JPH0225084B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a combustion device, and particularly to a combustion device such as a boiler device suitable for reducing soot and nitrogen oxides in exhaust gas.

Conventionally, in large boiler systems with multi-stage multi-burners, the fuel injection direction of the burner is divided into two or three directions in order to reduce the production of nitrogen oxides (hereinafter referred to as _NOx ). It is.

However, the conventional technique described above has the disadvantage that it is necessary to increase the distance between the burners in each stage, resulting in an increase in the height of the boiler. In addition, due to the interference between adjacent flames, the flame length is extended because oxygen is not diffused in the interference area, and this causes soot to escape into the gas phase within the flame, resulting in the growth of soot particles. be. When the soot particles become large in this way, the time for oxidation by air increases, and complete combustion within the furnace is not possible, resulting in an increase in the generation of soot and dust.

The purpose of the present invention is to eliminate the above-mentioned drawbacks of the prior art and to avoid increasing soot and dust in exhaust gas.
The object of the present invention is to provide a small and compact combustion device that can reduce _NOx .

The present invention uses a plurality of divided nozzles in a combustion apparatus equipped with multi-burners in multiple stages and in multiple rows to prevent adjacent burner flames from interfering with each other.
The present invention is characterized in that the fuel injection directions of adjacent burner nozzles are made to be different in the vertical and horizontal directions.

Hereinafter, the present invention will be explained in more detail with reference to the drawings. FIG. 1 is a cross-sectional view of a boiler device having multi-burners in multiple stages and rows, and FIG. 2 is a view taken from A in FIG. 1. Fuel and combustion air (including a portion of exhaust gas as the case may be) are supplied into the furnace 1 from the first-stage burner 3, second-stage burner 4, third-stage burner 5, and fourth-stage burner 6, and are combusted. A pre-can air port 7 and a post-can air port 8 are provided in the upper part of each stage burner to perform secondary combustion. A hopper port 2 is provided at the bottom of the furnace 1, and a part of the combustion ash and soot can be extracted to adjust the amount of steam produced and the steam temperature. The burned gas is transferred to the heater 9
Heat is absorbed by the subsequent heat exchanger.

FIG. 3 is an enlarged front view of the fuel nozzle of the burner shown in the previous figure, in which fuel nozzle A11, fuel nozzle B12, and fuel nozzle C13 are provided at the top, while fuel nozzle D14, fuel nozzle E15 , a fuel injection port F16 is provided at the bottom. As shown in the figure, this fuel nozzle 10 injects fuel macroscopically in two directions, up and down. That is, FIG. 4 shows a side view of the fuel nozzle 10 shown in FIG.
The fuel from the fuel nozzle 13 is injected, and the fuel nozzle D14 and the fuel nozzle E are injected in the lower injection direction 18.
15 and fuel from fuel injection port F16 is injected. In the upper and lower injection directions 17, 18,
As shown in the figure, the injection angle α is set at a certain level or more so that the injection angles do not interfere with each other.

FIG. 5 shows the arrangement and fuel injection direction of a multi-burner according to the present invention in which flame interference is prevented using the above-mentioned two-split fuel nozzle. As is clear from the figure, the directions of the burner nozzles are set so that the fuel injection directions of adjacent burners on the upper, lower, left, and right sides are different from each other, and the burner nozzles are arranged to avoid interference of the injected fuel. For example, if the injection directions of the burner nozzles are set as upper injection direction 17 and lower injection direction 18 for a certain burner, the injection directions for adjacent burners are determined as left injection direction 19 and right injection direction 20. Ru.

According to the above embodiment, by arranging the two-split fuel nozzle so that the fuel injection directions of adjacent burner nozzles are all different, interference of fuel injection or flame between adjacent burners is avoided, and generation of soot and dust is reduced. Also, when performing denitrification combustion, each burner can fully demonstrate its function.
This enables even lower _NOx combustion. Furthermore, by providing an angle in the fuel injection direction, a space necessary for combustion can be secured even if the furnace is small, and therefore, for example, the height of the boiler can be made lower than before.

In the above embodiments, two-split fuel injection will be explained to simplify the explanation, but the present invention is similarly applicable to multi-split fuel nozzles such as three-split and four-split fuel nozzles. Although three fuel injection ports are provided for one injection direction in FIGS. 3 and 4, there is no particular limitation in the present invention, and the number may be one or more.

Note that the fuel used in the present invention is not limited to liquid fuel such as oil, but may also be fuel such as gas or pulverized coal.

As described above, according to the present invention, flame interference between adjacent burners is eliminated, so the generation of soot and dust can be reduced, and each burner can be further reduced.
Since O ₂ combustion is possible, the generation of NO _X can be reduced. Furthermore, since the distance between adjacent burners can be reduced, a small and compact combustion device can be achieved.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a boiler device having multi-stage and multi-row multi-burners, FIG. 2 is a view from A in FIG. 1,
FIG. 3 is a front view showing an embodiment of the fuel nozzle used in the present invention, FIG. 4 is a side view thereof, and FIG.
FIG. 2 is an explanatory diagram corresponding to a view A showing the burner arrangement and fuel injection direction of the boiler device having a multi-burner according to the present invention. 1...Boiler furnace, 3...1st stage burner, 4...
...Second stage burner, 5...Third stage burner, 6...Fourth stage burner, 7...Air port before can, 8...Air port after can, 10...Fuel nozzle, 11-13...Top Fuel injection port, 14-16...Lower fuel injection port, 17
...Top injection direction, 18...Bottom injection direction, 19
...Left injection direction, 20...Right injection direction.

Claims (1)

[Claims] 1 In a combustion device equipped with multi-burners in multiple stages and rows, a nozzle divided into multiple parts is used, and the fuel injection directions of adjacent burner nozzles are set to be different vertically and horizontally to prevent interference between adjacent burner flames. A combustion device characterized by: