JPH062808A - Slag tap type coal combustion unit - Google Patents

Abstract

PURPOSE:To perform a substantial complete removal of slag from combustion gas. CONSTITUTION:A plurality of feeding holes 3 in which coal and primary air 1 are fed into a vertical primary combustion chamber 2 in a tangential direction are arranged at the upper part of a wall 4 of the primary combustion chamber and combustion gas 5 swirls and flows downward. A cyclone inner cylinder 16 communicating with a secondary combustion chamber 7 is arranged at the upper part within the primary combustion chamber 2 and at the same time its lower part 17 is expanded in a tapered form, thereby combustion gas flowing in a downward swirled direction is directed to strike against the side wall 4 by the tapered expanded part 17 as indicated by a symbol 5a, reversed as indicated by a symbol 5b and then the combustion gas is flowed into the cyclone inner cylinder 16 of high temperature.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a slag tap type coal combustor used in a coal-fired gas turbine power plant or MHD (magnetic fluid) power plant.

[0002]

2. Description of the Related Art A slag tap type coal combustor is also called a slagging type coal gasifier, and there are conventional slag tap type coal gasifiers as shown in FIGS. 5 to 7, and FIG. The cross-sectional views, and FIGS. 6 and 7 are VI of FIG.
It is sectional drawing which follows the -VI line and the VII-VII line.

In FIG. 5, a plurality of (four in this example) charging holes 3 for charging coal and primary air 1 in a vertical type primary combustion chamber 2 in a tangential direction as shown in FIG. Conventionally, it is provided below the side wall 4 of the primary combustion chamber 2. Therefore, the combustion gas 5 generated by coal and the primary air 1 tangentially injected into the primary combustion chamber 2 through these injection holes 3 flows upward in the primary combustion chamber 2 while swirling upward, and the centrifugal force thereof is generated. The slag 6 is separated from the slag 6 and then flows into the secondary combustion chamber 7 provided on the top of the primary combustion chamber 2, and as shown in FIG. Secondary combustion is carried out with the secondary air 9 introduced from the above, and then it is supplied from the exhaust port 10 to a gas turbine, an MHD generator or the like not shown. On the other hand, the slag 6 separated from the combustion gas 5 falls into the water 14 in the sump 13 from the slag tap hole 12 provided in the bottom portion 11 of the primary combustion chamber 2 and is rapidly cooled to form fine particles. After that, it accumulates at the bottom of the sump 13 and is then taken out through the outlet 15 as appropriate.

[0004]

The conventional slag tap type coal combustor described above has the following problems. (1) Since the combustion gas 5 generated by the coal and the primary air 1 charged into the primary combustion chamber 2 is rising as an upward swirling flow, the inner surface of the side wall 4 of the primary combustion chamber 2 is formed into a liquid film. It is possible to prevent gravity from flowing down the slag 6. (2) When the slag 6 flows downward along the inner surface of the side wall 4 of the primary combustion chamber 2, the jet flow of coal and the primary air 1 injected from the lower part of the side wall 4 of the primary combustion chamber 2 At the wall, the falling film is cut and scattered in the primary combustion chamber 2. (3) Since the combustion gas 5 of coal and the primary air 1 is always an upward flow, the centrifugal force action is small for the slag 6'having a small particle size and riding on the gas flow in the primary combustion chamber 2 Gravitational separation is not sufficient.

Due to these three causes, the slag removal rate in the conventional slag tap type coal combustion chamber is 8%.
It remains around 0 to 90%, and for the coal-fired gas turbine power generation, it is necessary to specially install a slag removing device on the downstream side of the coal combustor to remove the slag from the combustion gas again. there were.

[0006] The present invention has been made to solve the problems of the prior art, and is a slag tap type coal combustor capable of almost completely removing slag from the combustion gas of coal and primary air. The purpose is to provide.

[0007]

In order to solve the above problems, the present invention provides a slag tap type coal combustor having a vertical primary combustion chamber, in which coal and primary air are fed into the primary combustion chamber. A plurality of injection holes for tangential injection are provided in the upper side wall of the primary combustion chamber, and a high temperature cyclone inner cylinder connected to the secondary combustion chamber provided on the top of the primary combustion chamber is used for primary combustion. It is provided in the upper part of the room, and the lower part of the high temperature cyclone inner cylinder is enlarged in a tapered shape.

[0008]

According to the above-mentioned means, the coal and the primary air are tangentially injected into the primary combustion chamber from the upper portion of the side wall thereof, and the combustion gas is generated between the sidewall of the primary combustion chamber and the high temperature cyclone inner cylinder. While swirling downward, which facilitates the flow of slag along the inner surface of the side wall of the primary combustion chamber,
Cutting down slag with coal and primary air jet stream,
Scattering is prevented.

The combustion gas that swirls downwards then flows so as to collide with the side wall of the primary combustion chamber by the taper expansion portion at the lower portion of the high temperature cyclone inner cylinder.
Collision separation of slag is performed. After that, the combustion gas is reversed and flows into the high temperature cyclone inner cylinder and flows into the secondary combustion chamber. By the reversal, a cross section with a zero flow velocity is formed, and gravity separation of the slag is sufficiently performed, and a small particle size is obtained. Since the slag of is also reliably removed, the slag is almost completely removed from the combustion gas.

[0010]

Embodiments of the present invention will be described in detail below with reference to FIGS. FIG. 1 is a sectional view showing an embodiment of a slag tap type coal combustor according to the present invention, FIG. 2 and FIG.
And FIG. 4 are respectively the lines II-II of FIG. III-II
It is sectional drawing which follows the I line and the IV-IV line, and is FIGS.
The same parts as those shown in are denoted by the same reference numerals, and overlapping description will be omitted.

1 to 4, a plurality of (4 in this example) charging holes 3 for charging coal and primary air 1 into a vertical type primary combustor 2 in a tangential direction are different from the conventional ones. If the primary combustion chamber 2
Although it was provided at the lower portion of the side wall 4 of the primary combustion chamber 2 (see FIG. 5), it is provided at the upper portion of the sidewall 4 of the primary combustion chamber 2 according to the present invention. Further, according to the present invention, the high temperature cyclone inner cylinder 16 connected to the secondary combustion chamber 7 provided on the top of the primary combustion chamber 2 is provided at the upper portion of the primary combustion chamber 2 as well. The lower portion 17 of the high temperature cyclone inner cylinder 16 is enlarged in a tapered shape.

According to this structure, the coal and the primary air 1 are introduced into the primary combustion chamber 2 from the upper portion of the side wall 4 in the tangential direction, and the combustion gas 5 thereof is the side wall of the primary combustion chamber 2. 4 and the high temperature cyclone inner cylinder 16 while swirling downward, which promotes the flow down of the slag 6 along the inner surface of the side wall 4 of the primary combustion chamber 2 and the coal and the primary air 1
The falling slag 6 is prevented from being cut and scattered by the jet flow of.

The combustion gas 5 swirling downwardly then collides with the side wall 4 of the primary combustion chamber 2 by the taper expanding portion 17 at the lower part of the high temperature cyclone inner cylinder 16 as indicated by reference numeral 5a. And the collision separation of the slag 6 is performed. After that, the combustion gas 5 is inverted as shown by the reference numeral 5b, flows into the high temperature cyclone inner cylinder 16 and flows into the secondary combustion chamber 7 as shown by the reference numeral 5c. As a result, the slag 6 is sufficiently separated by gravity, and the slag 6'having a small particle size is also surely removed, so that the slag 6 is almost completely removed from the combustion gas 5,
As a result, the combustion gas from which slag has been removed by almost 100% (which can be referred to as slag-free combustion gas because there is almost no slag) becomes 5d, and the secondary combustion chamber 7
From the exhaust port 10 of the gas turbine or MHD (not shown)
It is supplied to generators.

The high-temperature cyclone cylinder 16 includes, for example, a pipe 19 for introducing a combustor and cyclone inner cylinder cooling water 18.
Can be formed into a coil shape and the surface thereof can be covered with a heat insulating material.

[0015]

As described above, according to the present invention, in a slag tap type coal combustor having a vertical type primary combustion chamber, the injection holes for coal and primary air are provided on the upper side wall of the primary combustion chamber. And a high temperature cyclone inner cylinder is provided in the upper part of the primary combustion chamber to generate a downward swirling flow in a direction that promotes the downward flow of the slag flowing downward in the form of a film on the side wall of the primary combustion chamber. , It is possible to prevent cutting and scattering of the falling slag generated by the injection flow of coal and primary air at the lower part of the side wall of the primary combustion chamber due to the jet flow of coal and primary air. . Then, by reversing the combustion gas generated by installing the high temperature cyclone inner cylinder, it is possible to gravity separate the small particle size slag in the combustion gas at the zero flow velocity cross section, and further the combustion gas is increased by the taper expansion part at the lower part of the high temperature cyclone inner cylinder. It is possible to separate the slag by collision with the side wall of the combustion chamber, and it is possible to achieve a slag removal rate close to 100% as a whole.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a slag tap type coal combustor according to the present invention.

FIG. 2 is a sectional view taken along line II-II of FIG.

FIG. 3 is a sectional view taken along line III-III in FIG.

FIG. 4 is a sectional view taken along line IV-IV in FIG.

FIG. 5 is a cross-sectional view showing a conventional slag tap type coal combustor.

6 is a sectional view taken along line VI-VI of FIG.

7 is a sectional view taken along line VII-VII in FIG.

[Explanation of symbols]

 1 Coal and primary air 2 Primary combustion chamber 3 Input hole 4 Side wall 5 Combustion gas 6 Slag 7 Secondary combustion chamber 8 Input hole 9 Secondary air 10 Discharge port 11 Bottom 12 Slag tap hole 13 Sump 14 Water 15 Slag removal Outlet 16 High temperature cyclone inner cylinder 17 Taper expansion part 18 Cooling water 19 Pipe

Claims (1)

[Claims] 1. A slag tap type coal combustor having a vertical type primary combustion chamber, wherein a plurality of injection holes for introducing coal and primary air into the primary combustion chamber in a tangential direction are provided in the primary combustion chamber. A high temperature cyclone inner cylinder connected to the secondary combustion chamber provided on the upper portion of the side wall and on the top of the primary combustion chamber is provided on the upper portion of the primary combustion chamber, and the lower portion of the high temperature cyclone inner cylinder is tapered. A slag tap type coal combustor characterized by being expanded to.