US20150345788A1

US20150345788A1 - Combustion burner and pressurized gasification furnace

Info

Publication number: US20150345788A1
Application number: US14/654,681
Authority: US
Inventors: Yasuyuki Miyata; Yasuo Soda; Katsuhiko Yokohama; Shinya Hamasaki; Keisuke Matsuo
Original assignee: Mitsubishi Heavy Industries Ltd
Current assignee: Mitsubishi Heavy Industries Ltd
Priority date: 2012-12-26
Filing date: 2013-11-28
Publication date: 2015-12-03
Also published as: JP5575221B2; CN104903651B; WO2014103607A1; KR101742409B1; CN104903651A; JP2014126278A; KR20150088847A

Abstract

A combustion burner and a pressurized gasification furnace provided with: a burner main body (41) capable of blowing a fuel gas in which fuel and air are mixed; and an ignition torch (42) that is provided inside the burner main body (41) and propagates a flame from the base end part of the torch, with the flame being discharged from the tip end part. By arranging the tip end part (42 a) of the ignition torch (42) at the base-end side with respect to the tip end part (41 a) of the burner main body (41), the thermal load at the tip end part of the ignition torch during ignition is reduced, and thus the durability can be improved.

Description

TECHNICAL FIELD

The present invention relates to a combustion burner which is used in a furnace such as a pressurized gasification furnace, and a pressurized gasification furnace including the combustion burner.

BACKGROUND ART

For example, in a gasification furnace such as a coal gasification furnace, a start-up burner is provided with an ignition torch in the vicinity thereof to ignite the start-up burner.
As the ignition torch of the related art, for example, an ignition torch is described in PTL 1 as follows. The ignition torch of PTL 1 is configured to extend across the inside of a gasification furnace from the outside thereof so as to allow fuel and combustion air to be received from one end of the gasification furnace and allow a flame to be sent out from the other end of the gasification furnace, and an ignition unit is provided on one end side which is positioned outside the gasification furnace.

CITATION LIST

Patent Literature

[PTL 1] Japanese Unexamined Patent Application Publication No. 2011-117713

SUMMARY OF INVENTION

Technical Problem

In the ignition torch of the related art described above, the ignition unit is provided on the base end portion side which is positioned outside the gasification furnace. Therefore, when the start-up burner is ignited by using the ignition torch, the flame formed by the ignition unit propagates toward the tip end portion through the inside of a pipe and ignites fuel gas which is discharged from the tip end portion of the start-up burner. At this time, since the pipe of the ignition torch has a predetermined length, thermal elongation occurs during the propagation of the flame. In this case, the tip end portion of the ignition torch protrudes forward from the tip end portion of the start-up burner and thus is likely to receive a thermal load during the ignition. A flame stabilization unit is formed in the tip end portion of the ignition torch, and thus there is concern that the flame stabilization unit may be burned out by a thermal load during the ignition.
In order to solve the above-described problems, an object of the present invention is to provide a combustion burner and a pressurized gasification furnace capable of enhancing durability by reducing a thermal load on a tip end portion of an ignition torch.

Solution to Problem

In order to accomplish the object, a combustion burner of the present invention includes: a burner main body which is able to blow fuel gas which is a mixture of fuel and air; and an ignition torch which is disposed inside the burner main body and allows a flame to propagate from a base end portion of the ignition torch so as to be sent out from a tip end portion of the ignition torch, in which the tip end portion of the ignition torch is disposed on the base end portion side with respect to a tip end portion of the burner main body.
Accordingly, when the fuel gas which is blown from the burner main body is ignited and forms a flame, the tip end portion of the ignition torch is disposed on the base end portion side with respect to the tip end portion of the burner main body. Therefore, a thermal load on the tip end portion of the ignition torch due to the flame of the burner main body can be reduced, and thus durability can be enhanced and the life span can be extended.
In the combustion burner of the present invention, during a non-operation of the ignition torch, the tip end portion of the ignition torch is disposed closer to the base end portion side than the tip end portion of the burner main body.
Accordingly, the tip end portion is positioned at a retreat position during the non-operation of the ignition torch, and thus a thermal load on the tip end portion of the ignition torch due to the flame of the burner main body can be reduced.
In the combustion burner of the present invention, a time of the non-operation of the ignition torch includes a time before allowing the flame to propagate from the base end portion of the ignition torch to the tip end portion or a time after stopping the propagation of the flame by the ignition torch after an ignition of the fuel gas from the burner main body.
Accordingly, the tip end portion of the ignition torch is positioned at the retreat position before allowing a flame to propagate from the base end portion of the ignition torch to the tip end portion or after stopping the propagation of the flame by the ignition torch after the ignition of the fuel gas from the burner main body, and thus a thermal load on the tip end portion of the ignition torch due to the flame of the burner main body can be reduced.
In the combustion burner of the present invention, during an operation of the ignition torch, the tip end portion of the ignition torch is disposed at substantially the same position as that of the tip end portion of the burner main body.
Accordingly, the tip end portion of the ignition torch is positioned at substantially the same position as that of the tip end portion of the burner main body during the operation. Therefore, at this time, the ignition torch can appropriately ignite the fuel gas which is blown from the burner main body by the flame which propagates from the base end portion and is sent out from the tip end portion.
In the combustion burner of the present invention, a time of the operation of the ignition torch includes a time when the flame is allowed to propagate from the base end portion of the ignition torch to the tip end portion.
Accordingly, when the flame propagates from the base end portion of the ignition torch to the tip end portion, the tip end portion of the ignition torch is positioned at substantially the same position as that of the tip end portion of the burner main body, and thus the fuel gas which is blown from the burner main body can be appropriately ignited by the ignition torch.
In the combustion burner of the present invention, the position of the tip end portion during the non-operation of the ignition torch is set in consideration of a length of a pipe through which the flame propagates.
Accordingly, the position during the operation and the position during the non-operation in the ignition torch can be appropriately set.
In the combustion burner of the present invention, an ignition unit is provided in the base end portion of the ignition torch, and an on-off valve is provided on a downstream side in a fuel flow direction of the ignition unit.
Accordingly, since the ignition unit is provided in the base end portion of the ignition torch, regardless of the state of the tip end portion side, the inspection of the ignition unit can be easily performed. In addition, since the on-off valve is provided on the downstream side in the fuel flow direction of the ignition unit, the base end portion side and the tip end portion side can be separated from each other by closing the on-off valve. Therefore, even in a case where inspection is required, the ignition unit side can be separated from the flame by closing the on-off valve, and thus the inspection can be easily performed.
A pressurized gasification furnace of the present invention includes: a burner main body which is fixed to a furnace wall and is able to blow fuel gas which is a mixture of fuel and air into a furnace; and an ignition torch which is fixed to the furnace wall to be disposed inside the burner main body and allows a flame to propagate from a base end portion of the ignition torch so as to be sent out from a tip end portion of the ignition torch, in which the tip end portion of the ignition torch is disposed on the base end portion side with respect to a tip end portion of the burner main body.
Accordingly, the tip end portion of the ignition torch is disposed on the base end portion side with respect to the tip end portion of the burner main body when the fuel gas which is blown from the burner main body is ignited and forms a flame. Therefore, a thermal load on the tip end portion of the ignition torch due to the flame of the burner main body can be reduced, and thus durability can be enhanced and the life span can be extended.

Advantageous Effects of Invention

According to the combustion burner and the pressurized gasification furnace of the present invention, since the tip end portion of the ignition torch is disposed on the base end portion side with respect to the tip end portion of the burner main body, a thermal load on the tip end portion of the ignition torch due to the flame of the burner main body can be reduced, and thus durability can be enhanced and the life span can be extended.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic view illustrating a combustion burner according to an embodiment of the present invention.

FIG. 2 is a schematic view illustrating an action of the combustion burner of the embodiment.

FIG. 3 is a longitudinal sectional view of a coal gasification furnace container of the embodiment.

FIG. 4 is a cross-sectional view taken along line A-A of FIG. 3, illustrating a transverse sectional view of the coal gasification furnace container of the embodiment.

DESCRIPTION OF EMBODIMENTS

Hereinafter, an exemplary embodiment of a combustion burner according to the present invention will be described with reference to the accompanying drawings. In addition, the present invention is not limited by the embodiment, and in a case where there are a plurality of embodiments, a configuration obtained by combining the embodiments is also included in the present invention.

Embodiment

FIG. 1 is a schematic view illustrating a combustion burner according to an embodiment of the present invention, FIG. 2 is a schematic view illustrating an action of the combustion burner of the embodiment, FIG. 3 is a longitudinal sectional view of a coal gasification furnace container of the embodiment, and FIG. 4 is a cross-sectional view taken along line A-A of FIG. 3, illustrating a transverse sectional view of the coal gasification furnace container of the embodiment.
In the embodiment, as illustrated in FIGS. 3 and 4, a gasification furnace (pressurized gasification furnace) 1 includes a light oil combustion chamber 3, a combustor section 5, and a reductor section 7 in this order from the bottom. The light oil combustion chamber 3 is provided with start-up burners (combustion burners) 12. Although described later, the start-up burner 12 is configured such that an ignition torch 42 is disposed inside a burner main body 41.
The combustor section 5 is provided with pulverized coal burners 14 and char burners 16. The reductor section 7 is provided with gasification burners 18. In the light oil combustion chamber 3, light oil which is injected and sprayed by the start-up burners 12 is burned, and the generated combustion gas heats the combustor section 5 on the upper side. In addition, in the combustor section 5 which reaches a coal ignition temperature or higher, coal is burned with air which is a gasification agent that is only injected into the combustor section 5 and reaches a high temperature such that ash in the coal is melted and flows downward and high-temperature gas generated by the combustion in the combustor section 5 moves upward. In the reductor section 7, the high-temperature gas which moves upward from the combustor section 5 and coal which is newly injected react with each other, and thus the coal can be converted into gas with good efficiency.
In the embodiment, a plurality of start-up burners are arranged to oppose each other so as to form a swirling flow in the gasification furnace 1. As illustrated in FIG. 1, the start-up burner 12 is configured to include the burner main body 41 and the ignition torch 42. The burner main body 41 can blow fuel gas which is a mixture of fuel and air. The ignition torch 42 is disposed inside the burner main body 41 and allows a flame to propagate from the base end portion so as to be sent out from the tip end portion. In addition, the burner main body 41 is ignited by the flame of the ignition torch 42 and can form a flame as the start-up burner 12.
The burner main body 41 is provided with a fuel gas passage 53 which is formed between an outer cylinder 51 and an inner cylinder 52, and a nozzle 54 which is formed at the tip end portion and can blow the fuel gas into the gasification furnace 1. The outer cylinder 51 and the inner cylinder 52 have cylindrical shapes and are fixed to a furnace wall 1 a, and the base end portions thereof are provided with a fuel gas supply portion and a combustion air supply portion (not illustrated).
The ignition torch 42 is disposed inside the burner main body 41, has a cylindrical shape, and is fixed to the furnace wall 1 a. The ignition torch 42 is provided with a mixing chamber 20 in which fuel and combustion air are mixed with each other, an ignition unit 22, an on-off valve 24, a combustion pipe 26, and a flame stabilization unit 28 as main components in this order from the base end portion outside the gasification furnace 1.
The mixing chamber 20 is provided with a fuel supply port 30 and a combustion air supply port 31. Therefore, the fuel and the combustion air are sufficiently mixed with each other in the mixing chamber 20, and the mixture is ignited by the ignition unit 22 which is provided on the downstream side of the fuel flow. As the ignition unit 22, ignition by a glow plug, an igniter, or the like is appropriately used.
The mixing chamber 20 and the ignition unit 22 are disposed outside the gasification furnace 1. In addition, the on-off valve 24 is provided between the mixing chamber and the combustion pipe 26 which extends across the inside of the gasification furnace 1. The on-off valve 24 is provided outside the gasification furnace 1. The on-off valve 24 can allow a fluid between the ignition unit 22 side and the gasification furnace 1 side to flow or to be blocked by opening or closing the passage. The flame stabilization unit 28 which has a greater inner diameter than that of the combustion pipe 26 is provided in the tip end portion of the combustion pipe 26, and a flame stabilization plate 28 a is fixed to the inside of the flame stabilization unit 28.
In addition, an assist fuel pipe 32 through which assist fuel flows is inserted into the inside of the furnace from the outside of the furnace, and passes through the side of the combustion pipe 26 to extend to the flame stabilization unit 28. The assist fuel can be supplied to the flame stabilization unit 28 by the assist fuel pipe 32.
The start-up burner 12 of the embodiment described above is operated as follows.
Before the ignition of the ignition torch 42, first, only the combustion air is supplied from the combustion air supply port 31 to heat the ignition unit 22 to be red-hot. After the temperature of the ignition unit 22 is increased to an ignition temperature, the fuel is supplied from the fuel supply port 30 to the inside of the mixing chamber 20, and the fuel and the combustion air are mixed with each other. The air ratio (the amount of air actually injected/the amount of air theoretically needed) at this time is about 0.4 to 0.7.
The mixed fuel gas is ignited by the ignition unit 22 and forms a flame. The flame passes through the opened on-off valve 24 and propagates through the inside of the combustion pipe 26. In addition, the flame which reaches the flame stabilization unit 28 from the combustion pipe 26 becomes a main flame in the flame stabilization unit 28 and is burned. At this time, the assist fuel is supplied to the flame stabilization unit 28 from the assist fuel pipe 32. Accordingly, the main flame which grows in the flame stabilization unit 28 is stabilized and is burned.
On the other hand, the burner main body 41 blows the fuel gas which is a mixture of air and fuel into the gasification furnace 1 from the nozzle 54. In the ignition torch 42, when the main flame of the flame stabilization unit 28 is stabilized, the main flame flows out from the flame stabilization unit 28, and thus the fuel gas which is blown into the gasification furnace 1 from the burner main body 41 is ignited by the flame from the ignition torch 42, thereby igniting the start-up burner 12.
Next, a method of using the on-off valve 24 will be described.
The inside of the gasification furnace 1 is always maintained under a high temperature condition in a high pressure state in order to primarily accelerate the combustion gasification reaction of char. Therefore, in a case of inspecting the ignition torch 42, time for depressurizing all of the facilities of the gasification furnace during an operation under pressure to atmospheric pressure is necessary, and thus there is a burden of significant cost and energy consumption for operations of various types of power units during re-pressurization after the inspection.
As described above, in the case where the inspection of the ignition torch 42 is required, the on-off valve 24 which is provided on the downstream side of the fuel flow of the ignition unit 22 that is provided outside the gasification furnace 1 is used. That is, in a case where the ignition torch 42 has a problem during torch ignition or during the operation of the start-up burner and thus needs to be inspected, the on-off valve 24 is closed in this state. Accordingly, the inside of the gasification furnace 1 is blocked from the ignition unit 22 side, and thus the ignition unit 22 side is released to the air and the inspection operation is performed.
In the start-up burner 12 of the embodiment which is configured as described above, a tip end portion 42 a of the ignition torch 42 is disposed on the base end portion side (outside the furnace) with respect to a tip end portion 41 a of the burner main body 41.
Specifically, during the non-operation of the ignition torch 42, the tip end portion 42 a of the ignition torch 42 is disposed closer to the base end portion side than the tip end portion 41 a of the burner main body 41. A time of the non-operation of the ignition torch 42 indicates a time before allowing a flame to propagate from the base end portion of the ignition torch 42 to the tip end portion or a time after stopping the propagation of the flame by the ignition torch 42 after the ignition of the fuel gas from the burner main body 41.
In addition, during the operation of the ignition torch 42, the tip end portion 42 a of the ignition torch 42 is disposed at substantially the same position as that of the tip end portion 41 a of the burner main body 41. A time of the operation of the ignition torch 42 indicates a time when a flame is allowed to propagate from the base end portion of the ignition torch 42 to the tip end portion.
In this case, the position of the tip end portion 42 a during the non-operation of the ignition torch 42 is set in consideration of the length of a pipe (combustion pipe 26 and the like) through which the flame propagates. That is, since the ignition torch 42 has a predetermined length, when a flame propagates from the base end portion to the tip end portion, the base end portion is thermally elongated with respect to the furnace wall 1 a as the starting point and the ignition torch 42 is thermally elongated toward the tip end portion. Therefore, a retreat distance L during the non-operation of the ignition torch 42 is set so that the tip end portion 42 a of the ignition torch 42 is positioned at substantially the same position as that of the tip end portion 41 a of the burner main body 41 when the ignition torch 42 operates to allow a flame to propagate.
Hereinafter, the action and the effect of the start-up burner 12 of the embodiment will be described.
Before the start-up burner 12 is started, the tip end portion 42 a of the ignition torch 42 is positioned on the base end portion side with respect to the tip end portion 41 a of the burner main body 41 by the retreat distance L. Here, when the ignition torch 42 is operated, the flame propagates from the base end portion side to the tip end portion side, and thus the combustion pipe 26 is heated and reaches a high temperature, thereby causing thermal elongation toward the tip end portion side in the longitudinal direction. In this case, in the ignition torch 42, as illustrated in FIG. 2, the tip end portion 42 a is positioned at substantially the same position as that of the tip end portion 41 a of the burner main body 41. Therefore, the burner main body 41 ignites the fuel gas which is blown into the gasification furnace 1 by receiving the flame from the ignition torch 42 and thus can form a flame as the start-up burner 12.
Thereafter, when the flame of the start-up burner 12 (the burner main body 41) is stabilized, the propagation of the flame by the ignition torch 42 is stopped, and only the combustion air is supplied. Therefore, in the ignition torch 42, the combustion pipe 26 is cooled and the temperature thereof is reduced. In this case, the ignition torch 42 contracts toward the base end portion side in the longitudinal direction, and as illustrated in FIG. 1, the tip end portion 42 a is positioned at a position where the tip end portion 42 a retreats from the tip end portion 41 a of the burner main body 41. Therefore, since the tip end portion 42 a is held at the position where the tip end portion 42 a retreats from the tip end portion 41 a of the burner main body 41 toward the inside, a thermal load due to the flame of the burner main body 41 is reduced, and thus the burnout of the ignition torch 42 is prevented.
As described above, in the combustion burner of the embodiment, the burner main body 41 which can blow the fuel gas, which is a mixture of fuel and air, and the ignition torch 42 which is disposed inside the burner main body 41 and allows a flame to propagate from the base end portion so as to be sent out from the tip end portion are provided, and the tip end portion 42 a of the ignition torch 42 is disposed on the base end portion side with respect to the tip end portion 41 a of the burner main body 41.
Accordingly, the tip end portion 42 a of the ignition torch 42 is disposed on the base end portion side with respect to the tip end portion 41 a of the burner main body 41 when the fuel gas which is blown from the burner main body 41 is ignited and forms a flame. Therefore, a thermal load on the tip end portion 42 a of the ignition torch 42 due to the flame of the burner main body 41 can be reduced, and thus durability can be enhanced and the life span can be extended.
In the combustion burner of the embodiment, during the non-operation of the ignition torch 42, the tip end portion 42 a of the ignition torch 42 is disposed closer to the base end portion side than the tip end portion 41 a of the burner main body 41. Accordingly, the tip end portion is positioned at the retreat position during the non-operation of the ignition torch 42, and thus a thermal load on the tip end portion 42 a of the ignition torch 42 due to the flame of the burner main body 41 can be reduced.
Specifically, the tip end portion 42 a of the ignition torch 42 is positioned at the retreat position before allowing a flame to propagate from the base end portion of the ignition torch 42 to the tip end portion or after stopping the propagation of the flame by the ignition torch 42 after the ignition of the fuel gas from the burner main body 41, and thus a thermal load on the tip end portion 42 a of the ignition torch 42 due to the flame of the burner main body 41 can be reduced.
In the combustion burner of the embodiment, during the operation of the ignition torch 42, the tip end portion 42 a of the ignition torch 42 is disposed at substantially the same position as that of the tip end portion 41 a of the burner main body 41. Accordingly, the tip end portion 42 a of the ignition torch 42 is positioned at substantially the same position as that of the tip end portion 41 a of the burner main body 41 during the operation. Therefore, at this time, the ignition torch 42 can appropriately ignite the fuel gas which is blown from the burner main body 41 by the flame which propagates from the base end portion and is sent out from the tip end portion.
Specifically, when the flame propagates from the base end portion of the ignition torch 42 to the tip end portion, the tip end portion 42 a of the ignition torch 42 is positioned at substantially the same position as that of the tip end portion 41 a of the burner main body 41, and thus the fuel gas which is blown from the burner main body 41 can be appropriately ignited by the ignition torch 42.
In the combustion burner of the embodiment, the position of the ignition torch 42 during the non-operation is set in consideration of the length of the combustion pipe 26 through which the flame propagates. Accordingly, the position during the operation and the position during the non-operation in the ignition torch 42 can be appropriately set.
In addition, in the combustion burner of the embodiment, the ignition unit 22 is provided in the base end portion of the ignition torch 42, and the on-off valve is provided on the downstream side in the fuel flow direction of the ignition unit 22. Accordingly, regardless of the state of the inside of the gasification furnace 1, the inspection of the ignition unit 22 can be easily performed. In addition, the inside of the gasification furnace 1 and the ignition unit 22 side can be separated from each other by closing the on-off valve 24. As a result, even in a case where inspection is required due to various problems, the ignition unit 22 side can be separated from the gasification furnace 1 by closing the on-off valve 24, and thus the inspection can be easily performed regardless of the state of the inside of the gasification furnace 1.
In addition, in the gasification furnace 1 of the embodiment, the burner main body 41 which is fixed to the furnace wall 1 a and can blow the fuel gas, which is a mixture of fuel and air, into the inside of the furnace, and the ignition torch 42 which is fixed to the furnace wall 1 a to be disposed inside the burner main body 41 and allows a flame to propagate from the base end portion so as to be sent out from the tip end portion are provided, and the tip end portion 42 a of the ignition torch 42 is disposed on the base end portion side with respect to the tip end portion 41 a of the burner main body 41.
Accordingly, a thermal load on the tip end portion 42 a of the ignition torch 42 due to the flame of the burner main body 41 can be reduced, and thus durability can be enhanced and the life span can be extended.
In addition, in the above-described embodiment, the combustion burner of the present invention is applied to the gasification furnace 1 but is not limited to the gasification furnace 1. In addition, the ignition torch 42 is configured to include the ignition unit 22, the on-off valve 24, the combustion pipe 26, and the flame stabilization unit 28, but is not limited to this configuration and arrangement.

REFERENCE SIGNS LIST

1 GASIFICATION FURNACE
1 a FURNACE WALL
12 START-UP BURNER (COMBUSTION BURNER)
20 MIXING CHAMBER
22 IGNITION UNIT
24 ON-OFF VALVE
26 COMBUSTION PIPE
28 FLAME STABILIZATION UNIT
41 BURNER MAIN BODY
41 a TIP END PORTION
42 IGNITION TORCH
42 a TIP END PORTION

Claims

1. A combustion burner comprising:

a burner main body which is able to blow fuel gas which is a mixture of fuel and air; and

an ignition torch which is disposed inside the burner main body and allows a flame to propagate from a base end portion of the ignition torch so as to be sent out from a tip end portion of the ignition torch,

wherein the tip end portion of the ignition torch is disposed on the base end portion side with respect to a tip end portion of the burner main body.

2. The combustion burner according to claim 1,

wherein, during a non-operation of the ignition torch, the tip end portion of the ignition torch is disposed closer to the base end portion side than the tip end portion of the burner main body.

3. The combustion burner according to claim 2,

wherein a time of the non-operation of the ignition torch includes a time before allowing the flame to propagate from the base end portion of the ignition torch to the tip end portion or a time after stopping the propagation of the flame by the ignition torch after an ignition of the fuel gas from the burner main body.

4. The combustion burner according to claim 1,

wherein, during an operation of the ignition torch, the tip end portion of the ignition torch is disposed at substantially the same position as that of the tip end portion of the burner main body.

5. The combustion burner according to claim 4,

wherein a time of the operation of the ignition torch includes a time when the flame is allowed to propagate from the base end portion of the ignition torch to the tip end portion.

6. The combustion burner according to claim 1,

wherein the position of the tip end portion during the non-operation of the ignition torch is set in consideration of a length of a pipe through which the flame propagates.

7. The combustion burner according to claim 1,

wherein an ignition unit is provided in the base end portion of the ignition torch, and an on-off valve is provided on a downstream side in a fuel flow direction of the ignition unit.

8. A pressurized gasification furnace comprising:

a burner main body which is fixed to a furnace wall and is able to blow fuel gas which is a mixture of fuel and air into a furnace; and

an ignition torch which is fixed to the furnace wall to be disposed inside the burner main body and allows a flame to propagate from a base end portion of the ignition torch so as to be sent out from a tip end portion of the ignition torch,