Latent heat recovery heat exchanger

Abstract

To provide a latent heat recovery type heat exchanger in which a heat absorption pipe 2 is arranged in a heat exchange chamber 11 inside a housing 1 where combustion exhaust gas flows from a rear side to a front side, an upper guide plate 3 for bypassing downward combustion exhaust gas once, and a lower guide plate 4 for defining an exhaust flow channel 14 extending to an exhaust port 13 between the upper guide plate and itself are provided in the upper portion and the lower portion of the front end part of the heat exchange chamber 11, and a water falling port 5 for making drain water toward above the lower guide plate 4 flow down to a drain receiving part 112 recessed in the bottom face front end part of the heat exchange chamber 11 is provided so as to prevent the occurrence of air-blowing sound in the water falling port 5.SOLUTION: A rear end 4a of the lower guide plate 4 is positioned frontward of an upper end of a rear side wall 112a of the drain receiving part 112 so as to constitute the water falling port 5 by gaps generated therebetween. A suspended piece part 44 extending downward in a position separated forward from the rear side wall 112a of the drain receiving part 112 is extended to the rear end 4a of the lower guide plate 4. A folding part may be extended to the rear end 4a of the lower guide plate 4.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a latent heat recovery heat exchanger that includes a housing having an internal heat exchange chamber through which combustion exhaust gas flows from rear to front, and a plurality of heat absorption pipes arranged in the heat exchange chamber, and that recovers the latent heat contained in the combustion exhaust gas to heat water flowing through the heat absorption pipes. [Background technology]

[0002] Originally, this type of latent heat recovery heat exchanger had an exhaust port on the front plate of the housing, an upper guide plate at the top of the front end of the heat exchange chamber that diverts the combustion exhaust gas flowing into the upper part of the heat exchange chamber downward before directing it to the exhaust port, and a lower guide plate at the bottom of the front end of the heat exchange chamber that defines an exhaust flow path leading to the exhaust port between the upper guide plate and the heat exchange chamber. In latent heat recovery heat exchangers, moisture in the combustion exhaust gas condenses on the outer surface of the heat absorption pipe, generating highly acidic drain water. The upper guide plate prevents the combustion exhaust gas from proceeding directly to the exhaust port while still containing droplets of drain water.

[0003] In addition, a conventional latent heat recovery heat exchanger is known in which a downwardly recessed drain receiving section and a drain outlet for draining drain water from the drain receiving section are provided at the front end of the bottom surface of the heat exchange chamber, and a water outlet is further provided in the lower guide plate to allow drain water flowing above the lower guide plate to flow down to the drain receiving section (see, for example, Patent Document 1).

[0004] However, with this design, the edge of the lower guide plate, which is the cut edge of the water outlet, is exposed at the front edge of the water outlet, and combustion exhaust gases hit this edge, making it easy for wind noise to be generated and increasing the noise from the exhaust port. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2009-243725 Summary of the Invention [Problem to be solved by the invention]

[0006] In view of the above, an object of the present invention is to provide a latent heat recovery heat exchanger that can prevent the generation of wind noise and reduce noise from the exhaust port. [Means for solving the problem]

[0007] In order to solve the above problems, the present invention provides a latent heat recovery type heat exchanger comprising a housing having an internal heat exchange chamber through which combustion exhaust gas flows from rear to front, and a plurality of heat absorption pipes arranged in the heat exchange chamber, and configured to recover latent heat contained in the combustion exhaust gas to heat water flowing through the heat absorption pipes, wherein an exhaust port is opened in the front plate of the housing, an upper guide plate is provided at the upper front end of the heat exchange chamber to divert the combustion exhaust gas flowing into the upper part of the heat exchange chamber downwards and then guide it to the exhaust port, and a lower guide plate is provided at the lower front end of the heat exchange chamber to define an exhaust flow path leading to the exhaust port between the upper guide plate and the housing, and The front end of the face is provided with a drain receiving section recessed downward and a drain outlet for draining drain water in the drain receiving section, and further provided with a water outlet for allowing drain water heading up the lower guide plate to flow down into the drain receiving section, wherein the rear end of the lower guide plate is located forward of the upper end of the rear wall of the drain receiving section, the water outlet is formed by the gap created between the rear end of the lower guide plate and the upper end of the rear wall of the drain receiving section, and the rear end of the lower guide plate is provided with a hanging piece extending downward at a position forward and away from the rear wall of the drain receiving section, or a folded portion extending toward the face of the lower guide plate that is not hit by the combustion exhaust gas.

[0008] According to the present invention, the trailing edge of the lower guide plate, which forms the leading edge of the water outlet, is extended with a hanging piece or folded back portion, so that the edge of the lower guide plate is not exposed at the leading edge of the water outlet. This prevents wind noise caused by combustion exhaust gas hitting the edge of the lower guide plate, and reduces noise from the exhaust port. [Brief explanation of the drawings]

[0009] [Figure 1]1 is a perspective view of a latent heat recovery heat exchanger according to an embodiment of the present invention; [Figure 2] A cross-sectional side view taken along line II-II in Figure 1. [Figure 3] FIG. 3 is a perspective view of a lower guide plate provided in the latent heat recovery type heat exchanger according to the embodiment. [Figure 4] 3 is a cross-sectional side view similar to FIG. 2 of a latent heat recovery heat exchanger according to another embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] 1 and 2, a latent heat recovery heat exchanger A according to an embodiment of the present invention includes a housing 1 having an internal heat exchange chamber 11 through which combustion exhaust gas flows from rear to front (from right to left in FIG. 2), and a plurality of heat absorption pipes 2 arranged in the heat exchange chamber 11. The latent heat contained in the combustion exhaust gas is recovered to heat water flowing through the heat absorption pipes 2.

[0011] An inlet 12 is provided in the rear plate 1a of the housing 1, through which the combustion exhaust gas that has passed through a sensible heat recovery heat exchanger (not shown) flows in. An outlet 13 is provided in the front plate 1b of the housing 1, through which the combustion exhaust gas that has passed through the heat exchange chamber 11 flows out.

[0012] In this embodiment, six heat absorption pipes 2 are arranged vertically in the heat exchange chamber 11, extending in the front-rear direction while meandering in a horizontal direction perpendicular to the front-rear direction. Vertically adjacent heat absorption pipes 2, 2 are shifted in the front-rear direction by half the meandering pitch. On the outer surface of one horizontal side panel 1c of the casing 1, an inlet header 21 and an outlet header 22 are attached to which the upstream ends and downstream ends of the six heat absorption pipes 2 are connected, respectively. Water flowing through each heat absorption pipe 2 from the inlet header 21 to the outlet header 22 is heated by the recovery of latent heat due to condensation of moisture in the combustion exhaust gas on the outer surface of each heat absorption pipe 2.

[0013] The bottom surface 111 of the heat exchange chamber 11, which is formed by the bottom plate of the housing 1, is inclined downward toward the front. A downwardly recessed drain receiver 112 is provided at the front end of the bottom surface 111, into which drain water dripping from the outer surface of the heat absorption pipe 2 flows due to the inclination of the bottom surface 111. The drain receiver 112 has its lowest point in the horizontal center, and this part is provided with a drain outlet 113 for discharging the drain water in the drain receiver 112. The drain water drained from the drain outlet 113 is led to a neutralizer (not shown).

[0014] An upper guide plate 3 is provided at the upper front end of the heat exchange chamber 11. This upper guide plate 3 diverts the combustion exhaust gas that has flowed to the upper part of the heat exchange chamber 11 downward before guiding it to the exhaust port 13, so as to prevent the combustion exhaust gas from proceeding straight to the exhaust port 13 while still containing droplets of drain water. The upper guide plate 3 has a hanging plate portion 32 hanging down from an attachment portion 31 that is attached to the upper surface of the heat exchange chamber 11, and an inclined plate portion 33 that extends from the lower end of the hanging plate portion 32 at an angle upward toward the front toward the upper edge of the exhaust port 13.

[0015] A lower guide plate 4 is provided below the front end of the heat exchange chamber 11, defining an exhaust flow path 14 leading to the exhaust port 13 between the lower guide plate 4 and the upper guide plate 3. The rear end 4a of the lower guide plate 4 is located forward of the upper end of the rear wall 112a of the drain receiving portion 112. A gap formed between the rear edge of the lower guide plate 4 and the upper end of the rear wall 112a of the drain receiving portion 112 forms a water outlet 5 that allows drain water flowing above the lower guide plate 4 to flow down into the drain receiving portion 112.

[0016] The lower guide plate 4 has a first inclined plate portion 41 that extends forward from its rear end 4a, inclining upward toward the front, and a second inclined plate portion 42 that extends from the front end of the first inclined plate portion 41 toward the lower edge of the exhaust port 13, inclining upward toward the front at an angle substantially equal to that of the inclined plate portion 33 of the upper guide plate 3. The front end of the second inclined plate portion 42 is fixed to the lower edge portion 13a of the exhaust port 13, which is bent into a flange shape.

[0017] 3, a pair of tongue portions 43, 43 extending rearward are provided at the rear end 4a of the lower guide plate 4, positioned near both lateral ends. Each tongue portion 43 is fixed to the upper end of the rear wall 112a of the drain receiving portion 112. A hanging piece 44 extends downward from the rear wall 112a of the drain receiving portion 112 at a position spaced forward from the rear wall 112a of the drain receiving portion 112, on the portion of the rear end 4a of the lower guide plate 4 other than the tongue portions 43.

[0018] By extending the hanging piece 44 to the rear end 4a of the lower guide plate 4, which forms the front edge of the water outlet 5, the edge of the lower guide plate 4 is not exposed at the front edge of the water outlet 5. This prevents the generation of wind noise caused by combustion exhaust gas hitting the edge of the lower guide plate 4, and reduces noise from the exhaust port 13.

[0019] Next, another embodiment shown in Figure 4 will be described. The basic structure of this embodiment is not particularly different from that of the above-mentioned embodiment, and the same reference numerals are used for the components and parts. This embodiment differs from the above-mentioned embodiment in that a folded portion 45 is provided at the rear end 4a of the lower guide plate 4 on the side of the lower guide plate 4 that is not hit by the combustion exhaust gas, i.e., toward the front side of the first inclined plate portion 41. In this embodiment, the edge of the lower guide plate 4 is not exposed at the front edge of the water outlet 5, so wind noise caused by the combustion exhaust gas hitting the edge of the lower guide plate 4 is prevented, and noise from the exhaust port 13 can be reduced.

[0020] Although the embodiment of the present invention has been described above with reference to the drawings, the present invention is not limited to this and can be implemented with various modifications within the scope of the invention. [Explanation of symbols]

[0021] A...latent heat recovery heat exchanger, 1...housing, 1b...front plate portion, 11...heat exchange chamber, 111...bottom surface of heat exchange chamber, 112...drain receiving portion, 112a...rear wall of drain receiving portion, 113...drain outlet, 13...exhaust port, 2...heat absorption pipe, 3...upper guide plate, 4...lower guide plate, 4a...rear end of lower guide plate, 44...hanging piece portion, 45...folded portion.

Claims

[Claim 1] A latent heat recovery heat exchanger comprising a housing having an internal heat exchange chamber through which combustion exhaust gas flows from rear to front, and a plurality of heat absorption pipes arranged in the heat exchange chamber, and configured to recover latent heat contained in the combustion exhaust gas to heat water flowing through the heat absorption pipes, An exhaust port is opened in the front plate of the housing, an upper guide plate is provided at the upper front end of the heat exchange chamber to divert the combustion exhaust gas flowing into the upper part of the heat exchange chamber downwards and then guide it to the exhaust port, and a lower guide plate is provided at the lower front end of the heat exchange chamber to define an exhaust flow path leading to the exhaust port between the upper guide plate and the lower guide plate; The heat exchange chamber is provided at the front end of the bottom surface thereof with a downwardly recessed drain receiving portion and a drain outlet for draining drain water from the drain receiving portion, and further provided with a water outlet for allowing drain water flowing onto the lower guide plate to flow down to the drain receiving portion, A latent heat recovery type heat exchanger characterized in that the rear end of the lower guide plate is located forward of the upper end of the rear wall of the drain receiving portion, a water outlet is formed in the gap between the rear end of the lower guide plate and the upper end of the rear wall of the drain receiving portion, and a hanging piece portion extending downward at a position forward and away from the rear wall of the drain receiving portion or a folded portion extending toward the side of the lower guide plate that is not hit by the combustion exhaust gas is provided at the rear end of the lower guide plate.

Images