JP2010032166A - Combustion device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To raise a temperature of supplied air by improving a combustion device built into a hot-water supply device and by recovering heat from exhausted combustion gas. <P>SOLUTION: The supplied air is heated from both an inner cylinder 26 side (inner wall side) and an outer cylinder 41 side (outer wall side) to recover the heat from exhaust gas. A temperature of the outer cylinder 41 side (outer wall side) is raised by making an exhaust passage and an air supply passage partially contact with each other to raise the temperature of the supplied air from the inner cylinder 26 side (inner wall side) and the outer cylinder 41 side. In addition, the contact surface is inclined. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a combustion apparatus associated with a hot water supply apparatus for indoor installation, and in particular, is a combustion apparatus aimed at improving thermal efficiency and reducing costs and thus contributing to energy saving.

In order to prevent indoor air from being polluted, a hot water supply apparatus for indoor installation must take in air from the outside and discharge exhaust gas to the outside. Accordingly, a hot water supply apparatus for indoor installation requires an air supply duct for taking in air from the outside and an exhaust duct for discharging exhaust gas to the outside.
However, if an air supply duct and an exhaust duct are provided separately, duct work is required for installation, which is troublesome. Therefore, Patent Documents 1 and 2 disclose a configuration in which a duct having a double pipe structure having an inner cylinder and an outer cylinder is used, air is taken in from the outside by a single air supply / exhaust duct, and exhaust gas is discharged to the outdoors. .

In the indoor-installed combustion apparatus described in Patent Documents 1 and 2, a duct having a double pipe structure as described above is used.
By the way, although the duct of a double pipe structure has the fault that manufacture of a duct itself is troublesome, in the point of thermal efficiency, it is superior to the structure which uses an independent air supply duct and exhaust duct.
That is, when using a duct with a double pipe structure, high-temperature exhaust gas passes through the inner cylinder side and low-temperature outside air passes around it, so heat exchange is performed through the wall surface of the inner cylinder that separates the two. The supply air flowing around is heated by the high-temperature exhaust gas flowing in the inner cylinder. Therefore, the heat contained in the exhaust gas is recovered during the supply air, and the thermal efficiency is improved.
Japanese Utility Model Publication No. 4-35710 Japanese Utility Model Publication No. 61-13257

  Although the conventional combustion apparatus can recover the heat possessed by the exhaust gas, the recovery rate is low and is not satisfactory. For this reason, the conventional combustion apparatus is lacking in effective utilization of heat.

  However, global warming prevention is now a global theme, and as a real problem, the shortage of resources such as oil is becoming more serious. In that sense, the use of the heat it holds is one effective means for solving such problems, even if it is a discarded gas.

Outlined to achieve the above object, the present invention recovers heat from exhaust gas by heating the air supply from both the inner cylinder side (inner wall side) and the outer cylinder side (outer wall side).
That is, in the conventional combustion apparatus, high-temperature exhaust gas passes through the inner cylinder side, and low-temperature outside air passes around the inner cylinder side. The temperature rises, but the temperature on the outer cylinder side is low. For this reason, the supply air whose temperature has been raised is lost due to contact with the outer cylinder.
Therefore, the present invention provides a combustion apparatus for indoor installation, in which a part of the exhaust passage and the air supply passage are brought into surface contact with each other to raise the temperature of the outer cylinder side (outer wall side), and the supply air is supplied to The temperature rises from both the outer cylinder side.
Another feature is that the joint surface is inclined.

  A first aspect for solving the above-described problem includes a blower, a burner portion, an exhaust collecting portion, an air supply / exhaust tube and an air supply path forming member, and the air supply / exhaust tube includes an inner tube and an outer tube. The inner cylinder is an exhaust side flow path and constitutes a part of the exhaust flow path for discharging combustion gas to the outside, and the space between the outer periphery of the inner cylinder and the outer cylinder is an air introduction side flow path. A part of the air introduction path for introducing air from the outside, the air introduction side flow path of the supply and exhaust cylinder and the blower are connected via a connection part, and the exhaust collecting part and the supply air are further downstream of the burner part. There is an inner cylinder of the exhaust cylinder, the combustion gas discharged from the burner part is collected in the exhaust gas collection part, the flow path is throttled in the exhaust gas collection part, and the exhaust gas collection is provided. The portion has a cross wall portion that intersects the flow direction of the combustion gas in a part of the wall surface forming the flow path, and the air supply path forming portion Includes a cover portion that covers the exhaust collecting portion, and a gap that forms a part of the air introduction path is provided between the cover portion of the air supply path forming member and the exhaust collecting portion, and the cover portion A combustion apparatus comprising a contact wall in contact with an intersecting wall portion of an exhaust collecting portion.

In the combustion apparatus of the present invention, the air supply path forming member is provided, the cover portion of the air supply path forming member covers the exhaust collecting portion, and a gap forming a part of the air introduction path between the covering portion and the exhaust collecting portion. Is formed. Accordingly, the air supply passes through the gap formed in the cover portion and the exhaust collecting portion and flows to the blower side. That is, the cover portion constitutes the outer wall side of the air introduction path.
In the present invention, the covering portion described above includes a contact wall and is in contact with the intersecting wall portion of the exhaust collecting portion. Here, the intersecting wall portion of the exhaust collecting portion is a wall surface on which the combustion gas directly collides, and is a portion where the combustion gas stays and becomes high temperature. Therefore, the contact wall that contacts the intersecting wall portion is in a high temperature state, and this heat is conducted to other parts of the covering portion.
As described above, since the cover portion constitutes the outer wall side of the air introduction path, the heat of the exhaust collecting portion is conducted to the outer wall side of the air introduction path, and the air passing therethrough is also heated from the outer wall side. The
In the combustion apparatus of the present invention, the supply air temperature is also raised from the inner wall side of the air introduction path as in the prior art, so that heat conduction is received from both the inner wall side and the outer wall side of the air introduction path, and the heat recovery efficiency is high. .

  According to the second aspect, the gap is provided with an opening for sending the supplied air to the blower side, and the position of the opening and the contact wall of the air supply path forming member are at the opposing positions and are in contact with each other. The wall and the crossing wall portion constitute an inclined wall inclined with respect to the flow of the fuel gas.

As a result of the second aspect, the intersecting wall portion forms a canopy such as a combustion chamber, and the inclined surface guides the combustion gas to the exhaust passage, thereby preventing the combustion gas from stagnation.
Moreover, according to the 2nd aspect, a contact wall exists in the position which opposes the position of the opening which sends out the air supplied from the space | gap. Here, the position facing the position of the opening described above is a position where there is little air flow. That is, in the present invention, the space between the outer periphery of the inner cylinder and the outer cylinder becomes the air introduction side flow path, and the air flowing through the portion flows into the gap between the cover portion of the air supply path forming member and the exhaust collecting portion. And it is supplied to an air blower through the opening provided in the space | gap. Therefore, the air flows from the space between the outer periphery of the inner cylinder and the outer cylinder toward the opening side in the above-described gap, and the air flow tends to stay at the position facing the opening position and the flow rate is slow. . Therefore, the air that flows into a position facing the position of the opening hardly takes heat away from the exhaust collecting portion. That is, the part has low heat exchange efficiency with the supply air.
Therefore, in the present invention, a place where heat exchange with the supply air is difficult is selected as the intersecting wall portion, and the heat of the exhaust collecting portion is conducted to the outer wall side of the air introduction path.

  According to a third aspect, in the first or second aspect, the intersecting wall portion and the contact wall of the covering portion are integrated by welding, screws, or scissors.

  As a result of the third aspect, the intersecting wall portion and the contact wall of the covering portion are in close contact with each other, and the heat conduction between them is performed smoothly.

  According to the fourth aspect, in any one of the first to third aspects, a heat exchanger is interposed downstream of the burner portion.

  In the fourth aspect, the water heater can be configured by passing water through the heat exchanger.

  The combustion apparatus of the present invention has excellent heat recovery efficiency from exhaust gas and high heat efficiency.

Embodiments of the present invention will be further described below. In the embodiment described below, the present invention is applied to a water heater.
A water heater 1 according to the present invention has a combustion device 3 disposed in a casing 2. As shown in FIGS. 1 to 4, the combustion device 3 includes a blower 5, a burner unit 6, a heat exchange unit 7, an exhaust collection unit 8, an air supply path forming member 10 and a communication path forming member 11. ing.
The blower 5 is a known sirocco fan or turbo fan. A cylindrical blade 13 is arranged in the casing 12 and the blade 13 is rotated by a motor 15.

The burner portion 6 has the same configuration as that of a known one, and a plurality of burners 17 are built in a rectangular case 16.
The heat exchanging portion 7 has the same configuration as that of a known one, and a pipe and a heat transfer plate are arranged in a rectangular case 18. The case 16 of the burner unit 6 and the case 18 of the heat exchange unit 7 have the same cross-sectional shape.

The exhaust collecting portion 8 is made by bending a metal plate, covers the heat exchanging portion 7, and is a lid-like member having five surfaces excluding the bottom surface.
That is, the exhaust collecting portion 8 is a member having a front plate (inclined wall) 20, a right side plate 21, a left side plate 22, a back plate 23 and a top plate 25 as shown in FIG.
Here, the front plate 20 is inclined with respect to the axis of the combustion device 3. On the other hand, the right side plate 21, the left side plate 22, and the back plate 23 are parallel to the axis of the combustion device 3.
The top plate 25 is perpendicular to the right side plate 21 and the like. An inner cylinder 26 is provided on the top plate 25. The inner cylinder 26 is hollow, and the inner cylinder 26 communicates the front and back of the exhaust collecting portion 8.

The air supply path forming member 10 has a complicated shape as shown in FIG. 2, and is largely divided into a cover portion 27 and an outer cylinder 41.
The cover portion 27 is a lid-shaped portion having five surfaces excluding the bottom surface, and has a shape in which a part on the front side is inclined and a part on the back side is cut off.
The air supply path forming member 10 is also made by bending a metal plate, covers the heat exchanging portion 7, and is a lid-like member having five surfaces excluding the bottom surface.
That is, the air supply path forming member 10 includes a front plate 30, a right side plate 31, a left side plate 32, a back plate 33, and a top plate 35 as shown in FIG.
Here, the front plate 30 has a two-stage shape, the lower half portion being an inclined wall 36 and the upper half being a vertical wall 37. In the present embodiment, the inclined wall 36 functions as a contact wall.
The size, shape, and angle of inclination of the inclined wall (contact wall) 36 of the front plate 30 are equal to those of the front plate (inclined wall) 20 of the exhaust collecting portion 8 described above.

The right side plate 31, the left side plate 32, and the back plate 33 are parallel to the axis of the combustion device 3. The back plate 33 is provided with an opening 40 as shown in FIG. As described above, the opening 40 is provided on the back plate 33 and is provided on the wall surface facing the front plate 30. Further, as described above, the inclined wall (contact wall) 36 is a part of the front plate 30, and the position of the inclined wall 36 is a position facing the opening 40.
The top plate 35 is perpendicular to the right side plate 31 and the like. An outer cylinder 41 is provided on the top plate 35. The outer cylinder 41 is hollow, and the outer cylinder 41 communicates the front and back of the exhaust collecting portion 8.

The communication path forming member 11 is a member having a substantially pentagonal shape as shown in FIG. 2, and an outer wall is formed by bending a metal plate and combining it with screws (not shown) to cover the outside, and the inside is shown in FIG. Thus, the cavity 43 is formed.
An introduction side opening 45 is provided on the front side and the upper side of the communication path forming member 11. The shape of the opening 45 is a rectangle and extends in a direction perpendicular to the axis of the combustion device 3.
Around the opening 45, an outwardly protruding portion 46 is formed.

A discharge-side opening 47 is provided on the front side of the communication path forming member 11 and on the lower side. The discharge side opening 47 is circular. An outwardly protruding portion 50 is also formed around the discharge side opening 47.
The cavity 43 in the communication path forming member 11 communicates with the outside only through the introduction side opening 45 and the discharge side opening 47 described above.

  In addition, two step forming members 51 are provided on the front side of the communication path forming member 11.

Next, the positional relationship between the above-described members will be described.
In the combustion apparatus 3 of the present embodiment, the blower 5 is located at the lowest position, and the discharge part of the blower 5 is connected to the burner part 6. A heat exchanging portion 7, an exhaust collecting portion 8, and an air supply path forming member 10 are sequentially stacked on the upper portion of the burner portion 6.
The case 16 of the burner unit 6 and the case 18 of the heat exchange unit 7 have the same cross-sectional shape, and a series of combustion gas flow paths are formed by the case 16 of the burner unit 6 and the case 18 of the heat exchange unit 7. ing.
The exhaust collecting portion 8 is in a position covering the case 18 of the heat exchanging portion 7 and converges the series of combustion gas flow paths described above.

The air supply path forming member 10 covers the exhaust collecting portion 8. That is, the cover part 27 of the air supply path forming member 10 covers the exhaust collecting part 8, and the outer cylinder 41 of the air supply path forming member 10 is positioned outside the inner cylinder 26 of the exhaust collecting part 8. That is, the outer cylinder 41 of the air supply path forming member 10 and the inner cylinder 26 of the exhaust collecting portion 8 are arranged concentrically, and an annular space 52 is formed between the outer cylinder 41 and the inner cylinder 26. In the present embodiment, an air supply / exhaust cylinder 58 is configured by the outer cylinder 41 of the air supply path forming member 10 and the inner cylinder 26 of the exhaust collecting portion 8.
When the relationship between the cover portion 27 of the air supply path forming member 10 and the exhaust collecting portion 8 is seen, the inclined wall 36 of the cover portion 27 is in contact with the front plate (inclined wall) 20 of the exhaust collecting portion 8. In the present embodiment, the inclined wall 36 of the cover portion 27 and the front plate (inclined wall) 20 of the exhaust collecting portion 8 are joined by spot welding 53.

  The other portions of the cover portion 27 are all separated from the exhaust collecting portion 8, and a gap 55 that forms a part of the air introduction path is formed therebetween.

The communication path forming member 11 is on the back side of the can structure in which the burner unit 6 and the heat exchange unit 7 are combined. The introduction side opening 45 of the communication path forming member 11 is connected to the opening 40 provided in the back plate 33 of the air supply path forming member 10.
The discharge side opening 47 of the communication path forming member 11 is connected to the air supply port of the blower 5.

In the combustion device 3 of the present embodiment, an annular space 52 is formed between the outer cylinder 41 and the inner cylinder 26 between the cover portion 27 of the air supply path forming member 10 and the upper surface side of the exhaust collecting portion 8. Further, the gap 55 communicates with the cavity 43 in the communication path forming member 11 through the opening 40, and the cavity 43 in the communication path forming member 11 is connected to the air supply port of the blower 5.
On the other hand, the burner unit 6 and the heat exchange unit 7 are integrated to form a can-like body and form a series of flow paths. And the discharge part of the air blower 5 is connected to the above-mentioned can-like body. The flow path of the can-like body is converged at the exhaust collecting portion 8 and communicated with the inner cylinder 26.

Next, the function of the combustion apparatus 3 of this embodiment is demonstrated.
The combustion device 3 activates the blower 5 described above to forcibly supply air to the burner unit 6. That is, outside air is sucked into the blower 5 through the annular space 52, the gap 55, and the communication path forming member 11 and supplied to the burner unit 6.
On the other hand, fuel gas is supplied from a fuel supply valve (not shown) to the burner 17 in the burner section 6, and the fuel gas is ignited by ignition means (not shown) to start combustion.
The combustion gas passes through the heat exchanging section 7, and heat is exchanged therebetween.
The combustion gas is discharged from the heat exchange unit 7 and collides with the exhaust collecting unit 8. That is, the front plate (inclined wall) 20 of the exhaust collecting portion 8 is a wall surface that is inclined with respect to the axis of the combustion device 3 and is an intersecting wall portion that intersects the flow direction of the combustion gas. The combustion gas discharged from the cylinder collides with a front plate (inclined wall) 20 that is an intersecting wall portion. Further, the top plate 25 of the exhaust collecting portion 8 is a wall surface orthogonal to the axis of the combustion device 3 and is an intersecting wall portion intersecting with the flow direction of the combustion gas. The combustion gas also collides with the top plate 25 which is an intersecting wall portion.
Then, the combustion gas is guided to the exhaust collecting portion 8, enters the inner cylinder 26, and is discharged to the outside by a duct (not shown).

In this way, the combustion gas that has finished the heat exchange in the heat exchanging section 7 collides with the exhaust collecting section 8 and changes its direction, and is discharged to the outside through the inner cylinder 26.
Therefore, the path through which the combustion gas passes is heated by the heat remaining in the combustion gas.
In particular, the exhaust collecting portion 8 is an intersecting wall portion that intersects the flow direction of the combustion gas, and is a member that the combustion gas collides with, so that the temperature rises to a higher temperature.
In this embodiment, the inclined wall (contact wall) 36 of the covering portion 27 of the air supply path forming member 10 is brought into surface contact with the front plate (inclined wall) 20 of the exhaust collecting portion 8 that is an intersecting wall portion. The space is close by spot welding 53.
Therefore, the heat of the front plate (inclined wall) 20 of the exhaust collecting portion 8 is transmitted to the inclined wall 36 of the air supply path forming member 10 to conduct heat to other parts of the air supply path forming member 10 to form the air supply path. The entire member 10 is heated.

As described above, many portions of the cover portion 27 are separated from the exhaust collecting portion 8, and there is a gap 55 between them, and the gap forms a part of the air introduction path.
More specifically, the cover 27 of the air supply path forming member 10 constitutes the outer wall of the air introduction path, and the top plate 25 of the exhaust collecting part 8 constitutes the inner wall of the air introduction path.
Further, as described above, the top plate 25 of the exhaust collecting portion 8 that is the inner wall of the air introduction path is a part where the combustion gas collides, and therefore the temperature is high, and the covering portion 27 that is the outer wall of the air introduction path is the exhaust collecting portion 8. The temperature is raised by heat conduction from the front plate (inclined wall) 20.
Therefore, in the air introduction path formed by the air supply path forming member 10, both the inner wall and the outer wall are hot, and the temperature of the air passing therethrough is increased.
Further, since heat is further conducted from the cover portion 27 of the air supply path forming member 10 to the outer cylinder 41, the temperature of the outer cylinder 41 is also raised, and both the inner wall and the outer wall of the portion of the air supply / exhaust cylinder 58 are also hot. The air passing here is heated.

  Returning to the description of the air supply side, as described above, the air supply is supplied to the burner portion 6 via the annular space 52 of the air supply / exhaust tube 58 and the gap 55 between the cover portion 27 and the exhaust collecting portion 8. The Therefore, the supply air is heated from both the inner wall and the outer wall in the air supply / exhaust cylinder 58 part up to the burner part 6 and the gap 55 between the cover part 27 and the exhaust collecting part 8, and the exhaust heat is recovered. Therefore, the combustion apparatus 3 of this embodiment has high thermal efficiency.

  In the above-described embodiment, the configuration in which the inclined wall (contact wall) 36 of the cover portion 27 and the front plate (inclined wall) 20 of the exhaust collecting portion 8 are spot welded is exemplified. The two may be brought into close contact with each other.

In the embodiment described above, the cover portion 27 is provided with the inclined wall (contact wall) 36 and the inclined wall 36 is brought into surface contact with the front plate (inclined wall) 20 of the exhaust collecting portion 8. 27 and the exhaust collecting portion 8 may be brought into contact with each other.
FIG. 5 is a cross-sectional view of a combustion apparatus showing another embodiment of the present invention. As shown in FIG. 5, a step is provided in the exhaust collecting portion 8, and a part of the cover portion 62 is provided on one step portion 61. You may make surface contact.

In the previous embodiment, there is no gap between the front plate (inclined wall) 20 of the exhaust collecting part 8 and the cover part 62, and the supply air does not flow into the part. It is also possible to supply air to the portion of the eight front plates (inclined walls) 20.
FIG. 6 is a cross-sectional view of a combustion apparatus showing still another embodiment of the present invention. In the combustion apparatus shown in FIG. 6, the end portion of the cover portion 62 is folded back, and the folded portion 63 is brought into surface contact with the front plate (inclined wall) 20 of the exhaust collecting portion 8.
According to this embodiment, the upper surface side of the front plate (inclined wall) 20 of the exhaust collecting portion 8 also constitutes a part of the air introduction path.

  In the previous embodiment, the opening 40 for discharging air from the cover 27 to the blower 5 side and the front plate (inclined wall) 20 are provided at the opposing positions, but the inclined wall is provided on the other wall surface. It may be in surface contact with a part of the exhaust collecting portion 8. In this case, the inclined wall of the exhaust collecting portion 8 is provided on any one or a plurality of wall surfaces of the right side plate 21, the left side plate 22, and the back plate 23, and the inclined wall serving as the contact wall at the corresponding position of the air supply path forming member 10 A wall will be provided.

  In the embodiment described above, the burner using gas as fuel is exemplified, but the present invention can also be applied to a combustion apparatus using liquid fuel such as petroleum.

The disassembled perspective view of the water heater concerning this invention. The disassembled perspective view of the main-body part of a combustion apparatus. The right view which shows the main-body part of the combustion apparatus in FIG. 1 schematically. FIG. 2 is a right side cross-sectional view schematically showing a main body portion of the combustion apparatus in FIG. 1. Sectional drawing of the combustion apparatus which shows other embodiment of this invention. Sectional drawing of the combustion apparatus which shows other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 3 Combustion apparatus 5 Blower 6 Burner part 7 Heat exchange part 8 Exhaust collection part 10 Supply air path formation member 11 Communication path formation member 20 Front board (inclined wall) (crossing wall part)
26 Inner cylinder (exhaust side flow path)
27 Cover 36 Inclined wall (contact wall)
41 outer cylinder 43 cavity 55 air gap (air introduction path)
58 Air supply and exhaust cylinder

Claims (4)

A blower, a burner part, an exhaust collecting part, an air supply / exhaust tube and an air supply path forming member;
The air supply / exhaust cylinder has an inner cylinder and an outer cylinder, and the inner cylinder is an exhaust side flow path and forms part of an exhaust flow path for discharging combustion gas to the outside. The space between is an air introduction side flow path and constitutes a part of the air introduction path for introducing air from the outside,
The air introduction side flow path of the supply / exhaust cylinder and the blower are connected via a connection part, and further, there is an exhaust collecting part and an inner cylinder of the supply / exhaust cylinder on the downstream side of the burner part, and the combustion gas discharged from the burner part is It is collected at the exhaust collecting part, and the flow path is restricted within the exhaust collecting part to flow to the inner cylinder side of the supply / exhaust cylinder,
The exhaust collecting portion has an intersecting wall portion that intersects the flow direction of the combustion gas at a part of a wall surface forming the flow path, and the air supply path forming member includes a cover portion that covers the exhaust collecting portion. A gap forming a part of the air introduction path is provided between the cover portion of the air supply path forming member and the exhaust collecting portion, and the cover portion is in contact with the intersecting wall portion of the exhaust collecting portion. A combustion apparatus comprising a wall.   The air gap is provided with an opening for sending the supplied air to the blower side, the position of the opening and the contact wall of the air supply path forming member are in opposing positions, and the contact wall and the intersecting wall portion are fuel gas. The combustion apparatus according to claim 1, wherein the combustion apparatus constitutes an inclined wall inclined with respect to the flow of the gas.   The combustion apparatus according to claim 1 or 2, wherein the intersecting wall portion and the contact wall of the covering portion are integrated by welding, screws, or scissors.   The combustion apparatus according to any one of claims 1 to 3, wherein a heat exchanger is interposed downstream of the burner portion.

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