JP2002139205A - Combustion apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To suppress NOx and HC and realize a compact burner. SOLUTION: There are provided a first burner inflow port 53 into which fuel gas and air flow and which is communicated with a first flame port 52, and second burner inflow ports 59a, 59b which are independently communicated to second flame ports 58a, 58b of opposite sides of the first flame port 52 and which are located at an upper or lower portion of the first burner inflow port 53. Hereby, uniform concentration premixed gas is supplied to the second flame ports 58a, 58b without requiring high accuracy assembling, and hence a thin fuel flame is more stabilized than a thick fuel flame with a wide air excess rate, and an input ratio of fuel gas of thin fuel premixed gas as well as the air excess rate are more increased than in prior art, and further low NOx is achieved while suppressing the production of HC and CO. Moreover, the second burner inflow ports 59a, 59b are located at an upper or lower portion of the first burner inflow port 53, so that the width of the burner is more reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combustion apparatus mainly for household or business use, and more particularly to a combustion apparatus using a light-and-dark combustion system for achieving ultra-low NOx.

[0002]

2. Description of the Related Art As global environmental conservation is called for, there is a demand for further reduction of environmentally harmful substances such as NOx (nitrogen oxide) and HC (hydrocarbon) contained in exhaust gas from combustion equipment. In household or commercial combustion devices, a so-called lean-burn method is employed to reduce NOx.

A conventional combustion apparatus of this type is disclosed in Japanese Patent No. 2690.
No. 447 and Japanese Patent No. 1898150 were common. Patent 269044
FIG. 4 shows a combustion apparatus described in Japanese Patent Publication No. 7-107. The burner module 1 includes a first burner 2 and second burners 3a and 3b. The first burner 2 forms a first burner port 4, a first burner inlet 5 into which fuel and air flow into the side, and a first passage 6 extending from the first burner inlet 5 to the first burner port 4. ing.
Above the first burner inlet 5, a second burner inlet 7, a throat portion 8, and throat outlets 9a and 9b are formed.

[0004] The second burners 3a and 3b are respectively connected to the second flame ports 10a and 10b on both sides of the first flame port 4 and the throat outlet 9 respectively.
The second passages 11a and 11b are formed so as to be continuous with the second flame ports 10a and 10b from the first and second flame ports 10a and 10b. A first nozzle 12 and a second nozzle 13 from which fuel gas is ejected are provided to face the first burner inlet 5 and the second burner inlet 7, respectively.

Then, the fuel gas ejected from the first nozzle 12 and the air supplied by the fan (not shown) flow from the first burner inlet 5. The fuel and air are mixed in the first passage 6 to become a premixed gas having an excess air ratio of greater than 1 (hereinafter referred to as a light premixed gas), which is blown out from the first flame port 4 to form a so-called light flame.

On the other hand, fuel gas ejected from the second nozzle 13 and air supplied by a fan (not shown) flow in from the second burner inlet 7. The fuel and the air are mixed in the throat section 8, and a premixed mixture having an excess air ratio smaller than 1 (hereinafter referred to as a rich premixed mixture) is divided into two at the throat outlets 9a and 9b, and the second passages 11a and 9b are respectively provided. Jets are ejected from the second flame ports 10a and 10b through 11b to form a so-called rich flame. An unstable light flame having a low flame temperature and low NOx generation is stabilized by a dense flame having a high flame temperature formed on both sides.

Here, the NOx amount can be suppressed as the ratio of fuel input to the lean flame with respect to the total fuel input amount increases, and as the excess air ratio of the lean premix increases. However, the flame is easily destabilized, and HC and CO are easily generated.
HC and CO are mainly generated from a light flame.

[0008] A second conventional example, Japanese Patent No. 1898150
FIG. The first burner 20 is provided with a first burner port 21, a first burner inlet 22 into which fuel and air flow into a lower portion, and a first burner inlet 2 through a first burner inlet 22.
A first passage 23 connected to the first passage 23 is formed. Also, the second burners 24a and 24b are second burners 25a and 25b, respectively.
And second burner inlets 26a, 26b into which fuel and air flow in on both sides of the first burner inlet 22, and second burners 25a, 26b from the second burner inlets 26a, 26b.
Second passages 27a and 27b connected to 5b are formed.
A first nozzle 28 is provided to face the first burner inlet 22. The second nozzles 29a and 29b are provided to face the second burner inlets 26a and 26b, respectively.

The fuel gas ejected from the first nozzle 28 and the air supplied by the fan (not shown) flow in from the first burner inlet 22, and the fresh premixed gas is ejected from the first flame port 21. A light flame is formed. On the other hand, the second nozzle 29a,
Fuel gas ejected from 29b and air supplied by a fan (not shown) flow in from the second burner inlets 26a, 26b, and rich premixed gas is ejected from the second flame ports 25a, 25b to produce rich flame. It is formed.

[0010]

However, the combustion device described in Japanese Patent No. 2690447 has a second flame opening 1
Since only one inlet for fuel gas and air for supplying the rich premixed air to 0a and 10b is provided as the second burner inlet 7 and is used as a common inlet, high-precision assembly is required for the equipment. There was a problem that it was required to further reduce NOx. The details will be described below. The fuel gas and air flowing from the second burner inlet 7 are mixed in the throat section 8.
The fuel gas ejected from the second nozzle 13 has a high flow velocity (1
0 m / s or more), and it is difficult to mix completely because the passage length of the throat portion 8 is short.

Here, when the second nozzle 13 is eccentric from the center line XY of the second burner inlet 7 and is deviated to either side of the throat outlet 9a or 9b, the fuel at the deviated side of the throat outlet is The gas amount increases and the premixed gas concentration becomes high. At the other throat outlet, the fuel gas amount decreases and the premixed gas concentration decreases. Thereby, the second flame outlet 10a
And 10b differ in the concentration of the premixed gas.

In this state, particularly when the excess air ratio becomes larger than a desired value, the rich flame at the second flame port on the lighter side becomes unstable, and as a result, the lean flame also becomes unstable, and the amount of generated HC and CO is reduced. Increases rapidly. For this reason, the width of the excess air ratio in which stable combustion can be performed is narrowed, and it is difficult to further reduce NOx. In addition, a high-precision assembly was required to minimize the above-mentioned problems.

On the other hand, in the combustion device described in Japanese Patent No. 1898150, since the second burner inlets 26a and 26b are formed on both sides of the first burner inlet 22, the width of the burner increases, and Burner 20 and second burner 24
When a plurality of burner modules composed of a and 24b are arranged, there is a problem that the size of the appliance is increased.

[0014]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a first burner inlet through which fuel gas and air flow into a first flame, and second flames on both sides of the first flame. And a plurality of second burner inlets located above or below the first burner inlet independently of the mouth.

According to the above invention, equal amounts of fuel and air can be respectively supplied to the second flame port without requiring high-precision assembly, and a premixed gas having a uniform concentration is formed to form a uniform mixture. A strong flame can be formed. Thus, under a wide excess of air, the rich flame stabilizes the lean flame. Further, since the second burner inlet is located above or below the first burner inlet, the width of the burner can be reduced.

[0016]

According to the first aspect of the present invention, in the combustion apparatus, a first burner forming body forming a first flame port and a second burner forming a second flame port sandwiching the first flame port are provided. A forming body, a first burner inlet through which fuel gas and air flow into the first burner, and independently communicate with the second burner on both sides of the first burner and the first burner flow. A plurality of second burner inlets located above or below the inlet.

Then, equal amounts of fuel and air can be respectively supplied to the second flame ports on both sides of the first flame port without requiring high-precision assembly, and a premixed gas having a uniform concentration is formed.
A uniform intense flame can be formed. Therefore, under a wide range of excess air ratio, the rich flame stabilizes the light flame, and the fuel gas input ratio and the excess air ratio of the lean premixed gas can be made larger than before, and further lowering HC and CO while suppressing HC and CO NO
x can be achieved. Further, since the second burner inlet is located above or below the first burner inlet, the width of the burner can be reduced.

According to a second aspect of the present invention, there is provided a mixing passage for mixing fuel and air by means of a pair of convex portions formed on the second burner forming body and having a mirror symmetry with each other and the first burner forming body. And the upstream end of the mixing passage is used as a second burner inlet.

In addition, while having a simple structure, it is possible to form a mixing passage independently communicating with the second flame ports on both sides of the first flame port, and to promote the mixing of the fuel gas and the air to achieve a uniform concentration of the premix. Air can be supplied to the second flame outlet.

According to the third aspect of the present invention, particularly, the excess air ratio of the premixed gas ejected from the first flame port is increased and the fuel gas input ratio is increased as compared with the second flame port. The burner inlet is located below the second burner inlet.

The length of the passage from the first burner inlet to the first flame port can be lengthened, and a sufficiently mixed, lightly mixed gas having a uniform concentration can be formed and supplied to the first flame port. Therefore, a uniform light flame can be formed, and generation of NOx, HC, and CO can be suppressed.

The invention according to claim 4 has, in particular, a second nozzle having a plurality of fuel gas outlets facing the second burner inlet.

In addition, the number of nozzles for supplying fuel gas to the second flame ports on both sides of the first flame port can be made one, so that the structure can be simplified and the assembly and adjustment can be easily performed.

The invention according to claim 5 forms a mixing promoting means in which the first burner forming body or the second burner forming body faces the mixing passage.

Since the mixing can be promoted even in a short mixing passage, a more uniform premixed gas can be supplied to the second flame port.

[0026]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 is a perspective view showing a combustion apparatus according to Embodiment 1 of the present invention, FIG. 2 is a sectional view taken along the plane ABCD of FIG. 1, and FIG. It is sectional drawing in an EFGH plane.

1 to 3, reference numeral 50 denotes a burner module. A plurality of burner modules 50 are arranged in parallel (not shown). The burner module 50 is composed of two types of burners. A pair of first burner forming bodies 51a and 51b, which are mirror-symmetrical to each other, are overlapped, and the first burner port 52, the first burner inlet 53 into which the fuel gas and the air flow into the side, and the first burner inlet 53 A first passage 54 connected to the first flame port 52 is formed. The first flame port 52 which is subdivided by the slit 55 is formed.

Also, convex portions 56a, 56 which are mirror-symmetrical to each other.
b, a pair of second burner forming bodies 57a,
7b is put on the outside of the first burner forming bodies 51a, 51b, respectively. Second burner forming body 57a and its convex portion 56
a and the first burner forming body 51a are the second flame port 58a, the second burner inlet port 59a into which the fuel gas and the air flow, the mixing passage 60a from the second burner inlet port 59a to the second flame port 58a, Two passages 61a are formed. Similarly, the second burner forming body 57b, its convex portion 56b, and the first burner forming body 51b are connected to the second burner port 58b and the second burner inlet 59.
b, a mixing passage 60b and a second passage 61b are formed. Here, the second flame ports 58a and 58b are formed so as to sandwich the first flame port 52. The second burner inlets 59a, 59b, which are upstream openings of the mixing passages 60a, 60b, are located above the first burner inlet 53. 62a and 62b are mixing promoting means facing the mixing passages 60a and 60b, respectively, and are formed by providing projections on the first burner forming bodies 51a and 51b and the second burner forming bodies 57a and 57b.

A first fuel gas injection port 64 provided in the first nozzle 63 faces the first burner inlet 53. The second nozzle 65 is a so-called multi-port nozzle, and the second fuel gas injection ports 66a and 66b provided in the second nozzle 65 are provided to face the second burner inlets 59a and 59b, respectively.

Next, the operation and operation will be described. The fuel gas jetted from the first fuel gas jet port 64 and the air supplied by the fan (not shown) flow from the first burner inlet 53. The amount of fuel gas ejected from the first fuel gas ejection port 64 is larger than the sum of the amount of fuel gas ejected from the second fuel gas ejection ports 66a and 66b. The air flowing from the first burner inflow opening 53 is supplied to the first burner inflow opening 53.
And the opening area (not shown) arranged on the upstream side. In the first passage 54, the fuel and the air are mixed to form a light premixed air having an excess air ratio of more than 1. Since the first burner inlet 53 is located below the second burner inlets 59a and 59b, the length of the passage to the first flame port 52 can be increased. As a result, a well-mixed light premixture is formed. This light premixed gas is blown out from the first flame port 52 to form a light flame.

On the other hand, the fuel gas injected from the second fuel gas injection ports 66a and 66b and the air supplied by the fan (not shown) flow into the second burner inlets 59a and 59b, respectively. The convex portions 56a, 56b, which are mirror-symmetrical to each other, and the second burner inlets 59a, 59b formed by the first burner forming bodies 51a, 51b, respectively, form second flame ports 58a, 58.
Since it communicates independently with b, even though the configuration is simple, the same amount of fuel and air can be introduced even if the position of the second nozzle 65 is slightly deviated from the center line XY. Since the second burner inlets 59a and 59b are formed above the first burner inlet, the width of the burner module 50 can be reduced.

The air flowing in from the second burner inlets 59a, 59b is adjusted by the opening areas of the second burner inlets 59a, 59b and the openings (not shown) arranged on the upstream side. The fuel and the air are mixed in the mixing passages 60a and 60b, and the premixed air having an excess air ratio of less than 1 (hereinafter referred to as a rich premixed air). The rich premixed gas sufficiently mixed by the mixing promoting means 62a, 62b is supplied to the mixing passages 60a, 60b.
Formed.

As described above, a rich premixed gas having a uniform concentration is ejected from the second flame ports 58a and 58b, and a uniform rich flame is formed. Therefore, under a wide range of excess air ratio, the rich flame stabilizes the lean flame, and the fuel gas input ratio and the excess air ratio of the lean premixed gas can be made larger than before, and HC, CO
While reducing NOx.

In the first embodiment, the fuel has been described as a gaseous fuel such as city gas. However, a liquid fuel such as kerosene can be vaporized and used.

[0036]

As described above, according to the first to fifth aspects of the present invention, high-precision assembly is not required.
An equal amount of fuel and air can be respectively supplied to the second flame ports on both sides of the first flame port to form a premixed gas having a uniform concentration,
A uniform intense flame can be formed.

Thus, under a wide range of excess air ratio, the rich flame stabilizes the lean flame, and the fuel gas input ratio and the excess air ratio of the lean premixed gas can be increased as compared with the conventional case.
Further reduction of NOx can be achieved while suppressing C and CO. Further, since the second burner inlet is located above or below the first burner inlet, the width of the burner can be reduced.

[Brief description of the drawings]

FIG. 1 is a perspective view of a combustion device according to a first embodiment of the present invention.

FIG. 2 is a sectional view of a main part of the embodiment.

FIG. 3 is a sectional view of a main part of the embodiment.

4 is a perspective view of a conventional combustion device. FIG. 4 is a sectional view of a main part of a conventional combustion device.

FIG. 5 is a front view of a conventional combustion device.

[Explanation of symbols]

 51a, 51b First burner forming body 52 First flame outlet 53 First burner inlet 56a, 56b Convex portion 57a, 57b Second burner forming body 58a, 58b Second flame outlet 59a, 59b Second burner inlet 60a , 60b mixing passages 62a, 62b mixing promoting means 65 second nozzle 66a, 66b second fuel gas ejection port

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Ma Tatemori 1006 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. F term (reference) 3K017 AA01 AA06 AB02 AB07 AB09 AC01 AD04 AD11 3K065 TA01 TA04 TD05 TH04

Claims (5)

[Claims] 1. A first burner forming body that forms a first burner port, a second burner forming body that forms a second burner port across the first burner port, and a fuel gas and air flow into the first burner forming body. A first burner inlet communicating with the flame outlet, and a plurality of second burner inlets which are independently communicated with the second flame outlet and located above or below the first burner inlet. Combustion equipment. 2. A mixing passage for mixing fuel and air is formed by a pair of projections formed on the second burner forming body and being mirror-symmetrical to each other, and an upstream end of the mixing passage is formed. 2. The combustion device according to claim 1, wherein the combustion device is an inlet for the second burner. 3. The method according to claim 1, wherein the excess air ratio of the premixed gas ejected from the first burner port is increased and the input ratio of the fuel gas is increased as compared with the second burner port. The combustion device according to claim 1, which is located below the inlet. 4. A fuel supply system according to claim 1, further comprising a second nozzle having a plurality of fuel gas outlets facing the second burner inlet.
Or the combustion device according to 3. 5. The first burner forming body or the second burner forming body forms a mixing promoting means facing a mixing passage.
5. The combustion device according to any one of 4.