JP2003343924A - Clearance seal structure for heat exchanger - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent discharge of the combustion gas, while bypassing a layered heat exchanger, by nearly air-tightly sealing groove parts formed in the periphery of the layered heat exchanger. <P>SOLUTION: In order to prevent flow-out of the combustion gas through a combustion gas discharge port 20b, while bypassing the layered heat exchanger 21, seal plates 51 and 52 for sealing a clearance between a case member 20 and the layered heat exchanger 21 are provided. In order to nearly air-tightly seal a plurality of groove parts in the periphery of the layered heat exchanger 21 with the seal plates 51 and 52, a tip part of each seal plate 51 and 52 on a layered heat exchanger 21 side thereof is provided with a comb teeth shape part by forming a plurality of projecting pieces projecting into a plurality of grooves 40. The seal plates 51 and 52 are arranged so that the comb teeth shape parts are displaced in the layer direction of a flow passage forming plate 30 to prevent bypass of the combustion gas from the groove parts to the gas discharge port 20b. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gap seal structure for a heat exchange device, and more particularly, to prevent combustion gas from bypassing the stacked heat exchanger and flowing to the outside to improve the heat exchange efficiency of the heat exchange device. Regarding what can be improved.

[0002]

2. Description of the Related Art Conventionally, various types of heat exchange devices have been used which are provided in various combustion equipment such as a water heater and heat a fluid such as hot water by high temperature combustion gas generated in a burner. However, for example, there is one including a laminated heat exchanger having a structure in which a plurality of flow path forming plates having flow paths inside are stacked. This laminated heat exchanger can be configured compactly while ensuring a required heat transfer area, and the heat exchange device can be downsized.

In this heat exchange device, the combustion gas introduced into the case member for accommodating the laminated heat exchanger is
While heating the fluid flowing through the flow passages of the plurality of flow passage forming plates, the fluid is discharged from the combustion gas discharge port of the case member to the outside of the heat exchange device while passing between the flow passage forming plates. Here, in manufacturing the heat exchange device, it is unavoidable that a gap is formed between the case member and the laminated heat exchanger, but the combustion gas bypasses the heat exchanger to the combustion gas discharge port from this gap. When it flows,
Since a part of the combustion gas is discharged to the outside without heat exchange with the fluid, the heat exchange efficiency is considerably reduced.

Therefore, it is necessary to close this gap by some means, but since the laminated heat exchanger has a structure in which a plurality of flow passage forming plates are laminated as described above, these flow passage forming plates are formed. As a result, a plurality of groove portions are inevitably formed on the outer peripheral portion of the laminated heat exchanger. However, the conventional laminated heat exchanger is not configured to block such a groove portion, and a part of combustion gas is discharged from the groove portion to the outside by bypassing the laminated heat exchanger. However, there is a problem that the heat exchange efficiency decreases.

As a countermeasure against this, first, it is easily conceived to close the groove with a sealing member made of synthetic resin. Further, a closing plate for closing the gap between the case member and the heat exchange device is provided, and in order to close the plurality of groove portions in an airtight manner, a substantially comb-like shape is formed at the tip end portion of the closing plate on the laminated heat exchanger side. Providing a comb-tooth-shaped part with a plurality of protruding pieces formed on each side, the plurality of protruding pieces of the comb-tooth-shaped part are respectively projected into the plurality of grooves so as to prevent the combustion gas from flowing out from the groove to the combustion gas discharge port. It is also conceivable that the plurality of groove portions are closed by such a configuration.

[0006]

However, when the seal member is configured to close the groove, the heat exchange device is also a latent heat recovery type heat exchange device capable of recovering the latent heat of water vapor in the combustion gas. In this case, water vapor is condensed inside the case member to produce water, but this condensed water is acidic because it contains nitrogen oxides and sulfur oxides in the combustion gas.
Therefore, the seal member that closes the groove must be made of a material having high corrosion resistance, which is disadvantageous in manufacturing cost.

When the groove is closed by the comb-tooth shaped portion of the closing plate, the widths of the plurality of grooves are not always constant due to factors such as manufacturing errors, and the widths of the plurality of grooves protrude into the plurality of grooves, respectively. If the width of the protruding piece is set to be almost the same as the width of the groove, if the width of the plurality of grooves varies, it becomes impossible to project the protruding piece into the groove and close the groove. It is necessary to make the width of the piece narrower than the width of the groove.

In this case, however, the amount of the combustion gas flowing out of the groove can be suppressed by the protruding piece as compared with the case where the groove is not completely closed, but the combustion gas is laminated from the gap between the protruding piece and the groove. Since it is not possible to completely prevent the heat exchanger from bypassing and flowing to the combustion gas exhaust port, the heat exchange efficiency decreases. An object of the present invention is to close the groove formed on the outer peripheral portion of the laminated heat exchanger in a substantially airtight manner to prevent combustion gas from bypassing and exhausted from the laminated heat exchanger. Improving efficiency, etc.

[0009]

A gap seal structure for a heat exchange device according to claim 1 has a case member having a combustion gas introduction port and a combustion gas discharge port, and a plurality of flows disposed inside the case member. In a heat exchange device including a laminated heat exchanger having a structure in which path forming plates are laminated, a closing plate for closing a space between a case member and the laminated heat exchanger is provided, and the closing heat exchanger side of the closing plate is provided. In addition, a comb-tooth-shaped portion is provided in which a plurality of protruding pieces protruding into the plurality of grooves on the outer peripheral portion of the laminated heat exchanger are formed in a comb-tooth shape.

The combustion gas introduced into the case member through the combustion gas introduction port exchanges heat with the fluid flowing through the flow passages formed inside the plurality of flow passage forming plates to heat the fluid. However, it passes between the plurality of flow path forming plates and is discharged from the combustion gas discharge port to the outside of the heat exchange device. here,
In manufacturing the heat exchange device, it is unavoidable that a gap is created between the case member and the laminated heat exchanger, but a part of the combustion gas bypasses the laminated heat exchanger through this gap and the combustion gas exhausted. In order to prevent the flow to the outlet, a closing plate that closes between the case member and the laminated heat exchanger is provided.

Here, a plurality of groove portions are formed on the outer peripheral portion of the laminated heat exchanger by a plurality of laminated flow path forming plates, and a part of the combustion gas flows from the plurality of groove portions to the laminated heat exchanger. Although it will be discharged by bypassing the device, a comb-tooth-shaped part is formed at the tip of the closing plate on the side of the laminated heat exchanger in which a plurality of protruding pieces projecting into these grooves are formed in a substantially comb-tooth shape. Since the plurality of groove portions are provided by these projecting pieces, it is possible to close the space between the case member and the laminated heat exchanger in a substantially airtight manner. Therefore, it is possible to prevent the combustion gas from bypassing the laminated heat exchanger and flowing to the combustion gas discharge port, and improve the heat exchange efficiency.

According to another aspect of the present invention, there is provided a gap sealing structure for a heat exchange device, wherein a case member having a combustion gas inlet and a combustion gas outlet is provided, and a plurality of flow path forming plates disposed inside the case member are laminated. In a heat exchange device including a laminated heat exchanger having a structure, a plurality of closing plates that close the space between the case member and the laminated heat exchanger are provided, and the plurality of closing plates are laminated on the laminated heat exchanger side. It is characterized in that each of the comb-tooth-shaped portions is formed by forming a plurality of projecting pieces projecting into a plurality of groove portions on the outer peripheral portion of the mold heat exchanger into a comb-tooth shape.

The seal structure of this heat exchange device is also claimed in claim 1.
In the same manner as in the invention described above, the groove portion is closed by a comb tooth-shaped portion formed by forming a plurality of protruding pieces protruding into the plurality of groove portions into a substantially comb tooth shape, and a closing plate is provided between the case member and the laminated heat exchanger. It is configured to close. Here, the widths of the plurality of groove portions are not always constant due to factors such as manufacturing errors. Therefore, even if the widths of the groove portions vary, the plurality of protruding pieces can be protruded into the plurality of groove portions to close the groove portions. In addition, the width of the protruding piece needs to be narrower than the width of the groove. However, since only one comb-tooth-shaped portion of the closing plate creates a gap between the groove and the protruding piece, a part of the combustion gas bypasses the laminated heat exchanger from the gap and the combustion gas. It will flow to the outlet.

Therefore, if a plurality of such closing plates are provided and the plurality of closing plates are arranged so that the comb-shaped portions of the plurality of closing plates are displaced in the laminating direction of the flow path forming plates, any one of the combs will be formed. Even if there is a gap between the protruding piece of the tooth-shaped portion and the groove, the gap can be closed by another protruding piece of the tooth-shaped portion, so that the combustion gas bypasses the laminated heat exchanger from the groove. It is possible to almost completely prevent the gas from flowing into the combustion gas discharge port.

According to a third aspect of the present invention, there is provided a gap sealing structure for a heat exchange device according to the second aspect, wherein the plurality of closing plates are arranged such that a plurality of comb-tooth-shaped portions are at least partially in close contact with each other. It is characterized in that the two comb tooth-shaped portions are arranged so as to be located at positions displaced in the stacking direction of the flow path forming plates. Since the width of the protruding piece needs to be narrower than the width of the groove portion, there is a gap between the protruding piece and the groove portion of a certain comb tooth-shaped portion.
Since at least two comb-tooth-shaped portions are displaced in the laminating direction of the flow path forming plate, the above-mentioned gap should be closed by the protruding pieces of the other comb-tooth-shaped portions which are arranged so as to be offset from the comb-tooth-shaped portions. You can

According to a fourth aspect of the present invention, there is provided a gap seal structure for a heat exchange device according to the first aspect of the invention, wherein the closing plate has a plurality of slits located between a plurality of projecting pieces of the comb tooth-shaped portion, and a plurality of these slits. The present invention is characterized by having a plurality of bent portions formed in parallel with the slits at positions on the extension of the slit and alternately bent to the opposite side. Therefore, the projecting piece can be inclined with respect to the stacking direction of the flow path forming plates by the bent portion formed in parallel with the slit. That is, when the comb-tooth shaped portion is extended in the stacking direction, the protruding piece is formed so that the width in the stacking direction is slightly larger than the width of the groove portion, and the comb-toothed portion is bent at the bending portion to project the protruding piece. By inclining with respect to the stacking direction, it is possible to cause the projecting piece, which is wider than the groove, to project into the groove and close the groove almost completely.

According to a fifth aspect of the present invention, there is provided the gap seal structure for a heat exchange device according to the second or third aspect, wherein at least one of the plurality of closing plates is thin and elastically deformable when the gas pressure of combustion gas increases. It is characterized by being composed of a metal plate. As described above, the heat exchange efficiency can be improved by closing the case member and the laminated heat exchanger in a substantially airtight manner, but on the other hand, the case member and the laminated heat exchanger are always airtight. If it is blocked, the pressure fluctuation of the combustion gas is amplified in the case member in the unsteady state of the combustion equipment, such as when the output of the burner fluctuates, and the flame of the burner becomes unstable. Also, there is a possibility that a phenomenon called so-called oscillating combustion may occur, in which the device itself including this heat exchange device resonates and vibrates.

Therefore, by configuring at least one of the plurality of closing plates by a thin metal plate, when the gas pressure rises in an unsteady state, the rising gas pressure causes the thin metal plate to be constructed. The closing plate elastically deforms, and the comb-shaped portion is separated from the groove. Therefore, a part of the combustion gas from the groove temporarily bypasses the laminated heat exchanger and flows to the combustion gas discharge port, and the increased gas pressure is reduced, so that large fluctuations in gas pressure are suppressed. Thus, the occurrence of oscillatory combustion can be prevented. When the gas pressure decreases, the closing plate returns to the original state and the comb-shaped portion closes the groove, so that the combustion gas does not continuously leak from the groove after the gas pressure decreases.

According to a sixth aspect of the present invention, there is provided a gap sealing structure for a heat exchange device, wherein a case member having a combustion gas inlet and a combustion gas outlet is provided, and a plurality of flow path forming plates disposed inside the case member are laminated. In a heat exchange device having a laminated heat exchanger having a structure, between the case member and the laminated heat exchanger to prevent the combustion gas from bypassing the laminated heat exchanger and flowing to the combustion gas discharge port. Is a coil spring that is expandable in the stacking direction of the flow path forming plate, the coil spring closing the plurality of groove portions of the outer peripheral portion of the stacked heat exchanger in a substantially airtight manner, The tip end of the closing plate on the side of the laminated heat exchanger is brought into contact with the coil spring.

Instead of providing the comb-teeth-shaped portion on the closing plate as in the first aspect of the invention, a plurality of coil springs for closing the plurality of groove portions between the case member and the laminated heat exchanger in a substantially airtight manner are provided. By providing the coil spring with the tip end of the closing plate on the side of the laminated heat exchanger, the space between the case member and the laminated heat exchanger can be closed in a substantially airtight manner. Other operations are the same as those in claim 1, and the description thereof will be omitted.

[0021]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described. This embodiment is an example in which the present invention is applied to a latent heat recovery type heat exchange device (secondary heat exchange device) of a water heater. First, the water heater 1 will be briefly described. As shown in FIG. 1, the water heater 1 includes a burner 2, a primary heat exchange device 3 for recovering the sensible heat of the combustion gas from the burner 2, and a latent heat of water vapor in the combustion gas 2 The secondary heat exchange device 4 and a blower fan 5 for supplying combustion air to the burner 2 are provided. A gas supply pipe 10 for supplying fuel gas is connected to the burner 2.

As shown in FIGS. 1 and 2, the water supply port 32 of the secondary heat exchange device 4 is connected to the water supply pipe 11, while the hot water outlet 33 is connected to the primary heat exchange device 3 and the secondary heat exchanger. A connection pipe 12 for connecting the exchange device 4 is connected. The water supplied from the water supply pipe 11 to the secondary heat exchange device 4 is the secondary heat exchange device 4
Is heat-exchanged with the low-temperature combustion gas flowing from the primary heat exchange device 3, and is sent to the primary heat exchange device 3 via the connecting pipe 12. The hot water flowing into the primary heat exchange device 3 is further heat-exchanged with the high-temperature combustion gas from the burner 2 to be heated, and is supplied from the hot water outlet pipe 13 to various facilities such as a kitchen and a bath. .

Next, the secondary heat exchange device 4 will be described in detail. The secondary heat exchange device 4 performs heat exchange between the combustion gas whose temperature has decreased after the heat exchange with the hot water in the primary heat exchange device 3 and the water before entering the primary heat exchange device 3. In addition, the latent heat of water vapor in the combustion gas is also recovered to improve the heat exchange efficiency. As shown in FIGS. 3 and 4, the secondary heat exchange device 4 includes a case member 20 having a combustion gas introduction port 20a and a combustion gas discharge port 20b, and a plurality of flow paths arranged inside the case member 20. A laminated heat exchanger 21 having a structure in which the path forming plates 30 are laminated (hereinafter referred to as the heat exchanger 21) is provided.

A combustion gas introduction port 20 for introducing combustion gas from the primary heat exchange device 3 is provided at the rear end of the case member 20.
A is formed, and a combustion gas discharge port 20b for discharging combustion gas to the outside is formed at the front end of the case member 20. Moreover, the upper end of the case member 20 is closed by a top plate 22. The bottom plate 23 of the case member 20 is
The water is condensed inside and is inclined so that the water generated flows down, and a drain discharge pipe 24 extending downward is provided at the front end of the bottom plate 23. The condensed water generated inside the case member 20 contains nitrogen oxides and sulfur oxides in the combustion gas and exhibits acidity, and therefore is neutralized by a neutralization device (not shown) connected to the drain discharge pipe 24. After being discharged, it is discharged to the outside.

As shown in FIGS. 3 to 6, the heat exchanger 21
Has a structure in which a plurality of flow path forming plates 30 each having a flow path 36 through which hot water flows are laminated in front and back. The plurality of flow path forming plates 30 are joined by vacuum furnace brazing using a brazing material such as a copper alloy. As shown in FIG. 5, the plurality of laminated flow path forming plates 30 are sandwiched between the left and right end plates 31, and the left end flow path forming plate 30 has a water supply port 32 and a hot water delivery port 33. Are formed. Combustion gas flows downward from above between the plurality of flow passage forming plates 30.
Outer fins 34 for increasing the heat transfer area on the combustion gas side are provided between 0.

As shown in FIGS. 5 and 6, the flow path forming plate 30
Is obtained by stacking two plate members 30a and 30b and joining the plate members 30a and 30b by vacuum furnace brazing.
Between 0a and 30b, the water inflow part 35 into which water flows in from the water supply port 32 and the water inflowing from this water inflow part 35 are shown in FIG.
U-shaped channel 36 formed to flow in the direction of the arrow
And the hot water heated while passing through the flow path 36
The hot water outflow part 37 sending out to 3 is formed. Inner fins 38 for increasing the heat transfer area on the hot water side are provided in the flow path 36. As shown in FIGS. 5 and 6, each flow path forming plate 30 includes two plate members 30a,
There is a caulking portion 39 which is formed by the outer peripheral portion of 30b and projects to the outside.
9, a plurality of groove portions 40 are formed on the outer peripheral portion of the heat exchanger 21.

In this heat exchanger 21, the water introduced from the water supply port 32 is branched into the flow passage 36 of each flow passage forming plate 30 and passes through the flow passage 36 to exchange heat with the combustion gas. After being heated, it merges again and the hot water outlet 33
It is sent to the next heat exchange device 3. On the other hand, the combustion gas inlet 20
The combustion gas introduced into the case member 20 from a is
As shown by the solid arrow in FIG. 4, the hot water flowing through the flow path 36 is heated and flows between the stacked flow path forming plates 30 from the upper side to the lower side, and is discharged from the combustion gas discharge port 20b to the outside. Combustion gas is present on the upper side of the heat exchanger 21.
A gap seal structure 50 described below is provided to close the gap between the case member 20 and the heat exchanger 21 so as not to flow into the combustion gas exhaust port 20b by bypassing the.

Next, the gap seal structure 50 peculiar to the present invention will be described. The gap seal structure 50 is used in the heat exchanger 2
1 and the case member 20 are closed, and as shown by a dotted arrow in FIG. 4, a part of the combustion gas does not exchange heat with the hot water in the heat exchanger 21 and passes through the gap. Outlet 2
This is to prevent the flow to 0b.

As shown in FIGS. 3 and 4, the gap seal structure 50 prevents the combustion gas from bypassing the heat exchanger 21 and flowing to the combustion gas discharge port 20b, and the case member 20 and the heat exchanger 21. There are two closing plates 51 and 52 made of SUS304 before and after closing the space. The front closing plate 51 is relatively thick (for example, 0.5 mm), while the rear closing plate 52 is a thin plate (for example, 0.05 mm in thickness) whose front end portion can be easily elastically deformed. It is composed of.

The front closing plate 51 is attached to the case member 20.
It is attached to the heat exchanger 21 so that the position in the left-right direction can be adjusted, and is arranged so as to close the gap between the case member 20 and the heat exchanger 21 in a state of being curved so as to hang from the front to the rear. There is. On the other hand, the rear closing plate 52 is arranged so as to close the gap between the case member 20 and the heat exchanger 21 in a state of being curved so as to hang down from the rear to the front. These two closing plates 51, 52 are pressed against the heat exchanger 21 side by the top plate 22, and the vertical position does not shift inside the case member 20.

Here, most of the gap between the case member 20 and the heat exchanger 21 can be closed by these two closing plates 51 and 52, but as described above, the heat exchanger 2
Since the plurality of groove portions 40 are formed on the outer peripheral portion of 1, the part of the combustion gas will flow out from the plurality of groove portions 40 to the combustion gas discharge port 20b unless the plurality of groove portions 40 are closed. Therefore, as shown in FIGS. 7 to 10, the two closing plates 51, 52 are provided at the tip end portions on the heat exchanger 21 side,
In order to close the plurality of groove portions 40 on the outer peripheral portion of the heat exchanger 21 with the two closing plates 51 and 52 in a substantially airtight manner, the plurality of groove portions 4 are formed.
Comb-tooth-shaped portions 53 and 54 are provided, each of which has a plurality of protruding pieces 53a and 54a protruding inwardly formed in a substantially comb-tooth shape. The protruding piece 53a of the comb-tooth-shaped portion 53 of the closing plate 51 on the front side
A bent portion 53b that is bent backward is formed at the tip of the.

As shown in FIGS. 8 to 10, a plurality of groove portions 4 are formed.
In 0, the protruding piece 53a of the front side closing plate 51 protrudes into the groove 40 and abuts on the outer surface part of the heat exchanger 21, and the protruding piece 54a of the rear side closing plate 52 bends the protruding piece 53a. It is arranged so as to be in close contact with the portion 53b. Furthermore, the two comb-tooth-shaped portions 53 and 54 are arranged so as to be located at positions displaced in the left-right direction (the stacking direction of the flow path forming plates 30). For example, the comb tooth-shaped portion 5 of the front closing plate 51
3 is arranged close to the right side, and the closing plate 52 on the rear side is arranged.
It suffices to dispose the comb-tooth-shaped portion 54 in the leftward direction.

Since the widths of the plurality of groove portions 40 in the left-right direction are not always constant due to factors such as manufacturing errors, even if the widths of the groove portions 40 vary, a plurality of protruding pieces are formed. The widths of the protruding pieces 53a, 54a of the comb-tooth-shaped portions 53, 54 are formed to be slightly narrower than the width of the groove portion 40 so that the groove portions 40 can be closed by projecting the groove portions 40 into the groove portions 40. Has been done. Therefore, as shown in FIG. 10, by only projecting the protruding piece 53a of the comb-shaped portion 53 on one side into the groove 40, the groove 4 is formed.
Since a gap d in the left-right direction is formed between 0 and the protruding piece 53a, the combustion gas leaks from this gap d. However, since the other projecting piece 54a is arranged at a position displaced in the left-right direction with respect to the projecting piece 53a, the gap d is closed by this projecting piece 54a.

As described above, since the rear closing plate 52 is made of a thin plate, when the gas pressure of the combustion gas rises in an unsteady state, such as when the output of the burner 2 fluctuates, as shown in FIG. As shown by the chain line, the comb-tooth-shaped portion 54a is elastically deformed so as to float. Then, the gap d blocked by the protruding piece 54a is instantaneously opened, and the gap d
A part of the combustion gas flows through the combustion gas exhaust port 20b.

Next, the operation and effect of the gap seal structure 50 will be described. As shown in FIG. 4, when the combustion gas is introduced into the secondary heat exchange device 4 from the combustion gas introduction port 20a, the space between the case member 20 and the heat exchanger 21 is almost closed by the two closing plates 51 and 52. Since it is blocked, most of the combustion gas flows from the combustion gas exhaust port 20b to the secondary side while passing through the plurality of flow path forming plates 30 while heating the hot water as shown by the solid line arrow in FIG. It is discharged to the outside of the heat exchange device 4.

Here, a groove portion 40 is formed on the outer peripheral portion of the heat exchanger 21 by a plurality of flow path forming plates 30 stacked, and a part of the combustion gas is heat-exchanged through the groove portions 40. Although it will flow to the combustion gas discharge port 20b by bypassing the vessel 21, the protruding pieces 53a and 54a of the comb-tooth-shaped portions 53 and 54 project in the plurality of groove portions 40, so that combustion from the groove portion 40 occurs. Gas leakage can be suppressed.

The width of the protruding pieces 53a, 54a in the left-right direction is narrower than the width of the groove 40. For example, when the protruding piece 53a is inserted into the groove 40 as shown in FIG. A gap d is formed between the groove 40 and the groove 40, but since the gap d can be closed by the other protruding piece 54a, it is possible to close the plurality of grooves 40 substantially airtight by the two comb-tooth-shaped portions 53 and 54. You can Therefore, it is possible to suppress the combustion gas from being discharged from the combustion gas discharge port 20b without being heat-exchanged by the heat exchanger 21, and to improve the heat exchange efficiency.

Further, since the rear closing plate 52 is made of a thin plate which can be elastically deformed when the gas pressure of the combustion gas rises, the gas of the combustion gas is unsteady when the output of the burner 2 fluctuates. When the pressure rises, the gas pressure rises, as shown by the chain line in FIG.
Elastically deforms so as to float, and the gap d closed by the protruding piece 54a is momentarily opened.

Therefore, a part of the combustion gas flows to the combustion gas discharge port 20b through the gap d, and the gas pressure decreases,
It is possible to prevent the fluctuation of the gas pressure from being amplified, and prevent the flame of the burner 2 from becoming unstable and the oscillatory combustion to occur in the water heater 1. As the combustion gas instantaneously flows through the gap d, the gas pressure immediately drops, so that the elastically deformed comb tooth-shaped portion 54 returns to its original state and the gap d is closed again, and the gas pressure drops. After that, the combustion gas continues and the groove 4
It never leaks from zero.

Next, a description will be given of a modified form in which various modifications are made to the above embodiment. However, components having the same configurations as those in the above-described embodiment are designated by the same reference numerals, and the description thereof will be appropriately omitted. 1] As shown in FIG. 11, either one or both of the upper side and the lower side of the portions where the comb-tooth-shaped portions 53 and 54 are partially adhered to correspond to the caulked portion 39 as shown in FIG. A seal member 60 having a plurality of slits 60a and made of a synthetic resin (for example, made of PTFE) having excellent corrosion resistance may be provided. Alternatively, the seal member 60
You may interpose between the one comb tooth-shaped part 53,54. In addition to the two comb-tooth-shaped portions 53 and 54, the seal member 60 further closes the groove portion 40, so that the fuel gas is supplied to the groove portion 4.
Flow from 0 to the combustion gas discharge port 20b can be almost completely prevented.

As in the above embodiment, in order to prevent oscillating combustion, the comb-tooth-shaped portion 54 of the closing plate 52 at the time of increasing the gas pressure.
13 is elastically deformed so that the combustion gas instantaneously flows through the groove portion 40, as shown in FIG. 13, a plurality of slits 61a corresponding to the caulking portion 39 and a seal member 61 having an opening 61b are provided. When the closing plate 52 is elastically deformed and the comb-tooth-shaped portion 54 is lifted, the opening 6 is used.
Combustion gas is instantaneously discharged through 1b through combustion gas discharge port 20b.
It should flow to.

2] As shown in FIG. 14, the rear closing plate 7
A bent portion 74b that bends forward is formed on the protruding piece 74a of the second comb tooth-shaped portion 74, and in the groove portion 40, the rear side protruding piece 74a is in contact with the heat exchanger 21, and the front side closing plate is formed. The protruding piece 73a of the comb-tooth-shaped portion 73 of 71 may be arranged so as to be in close contact with the upper surface of the bent portion 74b of the protruding piece 74a on the rear side.

4] One of the two closing plates 51 and 52 may be omitted. In this case, the plurality of groove portions 40 are closed by the comb-teeth-shaped portion of one closing plate, and therefore, as shown in FIG.
A small amount of combustion gas is discharged from the combustion gas exhaust port 2 through the gap d shown in FIG.
Although it flows to 0b, the heat exchange efficiency can be remarkably improved as compared with the case where the groove 40 is not closed.

Further, when closing the gap with one closing plate, as shown in FIGS. 15 and 16, the closing plate 80 is
A plurality of slits 81b located between the plurality of protruding pieces 81a of the comb-tooth-shaped portion 81 and corresponding to the plurality of caulked portions 39 of the heat exchanger 21, and slits 81b parallel to the slits 81b at positions on the extension of the plurality of slits 81b. A plurality of bent portions 8 formed on the
A plurality of bent portions 8 that are 1c and are alternately bent to the opposite side
1c can also be configured.

With this structure, as shown in FIG. 16, the bent portion 81 formed in parallel with the slit 81b.
Due to c, the protruding piece 81a can be tilted vertically with respect to the left-right direction. That is, in the state where the comb-tooth-shaped portion 81 is extended to the left and right, the comb-tooth-shaped portion 8 is formed so that the left and right widths of the protruding pieces 81 a are larger than the width of the groove portion 40.
1 can be bent at the bent portion 81c, and the protruding piece 81a can be inserted into the groove portion 40 in a state where the protruding piece 81a is inclined with respect to the left-right direction. Even if the width is varied, the groove 40 can be closed almost airtightly by the protruding piece 81a.

5] As shown in FIGS. 17 and 18, the heat exchanger 21 includes a closing plate 91 for closing the space between the case member 20 and the heat exchanger 21, and a coil spring 92 which can extend in the left-right direction. A gap seal structure 90 is provided so that the coil spring 92 that closes the groove portion 40 in the outer peripheral portion of the heat exchanger 21 in a substantially airtight manner is provided, and the tip of the closing plate 91 on the heat exchanger 21 side is brought into contact with the coil spring 92.
May be configured. Therefore, even if the width of the groove portion 40 in the left-right direction varies due to factors such as manufacturing errors, the coil spring 92 can be expanded and contracted to push a part of the coil spring 92 into the plurality of groove portions 40. The heat exchange efficiency can be improved by closing it in a substantially airtight manner.

[0047]

According to the invention of claim 1, it is possible to prevent a part of the combustion gas from flowing between the case member and the laminated heat exchanger to bypass the laminated heat exchanger and flow to the combustion gas discharge port. In order to block the gap, the block plate can close the space between the case member and the laminated heat exchanger. Furthermore, since the comb-teeth-shaped portion is formed at the tip of the closing plate on the side of the laminated heat exchanger, the protruding pieces protruding into the plurality of grooves are formed in a substantially comb-like shape. It is possible to close the space between the case member and the laminated heat exchanger in a substantially airtight manner by closing the plurality of grooves on the outer peripheral portion of the exchanger. Therefore, it is possible to suppress the flow of the combustion gas from the groove portion to the bypass of the laminated heat exchanger to the combustion gas discharge port, and improve the heat exchange efficiency.

According to the second aspect of the present invention, since the plurality of groove portions of the outer peripheral portion of the laminated heat exchanger are closed in a substantially airtight manner by the plurality of closing plates, the plurality of closing plates on the side of the laminated heat exchanger. Since the comb-tooth-shaped portions, each of which has a plurality of protruding pieces protruding into the plurality of grooves and formed in a substantially comb-tooth shape, are provided at the tip end portion, the following effects can be obtained.

The widths of the plurality of groove portions are not necessarily constant due to factors such as manufacturing errors. Therefore, even if the widths of the groove portions are varied, the width of the protruding piece should be the same as the width of the groove portion in order to allow the protruding piece to protrude into the groove portion. It is necessary to make it narrower than the width, but by arranging multiple closing plates so that the comb-shaped portions of the closing plates are displaced in the stacking direction of the flow path forming plates The gap generated between the piece and the groove can be closed by the protruding piece of another comb-shaped portion that is arranged so as to be offset from the comb-shaped portion, so that the combustion gas from the groove forms a stacked heat exchanger. Bypassing can be almost completely prevented from flowing to the combustion gas exhaust port, and heat exchange efficiency can be improved.

According to the third aspect of the present invention, the plurality of closing plates are arranged such that the plurality of comb-tooth-shaped portions are at least partially in close contact with each other, and at least two comb-tooth-shaped portions are the flow path forming plates. Since it is arranged at a position displaced in the stacking direction of, the gap between the protruding piece and the groove portion of the comb tooth-shaped portion caused by making the width of the protruding piece narrower than the width of the groove portion, It can be closed by the protruding piece of the comb-tooth-shaped portion arranged at a position displaced from the comb-tooth-shaped portion in the stacking direction.

According to the fourth aspect of the present invention, the projecting piece can be inclined with respect to the laminating direction of the flow path forming plate by the bent portion formed in parallel with the slit. Therefore, it is formed in such a manner that the width of the protruding piece in the stacking direction is slightly larger than the width of the groove while the comb-tooth-shaped portion is extended in the stacking direction.
By bending the comb-shaped portion at the bending portion and inclining the protruding piece with respect to the stacking direction, the wide protruding portion can be protruded into the groove portion, and the groove portion can be closed in a substantially airtight manner by the protruding piece. it can. In addition, the same effect as that of the first aspect can be obtained.

According to the fifth aspect of the present invention, at least one of the plurality of closing plates is made of a thin metal plate that is elastically deformable when the gas pressure of the combustion gas rises. When the gas pressure of the combustion gas increases, the closing plate made of a thin metal plate elastically deforms due to the increased gas pressure, and the comb-tooth-shaped portion is separated from the groove. Therefore,
The combustion gas temporarily bypasses the laminated heat exchanger and flows out to the combustion gas discharge port from the groove portion, and the increased gas pressure is reduced to suppress the occurrence of oscillatory combustion.
Further, when the gas pressure decreases, the closing plate returns to the original state, so that the comb-teeth-shaped portion returns to the state of closing the groove portion, and the combustion gas does not continuously leak from the groove portion after the gas pressure decreases. In addition, the same effect as that of claim 2 or 3 can be obtained.

According to the sixth aspect of the present invention, between the case member and the laminated heat exchanger, a plurality of coil springs for closing the plurality of groove portions in a substantially airtight manner are provided, and the closing plate is laminated on the coil springs. By abutting the tip of the mold heat exchanger,
Since the space between the case member and the laminated heat exchanger can be closed in an almost airtight manner, the combustion gas is prevented from bypassing the laminated heat exchanger and flowing to the combustion gas outlet, improving heat exchange efficiency. Can be made.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram of a water heater according to an embodiment of the present invention.

FIG. 2 is a side view of the primary and secondary heat exchange devices.

FIG. 3 is a front view of a secondary heat exchange device.

FIG. 4 is a side view of FIG.

FIG. 5 is a front view of a laminated heat exchanger.

FIG. 6 is a side view of FIG.

FIG. 7 is a plan view of a closing plate.

FIG. 8 is a partial plan view of a comb-tooth-shaped portion that closes the groove.

9 is a sectional view taken along line IX-IX in FIG.

10 is a view taken along line XX of FIG.

FIG. 11 is a view corresponding to FIG. 9 showing a modified form.

FIG. 12 is a partial plan view of a seal member.

FIG. 13 is a partial plan view of a seal member.

FIG. 14 is a view corresponding to FIG. 9 showing a modified form.

FIG. 15 is a view corresponding to FIG. 10 showing a modified form.

16 is a sectional view taken along line XVI-XVI of FIG.

FIG. 17 is an enlarged view of a main part of the heat exchanger in which the groove portion is closed by the coil spring in the modified embodiment.

18 is a sectional view taken along line XVIII-XVIII in FIG.

[Explanation of symbols]

4 Secondary heat exchange device 20 case members 20a Combustion gas inlet 20b Combustion gas outlet 21 Stacked heat exchanger 30 flow path forming plate 40 groove 50, 90 gap seal structure 51, 52, 71, 72, 80, 91 Closure plate 53, 54, 73, 74, 81 Comb-shaped part 53a, 54a, 73a, 74a, 81a Projecting piece 81b slit 81c bent part 92 coil spring

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Takuji Saeki             93 Edomachi, Chuo-ku, Kobe No             Inside F-term (reference) 3L036 AA01 AA46

Claims (6)

[Claims] 1. A case member having a combustion gas introduction port and a combustion gas discharge port, and a laminated heat exchanger having a structure in which a plurality of flow path forming plates are laminated inside the case member. In the heat exchange device, a closing plate that closes the space between the case member and the laminated heat exchanger is provided, and the closing plate protrudes into a plurality of grooves on the outer peripheral portion of the laminated heat exchanger on the laminated heat exchanger side. A gap seal structure for a heat exchange device, characterized in that a comb-tooth-shaped portion in which a plurality of protruding pieces are formed in a comb-tooth shape is provided. 2. A case member having a combustion gas inlet and a combustion gas outlet, and a laminated heat exchanger having a structure in which a plurality of flow path forming plates are laminated inside the case member. In the heat exchange device, a plurality of closing plates that close the space between the case member and the laminated heat exchanger are provided, and a plurality of groove portions on the outer peripheral portion of the laminated heat exchanger are provided on the laminated heat exchanger side of the plurality of closing plates. A gap seal structure for a heat exchange device, wherein each comb tooth-shaped portion is formed by forming a plurality of protrusion pieces protruding inward in a comb tooth shape. 3. The plurality of closing plates are arranged such that the plurality of comb tooth-shaped portions are in close contact with each other at least partially, and at least two comb tooth-shaped portions are displaced in the stacking direction of the flow path forming plates. The gap seal structure for a heat exchange device according to claim 2, wherein the gap seal structure is arranged so as to be positioned. 4. The closing plate includes a plurality of slits located between the plurality of protruding pieces of the comb-tooth-shaped portion, and a plurality of bends formed in parallel with the slits at positions on the extension of the plurality of slits. The gap seal structure for a heat exchange device according to claim 1, further comprising a plurality of bent portions that are alternately bent to opposite sides. 5. At least one of the plurality of closure plates
The gap seal structure for a heat exchange device according to claim 2 or 3, wherein the one is made of a thin metal plate that is elastically deformable when the gas pressure of the combustion gas rises. 6. A case heat exchanger comprising: a case member having a combustion gas inlet and a combustion gas outlet; and a laminated heat exchanger arranged inside the case member and having a structure in which a plurality of flow path forming plates are laminated. In the heat exchange device, in order to prevent the combustion gas from bypassing the laminated heat exchanger and flowing to the combustion gas discharge port, a blocking plate that closes between the case member and the laminated heat exchanger is provided, and the flow passage is formed. A coil spring that can extend in the stacking direction of the plates, wherein a coil spring that closes a plurality of groove portions of the outer peripheral portion of the stacked heat exchanger in a substantially airtight manner is provided, and a tip of the closing plate on the stacked heat exchanger side. A gap seal structure for a heat exchange device, wherein a portion is brought into contact with the coil spring.