JP2014070800A - Combustion apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat exchanger for latent heat recovery of high thermal efficiency and a combustion apparatus.SOLUTION: A heat exchanger 6 for latent heat recovery for recovering exhausted latent heat held by combustion gas of a burner is constituted such that each of a pair of side surface walls 7a, 7b of a case member 8 oppositely facing to each other to cover a bottom surface, an upper surface and side surfaces of a combustion gas passage 2 formed in a lateral orientation is formed with openings 9a, 9b, the combustion gas flows from the opening 9a at one side surface toward the opening 9b formed at the other side surface and is exhausted. A heat receiving pipe passage 3 having a pipe passage extending in a direction crossing the flow of combustion gas is arranged in the passage space for the combustion gas through a clearance against the case member 8. Protruded walls 11 protruding downward are arranged at a top plate 10 covering the upper surface of the combustion gas passage space with a clearance against the heat receiving pipe passage 3 while crossing with the combustion gas flow so as to disturb a flow of the combustion gas passing through the combustion gas passage space by the protruded walls 11.

Description

  The present invention relates to a heat exchanger for latent heat recovery that is applied to a combustion apparatus such as a hot water heater and performs heat exchange by receiving heat of combustion gas, and a combustion apparatus including the same.

  FIG. 6 is a schematic system diagram showing an example of a water heater that is a combustion apparatus. Conventionally, various combustion apparatuses as shown in this figure have been proposed. In the figure, a burner 1 is disposed in a combustion chamber 20 provided in an instrument case 40, and a gas pipe 42 for supplying fuel to the burner 1 is connected to the burner 1. An open / close valve (not shown) for controlling supply / stop of fuel to the burner 1 and a proportional valve (not shown) capable of controlling the amount of fuel supplied to the burner 1 with the valve opening degree are interposed. It is installed.

  A combustion fan 5 that supplies and exhausts combustion of the burner 1 is provided below the burner 1. This water heater supplies air that is sucked from the outside to the burner 1 by the rotation of the combustion fan 5, performs burner combustion with this air and gas supplied through the gas pipe 42, and is generated by the burner combustion. The combustion gas is sent from the combustion chamber 20 to the exhaust port 18 side and exhausted by the rotation of the combustion fan 5.

  A main heat exchanger (primary heat exchanger) 4 for recovering sensible heat in the combustion gas of the burner 1 is disposed on the upper side of the burner 1, and the combustion gas is more than in the main heat exchanger 4. A latent heat recovery heat exchanger (secondary heat exchanger) 6 provided on the downstream side of the flow (upper side of the main heat exchanger 4) for recovering the sensible heat in the combustion gas and the exhaust latent heat possessed by the combustion gas. Is arranged. Each of the heat exchangers 4 and 6 has heat receiving pipes 34 and 3 made of metal or the like through which water as a heat receiving fluid that receives the heat of the combustion gas of the burner 1 passes, for example. In one or both of the heat exchangers 4 and 6, a plurality of fins may be provided outside the heat receiving pipes 34 and 3 with a space therebetween.

  A water supply pipe 46 serving as a water supply passage led from a water supply source is connected to the inlet side of the latent heat recovery heat exchanger 6, and the outlet side of the latent heat recovery heat exchanger 6 and the main heat exchanger are connected. The inlet side of 4 is connected via a connecting pipe 48. A hot water supply pipe 47 is connected to the outlet side of the main heat exchanger 4. In FIG. 6, the water supply pipe 46, the hot water supply pipe 47, and the connection pipe 48 are schematically shown by linear arrows. However, the water supply pipe 46, the hot water supply pipe 47, and the connection pipe 48 circulate water. For example, a pipe having a circular cross section.

  Normally, the water supply pipe 46 has a water thermistor (not shown) that detects the temperature of water supplied from the water supply pipe 46 and flows into the latent heat recovery heat exchanger 6, and the water that flows into the latent heat recovery heat exchanger 6. The hot water supply pipe 47 is provided with a hot water thermistor (not shown) capable of detecting the temperature of the hot water flowing out.

  Under the latent heat recovery heat exchanger 6, an appropriate drain discharge means for discharging the drain generated in the latent heat recovery heat exchanger 6 to the outside is provided. In the water heater shown in this figure, a drain tray 43 and a drain pipe 44 connected to the tray 43 are provided as drain discharge means. The distal end side of the drain pipe 44 is led out of the instrument case 40 and is configured to discharge the condensed water droplets accumulated in the receiving tray 43 to the outside.

  Combustion control of the burner 1 and rotation control of the combustion fan 5 are performed according to a sequence program given in advance by a combustion control device (not shown) based on detection signals of the respective sensors. The burner 1 is combusted by the gas supplied from the gas pipe 42 and the air sent by the combustion fan 5. As the burner 1 burns, the hot water heater passes through the water supply pipe 46 through the latent heat recovery heat exchanger 6 and the main heat exchanger 4 in order to make hot water. It has a hot water supply function that leads the hot water first.

  In the water heater provided with the latent heat recovery heat exchanger 6, the high-temperature combustion gas from the burner 1 is disposed from the upper side of the burner 1, for example, as shown by the broken arrow in FIG. 6. Through the lower side of the receiving tray 43 and enters the arrangement region side of the latent heat recovery heat exchanger 6 from the horizontal side. And the combustion gas which passed the arrangement | positioning area | region of the heat exchanger 6 for latent heat collection | recovery is exhausted from the exhaust port 18 side.

  Then, while the combustion gas passes through the main heat exchanger 4, heat exchange is performed between the combustion gas and water supplied to the main heat exchanger 4, and sensible heat of the combustion gas is recovered. . Further, while the combustion gas that has passed through the main heat exchanger 4 passes through the latent heat recovery heat exchanger 6, heat exchange is performed between the combustion gas and water supplied to the latent heat recovery heat exchanger 6. Thus, the sensible heat and latent heat of the combustion gas are recovered.

  The latent heat recovery of the combustion gas by the latent heat recovery heat exchanger 6 is performed by bringing the combustion gas containing water vapor into contact with the low temperature heat transfer surface below the saturation temperature to condense the water vapor in the combustion gas. That is, it recovers the latent heat of condensation that occurs when water vapor condenses, and usually recovers the enthalpy of the water vapor of the combustion gas that is discharged out of the combustion system such as a water heater as the combustion gas. is there.

  Thus, in the water heater provided with the latent heat recovery heat exchanger 6, when the combustion gas generated by the combustion of the burner 1 passes through the latent heat recovery heat exchanger 6, the water pipe in the latent heat recovery heat exchanger 6 is connected. When the passing water takes away the latent heat (exhaust latent heat) possessed by the water vapor in the combustion gas to increase the temperature (collecting the latent heat) and further passes through the main heat exchanger 4, the combustion thermal power of the burner 1 Since it is heated to produce hot water having a set temperature, the burner 1 can perform efficient heating.

  That is, by providing the heat exchanger 6 for recovering latent heat, for example, in a water heater, the thermal efficiency reaches about 90% or more on a high heating value (total heating value) basis, and the heat exchanger 6 for recovering latent heat is provided. High thermal efficiency is achieved compared to a normal water heater without.

  Various configurations of the latent heat recovery heat exchanger 6 have been proposed. For example, as shown in FIG. 7A, the heat receiving pipe 3 is arranged in a spiral shape, and the heat receiving pipe 3 A latent heat recovery heat exchanger 6 provided with a peripheral wall 49 surrounding the periphery has also been proposed (see, for example, Patent Document 1). In the proposed latent heat recovery heat exchanger 6, as shown by an arrow N in FIG. 7B, the combustion gas passes through the combustion chamber 20 of the combustion apparatus and the main heat exchanger 4 to recover the latent heat. As shown in the order of arrows N1 to N4 in FIG. 7 (a) by being introduced into the space 39 in the center of the latent heat recovery heat exchanger 6 from below the heat exchanger 6 and being blocked by the guide 50. In this manner, it flows between the heat receiving pipes 3 and is discharged.

JP 2008-298325 A

  By the way, in order to improve the thermal efficiency of the latent heat recovery heat exchanger 6, the rate at which the combustion gas passing through the latent heat recovery heat exchanger 6 and the fluid such as water passing through the heat receiving pipe 3 are in thermal contact with each other is increased. However, if the heat receiving pipe 3 comes into contact with the case of the latent heat recovery heat exchanger 6, the heat of the fluid in the heat receiving pipe 3 escapes to the outside through the wall of the case, which is not preferable. . For this reason, the latent heat recovery heat exchanger 6 is disposed at a distance from each other so that the heat receiving pipe 3 and the wall of the case do not come into contact with each other. The combustion gas flowing between the top plate and the top plate flows in a laminar flow without being disturbed, and the thermal efficiency cannot be improved by that amount.

  Further, the combustion apparatus such as a water heater is required to be reduced in size and price, and the latent heat recovery heat exchanger 6 provided in the combustion apparatus is also required to be reduced in size and price. On the other hand, in the proposed latent heat recovery heat exchanger 6 shown in FIG. 7, as described above, the space 39 (a large space in which the heat receiving pipe 3 for passing the combustion gas is not provided) is provided. Therefore, there has been a problem that the latent heat recovery heat exchanger 6 is enlarged.

  Further, in the combustion apparatus provided with the latent heat recovery heat exchanger 6 shown in FIG. 7, the combustion gas is blocked by the guide portion 50, and the heat receiving pipe as shown by arrows N1 to N4 in FIG. Since the exhaust gas is prevented from going straight in this way, the exhaust resistance increases and the rotational speed of the combustion fan 5 must be increased. There is also a problem that it leads to an increase in the size of the combustion apparatus.

  The present invention has been made in order to solve the above-mentioned problems, and an object of the present invention is to improve the heat efficiency with a simple configuration, and to realize a heat exchanger for latent heat recovery that can be reduced in size and price, and its An object of the present invention is to provide a combustion apparatus using a heat exchanger for recovering latent heat.

  In order to achieve the above object, the present invention has the following configuration as means for solving the problems. That is, the latent heat recovery heat exchanger according to the first aspect of the present invention is a latent heat recovery heat exchanger for recovering latent heat of exhaust gas held by the combustion gas of the burner, and a bottom surface of the combustion gas passage formed sideways. The case member has a case member covering the upper surface and the side surface, and an opening is formed in each of the pair of side walls facing each other of the case member. Combustion gas introduction opening to be introduced, and the combustion gas introduced into the case member from the combustion gas introduction opening flows toward the opening formed on the side wall on the other side of the case member And a heat receiving pipe having a pipe extending in a direction crossing the flow of the combustion gas in the passage space of the combustion gas through the gap with the case member. Disposed above the combustion gas passage space. A convex wall portion projecting downward is provided on the top plate of the case member covering the gas passage so as to cross the flow of the combustion gas through the gap from the heat receiving pipe, and the convex wall portion allows the combustion gas to flow. A configuration that disturbs the flow of the combustion gas passing through the passage space serves as a means for solving the problem.

  In addition to the configuration of the first invention, the heat exchanger for latent heat recovery according to the second invention is such that the top plate of the case member has a slope inclined downward as it goes from the upstream side to the downstream side of the flow of the combustion gas. It is formed.

  Further, the latent heat recovery heat exchanger according to the third aspect of the invention is provided in addition to the structure of the first or second aspect of the invention, in which openings are respectively formed in a pair of side walls facing each other of the case member. In addition, an opening is formed in one end side of the bottom wall, which is the bottom surface of the case member, and a side wall on the opposite side, and the opening formed in the bottom wall of the case member introduces combustion gas. The combustion gas introduced into the case member from the combustion gas introduction opening flows from one end side to the opposite side of the space of the case member, It is characterized by being configured to be discharged from an opening provided in the side wall of the case member.

  Furthermore, a combustion apparatus according to a fourth aspect is characterized by comprising the latent heat recovery heat exchanger according to the first, second, or third aspect.

  According to the heat-recovery heat exchanger according to the present invention, the combustion gas passes through the opening formed in the case member covering the bottom surface, the top surface, and the side surface of the combustion gas passage formed sideways. Having a structure that flows from the combustion gas inlet on one side (one side) toward the opening on the other side (opposite side), and a pipe that extends in a direction crossing the flow of the combustion gas A heat pipe is disposed in the combustion gas passage space with a space from the case member, but the top plate of the case member covering the upper surface of the combustion gas passage space has a lower side (that is, a combustion gas passage). A convex wall portion projecting toward the passage space side) is provided in a mode crossing the flow of the combustion gas via the heat receiving pipe line, and the flow of the combustion gas passing through the passage space of the combustion gas by the convex wall portion. This flow is disturbed by the combustion gas that is disturbed. A fluid through the conduit is easily in thermal contact, thereby improving the thermal efficiency.

  In addition, the latent heat recovery heat exchanger of the present invention has a configuration in which a convex wall portion that is not in contact with the heat receiving pipe line is formed on the top plate of the case member covering the passage space of the combustion gas so as to protrude downward. As in the invention described in Document 1, it is difficult to reduce the size as in the case of providing a large space in which the heat receiving pipe for passing the combustion gas is not provided in the center of the heat receiving pipe formed in a spiral shape. Therefore, the heat efficiency can be improved with a simple configuration, and the latent heat recovery heat exchanger can be realized that can be reduced in size and cost.

  Furthermore, since the combustion gas is lighter than air and tends to flow upward, the top plate of the case member is formed on a slope inclined downward as it goes from the upstream side to the downstream side of the flow of the combustion gas. Since the combustion gas which is going to flow upward hits the top plate of the slope and changes its direction downward, it becomes easier to contact the heat receiving pipe, so that the thermal efficiency can be further improved.

  And the combustion apparatus of this invention provided with such heat exchangers for latent heat recovery can realize an excellent combustion apparatus with high thermal efficiency at low cost.

It is a perspective view which shows the external appearance structure of one Example of the heat exchanger for latent heat recovery which concerns on this invention with the main heat exchanger and combustion chamber which are provided in the lower side. In the latent heat recovery heat exchanger of the embodiment, when cut by a plane explanatory view (a) and a line A-A in FIG. 2 (a) showing a state before the top plate is arranged on the side wall of the case member It is sectional drawing (b) of this, and perspective explanatory drawing (c). The perspective view (a) before arrange | positioning and fixing a top plate on the side wall of a case member in the heat exchanger for latent heat recovery of an Example, and typical sectional explanatory drawing (b) of the caulking structure of the tongue piece for bending of a flange ) And a front view (c) of the bending tongue piece. It is explanatory drawing which shows the passage route of the combustion gas in the combustion apparatus provided with the heat exchanger for latent heat recovery of an Example using the typical sectional drawing of the heat exchanger for latent heat recovery, and the main heat exchanger. Typical sectional explanatory drawing which shows the cross-sectional structure of the heat exchanger for latent heat recovery in the combustion apparatus provided with the other Example of the heat exchanger for latent heat recovery which concerns on this invention, and the passage route of combustion gas with the main heat exchanger It is. It is a system block diagram of an example of the combustion apparatus provided with the heat exchanger for latent heat collection | recovery. It is the top view (a) which shows the inside through and the sectional view (b) for explaining the example of the heat exchanger for latent heat recovery proposed conventionally.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the description of the present embodiment, the same reference numerals are assigned to the same name portions as those in the conventional example, and the duplicate description is omitted or simplified.

  FIG. 1 is a perspective view showing an external configuration of an embodiment of a heat exchanger for recovering latent heat according to the present invention together with a main heat exchanger 4 and a combustion chamber 20 provided below the heat exchanger 4. . As shown in the drawing, the latent heat recovery heat exchanger 6 of the present embodiment has a case member 8, and the case member 8 includes a bottom surface and an upper surface of the combustion gas passage 2 formed sideways. It is the aspect which covers a side surface. As shown in FIGS. 1 to 3A, the case member 8 includes a side wall (side wall) 7 in which the side surface of the combustion gas passage 2 covers the square in a square shape and a bottom surface of the combustion gas passage 2. It has a bottom wall 12 to be covered, and a top plate 10 made of a stainless steel plate of 0.5 mm, which is provided above the side wall 7 and covers the upper side of the passage 2 for the combustion gas. For example, it is integrally formed by deep drawing a stainless steel plate member having a thickness of 0.6 mm.

  Further, a flange 13 projecting in a bowl shape on the outer peripheral side of the side wall 7 is integrally formed with the side wall 7 at the upper end of the side wall 7 by the deep drawing process, The outer peripheral portion of the top plate 10 of the case member 8 is aligned and disposed.

  Note that a plurality of folding tongue pieces 15 are formed at intervals between the corners of the four corners of the outer peripheral portion of the flange 13 (outer peripheral corner portion 14) and the corner portions. As shown in FIGS. 2B and 2C, the piece 15 is formed so as to protrude above the flange 13 before the top plate 10 is arranged above the side wall 7 (FIG. 2 ( The folding tongue 15 is not shown in a). As shown in FIG. 3 (c), each folding tongue piece 15 is formed with a circular through hole 25 in the center portion so as to be easily bent, and as shown in FIG. 3 (a), After the top plate 10 is disposed on the upper side of the side wall 7, as shown in FIG. 3 (b), each folding tongue piece 15 is bent and crimped on the upper side of the top plate 10. Both the top plate 10 and the flange 13 are rounded at the outer corner portions 14 and 16, and the outer corner portion 14 of the flange 13 and the outer corner portion 16 of the top plate 10 are fitted into the screw holes 27. Screwed with screws 17.

  Openings 9a and 9b are respectively formed in a pair of side walls (sidewalls) 7a and 7b opposite to each other of the case member 8, and an opening 9a on one side of the case member 8 forms a gas introduction opening. The combustion gas flows and discharges from the gas introduction opening 9a toward the opening 9b formed on the other side surface. In the combustion gas passage space in which the side surface on the one side flows from the opening 9a on the other side toward the opening 9b on the other side, a plurality of spaces are spaced apart from each other in the direction crossing the flow of the combustion gas. A heat receiving pipe line 3 having an extended pipe line is disposed with a gap from the case member 8 (see FIG. 2). In FIG. 1 to FIG. 3, reference numeral 21 denotes a connection part of the heat receiving pipe line 3 with the water supply pipe 46, reference numeral 22 denotes a connection part between the connections of the heat receiving pipe line 3 48, and reference numeral 23 denotes the main heat. The connection part with the connection pipe 48 of the heat receiving pipe line 34 of the exchanger 4 is each shown.

  In the present embodiment, a convex wall portion 11 projecting downward on the top plate 10 of the case member 8 that covers the upper surface of the space of the combustion gas passage 2 is disposed between the heat receiving pipe line 3 and the combustion gas passage. The first feature is that a plurality of the fuel gas is provided so as to cross the flow, and the convex wall portion 11 disturbs the flow of the combustion gas passing through the space of the combustion gas passage 2. This convex wall part 11 is formed by denting the setting part of the top plate 10 downward. When the convex wall part 11 is formed in such a form and the top plate 10 is provided with irregularities, the top plate 10 Even if the thickness is small, the mechanical strength of the top plate 10 can be improved, whereby the mechanical strength of the case member 8 and the latent heat recovery heat exchanger 6 can be improved. Therefore, in addition to improving the thermal efficiency by disturbing the flow of the combustion gas through the space of the combustion gas passage 2, it is possible to reduce the weight and cost of the latent heat recovery heat exchanger 6.

  Further, the second feature of the present embodiment is that the top plate 10 of the case member 8 is formed on a slope inclined downward as it goes from the upstream side to the downstream side of the flow of the combustion gas. Thus, in this embodiment, the flow of the combustion gas can be further disturbed, and the thermal efficiency can be improved.

  In the present embodiment, the bottom wall 12 of the case member 8 is formed substantially in parallel with the top plate 10, so that it is formed on a slope inclined downward from the upstream side to the downstream side of the combustion gas flow. Yes. Therefore, the drain can be guided along the bottom wall 12 to the downstream side of the combustion gas, and when the latent heat recovery heat exchanger 6 of this embodiment is provided to form the combustion apparatus, the drain shown in FIG. The receiving tray 43 can be omitted.

  That is, the latent heat recovery heat exchanger 6 of the present embodiment is applied to, for example, a combustion apparatus having a system configuration substantially similar to that of FIG. 6, but as shown in the schematic cross-sectional view of FIG. The combustion gas that has passed through the heat exchanger 4 is formed in a lateral direction so as to become obliquely downward as it goes downstream of the flow of combustion gas when passing through the latent heat recovery heat exchanger 6 of this embodiment. Go through the gas passage 2. Then, as shown by the arrows in the figure, the flow is disturbed while colliding with the top plate 10 of the slope and the convex wall portion 11 formed on the top plate 10, and thereby, the heat receiving pipe 3 and the combustion gas are Since the thermal contact is performed efficiently, the heat exchanger 6 for recovering latent heat with high thermal efficiency can be realized, and the combustion device (hot water heater) formed by providing the heat exchanger 6 for recovering latent heat of this embodiment is provided. In addition, it is possible to provide an excellent combustion apparatus with a simple configuration and high thermal efficiency, and a drain tray can be omitted.

  In FIG. 4, illustration of the flow of the combustion gas passing between the heat receiving pipes 3 or below the arrangement area of the heat receiving pipes 3 and the bottom wall 12 of the case member 8 is omitted. Between the heat receiving pipes 3, the hot combustion gas passing through the space and the cold combustion gas cooled by the heat receiving pipe 3 intersect to disturb the flow, and below the heat receiving pipe 3, Since the hot combustion gas that has flowed downward and the combustion gas that has been cooled in the heat receiving pipe 3 at the bottom end intersect with each other and the flow is disturbed, the thermal efficiency can be increased. The heat efficiency of the latent heat recovery heat exchanger 6 can be made extremely high by disturbing the flow of the combustion gas passing through the upper side of the heat receiving pipe 3.

  Further, the combustion apparatus to which the latent heat recovery heat exchanger 6 of this embodiment is applied is not particularly limited. For example, as shown in FIG. 1, together with the combustion chamber 20 and the main heat exchanger 5. The combustion block assembly 19 is formed by being integrally fixed. The combustion block assembly 19 is inserted into the instrument case 40, and the upper end portion of the combustion block assembly 19 is connected to the inner wall of the instrument case 40. For example, it is possible to form a slim type combustion apparatus in which the lateral widths of the instrument case 40 and the combustion block assembly 19 are substantially equal. Although an actual combustion apparatus is formed of various parts, illustration and description of parts that are not related to the present invention are omitted.

  In addition, this invention is not limited to the said Example, It sets suitably. For example, the arrangement of the heat receiving pipes 3 provided in the latent heat recovery heat exchanger 6 is not particularly limited and is appropriately set, and a plurality of adjacent heat receiving pipes 3 are provided in close contact with each other. May be.

  Moreover, in the said Example, although the opening parts 9a and 9b were each formed in a pair of side wall 7a, 7b of the case member 8 which mutually opposes, instead, for example, in typical sectional drawing of FIG. It can also be set as shown. That is, an opening 9 a is formed on one end side of the bottom wall 12, which is the bottom surface of the case member 8, and an opening 9 b is formed on the side wall (side wall) 7 b on the opposite side, thereby forming the bottom wall 12 of the case member 8. The opening 9a forms a combustion gas introduction opening for introducing combustion gas, and the combustion gas introduced into the case member 8 from the combustion gas introduction opening is directed from one end side to the opposite side of the space of the case member 8. It is good also as a structure which flows out and is discharged | emitted from the opening part 9b provided in the wall 7b of the case side surface of the other side.

  Furthermore, in the said Example, although the bottom wall 12 of the case member 8 was diagonally formed so as to be substantially parallel with the top plate 10, the formation aspect of the bottom wall 12 is not specifically limited, It sets suitably. . Further, the top plate 10 is desirably formed obliquely as in the above embodiment, but may not be formed obliquely.

  Furthermore, in the said Example, although the concave part was formed in the side which made the setting location of the top plate 10, the convex wall part 11 was formed, the method of formation of the convex wall part 11 is not specifically limited, It sets suitably. Is.

  Furthermore, the formation mode of the side wall 7 of the case member 8 is not particularly limited, and is appropriately set so that the combustion gas passage 2 is appropriately formed. Is not particularly limited and is appropriately set, and the top wall 10 is provided with a convex wall portion 11 projecting downward from the heat receiving pipe 3 with a space therebetween to cross the flow of the combustion gas, By disturbing the flow of the combustion gas, the thermal efficiency of the latent heat recovery heat exchanger 6 can be improved, and the thermal efficiency of the combustion apparatus can be improved.

  Furthermore, in the said Example, although the combustion apparatus was set as the apparatus provided only with the hot water supply function, it is good also as a complex apparatus provided with other functions, such as a reheating function of a bath, and a heating function.

  Furthermore, the combustion apparatus of the present invention may be provided with a burner for oil combustion instead of the burner that performs gas combustion provided in the above-described embodiment, for example.

  INDUSTRIAL APPLICABILITY The present invention can improve the thermal efficiency of a latent heat recovery heat exchanger with a simple configuration, and therefore can be used as a domestic combustion device or a latent heat recovery heat exchanger provided in the combustion device.

DESCRIPTION OF SYMBOLS 1 Burner 2 Combustion gas passage 3 Heat receiving pipe 4 Main heat exchanger 5 Combustion fan 6 Heat exchanger for latent heat recovery 7, 7a, 7b Side wall 8 Case member 9a, 9b Opening 10 Top plate 11 Convex wall 12 Bottom wall

Claims (4)

  A heat exchanger for recovering latent heat of exhaust gas held by combustion gas of a burner, comprising a case member that covers a bottom surface, an upper surface, and a side surface of a passage of the combustion gas formed sideways, and the case member An opening is formed in each of the pair of side walls facing each other, and the opening on the one side is formed as a combustion gas introduction opening for introducing the combustion gas. Combustion gas introduced into the case member from the introduction opening flows toward the opening formed on the other side surface of the case member and is discharged from the opening. A heat receiving pipe line having a pipe line extending in a direction crossing the flow of the combustion gas is disposed in the passage space of the case member at a distance from the case member, and covers an upper surface of the passage space for the combustion gas. Projecting downward on the top plate of the case member The convex wall portion is provided in such a manner as to cross the flow of the combustion gas through the gap with the heat receiving pipe, and the convex wall portion disturbs the flow of the combustion gas passing through the passage space of the combustion gas. A heat exchanger for recovering latent heat.   The latent heat recovery heat exchanger according to claim 1, wherein the top plate of the case member is formed on a slope inclined downward from the upstream side to the downstream side of the flow of the combustion gas.   Instead of forming openings in the pair of side walls facing each other of the case member, openings are formed in one end side of the bottom wall, which is the bottom surface of the case member, and in the side wall on the opposite side. The opening formed in the bottom wall which is the bottom surface of the case member forms a combustion gas introduction opening for introducing combustion gas, and is introduced into the case member from the combustion gas introduction opening. The combustion gas is configured to flow from one end side to the opposite side of the space of the case member and discharged from an opening provided in the side wall of the opposite case member. The heat exchanger for recovering latent heat according to claim 1 or 2.   A combustion apparatus comprising the latent heat recovery heat exchanger according to claim 1, claim 2, or claim 3.

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