JP2010127553A - Combustion apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a combustion apparatus, inhibiting corrosion of an internal wall surface by inhibiting generation of an oxide-containing drain. <P>SOLUTION: The combustion apparatus 51 has: a burner case 57; a blower 53; and a pressure regulator 56. The pressure regulator 56 is configured to discharge gas supplied at a primary pressure while adjusting it to a secondary pressure according to a signal pressure of the blower 53, and the signal pressure of the pressure regulator 56 is detected from the blower 53 or the downstream side of the blower 53. The burner case 57 has a case body part 83 and an outer wall part 81, a mixing part 58 is disposed within the case body part 83, and a cooling air passage 89 is disposed between the case body part 83 and the outer wall part 81. The air flow the blower 53 is divided and carried, therefore, to the mixing part 58 and the cooling air passage 89. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a combustion apparatus used for a water heater or the like.

  In recent years, water heaters have become popular in ordinary households. It is necessary for a general household water heater to supply hot water from many places with a single water heater. For example, there are hot water taps and showers in the kitchen, bathroom, and wash basin in the house, and hot water is supplied to these with a single water heater. There are also many domestic water heaters that have the function of filling the bathtub with hot water or chasing the remaining hot water in the bathtub.

As described above, since the hot water heater for home use uses hot water at a plurality of locations, the required amount of hot water and the hot water temperature change frequently. For this reason, the combustion device built in the water heater needs to change the combustion amount in accordance with changes in the hot water supply amount and the hot water supply temperature.
Therefore, a combustion apparatus built in a domestic water heater is provided with a gas proportional valve in order to change the combustion amount. That is, a proportional valve is provided in the fuel supply path of the combustion apparatus, the opening of the proportional valve is adjusted according to the required amount of heat generation, and the amount of combustion is changed by controlling the amount of gas as fuel.

As one type of combustion apparatus, there is a combustion apparatus called an all primary air type. In the all primary air combustion apparatus, most of the air necessary for combustion is mixed in advance in a burner, and a mixed gas is discharged from a flame hole to be used for combustion.
Patent Document 1 discloses an all-primary air combustion apparatus having a proportional valve in a fuel gas supply path.

JP 2000-146163 A

By the way, since all primary air type combustion devices mix most of the air necessary for combustion in the burner in advance as described above, the ratio of the amount of air supplied to the burner and the fuel gas supplied to the burner (empty) (Referred to as the fuel ratio) has a small allowable error.
Therefore, in the conventional combustion apparatus, in order to keep the air-fuel ratio within the allowable range, the target value of the opening degree of the fuel gas proportional valve and the target value of the rotational speed of the blower are set, and the actual value of the fuel gas proportional valve is set. Electrical control is performed so that the opening degree and the like coincide with the target value.
That is, in the prior art, the opening degree of the fuel gas proportional valve is controlled to coincide with the target opening degree, and at the same time, the rotational speed of the blower is controlled to coincide with the target rotational speed.
If the required amount of combustion changes, each target value is recalculated and controlled so that the opening of the fuel gas proportional valve matches the new target value. At the same time, the rotational speed of the blower is adjusted to the new target value. Control to match the value.

  However, according to the structure of the prior art, when the required combustion amount changes, the air-fuel ratio falls outside the allowable range until the opening degree of the fuel gas proportional valve and the rotational speed of the blower coincide with the new target value. As a result, combustion is performed in an unstable state. Therefore, the conventional combustion apparatus has a technical problem to be solved that the combustion state becomes unstable during the transition period when the combustion amount is changed.

  In the conventional combustion apparatus, the fuel gas proportional valve is essential, but the fuel gas proportional valve is a precision machine that is electrically controlled and is generally expensive. Therefore, there is a demand to omit the fuel gas proportional valve.

In view of this, the inventors of the present invention prototyped a combustion apparatus having a configuration in which a zero governor is provided in the fuel gas supply passage and a pressure signal of the zero governor is extracted from the blower.
Here, the zero governor is a pressure adjusting device that discharges the gas supplied with the primary pressure to the secondary pressure, and has a signal pressure inlet that introduces the pressure as a signal, and is introduced from the signal pressure inlet. It is a pressure regulating device that reduces the pressure to a secondary pressure corresponding to the pressure to be discharged.
In the combustion apparatus prototyped by the present inventors, since the pressure signal is taken out from the blower, the supply pressure of the fuel gas changes following the increase / decrease in the amount of blown air. Therefore, the technical problem that the combustion state becomes unstable during the transition period when changing the combustion amount is solved. Further, in the prototype combustion apparatus, since the combustion amount can be changed by changing the blower amount of the blower, the fuel gas proportional valve is not necessarily required.

  However, the prototype combustion apparatus has an extremely high temperature in the vicinity of the burner during combustion, and there is a concern that nitrogen and oxygen in the air combine to generate nitrogen oxides (NOx). Further, when drain is generated in the combustion apparatus, the above-described nitrogen oxide (NOx) dissolves in the drain, and the drain becomes strongly acidic. Therefore, there is a concern that the internal wall surface of the combustion apparatus is corroded by an oxidizing action.

  Therefore, the present invention is to further improve the prototype combustion apparatus, and to develop a combustion apparatus capable of suppressing corrosion of the inner wall surface by suppressing the generation of drain containing oxide. It is to be an issue.

  Invention of Claim 1 for solving an above-mentioned subject has a burner case, an air blower, and a pressure regulator, The said burner case is a double structure provided with the outer wall part and the case main-body part. And having a cooling air flow path between the outer wall portion and the case main body portion, the case main body portion comprising a mixing portion that promotes mixing of fuel gas and air, and air and fuel gas. A flame hole portion in which a flame hole from which a mixed gas is discharged is provided, and the pressure regulator adjusts and discharges the gas supplied with the primary pressure to a secondary pressure according to a predetermined signal pressure. Yes, the signal pressure of the pressure regulator is detected from the blower or the downstream side of the blower, and the fuel gas discharged from the pressure regulator is introduced into the case body and discharged from the flame hole through the mixing part The downstream side of the blower communicates with the burner case and Blown from the machine are diverted to the cooling air flow path and the mixing unit in a burner casing, a combustion apparatus in which a part of the air, characterized in that the flow through the cooling air channel.

The pressure regulator employed in the combustion apparatus of the present invention performs the same function as the zero governor described above, and adjusts the gas supplied with the primary pressure to a secondary pressure corresponding to a predetermined signal pressure. Are discharged.
Also in the combustion apparatus of the present invention, since the signal pressure of the pressure regulator is detected from a part of the air passage or the blower, the pressure on the secondary side of the pressure regulator changes following the blower pressure of the blower. To do. In the present invention, the fuel supply path is connected to the downstream side of the pressure regulator, and the fuel gas adjusted to the secondary pressure is introduced into each fuel supply path. That is, the fuel gas is supplied to each fuel supply path at a pressure that changes according to the blowing pressure.
Further, since the amount of fuel gas supplied to the case main body follows the blowing pressure of the blower, a stable combustion state is maintained even in a transition period when the combustion amount is changed.
The combustion apparatus of the present invention has a burner case, and the burner case has a double structure including an outer wall portion and a case main body portion, and a cooling air flow path is provided between the two structures. . Thereby, since air flows not only in the mixing part but also in the cooling air flow path, the burner case and the like can be cooled.
That is, according to the present invention, the temperature of the burner case or the like can be lowered by the air flowing through the cooling air flow path, so that the combustion space can be prevented from becoming too hot even during combustion. As a result, in the combustion apparatus of the present invention, it is possible to suppress the generation of nitrogen oxides (NOx) that are likely to be generated when the combustion space becomes a high temperature state. Etc. can be prevented from being corroded.

  In the combustion apparatus of the present invention, a configuration is recommended in which a plurality of burners are provided in the case body, and each burner is provided with a mixing portion and a flame hole portion that promote mixing of fuel gas and air. 2).

  The invention according to claim 3 is the combustion apparatus according to claim 1, wherein a mixed gas in which air and fuel gas are mixed in advance is introduced into the mixing portion of the case main body.

  According to such a configuration, a configuration in which a mixed gas in which air and fuel gas are mixed in advance is introduced into the mixing portion of the case main body is recommended.

  The invention according to claim 4 is characterized in that the case body has an opening, the opening is arranged upstream of the mixing unit, and air is introduced from the opening into the cooling air flow path. The combustion apparatus according to claim 2 or 3.

  In the combustion apparatus of the present invention, the case body has an opening, and the opening communicates with the cooling air flow path. Therefore, air is reliably supplied to the cooling air flow path through the opening. Furthermore, since the opening is arranged upstream of the burner, the fuel gas can be prevented from flowing into the cooling air flow path.

  The invention according to claim 5 has a nozzle that discharges fuel gas, the nozzle is disposed through the case main body, and the tip of the nozzle is directed toward the inner direction of the burner case. The combustion apparatus according to any one of claims 1 to 4, wherein the combustion apparatus is arranged.

  In the combustion apparatus of the present invention, since the nozzle penetrates the case main body and the tip is arranged inward, the fuel gas can be more reliably prevented from flowing into the cooling air flow path. .

  The invention according to claim 6 is the combustion apparatus according to any one of claims 2 to 5, wherein the burner case has a rectangular shape, and a plurality of the burners are accommodated in parallel.

  In the combustion apparatus of the present invention, it is recommended that the burner case has a rectangular shape and a plurality of burners are accommodated in parallel.

  In the combustion apparatus of the present invention, since air is always supplied to the cooling air flow path and the burner case or the like can be prevented from becoming high temperature, generation of nitrogen oxides (NOx) in the combustion space can be suppressed. Thereby, since it is suppressed that the drain which adheres to the inner wall of a combustion apparatus becomes acidic, it can suppress that the said inner wall corroded by an oxidizing action.

Hereinafter, the combustion apparatus of the embodiment of the present invention will be described.
FIG. 1 is a configuration diagram of a combustion apparatus according to an embodiment of the present invention.
A combustion apparatus 1 shown in FIG. 1 is built in a water heater, and includes a combustion apparatus main body 2, a blower 3, a fuel supply path forming member 5, and a pressure regulating apparatus 6.
The blower 3 employed in the present embodiment is provided with a rotating blade in a casing like a sirocco fan or a turbo fan. Moreover, the motor which rotates the air blower 3 is a direct current motor or the alternating current motor controlled by the inverter, and can increase / decrease a rotation speed.
The combustion apparatus main body 2 includes four burners (mixing units) 8a, 8b, 8c, and 8d in a burner case 7.

The burner case 7 has a double structure of a case main body 9 and an outer wall portion 19. The case main body 9 is divided into two upper and lower stages as shown in the figure, the upper side functions as the burner mounting portion 10, and the lower side is It functions as the air flow path forming part 11. The air flow path forming portion 11 functions as a flow path for introducing air into the burners 8a, 8b, 8c, and 8d, and is a part of the air blowing path 37. Further, a flame is generated on the upper side of the burner mounting portion 10. That is, the upper side of the burner mounting portion 10 functions as the combustion space 14.
The burner mounting portion 10 is provided with three partitions 12a, 12b, and 12c, and the interior is divided into four chambers.

  The air flow path forming part 11 is an air chamber, and the blower 3 is attached to the lower part. The air flow path forming portion 11 is roughly divided into two areas, one of which is a supply flow path 28 for supplying air to the burner 8, and the other is supplied around the burner 8 and the combustion space 14. The cooling air flow path 29 is formed. Specifically, the supply flow path 28 and the cooling air flow path 29 are partitioned by the side wall 34 of the case body 9, and the air supplied to the supply flow path 28 is cooled from an opening 38 provided in the side wall 34. The air flow path 29 is supplied. That is, the supply flow path 28 and the cooling air flow path 29 are adjacent to each other with the side wall 34 interposed therebetween, and the opening 28 communicates the supply flow path 28 and the cooling air flow path 29. Note that air does not travel between the supply flow path 28 and the cooling air flow path 29 through the opening 38, but only flows from the supply flow path 28 side to the cooling air flow path 29 side.

  A damper (air channel closing means) 13 is provided at the center of the air channel forming part 11. The damper 13 swings from the center to the right with the hinge portion 15 as a base point. When the damper 13 is at the center position as shown in FIG. 1, the left set 16a of the supply flow path 28 of the air flow path forming section 11 and Air is supplied from the blower to both the right set 16 b and the cooling air flow path 29. On the other hand, when the damper 13 swings in the right direction, the ventilation path to the right group 16b is blocked, and the ventilation to the right group 16b is blocked. At that time, the ventilation of the cooling air passage 29 is not blocked.

Burners 8a, 8b, 8c, and 8d are inserted into the four chambers of the burner mounting portion 10, respectively. Each of the burners 8a, 8b, 8c, 8d has an air / gas inlet 18 at the end. A flame hole 17 is formed on the upper surface. The burners 8a, 8b, 8c and 8d employed in this embodiment are of the same shape and have the same capacity.
In the present embodiment, there are nozzles 20a, 20b, 20c, 20d in the vicinity of the air / gas inlet 18 of each burner 8a, 8b, 8c, 8d, and each burner 8a, 8b from the nozzle 20a, 20b, 20c, 20d. , 8c, 8d are introduced with fuel gas. The supply flow path 28 communicates with the end of each burner 8a, 8b, 8c, 8d, and air is introduced from the supply flow path 28 through the air / gas inlet 18 to each burner 8a, 8b, 8c, 8d. Is done. On the other hand, the cooling air flow path 29 communicates with the outside, and air is not supplied to each burner 8 via the air / gas inlet 18.

When air and gas are introduced from the air / gas introduction port 18, mixing of both is promoted while passing through the burner 8 a, and the mixed gas is released from the flame hole 17.
The burners 8a, 8b, 8c and 8d employed in this embodiment are all primary air burners, and all of the air necessary for combustion is mixed by the burners 8a, 8b, 8c and 8d.

The fuel supply path forming member 5 is a member that supplies fuel gas to the burners 8a, 8b, 8c, and 8d through the nozzles 20a, 20b, 20c, and 20d, and is a member in which four fuel supply paths are formed. It is.
That is, the fuel supply path forming member 5 is a member that can be said to be a bundle of fuel supply paths, and includes fuel supply paths 5a, 5b, 5c, and 5d. The fuel supply passages 5a, 5b, 5c and 5d may be ones in which the flow passages are distributed in a plane as will be described later (FIGS. 3 and 4), or a bundle of tubes (FIG. 2). Good.
The pipe resistance of the fuel supply paths 5a, 5b, 5c, 5d is set to a magnitude corresponding to the capacity of the burners 8a, 8b, 8c, 8d. In the present embodiment, since the burners 8a, 8b, 8c, and 8d have the same capacity, the pipe resistances of the fuel supply paths 5a, 5b, 5c, and 5d are substantially the same. That is, the cross-sectional area, the length, and the number and curvature of the curved paths are substantially equal.

On-off valves 21a, 21b, 21c, and 21d are provided in the middle of the fuel supply paths 5a, 5b, 5c, and 5d of the fuel supply path forming member 5, respectively.
At the end of the fuel supply path forming member 5, the ends (downstream) of the fuel supply paths 5 a, 5 b, 5 c, 5 d are connected to the nozzles 20.
On the other hand, at the front end of the fuel supply path forming member 5, the open ends of the fuel supply paths 5a, 5b, 5c, 5d are gathered to form an open end group 22. In the open end group 22, the cross-sectional areas of the fuel supply paths 5a, 5b, 5c, and 5d are reduced.
The cross-sectional areas of the open ends 22a, 22b, 22c, 22d of the fuel supply paths 5a, 5b, 5c, 5d are set to a size corresponding to the capacity of the burners 8a, 8b, 8c, 8d. In the present embodiment, since the burners 8a, 8b, 8c, and 8d have the same capacity, the cross-sectional areas of the opening ends 22a, 22b, 22c, and 22d of the fuel supply paths 5a, 5b, 5c, and 5d are the same.

FIG. 2 is a perspective view showing an example of a fuel supply path forming member.
In the fuel supply path forming member 5A shown in FIG. 2, the fuel supply paths 5Aa, 5Ab, 5Ac, and 5Ad are pipes having independent square cross-sections. On-off valves 21Aa, 21Ab, 21Ac, and 21Ad are provided in the middle of the fuel supply paths 5Aa, 5Ab, 5Ac, and 5Ad, respectively.
A nozzle 20A is connected to the end of each fuel supply path 5Aa, 5Ab, 5Ac, 5Ad.
The air flow path forming portion 5A has a manifold 23A, and the distal end side (upstream side) of the fuel supply paths 5Aa, 5Ab, 5Ac, and 5Ad is converged on the manifold 23A. The interior of the manifold 23A is divided into four flow paths according to the fuel supply paths 5Aa, 5Ab, 5Ac, and 5Ad.

A short tubular base portion 25A is provided on the upstream side of the manifold 23A. The inner diameter and the outer diameter of the base portion 25A are equal to the inner diameter and the outer diameter of the gas discharge port 31 of the pressure regulating device 6 to be described later. A partition member 27A protrudes from the base portion 25A. The partition member 27A is obtained by extending the partition wall of the flow path in the manifold 23A. In this embodiment, the partition member 27A has an arrow blade shape as shown in the figure and is partitioned into four regions 27Aa, 27Ab, 27Ac, and 27Ad. Open end group 22A is configured. Each section communicates with a flow path in the manifold 23A, and further communicates with each fuel supply path 5Aa, 5Ab, 5Ac, 5Ad. The areas of the four regions 27Aa, 27Ab, 27Ac, and 27Ad are the same. That is, the size relationship of the opening area of each fuel supply path 5Aa, 5Ab, 5Ac, 5Ad in the open end group 22A is in accordance with the capacity of the burner group which each fuel supply path 5Aa, 5Ab, 5Ac, 5Ad is responsible for.
The circumscribed circle of the partition member 27A is equal to the inner diameter of the base portion 25A. Therefore, the circumscribed circle of the partition member 27A is equal to the inner diameter of the gas discharge port 31 of the pressure regulating device 6.

3 and 4 show another embodiment of the air flow path forming member.
The fuel supply path forming members 5B and 5C shown in FIGS. 3 and 4 show examples in which the fuel supply paths 5a, 5b, 5c and 5d are distributed in a plane.
That is, the fuel supply passage forming member 5B (second embodiment) shown in FIG. 3 has a plate-like main body 24, and four holes are formed in the main body portion 24 to form fuel supply passages 5Ba, 5Bb, 5Bc. , 5Bd are formed.
A nozzle 20 is provided on the end surface of the main body 24 of the fuel supply path forming member 5B.
In addition, on-off valves 21Ba, 21Bb, 21Bc, and 21Bd are provided in the middle of the fuel supply paths 5Ba, 5Bb, 5Bc, and 5Bd, respectively.
A base portion 25B is provided on one surface side of the main body portion 24 of the fuel supply path forming member 5B. The shape of the base part 25B is the same as that of the base part 25A described above, is a short tube, and the partition member 27B protrudes. The partition member 27B has an arrow blade shape and is divided into four regions 27Ba, 27Bb, 27Bc, and 27Bd. Each partition communicates with a flow path in the main body 24, and further, each fuel supply path 5Ba, 5Bb, 5Bc, It communicates with 5Bd.
The circumscribed circle of the partition member 27B is equal to the inner diameter of the base portion 25B. Therefore, the circumscribed circle of the partition member 27B is equal to the inner diameter of the gas discharge port 31 of the pressure regulating device 6.
The size relationship of the opening area of each fuel supply path 5Ba, 5Bb, 5Bc, 5Bd in the open end group 22B depends on the capacity of the burner group that each fuel supply path 5Ba, 5Bb, 5Bc, 5Bd is responsible for.

The fuel supply path forming member 5C according to another embodiment (third embodiment) has a shape structure shown in FIG.
That is, the fuel supply path forming member 5C of the third embodiment is obtained by changing the base portion 25B of the fuel supply path forming member 5B of the second embodiment described above. The fuel supply path forming member 5C of the third embodiment is different from the fuel supply path forming member 5B of the second embodiment described above only in the base portion 25C, and the other portions are the same.
In the fuel supply path forming member 5B of the second embodiment, the partition member 27C protruding from the base portion 25C is constituted by three parallel plates. Also in the present embodiment, the above-described parallel plate is divided into four regions 27Ca, 27Cb, 27Cc, and 27Cd, and each partition communicates with each fuel supply path 5Ca, 5Cb, 5Cc, and 5Cd in the main body 24. .
The circumscribed circle of the partition member 27 </ b> C is equal to the inner diameter of the gas discharge port 31 of the pressure regulating device 6.
The size relationship of the opening areas of the fuel supply paths 5Ca, 5Cb, 5Cc, and 5Cd in the open end group 22C depends on the capacity of the burner group that each fuel supply path 5Ca, 5Cb, 5Cc, and 5Cd is responsible for.

Next, the pressure regulating device 6 employed in the present embodiment will be described.
The pressure regulator 6 is specifically a zero governor, and is a pressure regulator that discharges a gas supplied with a primary pressure to a secondary pressure and discharges it, and has a signal pressure inlet 32 for introducing the pressure as a signal. And a pressure adjusting device that reduces the pressure to a secondary pressure corresponding to the pressure introduced from the signal pressure introduction port 32 and discharges the secondary pressure.
That is, the pressure regulator 6 includes a gas inlet 30, a gas outlet 31, and a signal pressure inlet 32 as shown in FIG. 1, and decompresses the gas introduced from the gas inlet 30 and discharges it from the gas outlet 31. However, the pressure of the fuel gas discharged from the gas discharge port 31 varies depending on the pressure of the signal pressure introduction port 32.

As shown in FIG. 1, the pressure regulating device 6 has a gas passage formed in the outer shell 6h, and further includes a valve body 6a for adjusting the opening degree of the gas passage, a diaphragm 6b, a spring 6c, an adjustment mechanism 6d, and the like. Is.
That is, the diaphragm 6b forms a signal pressure chamber 6i inside the outer shell 6h. A signal pressure inlet 32 is opened in the signal pressure chamber 6i. Therefore, the signal pressure introduced from the signal pressure introduction port 32 is applied to the signal pressure chamber 6i. Accordingly, a signal pressure is applied to one of the diaphragms 6b.
Further, a secondary side communication chamber 6j is provided on the other side of the diaphragm 6b. The secondary side communication chamber 6j communicates with the secondary side gas passage (downstream of the valve body 6a) via the secondary side communication passage 6k. Therefore, the diaphragm 6b receives a pressure difference between the signal pressure Pt and the outlet pressure P2 of the pressure regulator 6.
The spring 6c supports the diaphragm 6b, and the strength of the spring 6 is adjusted by the adjusting mechanism 6d.

The valve body 6a adjusts the opening degree of the gas passage as described above, and is connected to the diaphragm 6b via the shaft 6m.
For example, when the pressure P1 of the gas introduced into the pressure regulator 6 fluctuates in the upward direction, the secondary pressure (the outlet pressure of the pressure regulator 6) P2 also fluctuates in the pressure side. However, the valve body 6a moves downward in accordance with the pressure fluctuation of the secondary pressure P2, and the secondary pressure P2 is changed to the lowering side so that the secondary pressure P2 becomes the signal pressure Pt. Further, when the atmospheric pressure Pt fluctuates to the rising side, the valve body 6a moves upward with the pressure fluctuation, and the secondary pressure P2 is adjusted to fluctuate to the rising side to become the signal pressure Pt. In this way, even when the fuel supply pressure P1 and the signal pressure Pt of the pressure adjusting device 6 change, the discharge pressure P2 of the pressure adjusting device 6 is adjusted to become the signal pressure Pt.

In the pressure adjusting device 6 described above, the gas inlet 30 is connected to a fuel gas supply source. Further, the gas discharge port 31 of the pressure adjusting device 6 is connected to the base portion 25A (or 25B, 25C) of the fuel supply path forming member 5A (or 5B, 5C).
A partition member 27A protrudes from the cap portion 25A of the fuel supply path forming member 5A. Further, the partition member 27A enters the gas discharge port 31 and divides the inside of the gas discharge port 31 into four regions 27Aa, 27Ab, 27Ac, and 27Ad.
In other words, in the present embodiment, the gas discharge port 31 of the pressure regulator 6 is directly connected to the fuel supply path forming member 5A (through a very short pipe line), and the outlet side of the pressure regulator 6 is immediately divided. It is connected to each fuel supply path 5Aa, 5Ab, 5Ac, 5Ad.

  The signal pressure of the pressure adjusting device 6 is detected from the discharge side of the blower 3. That is, it is detected from an intermediate portion between the blower 3 and the burner case 7 as shown in FIG. That is, the signal pressure take-out portion 33 opens at an intermediate portion (blower passage 37) between the blower 3 and the burner case 7, and the signal pressure take-out portion 33 and the signal pressure introduction port 32 of the pressure adjusting device 6 are connected by the conducting pipe 35. ing.

Next, the function of the combustion apparatus 1 will be described.
In the combustion apparatus 1 of the present embodiment, the blower 3 is rotated and the on-off valve 21 is opened, fuel and air are introduced into the burner (mixing unit) 8, and the mixing of both is promoted in the burner 8, and the flame of the burner 8. A mixed gas of fuel gas and air is discharged from the hole 17 to generate a flame in the combustion space 14.
That is, air is blown into the burner case 7 by rotating the blower 3. The air blown from the blower 3 once enters the air flow path forming part 11 in the burner case 7. Specifically, the supply flow path 28 and the cooling air flow path 29 are blown to the supply flow path 28, reaching the end of each burner 8 a, 8 b, 8 c, 8 d, and from the air / gas inlet 18. Air is supplied to the burners 8a, 8b, 8c, 8d. Further, the air blown to the cooling air passage 29 is not mixed with the fuel gas and is discharged from the periphery of the flame hole 17 through the exhaust port 39 connected to the outside. Thereby, since some air from the air blower 3 ventilates between the case main-body part 9 and the outer wall part 19, it can suppress that the burner case 7 grade | etc., Becomes high temperature even at the time of combustion.

When attention is paid to the amount of air introduced into each burner 8a, 8b, 8c, 8d, the amount of air introduced into the burners 8a, 8b, 8c, 8d is the air / gas of the burners 8a, 8b, 8c, 8d. The air pressure in the vicinity of the inlet 18, the opening area of the air / gas inlet 18, the internal resistance of the burners 8 a, 8 b, 8 c, 8 d, and the downstream resistance (exhaust resistance) of the burners 8 a, 8 b, 8 c, 8 d And a function of atmospheric pressure.
Here, the opening area of the air / gas inlet 18 does not change during combustion. Also, the internal resistance of the burners 8a, 8b, 8c, 8d is constant. Furthermore, the resistance (exhaust resistance) on the downstream side of the burners 8a, 8b, 8c, and 8d and the atmospheric pressure can be regarded as being substantially constant.

Therefore, the change in the amount of air introduced into the burners 8a, 8b, 8c, and 8d has the highest correlation with the change in the blowing pressure in the vicinity of the air / gas introduction port 18. Further, even if it is considered that the change in the amount of air introduced into the burners 8a, 8b, 8c, and 8d changes only by the pressure in the vicinity of the air / gas inlet 18, it can be said that there is no practical problem.
The air supplied from the blower 3 branches into the supply flow path 28 and the cooling air flow path 29 and is ventilated, but is supplied to the cooling air flow path 29 compared to the air supplied to the supply flow path 28. It can be said that there is almost no pressure loss of the air supplied to the supply flow path 28 because the amount of air to be ignored is negligible.
That is, it can be said that the pressure in the vicinity of the air / gas inlet 18 is determined by the discharge pressure of the blower 3 if the pressure loss of the burners 8a, 8b, 8c, and 8d is ignored.

  On the other hand, the fuel gas enters the pressure regulator 6 from the fuel gas supply source and is depressurized by the pressure regulator 6. The gas exiting the pressure adjusting device 6 enters the fuel supply path forming member 5A (or 5B, 5C), passes through the fuel supply paths 5Aa, 5Ab, 5Ac, 5Ad of the fuel supply path forming member 5A, and the nozzle 20 Discharged from. Each nozzle 20 is provided at a position facing the air / gas inlet 18 of each burner 8a, 8b, 8c, 8d, and the gas discharged from the nozzle 20 is discharged from the air / gas inlet 18 to each burner. 8 a, 8 b, 8 c, and 8 d are mixed with air and discharged from the flame hole 17. A flame is generated in the combustion space 14.

Here, paying attention to the amount of fuel gas introduced into each burner 8a, 8b, 8c, 8d, the amount of fuel gas introduced into the burner 8a, 8b, 8c, 8d is the fuel supply path 5a, 5b, 5c, 5d. Is the amount of gas passing through.
The amount of gas passing through the fuel supply paths 5a, 5b, 5c, 5d is determined by the gas pressure upstream of the fuel supply paths 5a, 5b, 5c, 5d and the opening area of the fuel supply paths 5a, 5b, 5c, 5d. This is a function of the internal resistance of the fuel supply paths 5a, 5b, 5c, and 5d, the opening diameter of the nozzle 20, and the atmospheric pressure on the discharge side of the nozzle 20.
Here, the opening area of the fuel supply paths 5a, 5b, 5c, 5d, the internal resistance of the fuel supply paths 5a, 5b, 5c, 5d, and the opening diameter of the nozzle 20 are constant and do not change during combustion. The change in the atmospheric pressure on the discharge side of the nozzle 20 is also small.

Therefore, the change in the amount of gas introduced into the burners 8a, 8b, 8c, 8d has the highest correlation with the change in the pressure of the gas upstream of the fuel supply paths 5a, 5b, 5c, 5d. Even if it is considered that the amount of gas introduced into the burners 8a, 8b, 8c, 8d is determined only by the pressure of the gas upstream of the fuel supply passages 5a, 5b, 5c, 5d, it can be said that there is no practical problem.
In the present embodiment, the gas discharge port 31 of the pressure adjusting device 6 is directly connected to the open ends (open end group 22) of the fuel supply passages 5a, 5b, 5c, 5d, and therefore the fuel supply passage 5a. , 5b, 5c, 5d varies in accordance with the discharge pressure of the pressure regulator 6, and the amount of gas introduced into the burners 8a, 8b, 8c, 8d depends on the discharge pressure of the pressure regulator 6. It can be said that even if it is determined solely by this, it can be practically used.

And in the combustion apparatus 1 of this embodiment, the signal pressure of the pressure regulating device 6 is detected from the discharge side of the blower 3, and the pressure regulating device 6 releases the fuel gas at a secondary pressure correlated with the signal pressure. The pressure of the fuel gas discharged from the pressure adjusting device 6 varies depending on the discharge pressure of the blower 3.
That is, in the combustion apparatus 1 of the present embodiment, the amount of air introduced into the burners 8a, 8b, 8c, and 8d and the amount of fuel gas both vary depending on the discharge pressure of the blower 3. That is, when the discharge pressure of the blower 3 increases and the amount of air introduced into the burners 8a, 8b, 8c, 8d increases, the signal pressure of the pressure adjusting device 6 rises and the gas discharge pressure from the pressure adjusting device 6 increases. Rises, the amount of gas flowing through the fuel supply paths 5a, 5b, 5c, 5d increases, and the amount of gas introduced into the burners 8a, 8b, 8c, 8d increases. In other words, in the combustion apparatus 1 of the present embodiment, when the amount of air introduced into the burners 8a, 8b, 8c, 8d increases or decreases, the amount of gas introduced into the burners 8a, 8b, 8c, 8d accordingly. Also increase or decrease. Therefore, in this embodiment, the ratio of the amount of air and the amount of gas introduced into the burners 8a, 8b, 8c, and 8d is always constant.
The ratio of the amount of air and the amount of gas introduced into the burners 8a, 8b, 8c, 8d is determined by the area of the air / gas inlet 18 of the burners 8a, 8b, 8c, 8d, the opening diameter of the nozzle 20, and the like. In this embodiment, the area of the air / gas introduction port 18 and the opening diameter of the nozzle 20 are designed so that the amount of air sufficient to burn the fuel gas is introduced from the air / gas introduction port 18. Yes.

Therefore, in this embodiment, air and fuel gas are always introduced into the burners 8a, 8b, 8c, and 8d at an appropriate ratio, mixed with air, discharged from the flame hole 17, and a flame is generated.
Moreover, increase / decrease in a combustion amount can be performed by changing the ventilation volume of the air blower 3. FIG. That is, in this embodiment, the ratio of the amount of air introduced into the burners 8a, 8b, 8c, and 8d and the amount of gas is always constant.
Therefore, if the rotation speed of the blower 3 is increased and the amount of blown air is increased, the amount of air introduced into the burners 8a, 8b, 8c, and 8d is increased, the amount of gas is also increased, and the amount of combustion is increased.
Conversely, if the rotational speed of the blower 3 is decreased and the amount of blown air is reduced, the amount of air introduced into the burners 8a, 8b, 8c, and 8d is reduced, the amount of gas is also reduced, and the amount of combustion is reduced.

If it is desired to further reduce the combustion amount, some of the four on-off valves 21a, 21b, 21c, and 21d are closed.
For example, when two of the four on-off valves 21a, 21b, 21c, and 21d in FIG. 1 are closed, the supply of fuel gas to the burners 8c and 8d in the right set 16b in FIG. Only the burners 8a and 8b of the left group 16a burn in the combustion space 14.
Even if the two on-off valves 21c and 21d are closed and only the on-off valves 21a and 21b are opened and only the burners 8a and 8b of the left group 16a are burned in the combustion space 14, the amount of air introduced into the burners 8a and 8b. And the ratio of gas amount does not change.

That is, even if the on-off valves 21c and 21d are closed, air continues to be introduced into all the burners 8a, 8b, 8c and 8d, and therefore the total amount of air discharged to the outside through the burners 8a, 8b, 8c and 8d is It does not change. Therefore, there is no change in the discharge pressure of the blower 3.
Accordingly, the signal pressure of the pressure adjusting device 6 does not change, and the pressure of the fuel gas discharged from the pressure adjusting device 6 does not change.
Since the on-off valves 21c and 21d are closed, the fuel does not flow in the fuel supply passages 5c and 5d that are the closed flow paths, but the fuel supply passages 5a and 5a that are the flow paths in which the on-off valves 21a and 21b are opened. The fuel gas flows through 5b. The flow rate flowing through the fuel supply paths 5a and 5b does not change because the pressure of the fuel gas discharged from the pressure regulator 6 does not change. That is, regardless of whether the on-off valves 21c and 21d are opened or closed, the same amount of fuel gas flows through the fuel supply passages 5a and 5b, which are flow paths in which the on-off valves 21a and 21b are opened.

In the above example, the case where two of the four on-off valves 21a, 21b, 21c, and 21d are closed has been described as an example. However, even if only one of the on-off valves 21 is closed, the three on-off valves 21 are closed. The same phenomenon occurs even when the valve is closed, and the ratio of air to gas supplied to the burner 8 to be burned does not change.
Therefore, the combustion apparatus 1 of the present embodiment, for example, from a state where only one burner 8 is burned with a minimum combustion amount to a state where all four burners 8a, 8b, 8c and 8d are burned with a maximum combustion amount, respectively. The amount of combustion can be changed, and the turndown ratio is high.

Further, in the present embodiment, a damper (air channel closing means) 13 is provided at the center of the air channel forming portion 11, and when the damper 13 swings in the right direction, the ventilation path to the right set 16b is blocked. Therefore, when the burners 8c and 8d of the right set 16b are not used, the damper 13 swings in the right direction to block the ventilation path to the right set 16b, and stops blowing air to the burners 8c and 8d. You can also. Even if the damper 13 blocks the ventilation path, air is always supplied to the cooling air flow path 29.
As a result, the load on the blower 3 can be reduced, which can contribute to energy saving. Moreover, the excessive temperature fall of combustion gas can also be prevented.

  If a part of the ventilation path is blocked by the damper 13, the overall blowing resistance changes and the ratio of air and fuel gas supplied to the burner 8 changes. However, in practice, the amount of change is small and functional. It doesn't matter.

Next, a procedure for burning the present embodiment will be described. FIG. 5 is a flowchart showing the operation at the time of ignition of the combustion apparatus of the embodiment of the present invention.
In the combustion apparatus 1 of this embodiment, a combustion request is waited in step 1. For example, if the combustion apparatus 1 is employed in a hot water heater, a hot water supply request is generated by an operation such as opening a currant, and a combustion request is generated.

  If there is a combustion request in step 1, the process proceeds to step 2 and the damper (air flow path closing means) 13 is opened. More specifically, as shown in FIG. 1, the damper 13 is moved to the center position so that air can be supplied from the blower 3 to both the left group 16a and the right group 16b of the air flow path forming unit 11. .

In step 3, the necessary amount of combustion is confirmed. That is, it is determined whether the required calorific value is the amount of heat that should be ignited in all four burners 8a, 8b, 8c, and 8d, or only the two burners 8a and 8b should be ignited. .
If the calorific value requested here is the amount of heat to be ignited in all four burners 8a, 8b, 8c, 8d, the routine proceeds to step 4 and subsequent steps, and preliminary blowing before ignition is performed. That is, pre-purge is executed.
Specifically, a timer is started in step 4, and the blower 3 is rotated to start blowing. Here, as described above, since the damper (air flow path closing means) 13 is opened in step 2, air is blown to all the burners 8a, 8b, 8c, 8d. Note that air is also supplied to the cooling air flow path 29 by this air blowing. And the air which ventilates to the cooling air flow path 29 is always supplied until the operation of the blower 3 is stopped.

When the time required for pre-purging is completed in step 6, the routine proceeds to step 7 where all the on-off valves 21a, 21b, 21c, 21d are opened and fuel gas is supplied to all four burners 8a, 8b, 8c, 8d. To do.
In step 8, ignition is performed with an igniter (not shown). Thereafter, the process proceeds to step 9, and the desired amount of combustion is adjusted by increasing / decreasing the amount of blown air.

On the other hand, when the required amount of combustion is confirmed in step 3, the required calorific value should ignite only the two burners 8a and 8b, and the burners 8c and 8d of the right set 16b should not be used. In this case, the process proceeds to step 10 side.
Specifically, a timer is started in step 10, and the blower 3 is rotated in step 11 to start blowing and pre-purge is performed. As described above, even if the required amount of heat generation is small and the burners 8c and 8d of the right set 16b should not be used, all the burners 8a, 8b, 8c, Pre-purge is performed for 8d.
That is, in the present embodiment, the damper (air flow path closing means) 13 is opened in step 2 as described above, so that all the burners 8a, 8b, 8c, 8d are blown.

When the time required for the pre-purge is completed in step 12, the process proceeds to step 13 and the damper 13 is closed. That is, the blowing to the burners 8c and 8d of the right set 16b is stopped.
Thereafter, the two on-off valves 21a and 21b are opened, and the fuel gas is supplied to the two burners 8a and 8b (step 14).
In step 15, ignition is performed with an igniter (not shown). Thereafter, the process proceeds to step 16, and the desired amount of combustion is adjusted by increasing / decreasing the amount of blown air.

  When the amount of combustion required during use of the water heater increases, the damper (air flow path closing means) 13 is opened again, and the closed on-off valves 21c and 21d are opened, and the burner 8c of the right set 16b is opened. Fuel gas and air are also introduced into 8 d and burned in the combustion space 14. In the present embodiment, since the pre-purging is performed on the burners 8c and 8d at the time of the first ignition, if the amount of combustion required during use of the water heater increases, the damper (air flow path) The combustion zone can be immediately increased by opening the closing means 13 and the on-off valves 21c and 21d.

Next, an operation when the amount of combustion required during combustion decreases will be described.
FIG. 6 is a flowchart showing the operation of the combustion apparatus according to the embodiment of the present invention, and describes the operation when the amount of combustion required during combustion decreases. FIG. 7 is a configuration diagram of the combustion apparatus showing the operation when the amount of combustion required during combustion decreases. FIG. 8 is a block diagram of the combustion apparatus showing the operation following FIG.

  That is, when it is found that the required combustion amount has decreased in step 1, the routine proceeds to step 2 where it is determined whether or not two or more burners 8 should be stopped. If it is sufficient to stop only one burner 8, the process proceeds to step 9, and only one on-off valve 21 is closed to return to normal control.

On the other hand, when it is necessary to stop two or more burners 8, two on-off valves 21 should not be closed simultaneously. That is, if two or more on-off valves 21 are closed at the same time, it takes some time for the fuel gas pressure to stabilize, and the combustion state temporarily becomes unstable. Therefore, when it is necessary to operate the plurality of on-off valves 21 to change the open / closed state of the plurality of on-off valves 21, the operation timing of each valve is shifted from about 0.5 seconds to about 2 seconds.
Specifically, when it is necessary to stop two or more burners 8, the process proceeds to step 3 and the on-off valve 21d is closed. As a result, as shown in FIG. 7, only one burner 8d stops combustion.

This state is maintained for a certain time (about 0.5 second to about 2 seconds) and waits for the combustion state to stabilize. That is, the timer starts counting in step 4, and waits for the timer to finish counting in step 5.
When it is confirmed in step 5 that the time has elapsed, the routine proceeds to step 6, where the other on-off valve 21c is closed and combustion of the burner 8c is stopped (FIG. 8).

In step 7, the temperature of the extinguished burner 8c is waited for. For example, a temperature sensor is provided in the vicinity or downstream of the burner 8c and waits for the temperature of the temperature sensor to decrease to a predetermined value. Alternatively, the time after the burner 8c is extinguished by a timer or the like is counted, and a time when the temperature is expected to drop sufficiently is waited.
Note that when the temperature drop of the burner 8 is predicted over time, the length of the burner 8 combustion time should be considered. That is, if the burner 8 burns only for a short time, the temperature rise is low, so that the time required for cooling is sufficient. On the other hand, if the burner 8 burned for a long time is expected to reach a considerably high temperature, a long cooling time should be ensured. However, when burning over a certain time, the temperature of the burner 8 becomes higher, so an upper limit should be set for the cooling time.

  If step 7 becomes yes, the process proceeds to step 8 where the damper (air flow path closing means) 13 is swung rightward to block the ventilation path to the right set 16b. After that, it returns to normal control. As described above, air is always flowing through the cooling air passage 29.

  The combustion apparatus 1 of the present embodiment can change the combustion amount by closing some of the on-off valves 21 as described above. However, even if some of the on-off valves 21 are closed, the combustion apparatus 1 can reach each burner 8. It has the feature that the flow path resistance is difficult to change. Therefore, in the combustion apparatus 1 of the present embodiment, when some of the on-off valves 21 are closed or opened conversely, the change in the air-fuel ratio of the burner 8 that is already combusting is extremely small.

Hereinafter, this reason will be described.
In the combustion apparatus 1 of the present embodiment, the plurality of fuel supply paths 5a, 5b, 5c, 5d individually supply fuel to the respective burner groups, and further, the gas discharge port 31 of the pressure regulator 6 is provided. It is directly connected (via a very short pipe line) to the fuel supply path forming member 5A, and the outlet side of the pressure regulating device 6 is immediately divided and connected to each fuel supply path 5a, 5b, 5c, 5d. .
That is, in the combustion apparatus 1 of the present embodiment, the fuel gas whose pressure is adjusted by the pressure regulator 6 is immediately divided into the respective fuel supply path forming members 5A, and the flow path through which the fuel gas flows is extremely short. It has the characteristics of

  In contrast, FIG. 24 shows a comparative example. In the combustion apparatus 100 shown in FIG. 24, there is a common flow path 101 downstream of the pressure regulating apparatus 6, and the common flow path 101 is branched and communicated with a plurality of fuel supply paths 5a, 5b, 5c, and 5d.

  In the embodiment described above, priority is given to stabilization of the combustion state, and when it is necessary to stop two or more burners 8, the operation timing of each on-off valve 21 is shifted by about 0.5 seconds to 2 seconds. However, the present embodiment is not limited to this configuration, and the plurality of on-off valves 21 may be closed simultaneously. When the plurality of on-off valves 21 are closed at the same time, the combustion amount can be changed in a short time.

In the combustion apparatus 100 shown in FIG. 24, the fuel gas reaching all the burners 8a, 8b, 8c, and 8d flows through the common flow path 101.
Therefore, in the combustion apparatus 100, the flow rate of the fuel gas flowing through the common flow path 101 varies depending on the number of burners 8a, 8b, 8c, 8d to be burned. More specifically, the flow rate of the fuel gas flowing through the common flow path 101 varies depending on the number of burners 8a, 8b, 8c, 8d to be burned.
Therefore, the flow resistance of the fuel gas passing through the common flow path 101 varies depending on the number of burners 8a, 8b, 8c, 8d to be burned. That is, according to Bernoulli's theorem, the channel resistance is proportional to the square of the flow velocity of the fluid passing therethrough. Therefore, for example, if some of the burners 8 are stopped during combustion, the flow rate of the fuel gas passing through the common flow path 101 is reduced, the flow resistance is reduced, and a large amount of fuel is supplied to the burning burner. Is done. On the other hand, the amount of air supplied to the burner 8 does not change. Therefore, in the combustion apparatus 100 shown in FIG. 24, if the number of burners to be burned is reduced, there is a concern that the fuel becomes excessive as compared with the normal state.

  On the other hand, in the combustion apparatus 1 shown in FIG. 1, since the common flow path is extremely short, even if the burners 8a, 8b, 8c and 8d to be burned change, the fluctuation of the overall flow path resistance is small. Therefore, in the combustion apparatus 1 of the present embodiment, when some of the on-off valves 21 are closed or opened conversely, the change in the air-fuel ratio of the burner 8 that is already combusting is extremely small.

Although the combustion apparatus 1 demonstrated above has four burners and the capacity | capacitance of this burner was all the same, you may mix the burners from which capacity | capacitance differs.
FIG. 9 is a configuration diagram of a combustion apparatus according to another embodiment of the present invention, and shows a configuration in which burners having different capacities are mixed.
Note that, among the components of the combustion apparatus 40 of the embodiment described below, the same components as those of the previous embodiment are denoted by the same reference numerals as those of the previous embodiment, and redundant description is omitted.

  The combustion apparatus 40 shown in FIG. 9 has three burners 41a, 41b, and 41c. The three burners 41a, 41b, 41c employed in the present embodiment have different capacities, the first burner 41a has a large capacity, and the second burner 41b and the third burner 41c have a small capacity. Specifically, the second burner 41b and the third burner 41c have the same capacity, and the first burner 41a is a burner having a capacity twice that of these.

The fuel supply passage forming member 43 employed in this embodiment has three fuel supply passages 43a, 43b, and 43c. The piping resistance of the fuel supply paths 43a, 43b, 43c is set to a size (inverse proportion) corresponding to the capacity of the burners 41a, 41b, 41c. In the present embodiment, the first burner 41a has a capacity twice that of the other burners 41b and 41c, so the pipe resistance of the fuel supply path 43a is half that of the other fuel supply paths 43b and 43c.
In addition, on-off valves 21a, 21b, and 21c are provided in the middle of the fuel supply paths 43a, 43b, and 43c, respectively.
At the end of the fuel supply path forming member 43, the ends (downstream) of the fuel supply paths 43 a, 43 b, 43 c are connected to the nozzles 20.
On the other hand, the front end portion of the fuel supply path forming member 43 constitutes the open end group 22 by gathering the open ends of the fuel supply paths 43a, 43b, and 43c. In the open end group 22, the cross-sectional areas of the fuel supply paths 43a, 43b, and 43c are reduced.
The cross-sectional areas of the open ends 22a, 22b, and 22c of the fuel supply paths 43a, 43b, and 43c are set to sizes corresponding to the capacities of the burners 41a, 41b, and 41c. In the present embodiment, in the present embodiment, the first burner 41a has a capacity twice that of the other burners 41b and 41c, so that the cross-sectional area of the open end 22a is the cross-sectional area of the other open ends 22b and 22c. Is twice as large.

  As described above, the amount of fuel gas introduced into the burners 41a, 41b, and 41c is the amount of gas that passes through the fuel supply passages 43a, 43b, and 43c, and the opening area and the interior of the fuel supply passages 43a, 43b, and 43c. It is a function of resistance. In this embodiment, the cross-sectional area of the open end 22a of the fuel supply passage 43a is twice the cross-sectional area of the open ends 22b and 22c of the other fuel supply passages 43b and 43c. Fuel gas twice as high as that of the burners 41b and 41c is supplied.

In the above-described embodiments, the burners 8 and 41 and the fuel supply paths 5 and 43 correspond to each other one to one, and one fuel supply path 5 and 43 always supplies fuel to one burner 8 and 41. However, for example, fuel may be supplied to two or more burners through one fuel supply path.
That is, a plurality of burners are divided into a plurality of groups, and a fuel supply path is provided for each group.
FIG. 10 is a configuration diagram of a combustion apparatus according to still another embodiment of the present invention, and has a mode in which fuel is supplied to a plurality of burners through one fuel supply path.

In the combustion apparatus 45 of this embodiment, four burners 8a, 8b, 8c, and 8d are built in the burner case 7, and the capacity of each burner 8a, 8b, 8c, and 8d is the same.
In the present embodiment, the four burners 8a, 8b, 8c, and 8d are divided into three groups. That is, the burners 8a and 8b are the first group burners, the burner 8c is the second group burner, and the burner 8d is the third group burner.

On the other hand, the fuel supply path forming member 43 has three fuel supply paths 43a, 43b, 43c as in the embodiment of FIG. The pipe resistance of the fuel supply paths 43a, 43b, 43c is set to a size (inverse proportion) corresponding to the capacity of each burner group. In the present embodiment, since the first group has twice the capacity as compared with the other groups, the piping resistance of the fuel supply path 43a is half that of the other fuel supply paths 43b and 43c.
In addition, on-off valves 21a, 21b, and 21c are provided in the middle of the fuel supply paths 43a, 43b, and 43c, respectively.
At the end of the fuel supply path forming member 43, the ends (downstream) of the fuel supply paths 43 a, 43 b, 43 c are connected to the nozzles 20. However, two nozzles are attached to the fuel supply path 43a.
On the other hand, the front end portion of the fuel supply path forming member 43 constitutes the open end group 22 by gathering the open ends of the fuel supply paths 43a, 43b, and 43c. In the open end group 22, the cross-sectional areas of the fuel supply paths 43a, 43b, and 43c are reduced.
The cross-sectional areas of the open ends 22a, 22b, and 22c of the fuel supply paths 43a, 43b, and 43c are set to sizes corresponding to the capacities of the burners 41a, 41b, and 41c. In the present embodiment, in this embodiment, the first burner 41a has a capacity twice that of the other burners 41b and 41c, so that the cross-sectional area of the open end 22a is the cross-sectional area of the other open ends 22b and 22c. Is twice as large.

  In this embodiment, the cross-sectional area of the opening end 22a of the fuel supply passage 43a is twice the cross-sectional area of the opening ends 22b and 22c of the other fuel supply passages 41b and 41c. Fuel gas twice as much as the group is supplied. Two burners 8a and 8b belong to the first group, and fuel is evenly distributed to the burners.

  In the embodiment described above, the fuel gas is distributed to each burner group in such a manner that the opening area in the open end group 22 which is the most upstream of each fuel supply path 43a, 43b, 43c corresponds to the capacity of the burner group. A fuel gas may be distributed to each burner group by providing a narrowed portion with a narrow area in the middle. Specifically, a configuration in which an orifice is provided in the middle of the fuel supply path, the flow path resistance is adjusted, and the fuel gas is distributed to each burner group can be considered. It is also conceivable to distribute the fuel gas to each burner group by adjusting the opening diameter of the nozzle 20.

Next, an embodiment closer to the actual configuration will be described.
FIG. 11 is a perspective view showing a practical configuration of the combustion apparatus of the present invention. 12 is a piping system diagram of the combustion apparatus of FIG. FIG. 13 is a front view of the combustion apparatus of FIG. 14 is a cross-sectional view taken along the plane AA of FIG. FIG. 15 is an exploded perspective view of the combustion apparatus of FIG.
The combustion device 51 shown in FIG. 11 is also built in the water heater, and is constituted by a combustion device main body 52, a blower 53, a fuel supply path forming member 55, and a pressure adjusting device 56.

The blower 53 employed in the present embodiment is provided with a rotary blade in the casing, as in the previous embodiment. Moreover, the motor which rotates the air blower 53 can increase / decrease a rotation speed. In the blower 53 employed in the present embodiment, the signal pressure extraction unit 80 is opened in the vicinity of the air outlet.
The combustion apparatus main body 52 has 20 burners 58 built in a burner case 57. In the burner case 57, the 20 burners 58 described above are divided into seven groups.
That is, as shown in FIG. 12, the first group 71a has four burners 58, the second group 71b has four burners 58, the third group 71c has three burners 58, and the fourth group. 71d includes two burners 58, the fifth group 71e includes two burners 58, the sixth group 71f includes two burners 58, and the seventh group 71g includes three burners 58.

  Furthermore, in the burner case 57, the left group 76a to which the first group 71a, the second group 71b, and the third group 71c belong, the fourth group 71d, the fifth group 71e, the sixth group 71f, and the seventh group 71g The right group 76b belongs to two groups.

FIG. 16 is an exploded perspective view of a burner case and a perspective view of a built-in burner. FIG. 17 is a perspective view showing a state in which a part of the side cover is removed in the direction B of FIG. 18 is a perspective view showing a state in which a part of the side cover is removed in the direction C of FIG.
The burner case 57 has a shelf 59 and is divided into two upper and lower stages as shown in the figure. The upper side functions as the burner mounting part 60 and the lower side functions as the air flow path forming part 61. The depth w of the shelf 59 is shorter than the depth W of the burner case 57, and there is no shelf 59 at the front side (front side in FIG. 16) as shown in FIGS. The top and bottom communicate. This part functions as the air vertical communication path 70.

  The shelf 59 has six partition plates 69 as shown in FIG. 16, and the shelf 59 is divided into seven burner installation areas. One group 71 of the burners 58 is arranged in each burner installation area.

  The air flow path forming part 61 is an air chamber, and a blower 53 is attached to the lower part. As described above, the air flow path forming unit 61 communicates with the burner 58 and is supplied with air that is supplied to combustion, and the air flow path forming unit 61 communicates with the outside and passes air that is not supplied with combustion. A cooling air passage 89. Specifically, as shown in FIG. 17, the burner case 57 includes a case body 83 and an outer wall 81, and the supply flow path 88 is located inside the case body 83, The path 89 is located outside the case main body 83. That is, the supply flow path 88 and the cooling air flow path 89 are divided by the side wall 87 of the case body 83. The side wall 87 is provided with an opening 98 at the lowest vertical end, and the supply flow path 88 and the cooling air flow path 89 communicate with each other through the opening 98.

  Further, the case body 83 has a detachable separation wall (side wall) 93 and is disposed at a position where a fuel supply path forming member 55 described later is attached. The separation wall 93 is provided with an opening 98 at the lower end in the vertical direction in the same manner as the side wall 87 described above, and the supply flow path 88 and the cooling air flow path 89 communicate with each other through the opening 98. Further, the separation wall 93 is provided with the same number of through holes 92 as the nozzles 20 through which the nozzles 20 of the fuel supply path forming member 55 are inserted. In this embodiment, 20 through holes 92 are provided (FIG. 22).

  The cooling air flow path 89 will be described in more detail. The cooling air flow path 89 is a space sandwiched between the side wall 87 and the outer wall part 81 of the case body 83, and the side wall 87 is in the internal direction. It is a groove-like channel that is recessed in the vertical direction and extends in the vertical direction. The cooling air flow path 89 in each side wall 87 is divided by a support member 84 extending in the air traveling direction. The cooling air flow path 89 in each side wall 87 has one support member 84m on the side wall 87a. The cooling air flow path 89 is divided into two parts, the support member 84m is arranged on the side wall 87b, the cooling air flow path 89 is divided into three parts, and the support member 84m is arranged on the side wall 87c. The cooling air flow path 89 is divided into two, and three support members 84n are arranged on the side wall 87d, and the cooling air flow path 89 is divided into four. Further, since the three support members 84n are arranged at the same position as the side wall 87d on the separation wall 93 arranged adjacent to the side wall 87d, the side wall 87d and the separation wall 93 are integrated to cool the separation wall 93. The air flow path 89 is divided into four. Since the support member 84 is sandwiched between the case body 83 and the outer wall 81, it is difficult to deform even when an external pressure is applied to the outer wall 81, and the cooling air flow path 89 is not easily blocked.

  As shown in FIG. 18, an exhaust port 91 is disposed at the downstream end of the cooling air passage 89 in the air traveling direction, and the air supplied to the cooling air passage 89 is exhausted. Released from the portion 91 to the outside. That is, the air supplied to the cooling air flow path 89 flows from the opening 98, rises along the cooling air flow path 89 arranged around the burner case 57, and is released to the outside. The burner case 57 and the like can be air-cooled. That is, as long as air is supplied from the blower 53, the combustion space 86 can be prevented from becoming a high temperature state even during combustion.

  In addition, inside the supply flow path 88, as shown in FIG. 16, the partition plate 69 at the boundary between the left set 76a and the right set 76b protrudes outward, and the damper (air flow path closing means) 13 is It is provided to shield the air flow path of the right set 76b.

  That is, the damper 13 is attached to the hinge 15 fixed to the upper surface forming the air flow path forming portion 61, and is swung up and down by 180 degrees (vertical direction and horizontal direction). Can be shielded. Specifically, when the damper 13 is located on the upper surface forming the air flow path forming portion 61, air is supplied from the blower to both the left set 76 a and the right set 76 b of the supply flow path 88 and the cooling air flow path 89. Is supplied. On the other hand, when the damper 13 is moved 180 degrees away from the upper surface of the air flow path forming portion 61, the air vertical communication path 70 communicating with the right set 76b is blocked, and the ventilation of the right set 76b is blocked. Even if the damper 13 blocks the ventilation path, air is always supplied to the cooling air flow path 89.

  The burner 58 has the same structure as that employed in the previous embodiment, and has an air / gas inlet 68 at each end. A flame hole 62 is formed on the upper surface. All the burners 58 employed in the present embodiment have the same shape and have the same capacity.

Next, the fuel supply path forming member 55 will be described. FIG. 19 is an exploded perspective view of the fuel supply path forming member. 20 is a perspective view of the fuel supply path forming member of FIG. 19 observed from the lower surface side. That is, FIG. 20 is a perspective view in the D direction of FIG. FIG. 21 is a perspective view of the open end group of the fuel supply path forming member. FIG. 22 is a perspective view of the fuel supply path forming member observed from the inside.
The fuel supply path forming member 55 is a member that supplies fuel gas to each burner 58 through each nozzle, and is a member in which seven fuel supply paths are formed according to the number of burner groups 71.
In the present embodiment, the fuel supply path forming member 55 includes a main body portion 63, a front lid 64, and a lower lid 65.

The main body portion 63 is a member in which the front plate portion 66 and the lower surface plate portion 67 are coupled and the side surface shape is an “L” shape, and grooves are formed in both the front plate portion 66 and the lower surface plate portion 67. ing.
In other words, seven grooves 50 as shown in FIG. The starting end portions of the seven grooves 50 are all concentrated at the substantially central portion of the lower surface plate portion 67. Moreover, in the site | part where the start end part of the groove | channel 50 concentrates, the wall surface (partition member) 73 which comprises the groove | channel 50 protrudes toward the outer side.

The terminal portions of the grooves 50 in the lower surface plate portion 67 are gathered on the side where the lower surface plate portion 67 and the front plate portion 66 are joined.
A communication hole (not shown) is provided at the joint between the lower surface plate portion 67 and the front plate portion 66, and each groove 50 provided in the lower surface plate portion 67 communicates with the groove 50 provided in the front plate portion 66.
In addition, a main valve (not shown) of an electromagnetic valve (open / close valve) 75 is provided in the communication hole between the lower surface plate portion 67 and the front plate portion 66, and each communication hole can be opened and closed individually.

  Next, paying attention to the front plate portion 66 side, the seven grooves 54 are also formed in the front plate portion 66 as described above. The starting ends of the seven grooves 54 on the front plate portion 66 side are the above-described communication holes, and are concentrated on the side where the lower surface plate portion 67 and the front plate portion 66 are joined (joining side). The other end of each groove 54 is concentrated on a side portion (open side) facing the above-described side of the lower surface plate portion 67.

A plurality of through-holes penetrating to the burner case 57 side are provided at the bottom of each groove 54 of the front plate portion 66 (near the open side). Each through hole is provided with a nozzle 20 as shown in FIG.
The number of nozzles 20 is the same as the number of burners 58, and the distribution corresponds to the number of burners 58 belonging to the burner group 71.
That is, among the seven grooves 54, four nozzles 20 are provided in the first groove 54a, four nozzles 20 are provided in the second groove 54b, and three nozzles 20 are provided in the third groove 54c. The second groove 54d is provided with two nozzles 20, the fifth groove 54e is provided with two nozzles 20, the sixth groove 54f is provided with two nozzles 20, and the seventh groove Three nozzles 20 are provided in 54g.

  Further, as shown in FIG. 22, each nozzle 20 is inserted through 20 through holes 93 provided in the separation wall (side wall) 93. Specifically, the nozzle 20 is arranged so as to be perpendicular to the separation wall 93, the tip of the nozzle 20 faces the inside of the burner case 57, and further, the tip of the nozzle 20 is positioned inside the separation wall 93. It is arranged in. Thereby, even if the fuel gas is released from the nozzle 20, the fuel gas can be prevented from flowing into the cooling air flow path 89.

A front lid 64 is attached to the front plate portion 66, and a lower lid 65 is attached to the bottom plate portion 67 to seal the open side of each groove. As a result, each of the grooves 54 of the front plate portion 66 forms a flow path with four surfaces closed. In the present embodiment, the flow path constituted by the grooves 54 and 50 and the front lid 64 or the lower lid 65 functions as the fuel supply path 72.
However, an opening 74 is provided at a portion where the starting end of the groove 54 of the lower lid 65 is concentrated, and the partition member 73 is exposed to the outside from the opening 74.
The opening of the lower lid 65 is divided into seven small openings by a part of the wall constituting the groove. In the present embodiment, the small opening is the upstream end of each fuel supply path 72, and a group of seven small openings constitutes the opening end group 22.

  In the present embodiment, the area of the small opening is proportional to the total capacity of the burners 58 belonging to the burner group 71.

Next, the pressure regulator 56 employed in the present embodiment will be described. The pressure regulator 56 is a zero governor as in the previous embodiment, and is a pressure regulator that discharges the gas supplied with the primary pressure to a secondary pressure, and introduces the signal pressure as a signal. The pressure adjusting device has a port 82 and discharges the secondary pressure by reducing the pressure to a secondary pressure corresponding to the pressure introduced from the signal pressure introducing port 82.
Hereinafter, the zero governor 56 employed in the present embodiment will be described.
The zero governor 56 employed in the present embodiment is a kind of pressure reducing valve, and is a device that reduces the pressure (primary pressure) of gas supplied from a gas supply source to a predetermined pressure (secondary pressure). However, a general pressure reducing valve regulates the secondary pressure to a set constant pressure, whereas the zero governor 56 employed in the present embodiment differs in that the discharge pressure varies according to the signal pressure.
That is, in the general pressure reducing valve, the secondary pressure is constant, whereas in the zero governor 56 employed in the present embodiment, the secondary pressure varies depending on the signal pressure. More specifically, the zero governor 56 employed in the present embodiment has a signal pressure introduction port 82, and the secondary pressure varies according to the pressure of the gas introduced from the signal pressure introduction port 82. In particular, in the present embodiment, the secondary pressure is adjusted to be equal to the pressure of the gas introduced from the signal pressure inlet 82 (signal pressure).

FIG. 21 is a conceptual diagram of a zero governor employed in the present embodiment.
The zero governor 56 employed in the present embodiment is a pilot type zero governor 56 and includes a main valve A and an auxiliary valve (pilot valve) B. In the zero governor 56, a main flow path D and an auxiliary flow path E are provided. A main valve A is provided in the main flow path D, and an auxiliary valve B is provided in the auxiliary flow path E.

  Here, the main channel D is a channel from the gas inlet c to the gas outlet d of the zero governor 56, and is a channel through which the gas supplied from the gas supply source is decompressed and discharged.

  The main flow path D is a series of flow paths constituted by an introduction path e connected to the gas inlet c, a parallel path f, and a discharge path g as shown in the figure. The introduction path e and the parallel path f communicate with each other through the first opening h, and the parallel path f and the discharge path g communicate with each other through the second opening i.

  The main valve A is a valve operated by the diaphragm a, and is provided in the main flow path D of gas. Specifically, the main valve A is provided in the second opening i of the main flow path D, and adjusts the opening degree of the second opening i. That is, the main valve A increases or decreases the passage area of the main flow path D. When the main valve A operates in the closing direction, the secondary pressure decreases, and when the main valve A operates in the opening direction, the secondary pressure increases. .

  The main valve A is operated by the diaphragm a as described above. That is, there is a working pressure chamber j having the diaphragm a as one of the constituent walls on one side of the diaphragm a. The other side of the diaphragm a is pressed by a spring u. Therefore, the diaphragm a moves and the main valve A moves so that the pressure in the working pressure chamber j and the pressing force of the spring u are in harmony.

The auxiliary flow path E is a part of the main flow path D branched, and communicates with one working pressure chamber j partitioned by the diaphragm a. Further, a part of the auxiliary flow path E is further branched to form a leak flow path k.
That is, the auxiliary flow path E is a flow path that reaches the working pressure chamber j through the branch chamber m and the pressure regulating chamber n.
More specifically, the branch chamber m communicates with the opening o provided in the parallel path f of the main flow path D, and the opening p in the branch chamber m and the opening q in the pressure regulating chamber n are indicated by a one-dot chain line. It communicates with a conduction path. Further, the opening r in the pressure regulating chamber n and the opening s in the working pressure chamber j are communicated with each other through a one-dot chain line conduction path.
As a result, a series of auxiliary flow paths E that reach the parallel path f, the opening o, the branch chamber m, the opening p, the opening q, the pressure regulating chamber n, the opening r, the opening s, and the working pressure chamber j are formed.
In addition, a leak opening t is provided in a part of the pressure regulating chamber n, and the leak opening t communicates with the discharge path g of the main flow path D through the leak flow path k. The leak opening t is a very small hole.

  The auxiliary valve B is a valve operated by the diaphragm b, and is provided in the leak opening t of the pressure regulating chamber n. That is, the auxiliary valve B adjusts the opening degree of the leak opening t and adjusts the pressure in the pressure regulating chamber n. In other words, the auxiliary valve B increases or decreases the passage area of the leak opening t. When the auxiliary valve B operates in the closing direction, the pressure in the pressure regulating chamber n increases, and when the auxiliary valve B operates in the opening direction, the pressure is regulated. The pressure in chamber n drops.

The diaphragm b has a secondary pressure acting on one wall surface and a signal pressure acting on the other wall surface, and operates according to the magnitude of the secondary pressure and the signal pressure.
That is, there is a signal pressure chamber v having the diaphragm b as one of the constituent walls on one side of the diaphragm b. The signal pressure chamber v communicates with the signal pressure introduction port 82.
A secondary side communication chamber w is provided on the other side of the diaphragm b. Here, the secondary side communication chamber w communicates with the discharge path g of the main flow path D through the secondary side communication path x. The secondary pressure of the zero governor 56 is applied to the secondary side communication chamber w.

  Accordingly, the diaphragm b has a signal pressure chamber v on one side and a secondary side communication chamber w on the other side so that the pressure in the signal pressure chamber v and the pressure in the secondary side communication chamber w are in harmony. Move to. Further, since the signal pressure is applied to the signal pressure chamber v by the gas introduced from the signal pressure introduction port 82 and the secondary pressure is applied to the secondary side communication chamber w, the diaphragm b has the signal pressure and the secondary pressure. Move to harmonize.

Further, the zero governor 56 employed in the present embodiment includes a first electromagnetic valve z and a second electromagnetic valve Z. The first electromagnetic valve z is provided in the first opening h of the main flow path D and opens and closes the main flow path D itself.
The second electromagnetic valve Z is provided in the opening o and opens and closes the auxiliary flow path E.

Next, the operation of the zero governor 56 employed in the present embodiment will be described.
The zero governor 56 is used with the gas inlet c connected to the gas supply source and the gas outlet d connected to the load side.
The signal pressure introduction port 82 is connected to a desired signal supply source.
The first solenoid valve z and the second solenoid valve Z are used in an open state. Therefore, both the main channel D and the auxiliary channel E are open.

The fuel gas flows through the main flow path D described above. That is, the fuel gas enters the introduction path e from the gas introduction port c and further flows through the parallel path f. And it flows into the discharge path g through the 2nd opening i, and is discharged | emitted from the gas discharge port d.
Here, since the main valve A is provided in the second opening i, the flow rate of the gas flowing through the discharge passage g is controlled by the main valve A. That is, the gas pressure upstream of the second opening i is a primary pressure and is the same pressure as the gas supply source, but the pressure downstream of the second opening i is reduced to a low pressure.

On the other hand, the gas flowing through the auxiliary flow path E flows into the working pressure chamber j through the branch chamber m.
However, since the pressure adjusting chamber n is provided with the leak opening t, the pressure in the working pressure chamber j depends on the opening degree of the leak opening t.
That is, when the leak opening t is closed, the auxiliary flow path E becomes the same pressure (primary pressure) as the pressure on the high pressure side (upstream side of the second opening i) of the main flow path D. On the other hand, when the leak opening t is opened, the gas in the pressure regulation chamber n leaks from the leak opening t, flows through the leak flow path k, and is discharged to the discharge path g side of the main flow path D. The pressure in n decreases.
An auxiliary valve B is provided in the leak opening t, and the auxiliary valve B is operated by the diaphragm b. The diaphragm b is located between the signal pressure chamber v and the secondary side communication chamber w as described above. The pressure in the signal pressure chamber v and the pressure in the secondary side communication chamber w move so as to match. That is, the diaphragm b moves so that the signal pressure and the secondary pressure are in harmony.

  Therefore, for example, when the signal pressure rises, the pressure in the signal pressure chamber v rises and the diaphragm b expands downward in the drawing, and the auxiliary valve B is pushed down to narrow the opening of the leak opening t. As a result, the flow rate of the gas leaking from the leak opening t decreases, and the pressure in the pressure regulating chamber n increases. Therefore, the pressure in the working pressure chamber j communicating with the pressure regulating chamber n rises, the diaphragm a bulges against the force of the spring u, pushes up the main valve A to increase the opening of the second opening i, The pressure (secondary pressure) on the low pressure side (downstream side of the second opening i) is increased by increasing the flow rate of the gas passing through the second opening i. That is, when the signal pressure increases, the secondary pressure increases.

  The same applies when the secondary pressure drops for some reason, the pressure in the secondary side communication chamber w drops, the diaphragm b bulges down in the drawing, the auxiliary valve B is pushed down, and the diaphragm b goes down in the drawing. The auxiliary valve B is pushed down to narrow the opening of the leak opening t. As a result, the flow rate of the gas leaking from the leak opening t decreases, the pressure in the pressure regulating chamber n and the working pressure chamber j rises, the diaphragm a bulges against the force of the spring u, and the main valve A opens. The pressure of the second opening i is increased to increase the pressure on the low pressure side (downstream side of the second opening i). That is, when the secondary pressure decreases, the main valve A moves in a direction for correcting the secondary pressure and increases the secondary pressure.

  Conversely, when the signal pressure decreases, the pressure in the signal pressure chamber v decreases, and is pushed by the pressure in the secondary side communication chamber w, the diaphragm b moves to the upper side of the drawing, opens the auxiliary valve B, and opens from the leak opening t. The amount of leakage in the pressure adjusting chamber n is increased and the pressure in the pressure regulating chamber n is decreased. As a result, the pressure in the working pressure chamber j communicating with the pressure regulating chamber n decreases, the diaphragm a is pushed by the force of the spring u and moves downward in the drawing, the main valve A is lowered, and the second opening i is opened. The pressure on the low pressure side (downstream side of the second opening i) is decreased by decreasing the flow rate of the gas passing through the second opening i. That is, when the signal pressure decreases, the secondary pressure also decreases accordingly.

  The same applies to the case where the secondary pressure rises. The pressure in the secondary side communication chamber w rises and the diaphragm b moves upward in the drawing, pushes up the auxiliary valve B, pushes up the auxiliary valve B, and opens the leak opening t. Open the opening. As a result, the flow rate of the gas leaking from the leak opening t increases, the pressure in the pressure regulating chamber n and the working pressure chamber j decreases, the diaphragm a moves to the lower side of the drawing, the main valve A is lowered, and the second The opening degree of the opening i is lowered, and the pressure on the low pressure side (downstream side of the second opening i) is lowered. That is, when the secondary pressure rises, the main valve A moves in a direction to correct this, and the secondary pressure is lowered.

  In the pressure adjusting device 56 described above, the gas inlet 30 is connected to a fuel gas supply source. The gas discharge port 31 of the pressure adjusting device 56 is attached to an opening 74 provided in the lower lid 65 of the fuel supply path forming member 55. That is, the gas discharge port 31 of the pressure adjusting device 56 is provided with a flange (not shown). The flange (not shown) is screwed around the opening 74, and the gas discharge port 31 is provided on the lower lid 65. The opening 74 is matched.

  Here, the partition member 73 protrudes from the opening 74 of the fuel supply path forming member 55 described above. The partition member 73 enters the gas discharge port 31 and divides the inside of the gas discharge port 31 into seven regions.

  Further, the signal pressure of the pressure adjusting device 56 is detected from the discharge side of the blower 53. That is, as shown in FIG. 11, the conducting pressure 85 connects between the signal pressure extraction portion 80 of the blower 53 and the signal pressure inlet 82 of the pressure adjusting device 56.

Next, the function of the combustion device 51 will be described.
In the combustion apparatus 51 of the present embodiment, the blower 53 is rotated and the on-off valve 75 is opened, fuel and air are introduced into the burner 58, the both are mixed in the burner 58, and the fuel gas is introduced from the flame hole 62 of the burner 58. A mixed gas of air is discharged, and a flame is generated in the combustion space 86.
That is, air is blown into the burner case 57 by rotating the blower 53. The air blown from the blower 53 once enters the air flow path forming part 61 in the burner case 57. Then, the blown air passes from the supply flow path 88 to the shelf 59 through the air vertical communication passage 70 which is a break of the shelf 59. The air reaches the end of each burner 58 and air is supplied from the air / gas inlet 68 to each burner 58. On the other hand, air that is not used for combustion flows into the cooling air flow path 89 from the opening 98 formed in the side wall 87 of the burner case 57, flows along the cooling air flow path 89, and passes through the exhaust port 91 to the outside. To be released. Thereby, since it can prevent that the burner case 57 grade | etc., Maintains a high temperature state, generation | occurrence | production of nitrogen oxides (NOx, mainly nitric acid) is suppressed. That is, since the oxide generated in the drain generated by the combustion is suppressed, the burner case 57 and the like are prevented from corroding due to the oxidizing action.

  Here, it can be said that the amount of air introduced into each burner 58 is determined by the discharge pressure of the blower 53 for the reason described above. Even when the combustion request is changed and the supply of combustion gas is partially stopped, the damper 13 provided in the air flow path forming unit 61 shields the air upper and lower communication passages 70 of the right set 76b, Air blown from the blower 53 is introduced into the left set 76 a and the cooling air flow path 89. As a result, air can be prevented from being introduced into the right set 76b where combustion is not performed. That is, since the invalid air is not continuously released from the flame hole 62 on the right set 76b side where combustion is not performed, it is possible to prevent the heat exchanger from being cooled by the invalid air and reducing the heat exchange efficiency. Note that the air discharged from the exhaust port portion 91 is heated by the amount of heat in the combustion space 86 in an amount that does not affect the signal pressure, and thus does not cool the heat exchanger.

  On the other hand, the fuel gas enters the pressure regulator 56 from the fuel gas supply source and is depressurized by the pressure regulator 56. The gas exiting the pressure adjusting device 56 enters the fuel supply path forming member 55, passes through each fuel supply path 72 of the fuel supply path forming member 55, and is discharged from the nozzle 20. Each nozzle 20 is provided at a position facing the air / gas introduction port 68 of each burner 58, and the gas discharged from the nozzle 20 enters each burner 58 through the air / gas introduction port 68 and is air And discharged from the flame hole 62.

Here, in the present embodiment, the 20 burners 58 are divided into seven burner groups 71. However, when attention is paid to the amount of fuel gas introduced into each burner group 71, the amount of fuel gas introduced into each burner group 71. Is the amount of gas passing through the fuel supply path 72.
The amount of gas passing through the fuel supply path 72 includes the gas pressure on the upstream side of the fuel supply path 72, the opening area of the fuel supply path 72, the internal resistance of the fuel supply path 72, the opening diameter of the nozzle 20, and the nozzle 20 It is a function depending on the atmospheric pressure on the discharge side.
Here, in the present embodiment, the opening at the end (upstream side) of each fuel supply path 72 is a small opening in the opening of the lower lid 65. In this embodiment, the area of the small opening is proportional to the total capacity of the burners belonging to the burner group 71.
Therefore, the ratio of the flow rate of the fuel gas flowing through each fuel supply path 72 is equal to the ratio of the total capacity (number of burners) of each burner group 71. Further, the number of nozzles 20 equal to the number of burners 58 to which the fuel supply passages 72 belong is provided, and the fuel gas flowing through the fuel supply passages 72 is divided into the burners 58 by the nozzles 20. Therefore, the fuel gas is equally supplied to any burner 58.

  Further, as described above, the amount of fuel gas introduced into each burner 58 has the highest correlation with the pressure of the fuel gas upstream of the fuel supply path 72, and the amount of fuel gas introduced into the burner 58 is Even if it is determined only by the discharge pressure of the pressure adjusting device 56, it can be said that there is no practical problem.

In the combustion device 51 of the present embodiment, the signal pressure of the pressure adjusting device 56 is detected from the discharge side of the blower 53, and the pressure adjusting device 56 releases the fuel gas at a secondary pressure correlated with the signal pressure. The pressure of the fuel gas discharged from the pressure adjusting device 56 varies depending on the discharge pressure of the blower 53, and the ratio of the amount of air introduced into the burner 58 and the amount of gas is always constant.
The ratio between the amount of air introduced into the burner 58 and the amount of gas is determined by the area of the air / gas inlet 68 of the burner 58, the opening diameter of the nozzle 20, etc., and in this embodiment, it is sufficient to burn the gas. The area of the air / gas inlet 68 and the opening diameter of the nozzle 20 are designed so that the amount of air becomes the ratio introduced from the air / gas inlet 68.

Therefore, in the present embodiment, air and fuel gas are always introduced into each burner 58 at an appropriate ratio, mixed with air, discharged from the flame hole 62, and a flame is generated.
Further, the combustion amount can be increased or decreased by changing the air flow rate of the blower 53. That is, as described above, in this embodiment, the ratio of the amount of air and the amount of gas introduced into each burner 58 is always constant.
In the present embodiment, the number of burners 58 that burn can be changed by closing some of the on-off valves 75.

  Therefore, the combustion apparatus 51 of the present embodiment is provided with the cooling air flow path 89 between the case main body 83 and the outer wall 81 of the burner case 57 and constantly blows air during combustion. The effect that can be cooled can be expected. In other words, since the combustion space does not reach a high temperature during combustion, it is possible to suppress the generation of nitrogen oxides (NOx, mainly nitric acid). Thereby, since it is suppressed that an oxide is contained in the drain which generate | occur | produces at the time of combustion, it can suppress that the inside of the burner case 57 is corroded by an oxidizing action.

  In the combustion apparatus 51 of the above-described embodiment, the fuel supply path 72 is branched in advance and connected to each burner (mixing unit) 58 and mixed with air in each burner 58. It is not limited. For example, as shown in FIG. 25, a configuration may be adopted in which fuel gas and air are mixed in advance to generate a mixed gas, and the mixed gas is introduced into the mixing unit.

It is a block diagram of the combustion apparatus of embodiment of this invention. It is a perspective view which shows an example of a fuel supply path formation member. It is a perspective view which shows other embodiment of a fuel supply path formation member. It is a perspective view which shows other embodiment of a fuel supply path formation member. It is a flowchart which shows the operation | movement at the time of ignition of the combustion apparatus of embodiment of this invention. It is a flowchart which shows operation | movement of the combustion apparatus of embodiment of this invention, and demonstrates operation | movement when the combustion amount requested | required during combustion reduces. It is a block diagram of the combustion apparatus which shows operation | movement when the combustion amount requested | required during combustion reduces. It is a block diagram of the combustion apparatus which shows the operation | movement following FIG. It is a block diagram of the combustion apparatus of other embodiment of this invention, and shows the structure where the burner from which capacity | capacitance differs is mixed. It is a block diagram of the combustion apparatus of further another embodiment of this invention, and has a mode which supplies a fuel to several burners with one fuel supply path. It is a perspective view which shows the actual structure of the combustion apparatus of this invention. It is a piping system diagram of the combustion apparatus of FIG. It is a front view of the combustion apparatus of FIG. It is sectional drawing in the AA plane of FIG. It is a disassembled perspective view of the combustion apparatus of FIG. (A) is an exploded perspective view of a burner case, (b) is a perspective view of a built-in burner. It is a perspective view which shows the state which removed a part of side cover in the B direction of FIG. It is a perspective view which shows the state which removed a part of side cover in the C direction of FIG. It is a disassembled perspective view of a fuel supply path formation member. It is a D direction perspective view of FIG. It is a perspective view of the opening end group of a fuel supply path formation member, (a) is in the state where the lower lid was attached, and (b) is in the state where the lower lid was removed. It is the perspective view which observed the fuel supply path formation member from the inside. It is a conceptual diagram of the zero governor employ | adopted by this embodiment. It is a block diagram of the combustion apparatus of other embodiment of this invention, and the aspect provided with the common flow path of fuel gas is shown. It is a block diagram which shows the combustion apparatus of other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,40,45,51 Combustion apparatus 3,53 Blower 5,43,55 Fuel supply path formation member 5a, 5b, 5c, 5d Combustion supply path 6,56 Pressure regulator 7,57 Burner case 8,58 Burner 9, 83 Case body 14, 86 Combustion space 17, 62 Flame hole 19, 81 Outer wall 21, 75 Open / close valve 28, 88 Supply flow path 29, 89 Cooling air flow path 43 a, 43 b, 43 c Combustion supply path 34, 87 Side wall 37 Air passage 38, 98 Opening 72 Fuel supply passage 93 Separation wall Pt Signal pressure

Claims (6)

A burner case, a blower, and a pressure regulator;
The burner case has a double structure including an outer wall portion and a case main body portion, and has a cooling air flow path between the outer wall portion and the case main body portion,
The case body includes a mixing portion that promotes mixing of fuel gas and air, and a flame hole portion in which a flame hole from which a mixed gas of air and fuel gas is discharged is disposed,
The pressure regulator adjusts and discharges the gas supplied with the primary pressure to a secondary pressure corresponding to a predetermined signal pressure, and the signal pressure of the pressure regulator is detected from the blower or the downstream side of the blower. And
The fuel gas discharged from the pressure regulating device is introduced into the case main body and discharged from the flame hole through the mixing unit.
The downstream side of the blower communicates with the burner case, and the blower from the blower is divided into the mixing unit and the cooling air flow path in the burner case, and a part of the blown air flows through the cooling air flow path. Combustion device characterized by.   2. The combustion according to claim 1, wherein a plurality of burners are provided in the case main body, and each burner is provided with a mixing portion and a flame hole portion that promote mixing of fuel gas and air. apparatus.   The combustion apparatus according to claim 1, wherein a mixed gas in which air and fuel gas are mixed in advance is introduced into the mixing portion of the case main body. The case body has an opening, and the opening is disposed upstream of the mixing unit.
The combustion apparatus according to claim 2 or 3, wherein air is introduced into the cooling air flow path from the opening. A nozzle for discharging fuel gas;
The nozzle is arranged through the case body,
The combustion apparatus according to any one of claims 1 to 4, wherein a tip portion of the nozzle is disposed toward an inner direction of the burner case.   6. The combustion apparatus according to claim 2, wherein the burner case has a rectangular shape, and a plurality of the burners are accommodated in parallel.

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