JP2023147758A - Latent heat recovery-type heat exchanger - Google Patents

Abstract

To effectively prevent scattering of drain water to the outside of an exhaust cylinder 3, in a latent heat recovery-type heat exchanger which includes: a housing 1 having a heat exchange chamber 11 in which a combustion exhaust gas flows from a rear part to a front part; and a plurality of heat absorption pipes 2 disposed in the heat exchange chamber 11, and in which the exhaust cylinder 3 into which the combustion exhaust gas flows through an exhaust port 13 formed on a front plate portion 1b, is mounted on the front plate portion 1b of the housing 1, a drain receiving portion 112 recessed to a lower portion and a drain port 113 are disposed on a front end portion of a bottom surface 111 of the heat exchange chamber 11, and further a cover plate 6 for covering the drain receiving portion 112 from an upper part is disposed.SOLUTION: A latent heat recovery-type heat exchanger is constituted to allow drain water on a cover plate 6 to fall down to a drain receiving portion 112 from one end in a lateral direction of a cover plate 6 by providing the cover plate 6 with down grade to one side in the lateral direction orthogonal to a longitudinal direction.SELECTED DRAWING: Figure 1

Description

The present invention includes a housing having an internal heat exchange chamber through which combustion exhaust gas flows from the rear to the front, and a plurality of heat absorption pipes arranged in the heat exchange chamber, and collects latent heat held by the combustion exhaust gas and transfers it to the heat absorption pipes. This invention relates to a latent heat recovery type heat exchanger that heats flowing water.

Originally, in this type of latent heat recovery type heat exchanger, an exhaust pipe was attached to the front plate of the casing through which combustion exhaust gas flows through an exhaust port opened in the front plate, and the exhaust pipe was installed in the heat exchange chamber. A drain receiving part recessed downward and a drain port for draining the drain water in the drain receiving part are provided at the front end of the bottom surface of the drain receiving part. Drain water is strongly acidic water that is generated when moisture in combustion exhaust gas condenses on the outer surface of the heat absorption pipe. Most of the drain water is drained from the drain receiver through the drain port, but some of the drain water in the drain receiver is swirled up by the combustion exhaust gas heading toward the exhaust port, scatters outside from the exhaust stack, and is discharged. It may contaminate the outside area of the cylinder.

Therefore, as a latent heat recovery type heat exchanger, there is conventionally known a heat exchanger provided with a cover plate that covers a drain receiving part from above, as disclosed in Patent Document 1. According to this, the combustion exhaust gas is obstructed by the cover plate and does not hit the drain water in the drain receiving part with force, and it is possible to suppress the swirling up of the drain water. Further, in this device, a hole is formed in the cover plate to allow the drain water on the cover plate to fall into the drain receiving portion, so that the drain water does not accumulate on the cover plate.

However, it has been found that this method causes the following problems. That is, when a hole is formed in the cover plate, the combustion exhaust gas that has gone under the cover plate flows upward through the hole, and an upward flow of combustion exhaust gas is generated within the hole. Then, a portion of the drain water that falls from the hole is swirled up by the upward flow of combustion exhaust gas and scattered outside the exhaust stack.

JP2016-223645A

In view of the above points, it is an object of the present invention to provide a latent heat recovery type heat exchanger that can more effectively prevent drain water from scattering to the outside of an exhaust stack.

In order to solve the above problems, the present invention includes a housing having an internal heat exchange chamber through which combustion exhaust gas flows from the rear to the front, and a plurality of heat absorption pipes arranged in the heat exchange chamber, so that the combustion exhaust gas has This is a latent heat recovery type heat exchanger that recovers latent heat to heat the water flowing through the heat absorption pipe, and combustion exhaust gas flows into the front plate of the casing through the exhaust port opened in the front plate. The exhaust pipe is attached, and the front end of the bottom of the heat exchange chamber is provided with a drain receptacle recessed downward and a drain port for draining the drain water in the drain receptacle, and a cover that covers the drain receptacle from above. In devices where a plate is provided, the cover plate has a downward slope in one horizontal direction perpendicular to the front-rear direction, so that drain water on the cover plate falls from one horizontal end of the cover plate to the drain receiver. It is characterized by the following.

According to the present invention, by providing the cover plate with a downward slope to one side in the lateral direction, the drain water on the cover plate falls from one lateral end of the cover plate to the drain receiving part, so that the drain water flows on the cover plate. There is no need to form a hole for the material to fall. Therefore, the upward flow of combustion exhaust gas generated in the hole does not cause drainage water to be stirred up. As a result, scattering of drain water to the outside of the exhaust stack can be effectively prevented.

Further, in the present invention, the lower surface of the exhaust flow path in the exhaust stack is located above the front end of the cover plate that reaches the front plate of the casing, and extends above the front end of the cover plate to form the exhaust flow path. It is desirable to provide a wall that reaches the same height as the lower surface. According to this, the wall functions as a barrier that prevents drain water on the cover plate from entering the exhaust flow path, and it is possible to more effectively prevent drain water from scattering to the outside of the exhaust stack. .

Furthermore, in the present invention, when the cover plate is formed into a stepped shape in which the front part is located lower than the rear part, the other end in the lateral direction of the front part of the cover plate is provided with a It is desirable to provide an upright baffle plate portion on the front portion of the cover plate to obstruct the flow of combustion exhaust gas. Here, when the combustion exhaust gas flows from the outside laterally over the front part of the cover plate, some of the drain water flowing down the step between the rear and front parts of the cover plate is swirled up by the flow of the combustion exhaust gas. Sometimes. If the flow of combustion exhaust gas from the outside in the lateral direction onto the front part of the cover plate is obstructed by the baffle plate as described above, drain water flowing down the step part can be suppressed from being rolled up, and the drain to the outside of the exhaust stack can be prevented. Splashing of water can be more effectively prevented.

FIG. 1 is a perspective view of a latent heat recovery type heat exchanger according to an embodiment of the present invention. FIG. 2 is a cut side view taken along line II-II in FIG. 1; 3 is a sectional view taken along line III-III in FIG. 2. FIG. FIG. 2 is an exploded perspective view showing the mounting structure of the exhaust stack in the latent heat recovery type heat exchanger of the embodiment. FIG. 3 is a perspective view of a cover plate provided in the latent heat recovery type heat exchanger of the embodiment.

Referring to FIGS. 1 and 2, a latent heat recovery heat exchanger A according to an embodiment of the present invention has a heat exchange chamber 11 in which combustion exhaust gas flows from the rear to the front (from the right to the left in FIG. 2). A plurality of heat absorption pipes 2 arranged in a heat exchange chamber 11 are provided. Then, the latent heat possessed by the combustion exhaust gas is recovered to heat the water flowing into the heat absorption pipe 2.

The rear plate part 1a of the housing 1 is provided with an inlet 12 through which combustion exhaust gas that has passed through a sensible heat recovery type heat exchanger (not shown) flows in, and the front plate part 1b of the housing 1 is provided with a heat exchange chamber. An exhaust port 13 is provided through which the combustion exhaust gas that has passed through the exhaust port 11 flows out. Furthermore, an exhaust pipe 3 into which combustion exhaust gas flows through an exhaust port 13 is attached to the front plate portion 1b. Inside the exhaust pipe 3, three upper and lower rectifying members 31, 32, 33 are installed, and there is a gap between the upper rectifying member 31 and the intermediate rectifying member 32, and between the intermediate rectifying member 32 and the lower rectifying member 33. Two upper and lower exhaust flow paths 3a and 3b are defined between the two. By narrowing the cross-sectional area of each exhaust flow path 3a, 3b, the flow velocity of the combustion exhaust gas is increased, and the combustion exhaust gas is prevented from stagnation near the exit of the exhaust pipe 3.

Referring also to FIG. 4, the mounting structure of the exhaust pipe 3 will be specifically described. In this embodiment, in order to attach the exhaust pipe 3, a mounting plate 4 having an opening 41 that matches the exhaust port 13 is provided. Then, the mounting plate 4 is stacked on the front surface of the front plate portion 1b with the packing 42 sandwiched therebetween, and the flange portion 34 at the rear end of the exhaust pipe 3 is stacked on the front surface of the mounting plate 4 with the packing 43 sandwiched therebetween. In this state, the flange portion 34 is fastened together with the packing 43, the mounting plate 4, and the packing 42 to the front plate portion 1b with screws 44. Further, a portion near the upper edge of the opening 41 of the mounting plate 4 is fastened to the front plate portion 1b together with the packing 42 using screws 45, and furthermore, the upper part of the flange portion 34 is fastened to the mounting plate 4 together with the packing 43 using screws 46. .

In this embodiment, in the heat exchange chamber 11, six heat absorption pipes 2 are arranged in the upper and lower directions, extending in the front-back direction while meandering in the lateral direction orthogonal to the front-back direction. The vertically adjacent endothermic pipes 2, 2 are shifted in position by half of the meandering pitch in the front-rear direction. An inflow header 21 and an outflow header 22 to which the upstream ends and downstream ends of the six endothermic pipes 2 are connected, respectively, are attached to the outer surface of the side plate 1c on one side in the lateral direction of the housing 1. Water flowing through each endothermic pipe 2 from the inflow header 21 to the outflow header 22 is heated by recovery of latent heat due to condensation of moisture in the combustion exhaust gas on the outer surface of each endothermic pipe 2.

A bottom surface 111 of the heat exchange chamber 11 constituted by the bottom plate of the housing 1 is inclined downward toward the front. At the front end of the bottom surface 111, a downwardly recessed drain receiving section 112 is provided, into which drain water dripping from the outer surface of the heat absorption pipe 2 flows due to the slope of the bottom surface 111. Referring to FIG. 3, the drain receiving part 112 has the lowest horizontal part that almost matches the exhaust port 13, and a drain port 113 for draining the drain water in the drain receiving part 112 is provided in this part. It is being Drain water drained from the drain port 113 is led to a neutralizer (not shown).

Further, a guide plate 5 is provided at the upper part of the front end of the heat exchange chamber 11 to guide the flow of combustion exhaust gas downward, thereby preventing the combustion exhaust gas from flowing straight into the exhaust stack 3 while containing splashes of drain water. We are trying to prevent this. Furthermore, a cover plate 6 is provided at the lower front end portion of the heat exchange chamber 11 to cover a portion of the drain receiving portion 112 near the exhaust port 13 from above. According to this, the combustion exhaust gas does not forcefully hit the drain water in the drain receiving part 112, and it is possible to suppress the drain water from being rolled up by the combustion exhaust gas.

Here, as clearly shown in FIG. 3, the cover plate 6 has a downward slope to one side in the lateral direction (to the right in FIG. 3). Therefore, the drain water on the cover plate 6 falls from one lateral end of the cover plate 6 to the drain receiving part 112. Therefore, there is no need to form a hole in the cover plate 6 to allow drain water to fall as in the conventional example. When the hole is formed, the combustion exhaust gas that has gone under the cover plate 6 flows upward from the hole, and an upward flow of combustion exhaust gas is generated within the hole. A portion of the drain water falling from the hole may be rolled up by the upward flow of combustion exhaust gas and scattered outside the exhaust stack 3. On the other hand, in this embodiment, since it is not necessary to form a hole as described above, such a problem does not occur and it is possible to effectively prevent drain water from scattering to the outside of the exhaust pipe 3.

Further, the lower surface of the exhaust flow path in the exhaust pipe 3, that is, the lower surface of the lower exhaust flow path 3b, is located above the front end of the cover plate 6 that reaches the front plate portion 1b of the housing 1. A wall portion 7 is provided that extends above the front end of the cover plate 6 and reaches the same height as the lower surface of the lower exhaust flow path 3b. According to this, the wall portion 7 functions as a barrier that prevents the drain water on the cover plate 6 from entering the lower exhaust flow path 3b. Therefore, scattering of drain water to the outside of the exhaust pipe 3 can be more effectively prevented.

In the present embodiment, the wall portion 7 is constituted by a hanging plate portion 33a curved at the rear end of the lower flow regulating member 33 within the exhaust pipe 3, but the wall portion 7 is not limited thereto. For example, the exhaust port 13 is formed to have a chord-shaped lower edge with a height that matches the lower surface of the lower exhaust flow path 3b, and the wall portion 7 is connected to the lower portion of the exhaust port 13 of the front plate portion 1b. It is also possible to configure

Referring also to FIG. 5, the cover plate 6 is formed in a stepped shape with a front portion 61 located below a rear portion 62 and a step portion 63 between the rear portion 62 and the front portion 61. The front portion 61 is sloped downward to one side in the lateral direction. Further, a fixing part 64 is provided which protrudes rearward from the rear part 62 in the shape of a tongue, and the fixing part 64 is spot welded to the bottom surface 111 of the heat exchange chamber 11. Note that an escape hole 61a is formed in the front portion 61 to prevent interference with the screw 44 for attaching the exhaust pipe 3.

In such a cover plate 6, when combustion exhaust gas flows from the outside in the lateral direction onto the front portion 61, a part of the drain water flowing down the stepped portion 63 may be rolled up by the flow of the combustion exhaust gas. Therefore, in this embodiment, the front part of the cover plate 6 is placed at the other end of the front part 61 of the cover plate 6 in the lateral direction (the direction opposite to the downward slope direction) from the outside of the end part in the lateral direction. An upright baffle plate portion 65 is provided on 61 to obstruct the flow of combustion exhaust gas. According to this, the drainage water flowing down the stepped portion 63 can be suppressed from being rolled up, and the scattering of the drainage water to the outside of the exhaust pipe 3 can be more effectively prevented.

Although the embodiments of the present invention have been described above with reference to the drawings, the present invention is not limited thereto. For example, in the embodiment described above, the cover plate 6 is provided to cover the portion of the drain receiving portion 112 that is close to the exhaust port 12, but the cover plate may be provided to cover a wider area of the drain receiving portion 112. It is possible.

A... Latent heat recovery type heat exchanger, 1... Housing, 1b... Front plate part, 11... Heat exchange chamber, 111... Bottom surface, 112... Drain receiving part, 113... Drain port, 13... Exhaust port, 2... Endothermic pipe , 3... Exhaust pipe, 3b... Lower exhaust flow path (exhaust flow path), 6... Cover plate, 61... Front part, 62... Rear part, 65... Baffle plate part, 7... Wall part.

Claims (3)

Equipped with a housing that has an internal heat exchange chamber through which combustion exhaust gas flows from the rear to the front, and multiple heat absorption pipes placed in the heat exchange chamber, the latent heat held by the combustion exhaust gas is recovered to heat the water flowing through the heat absorption pipes. A latent heat recovery type heat exchanger configured to
An exhaust pipe is attached to the front plate of the casing, through which combustion exhaust gas flows through an exhaust port opened in the front plate.
In the case where the front end of the bottom of the heat exchange chamber is provided with a drain receptacle recessed downward and a drain port for draining the drain water in the drain receptacle, and a cover plate is further provided to cover the drain receptacle from above. ,
The cover plate is provided with a downward slope in one lateral direction perpendicular to the front-rear direction, so that drain water on the cover plate falls from one lateral end of the cover plate to the drain receiver. A latent heat recovery type heat exchanger. The lower surface of the exhaust flow path in the exhaust stack is located above the front end of the cover plate that reaches the front plate portion of the housing, extends above the front end of the cover plate, and is connected to the lower surface of the exhaust flow path. The latent heat recovery type heat exchanger according to claim 1, characterized in that a wall portion reaching the same height is provided. The cover plate is formed in a stepped shape in which the front part is located lower than the rear part, and the front part of the cover plate is placed at the other end in the lateral direction of the front part of the cover plate from the outside in the lateral direction of the end. 3. The latent heat recovery type heat exchanger according to claim 1, further comprising an upright baffle plate portion that obstructs the flow of combustion exhaust gas.

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