tube 50 is attached to the case body 10, a certain size required for inserting the endothermic tube 50 between the folded portion 52 on the other side wall 15 side of the endothermic tube 50 and the other side wall 15. The extra space is secured. However, if there is such a marginal space, the combustion exhaust gas introduced into the casing 2 from the exhaust inlet 401 flows into this marginal space where the exhaust resistance is low and does not contact the heat absorption pipe 50 efficiently, and the thermal efficiency is high. May decrease. In consideration of such circumstances, in the present embodiment, rectification is preferably provided between the other side wall 15 and the folded portion 52 on the other side wall 15 side of the heat absorption pipe 50 to block the flow of combustion exhaust gas to the marginal space. A plate 45 is provided. With this rectifying plate 45, the combustion exhaust gas flows toward the heat absorption tube 50 and easily comes into contact with the heat absorption tube 50, so that the thermal efficiency can be improved.

  The rear wall 11 is formed with a third bulging portion 115 that is bulged outwardly from the case main body 10 and has a substantially arc shape as viewed from above by drawing. The third bulging portion 115 is formed so as to bend outward from each corner portion in the left-right direction toward the outside of the central portion. With this configuration, the inner portion of the back wall 11 accompanying drawing processing is formed. Therefore, it is possible to secure a space necessary for the smooth circulation of the combustion exhaust between the back wall 11 and the heat absorption pipe 50, and to improve the strength of the casing 2 as a whole. Has also contributed.

  As shown in FIGS. 2 and 5, the bottom wall 13 is inclined upward from the back wall 11 side to the front wall 12 side in order to smoothly drain the drain generated in the casing 2 to the outside. A drain drain port 17 for discharging the drain to the outside of the casing 2 is provided at the lowest position of the inclined surface. The drain drain port 17 is connected to an external neutralizer via a drain drain pipe (not shown).

  A first support convex 131 that bulges inward of the case body 10 is formed by drawing on one end of the bottom wall 13 in the left-right direction (end on the side of the side wall 14). The first support protrusion 131 abuts the folded portion (the lower folded portion on the side wall 14 side) 521 on the tube end portions 53 and 54 side of the heat absorption tube 50 disposed at the lowest position in the casing 2 from below. It swells to a position where it can be supported, and its upper surface is formed in a planar shape between the upstream end insertion hole 141 and the downstream end insertion hole 142.

  As shown in FIG. 2 and FIG. 6, a second support convex portion that bulges inward of the case body 10 at the other side end portion (the end portion on the other side wall 15 side) of the bottom wall 13 in the left-right direction. 132 is formed by drawing. The second support convex portion 132 has a folded portion (lower folded portion on the other side wall 15 side) 522 opposite to the tube end portions 53 and 54 of the heat absorption tube 50 disposed at the lowest position in the casing 2 from below. It swells to a position where it can be contacted and supported, and its upper surface is formed flat between the back wall 11 and the front wall 12.

  As shown in FIG. 2, a third support protrusion 133 that bulges inwardly of the case body 10 is formed by drawing at a substantially central portion in the left-right direction of the bottom wall 13. The third support convex portion 133 bulges up to a position where the straight pipe portion (lower straight pipe portion) 51 of the heat absorption pipe 50 disposed at the lowest position in the casing 2 can be abutted and supported from the lower side. The wall 11 and the front wall 12 are formed in a rib shape extending linearly with a constant width in the front-rear direction facing each other.

  Further, the third support convex portion 133 is extended so that one end is located at the front corner portion of the bottom wall 13 and the other end is located at a certain distance from the rear corner portion of the bottom wall 13. This also contributes to improving the strength of the casing 2 as a whole.

  An exhaust outlet 121 for leading the combustion exhaust gas introduced into the internal space of the casing 2 to the outside of the casing 2 is formed at a substantially central portion of the front wall 12 in the vertical and horizontal directions. The exhaust outlet 121 opens in a rectangular shape that is long in the left-right direction of the front wall 12. In addition, the exhaust outlet 121 may be provided in the top plate 40, and the opening position and shape are set suitably according to a usage form.

  As shown in FIGS. 1, 2 and 5, the top plate 40 is integrally formed by drawing a thin metal plate having corrosion resistance such as stainless steel, and has a substantially flat plate shape. A top plate main body 41, an upright portion 42 bent upward from the outer periphery of the top plate main body 41, a flange portion 43 bent horizontally so as to spread outward from the upper end of the upright portion 42, and a flange portion 43 And a hanging portion 44 bent downward from the outer peripheral edge.

  The back wall 11 side is inclined upward toward the flange portion 43 from the center portion in the front-rear direction of the top plate main body portion 41. Further, an exhaust inlet 401 for introducing combustion exhaust supplied from the appliance main body side of the hot water supply device into the internal space of the casing 2 is formed by burring at a substantially central portion of the inclined surface in the front-rear and left-right directions. . The exhaust inlet 401 opens in a rectangular shape that is long in the left-right direction of the top plate main body 41. Therefore, in a state where the case main body 10 and the top plate 40 are joined, the internal space of the casing 2 serves as a combustion exhaust passage that allows the exhaust inlet 401 and the exhaust outlet 121 to communicate with each other. In addition, the exhaust inlet 401 may be provided in the back wall 11, and the opening position and shape are set suitably according to a usage pattern.

  The standing upright portion 42 on the outer periphery of the top plate main body 41 is formed in a size that fits inside the inner peripheral edge of the opening 16 of the case main body 10, and the hanging portion 44 on the outer periphery of the flange portion 43 is formed on the outer periphery of the case main body 10. It is formed in a size that fits around the outer periphery of the top plate mounting portion 101. In addition, a band-shaped packing material 46 formed of an elastic resin having heat resistance and corrosion resistance is provided between the flange portion 43 and the top plate placement portion 101 of the case body 10. Airtightness between the flange portion 43 and the top plate placement portion 101 of the case body 10 is ensured. The packing material 46 is made of a material other than resin as long as it can maintain the airtightness between the flange portion 43 and the top plate placement portion 101 of the case body 10 and has heat resistance and corrosion resistance. It may be formed.

  As shown in FIGS. 2, 5, and 7, on the lower surface of the top plate main body 41 and at the one side end portion (the end portion on the one side wall 14 side) of the center portion in the front-rear direction, A first pipe presser 181 as an elastic pressing member that presses and comes into contact with a folded portion (upper folded portion on one side wall 14 side) 523 on the tube end portions 53 and 54 side of the endothermic tube 50 disposed at the top is disposed. ing. The first pipe presser 181 is a leaf spring formed of a single thin metal plate having corrosion resistance such as stainless steel, and has a predetermined elasticity in the vertical direction.

  The first pipe presser 181 is formed by bending a rectangular flat plate into a substantially inverted V shape, and its central upper portion 183 is formed in a flat shape that is long in the left-right direction of the top plate 40, and the top plate main body 41. It is fixed to the lower surface of the. In addition, elastic pieces 184 that are bent at a predetermined angle to the outside and below are provided at both ends in the front-rear direction of the central upper portion 183 (ends on the back wall 11 side and the front wall 12 side). The lower end portion 185 of the piece 184 presses and contacts the upper surface of the upper folded portion 523 on the one side wall 14 side of the heat absorption tube 50.

  When the case main body 10 and the top plate 40 are joined, the elastic piece 184 is pushed and bent further upward in a state where the lower end portion 185 is in contact with the upper folded portion 523 on the one side wall 14 side of the heat absorption tube 50. The upper folded portion 523 on the one side wall 14 side of the heat absorption tube 50 is pressed separately toward the first support convex portion 131 side by the repulsive force of the elastic piece 184. As a result, the lower folded portion 521 on the one side wall 14 side of the heat absorption tube 50 is pressed against the upper surface of the first support convex portion 131 of the bottom wall 13. The first pipe presser 181 has the same configuration as the second pipe presser 182 described later as long as the first pipe presser 181 is configured to press and contact the upper folded portion 523 on the one side wall 14 side of the heat absorption tube 50 from above. Alternatively, it may be formed using heat and corrosion resistant rubber.

  As shown in FIGS. 2, 6, and 8, the lowermost side of the top plate body 41 and the other side end (the end on the other side wall 15 side) of the central portion in the front-rear direction are the uppermost positions in the casing 2. A second pipe presser 182 as an elastic pressing member that presses and contacts a folded portion (an upper folded portion on the other side wall 15 side) 524 opposite to the tube end portions 53 and 54 of the endothermic tube 50 disposed on the upper side. It is installed. The second pipe presser 182 is a plate spring formed of a single thin metal plate having corrosion resistance such as stainless steel, and has a predetermined elasticity in the vertical direction.

  The second pipe presser 182 has a rectangular flat plate-shaped fixing piece 186 that is long in the front-rear direction of the top plate 40 at the upper portion thereof, and this fixing piece 186 is fixed to the lower surface of the top plate main body 41. In addition, a plurality of (here, three) elastic pieces 187 are provided at one side end of the fixed piece 186 (end on the center side of the top plate 40) to be bent downward at a predetermined angle. The lower end portion 188 of the elastic piece 187 presses and contacts the upper surface of the upper folded portion 524 on the other side wall 15 side of the heat absorption tube 50 separately. The number of elastic pieces 187 of the second pipe presser 182 is appropriately set according to the number of upper folded portions 524 on the other side wall 15 side of the heat absorption tube 50.

  When the case main body 10 and the top plate 40 are joined, the elastic piece 187 is pushed and bent further upward in a state where the lower end portion 188 is in contact with the upper folded portion 524 on the other side wall 15 side of the heat absorption tube 50. The upper folded portion 524 of the heat absorption tube 50 on the other side wall 15 side is pressed separately toward the lower second support convex portion 132 side by the repulsive force of the elastic piece 187. As a result, the lower folded portion 522 of the endothermic tube 50 on the other side wall 15 side is pressed against the upper surface of the second support convex portion 132 of the bottom wall 13. The second pipe presser 182 has the same configuration as the first pipe presser 181 described above as long as the second pipe presser 182 is configured to press and contact the upper folded portion 524 on the other side wall 15 side of the heat absorption tube 50 from above. Alternatively, it may be formed using heat and corrosion resistant rubber.

  Next, an example of a method for manufacturing a latent heat exchanger in the present embodiment will be specifically described with reference to FIG.

  In producing the latent heat exchanger 1, first, the pipe end portions 53 and 54 of the plurality of heat absorption pipes 50 are respectively inserted into the upstream end insertion hole 141 and the downstream end insertion hole 142 of the one side wall 14 of the case body 10. The pipe end portions 53 and 54 are led out from the side wall 14 by a predetermined length. At this time, in the heat absorption tube 50, the lower surface of the lower folded portion 521 on the one side wall 14 side comes into contact with the upper surface of the first support convex portion 131 on the bottom wall 13, and the lower surface of the lower folded portion 522 on the other side wall 15 is bottom. Arranged in the case body 10 in contact with the upper surface of the second support convex portion 132 of the wall 13 and the lower surface of the lower straight pipe portion 51 in contact with the upper surface of the third support convex portion 133 of the bottom wall 13. .

  A brazing material (for example, a paste-like nickel brazing material) is applied to the boundary between the tube end portions 53 and 54 of the heat absorption tube 50 and the upstream end insertion hole 141 and the downstream end insertion hole 142. The brazing material may be applied to the inner surfaces of the upstream end insertion hole 141 and the downstream end insertion hole 142 and the inner surfaces of the heat absorption pipe connection holes 160 and 170 of the header main bodies 61 and 71.

  In addition to the above, the joint cylinders 68 and 78 are fitted into the inlet 164 and the outlet 174 of the header lids 64 and 74, brazing material is applied to the boundaries thereof, and these are temporarily fixed. The bodies 64 and 74 are fitted into the header main bodies 61 and 71, and a brazing material is applied to the boundary.

  Then, the brazing process is performed by putting the sub-assembly coated with the brazing material into a high-temperature heating furnace as described above. As a result, each member is fixed by brazing at the location where the brazing material is applied. During the brazing process, the case body 10 and the endothermic tube 50 are heat-treated (solution treatment), so that residual stress in the case body 10 and the folded portion 52 generated by the deep drawing process is removed. Therefore, even if a strongly acidic drain contacts the surface of the case body 10 or the folded portion 52, stress corrosion cracking hardly occurs.

  Next, a rectifying plate 45 is inserted between the other side wall 15 and the folded portion 52 on the other side wall 15 side of the heat absorption tube 50 so as to cover the second bulging portion 155 from the inside of the other side wall 15, and the rectifying plate 45 is The other side wall 15 is screwed and joined from the outside. The rectifying plate 45 and the other side wall 15 may be joined by other joining methods such as welding or brazing.

  Further, the first pipe presser 181 and the second pipe presser 182 are joined to the lower surface of the top plate 40 by welding, and the packing material 46 is adhered along the lower surface of the flange portion 43. Then, the top plate 40 is placed on the upper portion of the case body 10 so that the flange portion 43 of the top plate 40 overlaps the upper surface of the top plate placement portion 101 of the case body 10 with the packing material 46 interposed therebetween. The latent heat exchanger 1 is manufactured by screwing the mounting portion 101 and the flange portion 43 together. In addition, you may use other joining methods, such as caulking, for joining with the top-plate mounting part 101 and the flange part 43. FIG.

  Further, when the top plate mounting portion 101 and the flange portion 43 are joined, the lower end portion 185 of the first pipe presser 181 of the top plate 40 is moved to the upper surface of the upper folded portion 523 on the one side wall 14 side of the heat absorption tube 50. Separately, the lower end portion 188 of the second pipe presser 182 of the top plate 40 comes into contact with the upper surface of the upper folded portion 524 on the other side wall 15 side of the heat absorption tube 50 in the pressed state. As a result, the folded portion 52 on the one side wall 14 side of each endothermic tube 50 is fixed so as to be sandwiched from above and below by the first pipe presser 181 and the first support convex portion 131, and the other side wall 15 side. The folded portion 52 is fixed by the second pipe presser 182 and the second support convex portion 132 so as to be sandwiched together from above and below.

  By the way, in the configuration in which both the pipe end portions 53 and 54 of the endothermic tube 50 are supported and fixed in a cantilever manner on the one side wall 14 of the case body 10, the other side wall 15 side of the endothermic tube 50 is welded or brazed. Since the heat absorption tube 50 cannot vibrate and be fixed, the support portion of the heat absorption tube 50 is likely to be deformed by the heat of the brazing process described above. Therefore, even if the uppermost and lowermost heat absorption tubes 50 are configured to abut against the top plate 40 and the bottom wall 13, respectively, unnecessary gaps are formed in these overlapping portions, and they are moved into the casing 2 during operation. The heat absorption tube 50 may vibrate due to the influence of the flow of the introduced combustion exhaust gas, the water hammer phenomenon, and the like, which may cause noise and deformation of the heat absorption tube 50.

  However, in the present embodiment, as described above, the folded portions 52 of the plurality of heat absorption tubes 50 are supported by the support convex portions 131 and 132 provided on the bottom wall 13 of the case body 10 and the pipe provided on the top plate 40. Since the pressers 181 and 182 are sandwiched and fixed together from above and below, each heat absorption tube 50 is stably fixed to the case body 10. Further, when the latent heat exchanger 1 is manufactured, the heat absorption tubes 50 and the case body 10 are first brazed, and then the top plate 40 is attached to the upper surface of the case body 10. Therefore, there is no possibility that the pipe holders 181 and 182 are deformed by being exposed to the heat of the brazing process.

  Therefore, before the top plate 40 is attached to the case body 10, due to variations in assembly accuracy and thermal deformation of each component after the brazing process, the endothermic tubes 50 and the support projections between the folded portions 52. Even if an unnecessary gap is formed in the overlapping portion between 131 and 132, when the top plate 40 is attached to the case body 10, the folded portion 52 of the heat absorption tube 50 is supported by the pipe pressers 181 and 182. Since it is pushed down to the 131, 132 side, each heat absorption tube 50 is stably fixed to the case body 10. Thereby, unnecessary gaps are hardly generated in the overlapping portions between the heat absorption tubes 50 or between the heat absorption tubes 50 and other members, and vibration of the heat absorption tubes 50 during operation can be reliably prevented. Therefore, noise and deformation are hardly generated.

  Further, unlike the above-described conventional latent heat exchanger, it is not necessary to fix the heat absorption tubes 50 together with the fixing members before brazing the heat absorption tubes 50 to the case body 10. The work is not complicated, and the overall structure of the latent heat exchanger 1 can be simplified. Further, no extra separate member other than the heat absorption pipe 50 is disposed in the passage of the combustion exhaust, and the combustion exhaust efficiently contacts the heat absorption pipe 50, so that the thermal efficiency is also improved.

  In particular, in the present embodiment, the folded portions 52 of the heat absorption tubes 50 that overlap in the contact state are pressed against each other in the overlapping direction by the appropriate elastic force of the pipe pressers 181 and 182 that are leaf springs, and thus the assembly accuracy varies. Each endothermic tube 50 is more stably fixed regardless of variations in dimensions of the endothermic tubes 50 themselves and variations in the thermal deformation of each component after brazing. Thereby, the said clearance gap is hard to produce further and the vibration of the heat absorption pipe | tube 50 at the time of a driving | operation can be prevented more reliably. Furthermore, each endothermic tube 50 is stably fixed by the case body 10 by fixing the folded portion 52 of each endothermic tube 50 formed in a flat cross section so as to be sandwiched from above and below. Can be reliably prevented.

  Further, in the present embodiment, the folded portions 52 of the heat absorption tube 50 are individually pushed down to the support convex portions 131 and 132 side of the bottom wall 13 by pipe pressers 181 and 182 having predetermined elasticity in the vertical direction. Since the fixing is performed, each heat absorption tube 50 is stably fixed even when the variation in assembly accuracy and the variation in thermal deformation of each component after brazing are large. Thereby, the unnecessary gap described above is less likely to occur, and the vibration of the heat absorption tube 50 can be more reliably prevented.

  Further, the first bulging portion 145 is provided on the one side wall 14 of the case main body to which the endothermic tube 50 is fixedly supported, so that the endothermic tube 50 can be accurately attached to the case main body 10 with little inclination. Therefore, each endothermic tube 50 is fixed more stably. Thereby, the unnecessary gap described above is less likely to occur, and the vibration of the heat absorption tube 50 can be more reliably prevented.

  Further, in the present embodiment, the case main body 10 is integrally formed with a single metal plate, and only the opening 16 on the upper surface of the case main body 10 that is less affected by the drain is covered with the top plate 40. Therefore, the casing 2 having excellent corrosion resistance can be produced simply by joining the case body 10 and the top plate 40 by screwing without performing welding or brazing.

  Next, an example of the hot water supply apparatus provided with the latent heat exchanger according to the present embodiment will be specifically described.

  As shown in FIG. 9, the hot water supply apparatus according to the present embodiment has a sensible heat exchanger 3 and the above-described latent heat exchanger 1, and latent heat exchange is performed below the sensible heat exchanger 3. A vessel 1 is provided. A gas burner 4 for combusting the gas supplied from the gas supply pipe is disposed at the upper part of the sensible heat exchanger 3, and the gas burner 4 is disposed on the side of the can body 41 covering the gas burner 4. A blower fan 5 for sending air for combustion is disposed.

  The sensible heat exchanger 3 has a plurality of fins 332 arranged side by side and a plurality of tube bodies 331 penetrating the fins 332. The space in which the fins 332 and the pipe body 331 are incorporated and the internal space of the latent heat exchanger 1 are partitioned vertically by the above-described top plate 40 and the exhaust inlet 401 of the top plate 40. It communicates through. Accordingly, during operation, the combustion exhaust gas sent into the sensible heat exchanger 3 is guided into the latent heat exchanger 1 through the exhaust inlet 401 and passes through the internal space of the casing 2 in which the heat absorption pipe 50 is disposed. After passing, it is discharged from the exhaust outlet 121 to the outside of the instrument body through an exhaust duct (not shown).

  In the hot water supply apparatus according to the present embodiment, gas combustion exhaust is generated by the gas burner 4, and this combustion exhaust is sequentially supplied to the sensible heat exchanger 3 and the latent heat exchanger 1. Then, the sensible heat of the combustion exhaust is recovered by the sensible heat exchanger 3, and the latent heat is further recovered from the combustion exhaust after the sensible heat recovery by the latent heat exchanger. At this time, combustion air is forcibly supplied to the gas burner 4 by the blower fan 5, and the combustion exhaust is guided to the latent heat exchanger 1 along the air flow.

  On the other hand, a water supply pipe connected to a water supply source such as a water pipe is connected to the joint cylinder 68 of the inflow header 60 provided in the latent heat exchanger 1, and a sensible heat exchange is performed to the joint cylinder 78 of the inflow header 70. The connection pipe connected to the water inlet side connection port of the pipe body 331 of the vessel 3 is connected. Accordingly, the cold water supplied from the water supply pipe sequentially passes through the heat absorption pipe 50 of the latent heat exchanger 1 and the pipe body 331 of the sensible heat exchanger 3, and absorbs latent heat and sensible heat to become hot water. It is sent from a hot water pipe connected to the outlet side connection port of the body 331 to a hot water supply terminal such as a bathroom or kitchen.

  As described above, in the present embodiment, the heat absorption tube 50 is stabilized with respect to the case body 10 by the support convex portions 131 and 132 of the bottom wall 13 of the case body 10 and the pipe pressers 181 and 182 of the top plate 40. Therefore, unnecessary gaps are hardly generated in the overlapping portions between the heat absorption tubes 50 or between the heat absorption tubes 50 and other members. As a result, vibration of the heat absorption tube 50 during operation is reliably prevented, and noise and deformation are unlikely to occur. Further, since the combustion exhaust efficiently contacts the heat absorption pipe 50, the thermal efficiency is also improved.

[Others]
(1) In the above embodiment, a latent heat exchanger used in a hot water supply apparatus having one heating circuit has been described. However, the present invention is also applied to a latent heat exchanger used in a hot water supply apparatus having two heating circuits. it can. In this case, the internal space of the casing is divided into two regions by a partition wall, and separate heat absorption tubes are accommodated in both internal spaces, and separate inflow headers and outflow headers are provided on both side walls.

  Specifically, one endothermic tube is accommodated in the first inner space surrounded by the back wall, the front wall, the bottom wall, the one side wall, and the partition wall, and both end portions of the one endothermic tube are on the one side wall. Supported and fixed. The other endothermic tube is accommodated in the second inner space surrounded by the rear wall, front wall, bottom wall, the other side wall and the partition wall, and both ends of the other endothermic tube are supported and fixed to the other side wall. Is done. Then, an inflow header and an outflow header are connected to the tube ends of both the heat absorption tubes. Support convex portions are respectively provided at one end portion of the bottom wall, the other end portion, and the left and right side lower end portions of the partition wall, and are provided on the lower surface of the top plate and vertically opposite to the respective support convex portions. A plurality of pipe pressers (elastic press members) are provided. Thereby, like the above-mentioned latent heat exchanger 1, the vibration of both heat absorption tubes during operation can be reliably prevented.

(2) In the above embodiment, since the heat absorption pipes 50 provided with the folded portions 52 are used at five locations, the support convex portions 131 and 132 are provided on the upper surfaces of the end portions on the side walls 14 and 15 side of the bottom wall 13. The pipe holders 181 and 182 are provided on the lower surfaces of the side walls 14 and 15 on the side walls 14 and 15 side of the top plate main body 41. However, when using an endothermic tube having a folded portion only at one location, the side wall 14 Since the folded portion is not provided on the side, the support convex portion is provided only on the upper surface of the end portion of the bottom wall 13 on the other side wall 15 side, and on the lower surface of the end portion on the other side wall 15 side of the top plate main body portion 41. Only pipe pressers are provided.

DESCRIPTION OF SYMBOLS 1 Latent heat exchanger 2 Casing 10 Case main body 11 Back wall 12 Front wall 13 Bottom wall 14 One side wall 15 The other side wall 16 Opening part 40 Top plate 50 Endothermic pipe 51 Straight pipe part 52 Folding part 53 Upstream pipe end part 54 Downstream Side pipe end portion 60 Inflow header 70 Outflow header 131 First support convex portion 132 Second support convex portion 181 First pipe presser (elastic presser member)
182 Second pipe presser (elastic presser member)

Claims (3)

A casing having an internal combustion exhaust passage, a plurality of heat absorption tubes accommodated in the casing, an inflow header for introducing a heated fluid into the heat absorption tube, and an outflow header for deriving the heated fluid from the heat absorption tube A latent heat exchanger with
The casing has a substantially rectangular box-shaped case body having an upper surface opened, and a top plate attached to the case body so as to cover the opening on the upper surface.
The heat absorption pipe has a piping structure in which a straight pipe portion extending toward both side walls of the case main body and a folded portion bent in a substantially semicircular arc shape are repeatedly connected, both on the upstream side and the downstream side. A tube end is supported and fixed to the one side wall, and at least the folded portion of each heat absorption tube is arranged so as to overlap vertically with each other in contact with each other,
On the bottom wall of the case body, a support convex portion is provided that abuts and supports the folded portion of the heat absorption pipe disposed at the lowest position in the casing from below,
A latent heat heat exchanger, wherein the top plate is provided with an elastic pressing member that presses and comes into contact with the folded portion of the heat absorption pipe disposed at the uppermost position in the casing from above. The latent heat exchanger according to claim 1,
The elastic pressing member is formed such that the upper part is fixed to the lower surface of the top plate and the lower part elastically contacts the folded portion of the heat absorption pipe disposed at the uppermost position in the casing. A latent heat heat exchanger that is a leaf spring.   A hot water supply apparatus comprising the latent heat exchanger according to claim 1.

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