JPS6358006A - Cyclone type combustor - Google Patents

Abstract

PURPOSE:To prevent the entrainment of slag caused by the revolving stream of combustion gas in the axial direction, separate and extract sufficiently the slag in the combustion gas, and prevent the generation of a revolving stream by a method wherein a communicating tube penetrating into the primary stage combustor is allowed to project to a proper depth and installed. CONSTITUTION:At the central part of a ceiling wall 18 in the primary stage combustor 16 a cylindrical communicating tube 19 is installed and its lower end is allowed to project to a proper depth inside the combustor 16. Further, at a wall 20 an air port 8 extending along the internal surface in the tangential direction is installed and this wall is formed into a cyclone type which is convergent towards the lower end. A plurality of burners 6 are installed at the wall 18 so as to surround the circumference of the tube 19. On the other hand, on the periphery of the wall 20 in the secondary combustor 17 a hollow cylindrical manifold 21 is attached. The combustor 17 formed in one body with the manifold 21 and the combustor 16 with the communicating tube are connected directly between the bottom part of the manifold and the upper end part of the tube 19. Thereby, the revolving stream of combustion gas is able to be certainly eliminated and therefore, uniform stream smoothening effect is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a cyclone fueled by coal, such as a coal-fired MHD light heavy plant combustor, a coal gasification furnace, a coal-fired boiler, a coal-fired gas turbine combustor, etc. Regarding type combustors.

Conventional technology pulverized coal, CW! J (Coal/Water Mixture) or COM (Coal/Heavy Oil Mixture): Various plants that generate high-temperature gas using coal as a fuel and use high-temperature thermal energy as a power source, such as coal-fired M HD (Magnet-Hyd)
As a conventional example of a combustor for a power generation plant or the like, there is the following cyclone type combustor.

As shown in FIGS. 3-4, the combustors are configured as horizontal (FIG. 3) or vertical (FIG. 4) MHD power plant combustion chambers, respectively. In both of these combustors 1, molten residue (slag) mixed in the combustion and soul gas of coal fuel is removed through a flat orifice-type throttle partition plate °2.
The first part separates and extracts the components on the furnace wall inside the combustion chamber.
In the stage combustion chamber 3 and MHD power generation, combustion gas is used as a working gas, and in order to increase the conductivity of the working gas,
A second stage/combustion chamber for supplying a combustion gas plasma in which NU, lithium compounds (specifically KOH water-soluble, etc.), a seed agent, are sprayed and evaporated into the combustion gas to ionize the high-temperature gas. It is divided into 4.

In the first stage combustion chamber 3, there is a burner 6 connected to a fuel supply system 5 such as pulverized coal to inject the fuel into the combustion chamber 4, and a primary combustion oxidizer (high temperature air supply system 7
An air port 8 for giving swirl to the combustion gas by connecting the oxidizing agent G-] is arranged at an appropriate position, and a slag discharge system 9 is installed at the bottom of the combustor 3. A slag reservoir 10 is provided for collecting molten slag separated from combustion gas.

- 10,000, the second stage combustion chamber 4 is connected to a pipe branched from the oxidant supply system 7, and a pipe 27' for injecting the secondary combustion oxidant o-2'2 into the combustion chamber 4 is connected. An air port 1 ] and a seed nozzle ] 3 for connecting to the seed supply system 12 for seed agent and spraying it into the combustion chamber 4 are arranged at appropriate positions, and the I11 end of the combustion chamber 4 (or the upper As mentioned above, the high-temperature gas plasma generated by the seeding agent evaporated in the four combustion chambers is rectified into a parallel flow like - and supplied to the end). A high-temperature duct 14 is provided with an open end communicating with a 16-plant channel (which is of rectangular cross-section in construction).

In this way, in order to completely separate and extract the slag in the first stage combustion chamber 3, a strong swirling vortex flow of the oxidizer is reversed in the combustion chamber, thereby applying centrifugal force to the particulate slag in the combustion gas. The molten slag is flown toward the inner circumferential wall of the combustion chamber 3 and separated on the wall surface, and the molten slag flows down along the wall surface and is collected in the slag reservoir 1o.

Also, usually in coal (although it varies depending on the coal camp),
15 to 30% of slag components are included as combustion reaction products, and the main component of this slag is S 1021 A'
It consists of 20 s + "yo r c a o, of which 5102 occupies about 50%.

The above M[(D power generation is approximately 2,500 to 3
．． There is a fee to generate a high temperature gas plasma at 000° and supply it to the power generation channel, however, silica (S102) i'!: 25 which is the main component of slag.
000 and a vapor pressure of 1aiIn in an atmosphere with a combustion gas temperature of 2,500'K or more.
02 means that it is visualized and evaporated and entrained in the combustion/dawn gas. Incidentally, other main components (Ai-00ak,...
) ￥i Relatively high ST vapor pressure is considered to be latm at approximately 3,000° or above.

Therefore, in order to remove slag in the combustion chamber, it is necessary to suppress the combustion flame temperature to about 2000° or less and separate and extract the slag components from the combustion gas in the form of molten mist or solid particles. For this reason, in the MHD power generation combustor, as shown in Figures 3 and 4, in the first stage combustion chamber 3, the input amount of fuel oxidizer, that is, the primary combustion oxygen supply amount G-1 is adjusted to the oxygen equivalent ratio (= WT, the theoretical oxygen amount required for complete combustion of fuel is kept below about 0.6 to 0.7, and the combustion flame temperature is reduced to about 2 by burning under fuel-rich conditions.
000°K or less to prevent evaporation and entrainment of slag components, and remove the slag in the first stage combustion chamber 3. after that,
In the second stage combustion chamber 4, a new oxidizer, i.e., oxygen G for secondary combustion, is added.
-2 is supplied, and the combustion gas in the first stage combustion chamber 3 is subjected to secondary combustion to generate high-temperature combustion gas of 25000x or more.

In addition, FIG. 5 shows a cyclone type slag tap combustion furnace applied to a normal coal-fired boiler as another conventional example. An unloader 1 connected to the first and second stage combustion chambers 3 and 4 is used to further drop the slag that flows down from the second stage combustion chamber 4 onto the throttle partition plate 2 into the slag sump 10.
5 is provided.

Problems to be Solved by the Invention The conventional cyclone type combustor described above, however, has the following problems.

(1) In recent years, in applicability evaluation to plants, a slag removal rate of 90% or more has been required. Because the strong swirling flow in the first-stage combustion chamber 3 is continuously formed in the second-stage combustion chamber 4, the slag that hits the wall and flows down is re-splattered by the swirling flow after the first-stage combustion chamber. However, some slag carries over to the second stage combustion chamber 4, making it difficult to improve the slag removal performance or efficiency (currently 70 to 80%).

f21 MHD! ! : In electric power generation, high-temperature gas plasma rectified into a parallel flow like a power generation channel connected to the outlet of the combustor 1, that is, a high-temperature duct, to a high-speed duct,
00~]000''Vs).

However, in the past, due to the law of energy conservation continuity of the strong swirling flow of the conduit first-stage combustion system 3, which was constructed with the purpose of removing slag, it was possible to eliminate the swirling vortex because it was continued on the downstream side. It has the disadvantage of being very vulgar.

A secondary nitrogen inlet is provided at the outer periphery of the combustion chamber for the secondary combustion oxidizer G-2 (high temperature air or acid type) in the second stage combustion chamber 4.
The main flow in the combustion chamber is oxidation (for the next and eighth combustion).
4 (1 藏 Ratio of momentum of two air currents G -1 and a-2, that is (0-1°v-1°p-1/G-2-V-2ρ-2
).

(Where ■=Blowout speed, ρ=Blowout gas density, and the subscript is the blowout nozzle position.) Here, 'In the combustion equipment in practical MHD power generation, oxidation 4J (high YNA nitrogen gas at 1200 to 1300°C) is used for combustion. Approximately 65 to 70% of the air is supplied to the first stage combustion chamber 3, and the remaining 30 to 35% is supplied to the second stage combustion chamber 4. ratio ζ1
). Therefore, 017G-2=
1-8 to 2.5, and the momentum is dominated by the mainstream vortex formed in the first stage combustor 16, so it can be seen that a swirling flow remains.

As described above, with the conventional technology, all of the slag cannot be sufficiently separated and collected from the main components connected to the combustor, resulting in deterioration in the performance of each device due to the accumulation of slag, and damage to the combustor wall. There were drawbacks and it was not possible to prevent the generation of a swirling flow provided for removing the slag.

Means for solving all the problems In order to solve the conventional problems, the present invention
A cyclone type combustor is equipped with a communication pipe that passes through the center of the ceiling wall, a burner is attached to the ceiling wall around the communication pipe, and an air port is provided that extends tangentially to the side wall. A cyclone-type first stage combustion engine with a side wall tapering toward the lower end, and an upper part of the communication pipe 3+? ! It consists of a second stage combustor that is directly connected to the combustor.

Effect: According to such a means, the communication -g penetrating into the first stage combustor is installed so as to protrude to an appropriate depth, so that the slag splash due to the swirling flow of combustion gas in the m-line direction is prevented. Entrainment can be prevented, and the slag in the combustion gas can be sufficiently separated and extracted due to the contact effect of the slag with the communication pipe as a combustion gas passage and the inner wall surface of the manifold. The mainstream can be dispersed smoothly and the mainstream vortex can be reliably eliminated.

EXAMPLE Hereinafter, a practical example of the present invention will be described in detail with reference to FIGS. 1 and 2. In these figures, the same parts as those shown in Figs. 3 to 5 are denoted by the same reference numerals, and detailed explanation thereof will be omitted.

As shown in FIG. 1, the first and second stage combustion chambers 3 are integrated through a conventional orifice-type throttle partition plate 2.
．． 4 instead of the first stage combustor 1 arranged vertically
The second stage combustor 6 and the horizontally arranged second stage combustor 17 have separate and independent combustor structures.

First, a cylindrical communication d19 is attached to the first stage combustor 16, with the central part of the ceiling wall 18 as its axis, and perpendicular to the castle direction. It is provided so as to protrude to the depth. An air port 8 is provided at a suitable position on the 1il 142o of this combustor, and extends in the direction of the combustor on the inner surface of the side wall. has been done.

Further, a plurality of burners 6 are placed at appropriate intervals on the ceiling wall 18 so as to surround the communication pipe 19, and the injection ports of these burners are attached toward the @ line of the combustor. There is. Then, at the bottom of the combustor 16, there is a slag reservoir]0
is provided.

On the other hand, in the center of one end of the 42-stage combustor 17, a seed nozzle [3] and a plurality of secondary nitrogen ports 11 are installed at appropriate positions around the seed nozzle. A duct 83'aN duct] 4 is provided at the other open end. Furthermore, a cylindrical manifold 21 with a hollow core is attached to a suitable position on the outer surface of the side wall 20 of the combustor, and an annular space is defined by this manifold and the side wall of the combustor 17. Furthermore, a plurality of gas jet nozzles 22 are provided at appropriate positions on the outer circumferential surface of the side wall at intervals and arranged in a top row.

The second stage combustor I is integrated with the manifold 21.
7 and a first stage combustor 16 having a communication pipe are directly connected to the upper end of the communication pipe 19 at the bottom of this manifold. That is, it is arranged perpendicularly to the first stage and second stage combustion 416.17.

Note that these directly connected combustors are provided with a downcomer 15 for dropping the molten slag f separated and collected in the second stage combustor 17179 into the slag sump 10 on the X stage combustor I6 side. be done.

Next, its effect will be explained.

In the first stage combustor 16, all N-th air ports 1] form a strong swirling flow in this combustor by fully injecting the secondary combustion oxidant G-2, and Pulverized coal is transported from the burner 6 installed in the combustor by a carrier gas (N2/mixed air), and is transported to the combustor 1 by a jet stream.
6, mixed with high-temperature air oxidizer, diffused, and combusted. Therefore, by arranging the nozzle 4 toward the axis of the combustor 16, the relatively large particles in the pulverized coal are allowed to overcome the momentum in the outer circumferential direction of the swirling airflow and penetrate into the space between the royal flow nitrogen, resulting in the spatial retention of fuel. The time rj1 is lengthened to improve combustion performance.

Furthermore, the slag generated in the combustor 16 is blown to the circumferential wall of the main body due to the centrifugal force of the swirling flow, is molten and flows down the wall in the direction of the wind, and is deposited in the slag reservoir 10 provided at the bottom of the main body. The slag is collected and taken out to the outside through the slag discharge system.

The clean gas having a temperature of about 2000"C, from which gold slag has been separated and removed in the first stage combustor 16, is guided through the communication pipe 19 to the manifold 21 of the second stage combustor 17, which is directly connected to the upper part.

At this point, the flow of combustion gas passing through the communication pipe 19 still forms a somewhat swirling flow, but it collides with the inner wall surface of the manifold building 21 that is perpendicular to the communication pipe 19 and disperses, forming swirl lag mist (particles of several micrometers or less). ) is the manifold hair [8] The combustion gas collides with the wall group of 8, and as the direction of the combustion gas flow changes, it adheres to the wall surface and flows, is collected at the lower part of the manifold 21, passes through the downcomer 15, and is combusted in the first stage. It is allowed to flow down to the lower part of vessel 1 and collected. The combustion gas is then radiated from the next gas jet nozzle 22 provided in the manifold 21 to the second stage combustor 17.
blown inside.

Note that FIG. 2 shows a modified PIJ of a cyclone type combustor having a one-crossing type as described above, and in this case, the arrangement of the second stage combustor 17 is changed from a groove type to a vertical type. A slag recovery duct 23 for sufficiently recovering slag is connected to the bottom of the manifold 21 and the slag sump 0.
Being useful.

Effects of the Invention As described above in detail, according to the present invention, the separation and removal rate of @molten slag can be greatly improved from the conventional 70 to 80% to 90 to 95%, and therefore, It is possible to obtain sufficient evaluations of the performance, reliability, and applicability to practical equipment of various plants that use coal as fuel. Moreover, the swirling flow of combustion gas can be reliably eliminated, and a similar rectification effect can therefore be obtained, and power generation performance can be greatly improved.

Moreover,! By making the multiple burners installed on the ceiling wall of the A1 stage combustor jet type, the mixing and diffusion effect of coal fuel such as pulverized coal and kerosene in the first stage combustor is enhanced.
Can be made smaller.

It should be noted that application to direct combustion of pulverized coal is also possible, as long as the combustor achieves high-temperature, high-load combustion.

[Brief explanation of drawings]

FIG. 1 is a schematic sectional view showing an example of a cyclone type device according to the present invention, and FIG. 2 is a schematic sectional view showing a modification thereof.
Figures 3-5 are schematic cross-sectional views showing three different conventional Suicron type combustors. 6...Burner, 8...Air port, 16...1st stage combustor,
17. Second stage combustor, 18. Ceiling wall, 19. Communication pipe, 20. Side wall, 21. Manifold, 22. Gas jet nozzle. Fig. 1 17; Second stage roaster 18: f:, 4) Moi sa! 19: Reach i pipe 20: Side wall zl; zz: *”Shot slag Figure 2 High temperature 11χ Ara 7: Maslag Figure 3

Claims (1)

[Claims] A communication pipe is installed through the central part of the ceiling wall, a burner is installed in said ceiling wall around the communication pipe, and the side wall is provided with an air opening extending tangentially to the side wall, said side wall tapering towards the lower end. A cyclone type combustor consisting of a cyclone type first stage combustor and a second stage combustor directly connected to the upper end of the communication pipe.