JP3716095B2

JP3716095B2 - Coal burning device

Info

Publication number: JP3716095B2
Application number: JP07035798A
Authority: JP
Inventors: 啓史菅; 啓樹山口; 康二大浦; 徳雄宮崎; 利光一ノ瀬
Original assignee: Mitsubishi Heavy Industries Ltd
Current assignee: Mitsubishi Heavy Industries Ltd
Priority date: 1998-03-19
Filing date: 1998-03-19
Publication date: 2005-11-16
Anticipated expiration: 2018-03-19
Also published as: JPH11264509A

Description

【０００１】
【発明の属する技術分野】
本発明は、発電用ボイラ等に適用される石炭焚燃焼装置に関する。
【０００２】
【従来の技術】
従来の石炭焚燃焼装置の一例を図７、図８に示してある。この燃焼装置は、風箱１、燃料管２、及びバーナノズル３によって構成されている。バーナノズル３には、隔壁４によって内側の一次側通路５と、外側の二次側通路６とが形成されている。一次側通路５は、中央を空間７によってさらに上下に分岐されていて、その空間７は前記した二次側通路６と連通している。
【０００３】
図７、図８に示した石炭焚燃焼装置は前記した構成を有しており、微粉炭燃料と搬送空気の混合物９は燃料管２から供給され、燃焼用空気１０は風箱１と燃料管２の間からバーナノズル３へ流入する。燃料と搬送空気の混合物９はバーナノズル３の一次側通路５を通る流れ１１、燃焼用空気１０はバーナノズル３の二次側通路６を通る流れ１２をそれぞれ形成し、火炉８へ流れた後、燃料が燃焼する。
【０００４】
燃焼用空気がバーナノズル３の二次側通路６を通る流れ１２の一部は空間７を通る燃焼用空気の流れ１３となる。この流れ１３により、空間７内には図８に示すように旋回流れ１４が生じる。この旋回流れ１４の影響により空間７と火炉８の間の中央部では、その周囲よりも圧力が低い領域が生じ、一次側通路５を通る燃料と搬送空気の混合物が一次側通路を通る流れ１１の一部が図７に示すように逆流する流れ１５となり、空間７内に燃料が逆流する。
このように燃焼装置内に燃料が滞留すると、高温の火炉８からの輻射熱により燃料が燃焼するため、バーナノズル３がその熱により変形する可能性がある。
【０００５】
【発明が解決しようとする課題】
本発明は、前記したように内側に燃料管と連通した一次側通路、外側に風箱と連通した二次側通路が形成され、その一次側通路が上下２つに分岐されるとともにその間に前記二次側通路と連通された空間が形成されている石炭焚燃焼装置において、前記空間に燃料が流入するのを抑制可能に構成した石炭焚燃焼装置を提供することを課題としている。
【０００６】
【課題を解決するための手段】
本発明は、前記課題を解決するため、上下２つに分岐された一次側通路の間に形成された空間内に、幅方向の中央部が両端部に比べてバーナ軸方向に長い形状をもつ剥離防止構造物を配置して前記空間内の上流側を閉塞した構成の石炭焚燃焼装置を提供する。
【０００７】
本発明による石炭焚燃焼装置では、上下２つに分岐された一次側通路の間の空間に対し前記した構成、即ち幅方向の中央部が両端部に比べてバーナ軸方向に長い形状とした剥離防止構造物により前記空間内の上流側を閉塞して配置してあるので、二次側通路からこの空間へ流入して来る燃焼用空気はこの剥離防止構造物の外形に沿い、前記幅方向の両端部から前記中央部に向けて円滑に流れる。
【０００８】
そのため、この空間に流入する燃焼用空気は流れの剥離が生じないか、もし生じても非常に弱いものとなる。従って、その空間内に一次側通路から燃料と搬送空気の流入が抑制され滞留燃料の燃焼によるバーナノズルの変形等を防ぐことができる。
【０００９】
本発明は、また、前記課題を解決するため、一端が二次側通路内にあり、中間が同二次側通路内でノズル中央方向に向かって折れ曲がり、他端が上下２つに分岐された一次側通路の間に形成された空間内にあって、二次側通路からの空気をその空間に導く案内板を配置した構成をもつ石炭焚燃焼装置を提供する。
【００１０】
このように構成した本発明の石炭焚燃焼装置においては、燃焼用空気は二次側通路から一次側通路間の空間に向けて、前記案内板の一端、中間、他端の順に同案内板に沿って円滑に流れ込むため、その空間から火炉へ速い流速で流出させられ、一次側通路からその空間へ流入しようとする燃料と搬送用空気の逆流が抑制される。
【００１１】
【発明の実施の形態】
以下、本発明による石炭焚燃焼装置について図１〜図６に示した実施の形態に基づいて具体的に説明する。なお、以下の実施の形態において、図７、図８に示した従来の装置と同じ構成の部分には説明を簡単にするため同じ符号を付してある。
【００１２】
（第１実施形態）
まず、図１〜図３に示した第１実施形態による石炭焚燃焼装置について説明する。この第１実施形態による石炭焚燃焼装置は、バーナノズル３が隔壁４により内側の一次側通路５と外側の二次側通路６に分かれている点、さらに内側の一次側通路５を上下に分岐し、その間の空間７が外側の二次側通路６に通じている点は先に説明した従来のものと同じである。
【００１３】
しかしながら、本実施形態の石炭焚燃焼装置では、空間７内には幅方向の中央部がバーナ軸方向に長い形状の剥離防止構造物１６が設置されている。この剥離防止構造物１６の構造は図３に示すようなもので、図２に示した巾Ｌと軸方向の長さＬ１の比は一例としてＬ１＝Ｌ／２である。
【００１４】
このように、本実施形態の石炭焚燃焼装置は、空間７内に剥離防止構造物１６を配設した以外図７、図８に示した装置と同じである。
【００１５】
本実施形態の石炭焚燃焼装置において、燃料と搬送空気の混合物９は燃料管２から、燃焼用空気１０は風箱と燃料管２の間からそれぞれバーナノズル３内に流入し、燃料と搬送空気の混合物９はバーナノズル３の一次側通路５、燃焼用空気１０はバーナノズル３の二次側通路６及び空間７を経て、火炉８へ流れた後、燃料が燃焼する。
【００１６】
風箱１と燃料管２の間から燃焼器内に流入した燃焼用空気は、バーナノズル３の二次側通路６を経て火炉８へ流れるが、その一部は一次側通路５の間の空間７を通る。この時、従来の構成では先に説明したように二次側通路６から空間７を含めたスペースへの急拡大流路となるため、流れが剥離し、空間７内に旋回流れ１４が生じ、その結果空間７の火炉側の開口部の中央部の圧力が周囲より低くなり、燃料と搬送空気の混合物９が火炉８へ流れる一次側通路５を通る流れ１１の一部が空間７内に逆流するようになっていた。
【００１７】
しかしながら、本実施形態の装置では、空間７内に、幅方向中央部のバーナ軸方向の長さが長い剥離防止構造物１６があり、図２に示すようにこの外形に沿って燃焼用空気の流れ１３が流れるため流れの剥離が生じないか非常に弱くなる。その結果、空間７の火炉側の開口部の幅方向中央付近と周囲との圧力差が小さくなり、燃料と搬送空気の混合物９が一次側通路を通る流れ１１が、空間７へ逆流する流れ１５となるのを抑制され、滞留燃料の燃焼によるバーナノズル３の変形を防止することができる。
【００１８】
（第２実施形態）
次に、図４〜図６に示した第２実施形態による石炭焚燃焼装置について説明する。この第２実施形態による石炭焚燃焼装置では、第１実施形態で採用した剥離防止構造物１６を省き、代りに案内板１７を設置している。
【００１９】
すなわち、この案内板１７は、図６に示した形状をしており、一端が二次側通路６にあり、二次側通路６内で折れ曲がり、他端が空間７内にあるように配置される。その他の構成は、第１実施形態による石炭焚燃焼装置と実質同じ構造である。
【００２０】
以上の構造を有するこの第２実施形態による石炭焚燃焼装置においては、燃焼用空気１０は一端が二次側通路６内、他端が空間７内にある形状の案内板１７の内側に沿って空間７内に流れ込むため、空間７の幅方向中央部付近から火炉８へ流出する燃焼用空気の流れ１３の流速が速くなり、第１実施形態の装置と同様に、燃料と搬送用空気の混合物９が一次側通路５を通る流れ１１が空間７へ逆流するのを抑制され、滞留した燃料の燃焼によるバーナノズル３の変形が防止できる。
【００２１】
【発明の効果】
以上説明したように、本発明は、石炭が搬送される燃料管が内設された風箱と、その先端部に配置されたバーナノズルとで構成された石炭焚燃焼装置であって、同バーナノズルは、内側に前記燃料管と連通した一次側通路、外側に前記風箱と連通した二次側通路が形成され、前記一次側通路が上下２つに分岐されるとともに、その間に前記二次側通路と連通された空間が形成されているものにおいて、前記一次側通路間の前記空間内に、幅方向の中央部が両端部に比べてバーナ軸方向に長い形状をもつ剥離防止構造物を配置して前記空間内の上流側を閉塞した石炭焚燃焼装置を提供する。
【００２２】
この燃焼装置によれば、一次側通路の間にある空間へ二次側通路から流入して来る燃焼用空気はその剥離防止構造物の外形に沿って同剥離防止構造物の幅方向の両端部から中央部に向けて円滑に導かれる。そのため一次側通路からその空間への燃料と搬送空気の流入が抑制される。
【００２３】
また、前記した剥離防止構造物に代えて一端が前記二次側通路内にあり、中間が同二次側通路内でノズル中央方向に向かって折れ曲がり、他端が前記一次側通路間の前記空間内にあって同二次側通路からの空気を前記空間に導く案内板を設置した本発明の石炭焚燃焼装置では、その一次側通路間の空間には案内板に沿って二次側通路から燃焼用空気が円滑に流れ込むのでバーナノズルの中央部付近から火炉内へ流出する燃焼用空気流の速度が速くなり、この空間へ一次側通路から燃料が逆流するのが抑制される。
【図面の簡単な説明】
【図１】本発明の第１実施形態による石炭焚燃焼装置の断面図。
【図２】図１のII−II線に沿う断面図。
【図３】剥離防止構造物の斜視図。
【図４】本発明の第２実施形態による石炭焚燃焼装置の断面図。
【図５】図４のＶ−Ｖ線に沿う断面図。
【図６】案内板の図面で（ａ）は平面図、（ｂ）は側面図、（ｃ）は（ｂ）図の右側面図。
【図７】従来の石炭焚燃焼装置の断面図。
【図８】図７のVIII−VIII線に沿う断面図。
【符号の説明】
１風箱
２燃料管
３バーナノズル
４隔壁
５一次側通路
６二次側通路
７空間
８火炉
９燃料と搬送空気の混合物
１０燃焼用空気
１１一次側通路を通る流れ
１２二次側通路を通る流れ
１３燃焼用空気の流れ
１４旋回流れ
１５逆流する流れ
１６剥離防止構造物
１７案内板[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a coal-fired combustion apparatus applied to a power generation boiler or the like.
[0002]
[Prior art]
An example of a conventional coal-fired combustion apparatus is shown in FIGS. This combustion apparatus is constituted by a wind box 1, a fuel pipe 2, and a burner nozzle 3. In the burner nozzle 3, an inner primary passage 5 and an outer secondary passage 6 are formed by a partition wall 4. The center of the primary side passage 5 is further branched by a space 7, and the space 7 communicates with the secondary side passage 6 described above.
[0003]
The coal soot combustion apparatus shown in FIGS. 7 and 8 has the above-described configuration, and a mixture 9 of pulverized coal fuel and carrier air is supplied from the fuel pipe 2, and the combustion air 10 is supplied from the wind box 1 and the fuel pipe. It flows into the burner nozzle 3 from between 2. The fuel and carrier air mixture 9 forms a flow 11 through the primary passage 5 of the burner nozzle 3, and the combustion air 10 forms a flow 12 through the secondary passage 6 of the burner nozzle 3, and flows to the furnace 8. Burns.
[0004]
A part of the flow 12 through which the combustion air passes through the secondary passage 6 of the burner nozzle 3 becomes a flow 13 of combustion air through the space 7. By this flow 13, a swirl flow 14 is generated in the space 7 as shown in FIG. Due to the influence of the swirl flow 14, a region where the pressure is lower than the surroundings is generated in the central portion between the space 7 and the furnace 8, and the mixture of the fuel and the carrier air passing through the primary side passage 5 flows through the primary side passage 11. As shown in FIG. 7, part of the flow becomes a flow 15 that flows backward, and the fuel flows backward in the space 7.
If the fuel stays in the combustion device in this way, the fuel is combusted by the radiant heat from the high-temperature furnace 8, and the burner nozzle 3 may be deformed by the heat.
[0005]
[Problems to be solved by the invention]
In the present invention, as described above, the primary side passage communicating with the fuel pipe on the inner side and the secondary side passage communicating with the wind box on the outer side are formed, and the primary side passage is branched into two upper and lower parts, and the An object of the present invention is to provide a coal-fired combustion apparatus in which a space communicating with a secondary side passage is formed and configured to be able to suppress fuel from flowing into the space.
[0006]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the present invention has a shape in which the central portion in the width direction is longer in the burner axial direction than both ends in the space formed between the primary passages branched into two upper and lower sides. There is provided a coal-fired combustion apparatus having a structure in which an anti-peeling structure is arranged to close the upstream side in the space .
[0007]
In the coal-fired combustion apparatus according to the present invention, the above-described configuration with respect to the space between the primary side passage branched into two upper and lower sides, that is, the peeling in which the central portion in the width direction is longer in the burner axial direction than both ends. since the anti-structures are arranged to close the upstream side of the space, the combustion air coming flowing from the second-side passage to the space had along the contour of the peeling prevention structure, the width direction Smoothly flows from both ends to the center .
[0008]
Therefore, the combustion air flowing into this space does not cause separation of the flow, or if it occurs, it becomes very weak. Therefore, inflow of fuel and carrier air from the primary side passage into the space is suppressed, and deformation of the burner nozzle due to combustion of the staying fuel can be prevented.
[0009]
In order to solve the above-mentioned problem, the present invention has one end in the secondary passage, the middle is bent toward the center of the nozzle in the secondary passage, and the other end is branched into two upper and lower ends. Provided is a coal-fired combustion apparatus having a configuration in which a guide plate that guides air from a secondary-side passage to the space is disposed in a space formed between primary-side passages.
[0010]
In the coal soot combustion apparatus of the present invention configured as described above, the combustion air is directed to the same guide plate in the order of one end, the middle, and the other end of the guide plate from the secondary side passage toward the space between the primary side passages. Therefore, the fuel and the carrier air that are about to flow into the space from the primary side passage are restrained from flowing back to the furnace.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the coal-fired combustion apparatus according to the present invention will be described in detail based on the embodiment shown in FIGS. In the following embodiments, the same reference numerals are given to the same components as those of the conventional apparatus shown in FIGS.
[0012]
(First embodiment)
First, the coal-fired combustion apparatus according to the first embodiment shown in FIGS. 1 to 3 will be described. In the coal-fired combustion apparatus according to the first embodiment, the burner nozzle 3 is divided into an inner primary passage 5 and an outer secondary passage 6 by a partition wall 4, and the inner primary passage 5 is further branched up and down. The point that the space 7 between them communicates with the outer secondary passage 6 is the same as the conventional one described above.
[0013]
However, in the coal-fired combustion apparatus of the present embodiment, the peeling prevention structure 16 having a shape in which the central portion in the width direction is long in the burner axis direction is installed in the space 7. The structure of the peeling prevention structure 16 is as shown in FIG. 3, and the ratio of the width L and the axial length L1 shown in FIG. 2 is L1 = L / 2 as an example.
[0014]
Thus, the coal-fired combustion apparatus of this embodiment is the same as the apparatus shown in FIGS. 7 and 8 except that the peeling prevention structure 16 is disposed in the space 7.
[0015]
In the coal-fired combustion apparatus of the present embodiment, the mixture 9 of fuel and carrier air flows into the burner nozzle 3 from between the fuel tube 2 and the combustion air 10 from between the wind box and the fuel tube 2, respectively. The mixture 9 flows through the primary side passage 5 of the burner nozzle 3 and the combustion air 10 passes through the secondary side passage 6 and the space 7 of the burner nozzle 3 and flows into the furnace 8, and then the fuel burns.
[0016]
Combustion air that has flowed into the combustor from between the wind box 1 and the fuel pipe 2 flows into the furnace 8 through the secondary side passage 6 of the burner nozzle 3, and part of the air is a space 7 between the primary side passages 5. Pass through. At this time, in the conventional configuration, as described above, since it becomes a rapidly expanding flow path from the secondary side passage 6 to the space including the space 7, the flow is separated, and the swirling flow 14 is generated in the space 7, As a result, the pressure at the center of the opening on the furnace side of the space 7 becomes lower than the surroundings, and a part of the flow 11 passing through the primary passage 5 through which the mixture 9 of fuel and carrier air flows to the furnace 8 flows back into the space 7. I was supposed to.
[0017]
However, in the apparatus of the present embodiment, there is a peeling prevention structure 16 having a long length in the burner axial direction at the center in the width direction in the space 7, and as shown in FIG. Since the flow 13 flows, the flow separation does not occur or becomes very weak. As a result, the pressure difference between the vicinity of the center in the width direction of the opening on the furnace side of the space 7 and the surroundings becomes small, and the flow 11 through which the mixture 9 of fuel and carrier air passes through the primary-side passage flows back to the space 7. And the deformation of the burner nozzle 3 due to the combustion of the staying fuel can be prevented.
[0018]
(Second Embodiment)
Next, the coal soot combustion apparatus according to the second embodiment shown in FIGS. 4 to 6 will be described. In the coal-fired combustion apparatus according to the second embodiment, the peeling prevention structure 16 employed in the first embodiment is omitted, and a guide plate 17 is installed instead.
[0019]
That is, the guide plate 17 has the shape shown in FIG. 6, and is arranged so that one end is in the secondary side passage 6, the second side passage 6 is bent, and the other end is in the space 7. The Other configurations are substantially the same as those of the coal-fired combustion apparatus according to the first embodiment.
[0020]
In the coal-fired combustion apparatus according to the second embodiment having the above-described structure, the combustion air 10 extends along the inside of the guide plate 17 having a shape in which one end is in the secondary passage 6 and the other end is in the space 7. Since the air flows into the space 7, the flow speed of the combustion air flow 13 flowing out from the vicinity of the center in the width direction of the space 7 to the furnace 8 is increased, and the mixture of fuel and air for transportation is the same as in the apparatus of the first embodiment. 9 is prevented from flowing back into the space 7 through the flow 11 passing through the primary passage 5, and deformation of the burner nozzle 3 due to combustion of the accumulated fuel can be prevented.
[0021]
【The invention's effect】
As described above, the present invention is a coal-fired combustion apparatus comprising a wind box in which a fuel pipe for carrying coal is installed, and a burner nozzle arranged at the tip thereof, , primary passage communicating with the fuel tube on the inside, the second-side passage in communication with the air box to the outside are formed, the with primary path is branched into two vertically the second-side passage therebetween and in that communicated with the space is formed, in the space between the primary side passage, arranged a release preventing structure center in the width direction has a long shape in the axial direction of the burner as compared with both end portions And a coal-fired combustion apparatus in which the upstream side in the space is closed .
[0022]
According to this combustion apparatus, the combustion air flowing into the space between the primary side passages from the secondary side passages extends along the outer shape of the separation prevention structure in the widthwise ends of the separation prevention structure. It is smoothly guided from the center toward the center . Therefore, inflow of fuel and carrier air from the primary side passage to the space is suppressed.
[0023]
Further, instead of the above-described peeling prevention structure, one end is in the secondary side passage , the middle is bent toward the center of the nozzle in the secondary side passage, and the other end is the space between the primary side passages. In the coal-fired combustion apparatus of the present invention, in which the guide plate for guiding the air from the secondary side passage to the space is installed, the space between the primary side passages extends from the secondary side passage along the guide plate. Since the combustion air flows smoothly, the speed of the combustion air flow flowing out from the vicinity of the center of the burner nozzle into the furnace is increased, and the backflow of fuel from the primary passage to this space is suppressed.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a coal-fired combustion apparatus according to a first embodiment of the present invention.
2 is a cross-sectional view taken along line II-II in FIG.
FIG. 3 is a perspective view of a peeling prevention structure.
FIG. 4 is a sectional view of a coal-fired combustion apparatus according to a second embodiment of the present invention.
5 is a cross-sectional view taken along line VV in FIG.
6A is a plan view, FIG. 6B is a side view, and FIG. 6C is a right side view of FIG.
FIG. 7 is a cross-sectional view of a conventional coal-fired combustion apparatus.
8 is a cross-sectional view taken along line VIII-VIII in FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Wind box 2 Fuel pipe 3 Burner nozzle 4 Bulkhead 5 Primary side passage 6 Secondary side passage 7 Space 8 Furnace 9 Fuel and carrier air mixture 10 Combustion air 11 Flow through the primary side passage 12 Flow through the secondary side passage 13 Combustion air flow 14 Swirl flow 15 Backflow flow 16 Separation preventing structure 17 Guide plate

Claims

A coal soot combustion apparatus comprising a wind box in which a fuel pipe for carrying coal is installed and a burner nozzle arranged at the tip thereof, wherein the burner nozzle is connected to the fuel pipe on the inside. side passage, the second-side passage in communication with the air box is formed on the outer side, the with primary path is branched into two vertically, are formed the secondary passage and communicated with a space therebetween In this configuration, a separation preventing structure having a shape in which the central portion in the width direction is longer in the burner axial direction than the both ends in the space between the primary side passages is closed to close the upstream side in the space . Coal soot combustion apparatus characterized by the above.

A coal soot combustion apparatus comprising a wind box in which a fuel pipe for carrying coal is installed and a burner nozzle arranged at the tip thereof, wherein the burner nozzle is connected to the fuel pipe on the inside. A secondary passage that communicates with the wind box is formed outside the side passage, the primary passage is branched into two upper and lower portions, and a space that communicates with the secondary passage is formed therebetween. One end is in the secondary side passage , the middle is bent toward the center of the nozzle in the secondary side passage, and the other end is in the space between the primary side passages. A coal-fired combustion apparatus comprising a guide plate for guiding air from a passage to the space.