JPH07208707A - Thick and thin fuel concentration combustion device - Google Patents

Abstract

PURPOSE:To reduce combustion sound and generating amount of NOx by a method wherein both sides injection ports, opposed to the same mixing chamber far thin fuel concentration combustion, are arranged so as to be positioned at different positions in lengthwise direction. CONSTITUTION:Fuel gas is supplied to a thin gas introducing passage 16 to inject and supply fuel gas or mixture into a thin fuel concentration combustion mixing chamber 11 while combustion air is supplied into a thin fuel concentration combustion unit 6 in parallel whereby thin mixture is mixed and produced, then, the thin mixture is discharged out of a burner for thin fuel concentration combustion (thin combustion unit) 6. In the mixing chamber 11 for thin fuel concentration combustion, fuel gas or mixture is injected and supplied from different positions in the lengthwise direction of flame port 10 for thin combustion at both sides of the mixing chamber 11 for thin combustion through both sides injection ports 18 respectively. Accordingly, the number of positions in the lengthwise direction, whereat the fuel gas or the mixture is injected into the thin fuel concentration combustion mixing chamber 11, is increased whereby the variability of concentration of the thin mixture, mixed and produced in the mixing chamber 11, is reduced. According to this method, combustion sound and generating amount of NOx can be reduced.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flat cylinder-shaped dense combustion portion having a rich flame port for burning a rich mixture formed on one end surface thereof, and a plurality of dense combustion portions are arranged side by side with each other to form a lean mixture. A light-mixing chamber is provided with an end face on the same side as the rich flame port for burning, and a light-mixing chamber communicating with the light-burning port, and a thin air introducing combustion air into the light-mixing chamber. A flat cylinder-shaped light combustion section provided with a fuel introduction port is formed between adjacent rich combustion sections with the rich combustion section as a constituent member, and the fuel gas or the air-fuel mixture for producing the light air-fuel mixture is formed. A fuel gas or a mixture is provided in which a light gas passage for conduction is provided so as to overlap with the rich combustion section when viewed from the mixture flame discharge direction from the rich flame port, and is guided by the gas passage for fresh gas. A plurality of jet ports for jetting air are provided separately for the fuel gas or the fuel gas for the light mixing chambers on both sides adjacent to the light gas communicating passage. In a state of ejecting aeration, is formed in the light-gas connecting passage dispersed in the longitudinal direction of the light-burning flame port, and a light-gas supplying means for supplying a fuel gas to the light-gas connecting passage, The present invention relates to a rich / lean combustion device provided with air supply means for supplying combustion air to the light / light introduction port.

[0002]

2. Description of the Related Art Such a rich-lean combustion device stabilizes a large amount of lean mixture discharged from the lean-flame port by the flame holding action of a rich flame formed by stable combustion of the rich mixture at the rich-flame port. By burning and lowering the combustion temperature, the amount of NOx (nitrogen oxide) generated is reduced as much as possible.
In such a rich / lean combustion device, conventionally, as shown in FIGS. 8 and 9, the ejection ports 18 on both sides corresponding to the same lean mixing chamber 11 are located at the same position in the longitudinal direction of the lean flame port 10. Was arranged like. In other words, the ejection ports 18 of the light gas communication passages 16 on both sides of the light mixing chamber 11 are arranged so as to face each other.

[0003]

In the above-mentioned prior art, the fuel gas or the air-fuel mixture is jetted into the light-mixing chamber in such a manner as to face each other from the ejection ports on both sides of the light-air mixing chamber. Becomes thicker near the jet, while
Since it becomes thinner in the portion corresponding to between the ejection ports in the longitudinal direction, the variation in the concentration of the light air-fuel mixture in the longitudinal direction becomes large. Therefore, since the combustion state of the light air-fuel mixture becomes unstable, the vibration of the light flame formed by combustion of the light air-fuel mixture, and due to the resonance of the device components accompanying the vibration of the light flame, etc. There is a problem that the combustion noise becomes loud. Further, the combustion temperature of the light mixture having a high concentration becomes high, and as a result, the combustion temperature of the entire light mixture becomes high, so that there is still room for improvement in terms of reducing the amount of NOx produced.

The present invention has been made in view of the above circumstances, and an object thereof is to reduce combustion noise and
It is to further reduce the amount of NOx generated.

[0005]

A first characteristic structure of a rich / lean combustion device according to the present invention is such that the jet outlets on both sides corresponding to the same lean mixing chamber are located at different positions in the longitudinal direction. It is located at the point.

A second characteristic configuration is that the rich combustion section has a rich mixing chamber communicating with the rich flame port and a rich introducing port for introducing fuel gas and combustion air into the rich mixing chamber. A rich gas supply means for supplying fuel gas to the rich inlet, the air supply means is configured to supply combustion air to the rich inlet, and the light gas A conduction path is formed in the rich combustion section in a state of being partitioned from the rich mixing chamber.

[0007]

The operation of the first characteristic configuration is as follows. By supplying the fuel gas to the fresh gas supply passage by the fresh gas supply means, the conductive fuel gas or the air-fuel mixture in the fresh gas supply passage is jetted and supplied from the jet outlet to the light mixing chamber. In parallel with this, by supplying combustion air to the light introduction port of the light combustion section by the air supply means, a light air-fuel mixture is generated in the light-air mixing chamber, and this light air-fuel mixture is supplied to the light air burner. Discharge from the light flame port. In the light mixing chamber, the fuel gas or the air-fuel mixture is jetted and supplied from different positions in the longitudinal direction of the light flame port on both sides of the light mixing chamber by the jet ports on both sides. Therefore, since the fuel gas or the air-fuel mixture is jetted to more positions in the longitudinal direction with respect to the light-mixing chamber, there is a variation in the concentration of the light-air mixture mixed and produced in the light-mixing chamber in the longitudinal direction. Becomes smaller.

FIG. 5 shows the measurement result of the concentration variation of the light air-fuel mixture in the longitudinal direction, and the solid line shows the measurement result of the concentration variation of the rich / lean combustion device according to the present invention. The result of measurement of the variation is shown by a broken line. According to the present invention,
It can be seen that the variation in the concentration of the light air-fuel mixture in the longitudinal direction is small. Incidentally, in FIG. 5, P is plotted on the horizontal axis.
Each position indicated by ₁ corresponds to the formation position of the jet port on one side in the present invention, and each position indicated by P ₂ corresponds to the formation position of the jet port on the other side in the present invention, indicated by P ₃ . Each position corresponds to the formation position of the ejection port in the prior art.
That is, at the position corresponding to P ₃ , two jet nozzles are arranged facing each other.

The operation of the second characteristic configuration is as follows. Regarding the generation of the rich mixture, the rich gas supply means and the air supply means supply the fuel gas and the combustion air to the rich introduction port to thereby generate the rich mixture in the rich mixing chamber of the rich combustion section. Are mixed and produced, and this rich air-fuel mixture is discharged from the rich flame port of the rich combustion section.

On the other hand, for the production of the lean mixture, a lean gas supply means different from the rich gas supply means is provided to the lean gas conduit formed in the rich combustion section, which is separated from the rich mixing chamber. By supplying the fuel gas by means of this, the conduction fuel gas or the air-fuel mixture in the light-gas communicating passage is jetted and supplied from the jet outlet to the light-mixing chamber, and in parallel with this, the air-supplying means of the light-burning section is used. By supplying combustion air to the light intake port, a light air-fuel mixture is mixed and produced in the light-air mixing chamber, and the light air-fuel mixture is discharged from the light-air flame port of the light-burner burner.

Therefore, the fuel gas supply amounts by the rich gas supply means and the light gas supply means can be appropriately adjusted so that the combustion in each of the rich combustion portion and the light combustion portion is favorably maintained. it can.

Further, although it is assumed that the rich combustion section and the light gas communication path are formed separately, they can be formed at the same time by forming them integrally, for example, by molding a sheet metal or the like. Since it can be manufactured, it can be easily manufactured as compared with the case where it is formed separately. Further, since a plurality of rich combustion sections are arranged in parallel, and at the same time when the lean combustion gas passage is provided in a state overlapping with the rich combustion section when viewed from the direction of the air-fuel mixture discharge from the rich flame port, the lean gas passage can be provided. The combustion device can be easily assembled.

[0013]

According to the first characteristic configuration, the variation in the concentration of the light air-fuel mixture in the longitudinal direction of the light-burning flame port is reduced and the combustion state of the light air-fuel mixture is stabilized, so that the combustion noise is higher than in the conventional case. Can be made smaller. Further, since the combustion temperature of the whole light air-fuel mixture is further lowered, it is possible to reduce the NOx generation amount as compared with the conventional case.

Further, according to the second characteristic configuration, the combustion state of the rich air-fuel mixture and the light air-fuel mixture is more stable, and as a result, the rich-lean combustion is more stable, so that the combustion noise can be further reduced. It became so. Also, the manufacturing cost can be reduced.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments will be described below with reference to the drawings. First, FIGS. 1 to 4 show a rich / lean combustion device as a burner unit used in a hot water supply device or the like.

Inside the box-shaped frame body 2 installed in the burner case 1, a large number of flat burners 3 for rich combustion, which are dense combustion sections, are arranged in parallel at a predetermined interval, and below the box-shaped frame body 2 the burner case 1 is provided.
An air chamber 5 in which a discharge port 4a of a combustion air supply fan 4 is opened is formed as an air supply means at the bottom of the.

Further, by arranging the flat burners 3 for rich combustion at predetermined intervals as described above, the burner 6 for lean combustion as a light burn portion is provided between the burners 3 for adjacent rich combustion.
As described above, the rich combustion burner 3 is used as a burner constituent member in this way to form the light combustion burner 6 located between the adjacent rich combustion burners 3 to thereby complete the entire apparatus. The configuration is simplified.

The rich combustion burner 3 discharges a rich air-fuel mixture having a small primary air ratio, a rich upper flame port 7, a rich mixing chamber 8 communicating with the rich upper flame port 7, and the rich air chamber. A rich side inlet 9 for introducing combustion air for producing a rich mixture and fuel gas is formed in the mixing chamber 8. On the other hand, for a lean combustion formed between the rich burners 3 Burner 6
An upper light burner outlet 10 for discharging a light air fuel mixture having a large primary air ratio, and a lighter mixing chamber 1 communicating with the upper light burn outlet 10 for light use.
1 and a lower light introducing port 12 for introducing combustion air into the light mixing chamber 11, and the air adjusting lower chamber forming the bottom wall of the box-shaped frame 2 is provided to the light lower introducing port 12. Combustion air is supplied upward from the air chamber 5 through the perforated plate 13.

The light gas passage 16 for introducing the air-fuel mixture for producing the air-fuel mixture, and the light side inlet 17 for introducing the fuel gas and the combustion air into the light gas passage 16 are provided as described above. Each of the combustions is separated from the rich mixing chamber 8 and the thick side inlet 9 and overlaps with the rich combustion burner 3 when viewed from the direction of the air-fuel mixture discharge from the upper upper flame mouth 7. It is formed integrally with the burner 3 for use. A plurality of ejection ports 18 for ejecting the fuel gas or the air-fuel mixture guided by the light gas passage 16 are separately ejected to the air mixture chambers 11 on both sides adjacent to the light gas passage 16. In this state, they are distributed and arranged in the longitudinal direction of the lightening flame port 10 to form the lightening gas passage 16.

Further, regarding the plurality of jet outlets 18 dispersedly arranged in the longitudinal direction, the jet outlets 18 on both sides corresponding to the same light mixing chamber 11 are arranged at different positions in the longitudinal direction. I am doing it. To further describe, the ejection ports 18 on the other side are positioned at positions corresponding to the centers in the longitudinal direction of the ejection ports 18 on the one side of the light mixing chamber 11, that is, on both sides in a top view. The spouts 18 are arranged in a staggered manner.

Reference numeral 14 in the figure denotes a rich gas supply means for individually injecting the fuel gas supplied from the rich gas supply passage 15 into the rich side inlets 9 of the rich combustion burners 3 individually. This is a rich gas nozzle, and this rich gas nozzle 14
The combustion air introduced from the air chamber 5 is sucked into the rich side introduction port 9 at a predetermined ratio by the ejector action as the fuel gas is blown into the rich mixing chamber 8 through the rich mixing chamber 8. The air is mixed and generated, and the rich air-fuel mixture is discharged from the thickening upper flame port 7.

Further, the lean gas nozzle 20 as a lean gas supply means for individually blowing and supplying the fuel gas supplied from the lean gas supply passage 19 to the lean side inlets 17 of the lean burners 6 respectively. Is provided. That is, for the light mixture, the light gas nozzle 20 to the light side inlet 17
When the fuel gas is blown into the air, the combustion air introduced from the air chamber 5 is sucked into the lean side inlet 17 at a predetermined ratio by the ejector action, and the mixture of the blown fuel gas and the sucked air is leaned. The above-described generation in the light gas passage 16 is performed in the light gas passage 16 by premixing in the light gas passage 16 and to the light mixing chamber 11 to which combustion air is ventilated from the lower light lower inlet 12. By injecting the air-fuel mixture in a dispersed state from the plurality of ejection ports 18, a light-air mixture having a uniform mixing state is mixed and generated in the light-air mixing chamber 11, and the light-air mixture is discharged from the light-air upper flame outlet 10. It is as a configuration. Since the ejection ports 18 on both sides corresponding to the same light mixing chamber 11 are arranged at different positions in the longitudinal direction, as shown by the solid line in FIG. The variation in the concentration of the light air-fuel mixture is small.

Regarding the combustion mode of the rich-lean burner, by burning the rich air-fuel mixture, which has a small primary air ratio and enables stable independent combustion, at the above-mentioned rich upper flame port 7, the adjacent lean-burn mixture is burned. The light air-fuel mixture having a large primary air ratio discharged from the upper flame outlet 10 for combustion is stably and continuously burned by the flame holding action of the rich air-fuel mixture combustion flame.
It is intended to reduce the generation of x.

Each of the rich gas supply path 15 and the light gas supply path 19 has both gas supply paths 15 and 1.
The individual gas amount adjustment valves V1 and V2 for individually adjusting the fuel gas supply amount of No. 6 are provided, and both gas supply passages 15,
The main gas supply path 21 on the upstream side of the branch point of 19 is provided with a main gas amount adjusting valve V3 for adjusting the total amount of the supplied fuel gas, and the main gas supply amount of the fuel gas supply amount of the rich-lean combustion device is adjusted. The adjustment (in other words, the input adjustment of the entire device) is basically performed by the main gas amount adjusting valve V3, while the combustion in the rich burner 3 and the light burner 6 is favorably performed. Adjusting the fuel gas ratio on the rich burn side and the lean burn side so that it is maintained (ie,
(Adjusting the fuel gas ejection amount ratio between the rich gas nozzle 14 and the light gas nozzle 20) is performed by both gas supply paths 15 and 19.
The individual gas amount adjusting valves V1 and V2 are used.

[Other Embodiments] Next, other embodiments will be listed.

The arrangement form in which the ejection ports 18 on both sides of the light mixing chamber 11 are dispersed in the longitudinal direction can be variously changed. In the above-described embodiment, the ejection ports 18 on one side are arranged so that the ejection ports 18 on the other side are located at positions corresponding to the centers in the longitudinal direction of the ejection ports 18 on one side. Then, the jet outlets 18 on the other side may be arranged at positions corresponding to the positions displaced from the center in the longitudinal direction between the jet outlets 18 on the one side of the light mixing chamber 11. Further, in the above-mentioned embodiment, the light-mixing chamber 11 is arranged such that one jetting port 18 on the other side exists between the jetting ports 18 on one side. It may be arranged such that two or more jet outlets 18 on the other side exist between the jet outlets 18 on one side of the chamber 11.

In the above-described embodiment, although the lean gas passage 16 is formed in the rich burner 3 below the rich mixing chamber 8, the lean gas passage 16 in the rich burner 3 is formed. The formation position can be variously changed, and for example, as shown in FIG. 6, the structure may be such that the light gas communication passage 16 is formed between the lower portion 8a and the upper portion 8b of the concentration mixing chamber 8.

In the above-described embodiment, the light gas passage 16 is formed integrally with each rich combustion burner 3 in a state of being partitioned from the rich mixing chamber 8 and the rich side inlet 9. However, instead of this, as shown in FIG. 7, the gas mixture passage 16 for light is not separated from the mixing chamber 8 for concentration and the side inlet 9 for concentration, and the mixing chamber 8 for concentration is lightened. The structure may be such that it also functions as the working gas passage 16.

In the above-described embodiment, the combustion gas is supplied to the fresh gas passage 16 together with the fuel gas so that the fresh gas passage 16 functions as a premixed gas mixture passage. However, instead of this, the light gas supply means may be configured to supply only the fuel gas to the light gas communication passage 16.

It should be noted that reference numerals are given in the claims for convenience of comparison with the drawings, but the present invention is not limited to the structures of the accompanying drawings by the entry.

[Brief description of drawings]

FIG. 1 is an enlarged sectional view of a right side view showing an embodiment.

FIG. 2 is an enlarged sectional view of a front view showing an embodiment.

FIG. 3 is a cutaway perspective view showing an embodiment.

FIG. 4 is a view on arrow I-I in FIG.

FIG. 5 is a diagram showing variations in the concentration of the light air-fuel mixture in the longitudinal direction of the lightening flame port.

FIG. 6 is an enlarged front sectional view showing another embodiment.

FIG. 7 is an enlarged sectional view of a right side view showing another embodiment.

FIG. 8 is a right side enlarged cross-sectional view showing a conventional example.

9 is a view taken along the line II-II in FIG.

[Explanation of symbols]

 3 Thick Combustion Section 4,5 Air Supply Means 6 Light Combustion Section 7 Thick Flame Port 8 Thick Mixing Chamber 9 Thick Inlet 10 Light Lean Mouth 11 Light Mixing Chamber 12 Thick Inlet 14 Thick Gas Supply Means 16 Light Gas Passage 18 Gas Jet 20 Light Gas Supply Means

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shinobu Ishihara 1-152 Oka, Minami-shi, Minato-ku, Osaka City, Osaka Prefecture Harman Co., Ltd.

Claims (2)

[Claims] 1. A plurality of flat cylinder-shaped rich combustion portions (3), each having a rich flame port (7) for burning a rich air-fuel mixture formed on one end surface thereof, are arranged in parallel with each other with a space therebetween. A light mixing chamber (11) provided with a burning light flame port (10) on the same end surface as the rich flame port (7) and communicating with the light flame port (10); and A light introduction port (1) for introducing combustion air into the light mixing chamber (11)
2) is provided between the adjacent rich combustion portions 3 with the rich combustion portion 3 as a constituent member to form a lean mixture. The lean gas passage (16) through which the fuel gas or the air-fuel mixture for electricity flows is overlapped with the rich combustion section (3) as seen in the direction of the air-fuel mixture discharge from the rich flame port (7). And a plurality of jet ports (18) for ejecting the fuel gas or the air-fuel mixture guided by the fresh gas passage (16) are provided on both sides of the fresh gas passage (16). The fuel gas or the air-fuel mixture is separately ejected to the chamber (11), the fuel gas or the air-fuel mixture is dispersed in the longitudinal direction of the fresh flame port (10) and is formed in the fresh gas communication passage (16); A light gas supply means (20) for supplying a fuel gas to the light gas passage (16), and the light introduction port (12). A rich / lean combustion device provided with air supply means (4,5) for supplying combustion air to the same, wherein the jet outlets (18) on both sides corresponding to the same lean mixing chamber (11), The rich / lean combustion device arranged so as to be located at a different position in the longitudinal direction. 2. A rich mixing chamber (8) communicating with the rich flame port (7) in the rich combustion section (3), and fuel gas and combustion air in the rich mixing chamber (8). A rich inlet (9) for introduction is formed, a rich gas supply means (14) for supplying a fuel gas to the rich inlet (9) is provided, and the air supply means (4, 5) are The rich combustion part (9) is configured to supply combustion air to the rich inlet (9), and the light gas communication passage (16) is partitioned from the rich mixing chamber (8). The thick and thin combustion device according to claim 1, which is formed in 3).