JP2551268B2 - Combustion device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rich / lean combustion type combustion apparatus for burning two kinds of air-fuel mixture, a lean air-fuel mixture and a rich air-fuel mixture.

[0002]

2. Description of the Related Art Among conventional combustion systems, the all-primary combustion system is an effective combustion system capable of achieving high-density combustion by shortening the flame and reducing NO _X emission. is there. However, this all-primary air combustion method has a narrow combustion range in principle and has poor flame stability. Therefore, various flame holding mechanisms have been proposed, but none of them have sufficient performance.

As a combustion method for improving such problems and achieving low NO _x , a light air-fuel mixture having a large excess air ratio and a rich air mixture having a small excess air ratio are burned to form a light air-fuel mixture flame. It is well known that a so-called rich / lean combustion method of holding with a rich mixed flame is effective, and an example of a conventional rich / lean combustion system combustion device is shown in FIG.

That is, the combustion apparatus 11 has a flame hole plate 12 provided with a large number of flame holes, and produces a main mixture chamber 13 for producing a light mixture and a rich mixture having a gas concentration higher than that of the main mixture chamber 13. A plurality of light mixture passages 15 are formed separately from the sub-mixing chamber 14 and communicate with the main mixing chamber 13 to guide the light mixture to the flame hole plate 12.
A partition 17 forms a rich mixture passage 16 that communicates with the sub-mixing chamber 14 and guides the rich mixture from around the light mixture passage 15 to the flame hole plate 12. 18 is a rich mixture passage 1
6, a speed reducer provided at 6, a straightening plate 19 and gas nozzles 20 and 21.

Therefore, the light air-fuel mixture formed in the main mixing chamber 13 forms a main flame on the flame hole plate 12, and the rich air mixture formed in the sub-mixing chamber 14 supplements flames on the flame hole plate 12. To form. Due to this supplementary flame, dark and light combustion is performed in which the main flame is held.

[0006]

Such a rich / lean combustion type combustion apparatus can be expected to have a sufficient effect in reducing NO _x and in stable combustion, but in order to stabilize the unstable main flame of combustion. It was necessary to further improve the hold function of the main flame by supplementary flame and reduce combustion noise.

The present invention has been made in view of the above problems, and an object of the present invention is to stabilize the main flame by improving the holding function of the main flame in a rich-lean combustion type combustion device. At the same time, it is to reduce the flame hole load, widen the combustion stable range, and reduce combustion noise.

[0008]

In order to achieve the above-mentioned object, a combustion apparatus of the present invention is provided with a light air-fuel mixture passage for guiding a light air-fuel mixture to a flame plate, and a rich air-fuel mixture from around the light air-fuel mixture passage. In a case where a rich mixture passage leading to a flame plate is separated and formed, a tubular portion having a light mixture passage inside and a rich mixture passage in the periphery is projected on a partition wall, and the upper end of the tubular portion and the flame plate It is configured to have a gap between and.

[0009]

[Operation] During combustion, the light air-fuel mixture supplied from the light air-fuel mixture passage to the flame hole plate forms the main flame, and the heavy air-fuel mixture supplied to the flame hole plate from the rich air-fuel mixture passage forms the supplementary flame. Since there is a gap between the upper end of the tubular part protruding from the partition wall that separates the light-air mixture passage and the rich-air mixture passage from the flame hole plate, the light-air mixture and the rich mixture are mixed near the upper end of the tubular part. The air mixes with each other to form a flame having a higher burning velocity than the supplementary flame between the supplementary flame on the flame plate and the main flame above the flame. This flame improves the hold function of the main flame, stabilizes the main flame, reduces the load on the flame hole, and reduces combustion noise.

[0010]

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a cross-sectional view of an essential part showing an embodiment of the present invention, in which a combustion device 1 has a flame hole plate 2 provided with a large number of flame holes,
A main mixing chamber 3 that creates a light air-fuel mixture with an excess air ratio of more than 1.
A plurality of sub-mixing chambers 4 for forming a rich air-fuel mixture having a gas concentration higher than that of the main mixing chamber 3 are formed separately by partition walls 5 and communicate with the main mixing chamber 3 to introduce a light air-fuel mixture to the flame hole plate 2. The light mixture channel 6 and the rich mixture passage 7 that communicates with the sub-mixing chamber 4 and guides the rich mixture from the periphery of the light mixture passage 6 to the flame hole plate 2 are formed by the tubular portion 8 protruding from the partition wall 5. Has been formed. The upper end of the tubular portion 8 is provided so as to have a gap 9 of about 0.1 mm to 3 mm with the flame hole plate 2. Reference numeral 10 is a speed reducing means provided in the rich mixture passage 7.

Therefore, the light air-fuel mixture formed in the main mixing chamber 3 forms a main flame on the flame hole plate 2, and the rich air mixture formed in the sub-mixing chamber 4 supplements flames on the flame hole plate 2. To form. As the supplementary flame, dark and light combustion is performed in which the main flame is held and burned stably.

At this time, since the gap 9 is provided between the upper end of the tubular portion 8 which separates the light-air mixture passage 6 and the rich-air mixture passage 7 from each other and the flame hole plate 2, the light-air mixture and the rich mixture are mixed. Mixing is performed in the vicinity of the gap 9 at the upper end of the tubular portion 8 in contact with air, and this mixed flame is formed between the main flame and the supplementary flame on the flame hole plate 2. This flame becomes a flame having a higher burning speed than the supplementary flame, improves the hold function of the main flame, makes the flame between the main flame and the supplementary flame continuous, and improves the area efficiency of the flame hole plate 2, Hole load can be reduced. Therefore, the combustion noise can be reduced by improving the stabilization of the main flame and reducing the flame hole load.

[0013]

As described above, according to the combustion apparatus of the present invention, since the gap is provided between the upper end of the tubular portion that separates and forms the lean mixture passage and the rich mixture passage from the flame hole plate, In the vicinity of the upper end of the part, the light air-fuel mixture and the rich air-fuel mixture are mixed, and on the flame hole plate above the upper end of the tubular part, a mixed flame having a higher combustion speed than the supplementary flame is formed to continue the main flame and the supplementary flame, It is possible to improve the hold function of the main flame to stabilize the main flame, reduce the load on the flame hole, and reduce the combustion noise.

[Brief description of drawings]

FIG. 1 is a sectional view of an essential part showing an embodiment of the present invention.

FIG. 2 is a schematic configuration diagram of a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Combustion device 2 Flame hole plate 5 Partition wall 6 Light mixture passage 7 Rich mixture passage 8 Tubular part 9 Gap

Claims (1)

(57) [Claims] 1. A structure in which a partition wall separates and forms a light air-fuel mixture passage that guides a light air-fuel mixture to a flame hole plate and a rich air-fuel mixture passage that guides a rich air-fuel mixture from around the light air-fuel mixture passage to a flame hole plate. A combustion device characterized in that a tubular portion having a light mixture passage inside and a rich mixture passage around the partition is provided in a protruding manner, and a gap is provided between the upper end of the tubular portion and the flame hole plate.