JPH0639217Y2 - Cyclone type coal combustor - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a cyclone type coal combustor for coal-fired MHD (Magnet Hydro Dynamics) power generation, for a spouted bed type coal gasifier, for a coal-fired gas turbine, etc. Regarding

[Conventional technology]

FIG. 4 shows a conceptual diagram of the structure of a cyclone type coal combustor according to the prior art.

1st stage combustion chamber 1 from coal injection nozzle 2 of the combustor head
The fuel 13 injected into the interior is diffused by the strong swirling flow of the oxidant (oxygen or high temperature air) 12 blown from the cyclone nozzle 8 provided along the inner wall surface of the combustion chamber body along the cut line direction. The residue (coal slag) that is mixed and burned and produced by the combustion reaction is urged against the inner wall surface of the combustion chamber by the centrifugal force of the air flow, blocked by the rear partition wall 4, and the slag outlet 9 provided in the lower part. Flows into the slag pot 11 from the combustion chamber, is separated and collected outside the system from the combustion chamber, and is discharged as slag 14. The high-temperature combustion gas from which the coal slag has been removed is introduced into the second-stage combustion chamber 5 through the outlet 7A formed by the weir 7 provided in the central portion of the rear partition wall 4.
In addition, 15 is a high temperature gas discharged from the second stage combustion chamber 5.

[Problems to be solved by the invention] It is well known that the practical use of the next-generation coal utilization technology is to remove combustion residues (coal slag) in the combustion chamber as efficiently as possible to obtain a high-temperature clean gas. It is important to make a combustor that manufactures, and research and development is progressing in various fields.

FIG. 5 shows the flow of the high temperature combustion gas in the combustor and the flow pattern of the molten slag flowing along the inner wall surface of the combustor in the above-mentioned conventional cyclone type coal combustor. As shown in the figure, the oxidizer (oxygen or high temperature air) 12 blown out from the cyclone nozzle 8 provided along the inner wall surface of the combustion chamber body along the cutting line is an axial cross section of the combustion chamber wall surface. Against, from the cyclone nozzle 15 degrees ~ 20
It spreads at a widening angle (α) and generates a spiral rib flow B in the axial direction along the peripheral wall of the combustion chamber. On the other hand, the residue in the combustion flame is in the form of molten mist and is pushed against the inner wall surface of the combustion chamber by the centrifugal force of the swirling vortex flow of the oxidizer, and is pushed to the wake along the axial rib flow a of the inner wall surface. It flows down into the slag pot 11 from the slag outlet 9 at the lower part of the wake side. Here, a part of the molten slag that has collided with the partition wall surface by riding on the rib flow a is attracted by the mainstream gas flowing toward the high temperature gas outlet 7A in the central portion of the partition wall 4, and gets over the weir 7 of the partition wall. ,
There is a drawback that carry-over to the wake occurs and the slag removal performance is deteriorated.

The present invention is intended to prevent such an overflow phenomenon of molten slag.

[Means for Solving the Problems]

The present invention is a cyclone type coal combustor in which a swirling airflow is formed in a combustion chamber, and coal is separated into inner walls of a combustor by a centrifugal force action of the swirling flow in a molten state and discharged to the outside of the system. Guide vanes along the swirl flow in the combustion chamber were provided on the partition wall surface of the combustion chamber.

[Action]

In the present invention, the swirling main-stream gas flow that collides with the surface of the partition wall on the wake side of the combustion chamber collides with the side surface of the guide vane protruding from the partition surface to become turbulent, and the swirl flow and the axial center are formed on the partition surface. The flow on the other side is erased, and a stagnation vortex portion of the flow occurs at the corner portion of the partition wall surface. Therefore, the flow of the molten slag, which is pushed by the rib flow along the inner wall surface of the combustion chamber, is confined in the stagnation vortex region formed at the corner of the partition wall, flows downward along the partition wall, and at the partition wall surface. Carryover of molten slag due to the centripetal force of the air flow is prevented.

Further, the molten slag colliding with the intermediate area of the partition wall surface collides with the side surface of the guide vane along the swirling flow, flows outward along the guide vane, flows into the stagnation vortex region of the partition wall corner, and Along the wall, the carry-over of the molten slag due to the centripetal force of the air flow on the partition surface is prevented.

As described above, according to the present invention, carryover of molten slag is prevented, and the performance of the combustor is improved.

[Embodiment] An embodiment of the present invention will be described with reference to FIGS.

The cyclone type coal combustor according to the present embodiment includes a coal (pulverized coal, pulverized coal / water mixed fuel (CWM) or pulverized coal / oil mixed fuel (COM)) burner 2, a combustion chamber head 3, a first combustion chamber. 1, a partition wall 4 on the downstream side of the first combustion chamber, a slag downflow port 9 provided in the lower portion of the first combustion chamber 1, a slag pot 11 connected to the slag flowdown port 9 and the partition wall 4 It is composed of the second combustion chamber 5 provided on the downstream side, and includes the combustion chamber head 3
A swirler 10 for injecting an auxiliary oxidant is installed inside, and a cyclone nozzle 8 for injecting an oxidant (high temperature air) is provided in the body of the first combustion chamber so as to be inscribed in the body wall and open in the tangential direction. On the upstream surface of the partition wall 4, three guide vanes 6 inclined along the swirling flow in the first combustion chamber 1 by the cyclone nozzle 8 are radially arranged, and further in the center of the partition wall 4,
A cylindrical weir 7 that forms a gas outlet 7A is provided.

In this embodiment, the fuel injected from the injection port of the coal burner 2 into the combustion chamber is mixed with the high temperature air 12 supplied from the swirler 10 and the cyclone nozzle 8 and burned. Here, a strong swirling flow of high-temperature air is formed in the combustion chamber by the high-temperature air 12 from the cyclone nozzle 8 that opens in the cut line direction on the wall of the combustion chamber, and the residue (coal ash) in the combustion gas is formed. 16
Is melted and separated into the peripheral wall of the combustion chamber by the centrifugal force of the air flow, and is pushed backward along the wall and flows down from the opening 9 of the slag pot 11 provided in the lower part of the combustion chamber.
The slag 14 is discharged to the outside of the system by a discharge device connected to the bottom of the slag pot 11. On the other hand, the clean combustion gas from which the coal ash has been separated and removed is mixed with a new oxidizer in the second combustion chamber 5 to produce a high temperature combustion gas 15 at a predetermined temperature, and the main component (MHD) that uses the high temperature gas as an operating source Power generation channel, boiler, gas turbine, etc.).

FIG. 3 shows the structure and flow action of the first combustion chamber partition wall in this embodiment. The mainstream gas flow (solid line) that collides with the surface of the partition wall 4 forms a turbulent boundary layer on the wall surface, and the flow in the swirling direction collides with the side surface of the protruding guide vane 6 and becomes turbulent, and swirl flow on the wall surface. And the flow toward the radial axis is eliminated, and a flow stagnation vortex opening is formed at the corner of the partition wall 4. Therefore, the flow of the molten slag 16 pushed by the rib flow a on the inner peripheral wall surface of the combustion chamber is
Is confined in the stagnation vortex region mouth of the flow formed in the corner part of the flow path, flows down along the partition wall 4 and flows to the slag flow-down opening 9 in the lower part of the first combustion chamber, and is caused by the centripetal action of the air flow on the partition wall surface. Carryover of molten slag can be prevented.
Further, the molten slag that collides with the intermediate area of the surface of the partition wall 4 collides with the side surface of the guide vane 6 provided along the swirling flow, flows outward along the guide vane 6 as shown by the dotted line, It flows to the stagnation vortex region mouth of the corner portion of the partition wall 4, and likewise flows down along the partition wall 4 and flows into the slag flow-down opening 9.

In this way, in this embodiment, the carryover of slag from the partition wall weir 7 into the production gas can be prevented, and the performance of the combustor can be improved.

The slag removal rate in a conventional cyclone type coal combustor is
It was about 70% to 80%, but according to this example, 90%
The above slag removal rate was achieved.

[Effect of device]

The present invention has a simple structure in which a guide vane that follows the swirling flow in the combustion chamber is provided in the partition wall on the downstream side of the combustion gas flow in the combustion chamber. Combustion gas can be obtained.

[Brief description of drawings]

FIG. 1 is a sectional view of an embodiment of the present invention, FIG. 2 is a sectional view taken along the line AA in FIG. 1, and FIG. 3 is an explanatory view of a flow in a combustion chamber of the present embodiment, FIG. 4 is a cross-sectional view showing a conventional cyclone type coal combustor, and FIG. 5 is an explanatory view showing a flow in a combustion chamber of the conventional coal combustor. DESCRIPTION OF SYMBOLS 1 ... 1st stage combustion chamber, 2 ... Coal burner, 3 ... Combustion chamber head, 4 ... Partition wall, 5 ... 2nd combustion chamber, 6 ... Guide vane, 7 ... Weir, 7A ... Gas outlet, 8 ... Cyclone nozzle , 9 ... slag downflow port, 10 ... swirler, 11 ... slag pot, 12 ... oxidizer, 13 ... coal, 14 ... slag, 15 ... hot gas, 16 ... molten slag

Claims (1)

[Scope of utility model registration request] 1. A cyclone-type coal combustor in which a swirl flow is formed in a combustion chamber, and coal ash in a molten state is separated into an inner wall surface of the combustor by a centrifugal force action of the swirl flow and discharged to the outside of the system. A cyclone-type coal combustor, characterized in that guide vanes are provided along a swirl flow in the combustion chamber on a partition surface of the downstream combustion chamber.