JP4877735B2

JP4877735B2 - Boiler equipment

Info

Publication number: JP4877735B2
Application number: JP2006010722A
Authority: JP
Inventors: 伸一郎野村; 聡彦嶺; 浩明金本; 秀久吉廻; 彰馬場; 紀之大谷津; 聡多田隈
Original assignee: Babcock Hitachi KK
Current assignee: Mitsubishi Power Ltd
Priority date: 2006-01-19
Filing date: 2006-01-19
Publication date: 2012-02-15
Anticipated expiration: 2026-01-19
Also published as: JP2007192452A

Description

本発明は、石炭焚きボイラなどのボイラ装置に係り、特に排ガス中の窒素酸化物及び一酸化炭素を低減するのに好適なボイラ装置に関する。 The present invention relates to a boiler device such as a coal-fired boiler, and more particularly to a boiler device suitable for reducing nitrogen oxides and carbon monoxide in exhaust gas.

火力発電所で石炭などの化石固体燃料を燃焼する場合に生成する窒素酸化物（以後ＮＯｘということがある）等の環境汚染物質の低減のために、火炉内を燃焼域、還元域、再燃焼域に分け、還元域でのＮＯｘを低減することが行われている。すなわち、燃焼域では理論空気比以下で燃料を燃焼させ、燃料中の窒素分から発生したＮＯｘを低酸素濃度の還元領域において還元し、炉出口でのＮＯｘを低減する二段燃焼方式が主流になっている。
特開平９−１９６３０９号公報特開平６−１４７４５８号公報特開平９−１２６４１２号公報特許第２９５４６４３号公報実願昭６２−１９４２２９号（実開平０１−１０１０１１号）マイクロフィルム特表２００５−５１７１４９号公報 To reduce environmental pollutants such as nitrogen oxides (hereinafter sometimes referred to as NOx) generated when burning fossil solid fuels such as coal in a thermal power plant, the furnace has a combustion zone, reduction zone, and reburning. It is divided into zones and NOx in the reduction zone is reduced. In other words, the two-stage combustion method, in which fuel is burned at a stoichiometric air ratio or less in the combustion zone, NOx generated from nitrogen content in the fuel is reduced in the reduction region with a low oxygen concentration, and NOx at the furnace outlet becomes the mainstream. ing.
JP-A-9-196309 JP-A-6-147458 Japanese Patent Laid-Open No. 9-126212 Japanese Patent No. 2954643 No. 62-194229 (No. 01-101011) No. Microfilm JP 2005-517149 A

前記特許文献１、２記載の発明では、アフターエアポート内のエアーを主流成分と副流成分などに分けることでバーナで生じた燃料の未燃焼成分を低減し、排ガスの低ＮＯｘ濃度化を図っているが、特許文献１記載の発明ではアフターエアポート内の主流と副流のエアーの圧力損失が一定状態であり、主流と副流の流量比率は固定されている。また、特許文献２記載の発明では、アフターエアポート内のエアー噴流は旋回流と直進流の組み合わせであるが、直進流を増して貫通性を上げれば、火炉の上流から下流に流れる燃料の未燃分がエアー直進流の左右方向へすり抜けることが多くなり、逆に直進流を減らすと、その貫通力が低下する問題点がある。 In the inventions described in Patent Documents 1 and 2, the air in the after-airport is divided into a mainstream component and a substream component, thereby reducing the unburned components of the fuel generated in the burner and reducing the NOx concentration of the exhaust gas. However, in the invention described in Patent Document 1, the pressure loss of the main flow and the sub flow air in the after-air port is constant, and the flow rate ratio of the main flow and the sub flow is fixed. In the invention described in Patent Document 2, the air jet in the after-air port is a combination of a swirl flow and a straight flow. However, if the straight flow is increased to improve the penetration, unburned fuel flowing from the upstream to the downstream of the furnace Minutes often pass in the left-right direction of the straight air flow, and conversely, if the straight flow is reduced, the penetrating force decreases.

また、前記特許文献３〜５には、比較的低温の火炉出口排ガスをバーナとアフターエアポートの間の火炉壁から炉内に供給してサーマルＮＯｘ及びフューエルＮＯｘの発生量を抑えることができることが開示されている。 Patent Documents 3 to 5 disclose that a relatively low-temperature furnace outlet exhaust gas can be supplied into the furnace from the furnace wall between the burner and the after-air port to suppress the generation amount of thermal NOx and fuel NOx. Has been.

しかし、これら特許文献記載の方法でも火炉内での異なるガス同士が十分均一に混合できなく、ＣＯ濃度とＮＯｘ濃度の低減化効果が不十分であった。
さらに、特許文献６にはアフターエアポート内のエアーを水平方向に主流成分と副流成分などに分けることでバーナで生じた燃料の未燃焼成分を低減し、排ガスの低ＮＯｘ濃度化を図る構成が開示されているが、各分割されたエアー噴流は直進流であり火炉水平断面全域にエアーを搬送することができないので火炉の上流から下流に流れる燃料の未燃分がエアー直進流の左右方向へすり抜けることが多くなる。 However, even in the methods described in these patent documents, different gases in the furnace cannot be mixed sufficiently uniformly, and the effect of reducing the CO concentration and the NOx concentration is insufficient.
Further, Patent Document 6 has a configuration in which the unburned components of the fuel generated in the burner are reduced by dividing the air in the after airport horizontally into a mainstream component and a substream component, thereby reducing the NOx concentration of the exhaust gas. Although disclosed, each divided air jet is a straight flow, and air cannot be conveyed across the entire horizontal cross section of the furnace, so the unburned fuel flowing from the upstream to the downstream of the furnace moves in the left-right direction of the straight air flow. More slipping through.

本発明の課題は、火炉内で石炭などの固体燃料の燃焼性を損なうこと無く、未燃ガスのすり抜けを防止し、火炉中央部のみならず火炉側壁においても燃焼排ガス中のＣＯ濃度とＮＯｘ濃度の低減化効果が達成できるボイラ装置を提供することである。 An object of the present invention is to prevent the passage of unburned gas without impairing the combustibility of a solid fuel such as coal in the furnace, and the concentration of CO and NOx in the combustion exhaust gas not only in the center of the furnace but also in the side wall of the furnace. It is providing the boiler apparatus which can achieve the reduction effect of this.

本発明の上記課題は次の解決手段により解決される。
請求項１記載の発明は、石炭を含む固体燃料を火炉で燃焼させるボイラ装置において、火炉の対向する一対の壁面に理論空気比以下の空気量で固体燃料を燃焼させるバーナを一段毎に複数個、かつ燃焼ガス流れ方向に一段以上設け、火炉の対向する一対の壁面の前記バーナの下流側であって、該バーナでの固体燃料の燃焼に不足する燃焼用エアを火炉内に噴出するアフターエアポートを一段毎に複数個、かつ燃焼ガス流れ方向に一段以上設け、前記アフターエアポート内には、該アフターエアポートから火炉内に吹き出す燃焼用エアの方向を水平方向に３分割以上に分割し、該各分割エアの方向が互いに同一方向にならないような形状を有するエア分割部材を設け、該エア分割部材は、前記アフターエアポートから火炉内に吹き出す燃焼用エアの方向を変更可能に設けられたボイラ装置である。 The above-described problems of the present invention are solved by the following solution means.
According to the first aspect of the present invention, in a boiler apparatus for burning a solid fuel containing coal in a furnace, a plurality of burners for burning the solid fuel at an air amount equal to or less than the theoretical air ratio are provided on a pair of opposing wall surfaces of the furnace for each stage. And an after-air port that is provided in the combustion gas flow direction at one or more stages and is downstream of the burner between a pair of wall surfaces facing the furnace, and injects combustion air that is insufficient to burn solid fuel in the burner into the furnace Are provided in each stage, and one or more stages are provided in the direction of combustion gas flow, and in the after-air port, the direction of the combustion air blown out from the after-air port into the furnace is divided into three or more parts in the horizontal direction. an air dividing member having a shape such that the direction of the divided air is not in the same direction to each other is provided, the air split member, combustion d to be blown into the furnace from the after Airport A boiler apparatus which is provided can be changed in the direction of.

請求項１記載の発明によれば、エア分割部材により燃焼用エアを火炉内に水平方向に３分割以上に分割して、それぞれの噴出方向を変えることで、分割された噴出流が互いに直接衝突することによる急速な混合を避けるとともに、水平断面に幅広く噴流を形成することで、燃焼ガスと未燃焼ガスの混合を促進し、未燃ガスのすり抜けを防止することができる。その結果、燃焼ガス中のサーマルＮＯｘ生成を抑制し、かつＡＡＰの水平断面方向に広く噴流を拡散させて燃焼ガス中のＣＯのすり抜け防止にも役立つ。
また、エア分割部材によってＡＡＰから火炉内に吹き出すエアの方向を変更できるため、ＡＡＰからの噴流の噴出方向を調整することで対向する火炉壁からのエア噴出流との急速な衝突を避けることができ、更なるサーマルＮＯｘ生成の抑制と燃焼ガス中のＣＯのすり抜け防止効果に役立つ。 According to the first aspect of the invention, the combustion air is divided into three or more parts in the horizontal direction in the furnace by the air dividing member, and the respective jet directions are changed so that the divided jet flows directly collide with each other. In addition to avoiding rapid mixing by forming a jet in a horizontal section, mixing of combustion gas and unburned gas can be promoted, and slipping of unburned gas can be prevented. As a result, the generation of thermal NOx in the combustion gas is suppressed, and the jet is diffused widely in the horizontal cross-sectional direction of the AAP to help prevent the CO in the combustion gas from slipping through.
Moreover, since the direction of the air blown out from the AAP into the furnace can be changed by the air dividing member, it is possible to avoid a rapid collision with the air jet flow from the facing furnace wall by adjusting the jet direction of the jet flow from the AAP. This is useful for further suppressing the generation of thermal NOx and preventing CO from slipping through the combustion gas.

請求項２記載の発明は、エア分割部材が、該エア分割部材から燃焼用エアを火炉内に３分割以上に分割したエアの中で主流となる中央部の燃焼用エアを噴出する最も大きい断面積を持つ分割噴出流の出口開口面積がアフターエアポート（ＡＡＰ）の全出口開口面積の６０％以上を占める構成からなる請求項１記載のボイラ装置である。 According to a second aspect of the present invention, the air dividing member ejects the combustion air in the central portion which is the mainstream among the air obtained by dividing the combustion air from the air dividing member into three or more parts in the furnace. The boiler apparatus according to claim 1, wherein the outlet opening area of the divided jet flow having an area occupies 60% or more of the total outlet opening area of the after-airport (AAP).

請求項２記載の発明によれば、主流の出口開口面積がＡＡＰの全出口開口面積の６０％以上を占める構成とすることにより、主流の水平方向左右両側にできる副流に主流の噴出流が引き込まれることなく、主流の噴出流が火炉中央部に向けて貫通力を失うことがない。その結果、火炉中央部で未燃ガスがすり抜けることが無くなる。 According to the second aspect of the present invention, the mainstream outlet opening area occupies 60% or more of the total outlet opening area of the AAP. Without being drawn in, the mainstream jet flow does not lose its penetration force toward the center of the furnace. As a result, unburned gas will not slip through the center of the furnace.

請求項３記載の発明は、一つのアフターエアポートに設けられたエア分割部材により分割されたエア噴出流の噴出方向は、対向する壁面に設けられた隣接する合計４個のアフターエアポートで作る平面の中心に向かい、水平方向に噴出する角度（θo）を超えない範囲にある請求項１又は２に記載のボイラ装置である。 In the invention according to claim 3, the jet direction of the air jet flow divided by the air dividing member provided in one after-air port is a plane formed by a total of four after-air ports adjacent to each other provided on the opposing wall surfaces. It is a boiler apparatus of Claim 1 or 2 which exists in the range which does not exceed the angle ((theta) o) ejected toward a center and a horizontal direction.

請求項３記載の発明によれば、前記した条件に合致したアフターエアポートからエア噴出流を噴出させることで火炉出口排ガス中のＣＯ濃度とＮＯｘ濃度を従来より低減できる。 According to the third aspect of the present invention, the CO concentration and NOx concentration in the exhaust gas from the furnace outlet can be reduced as compared with the prior art by causing the air jet flow to be ejected from the after-air port that meets the above-described conditions.

請求項４記載の発明は、一つのアフターエアポートから火炉内に噴出する燃焼用エア噴出流の内で主流以外の燃焼用エア噴出流である副流の水平方向の噴出角度（θ）の、前記隣り合う合計４個のアフターエアポートで作る平面の中心に向かい、水平方向の噴出角度（θo）に対する比率である２次噴出角度（θ／θo）が、
０．４≦２次噴出角度θ／θo≦１
となるように設定した請求項３に記載のボイラ装置である。 According to a fourth aspect of the present invention, the horizontal injection angle (θ) of the side flow which is a combustion air jet flow other than the main flow among the combustion air jet flows jetted from one after-air port into the furnace, The secondary ejection angle (θ / θo), which is a ratio to the horizontal ejection angle (θo), is directed to the center of the plane formed by a total of four after-airports adjacent to each other.
0.4 ≦ secondary ejection angle θ / θo ≦ 1
It is a boiler apparatus of Claim 3 set so that it may become.

請求項４記載の発明によれば、火炉出口排ガス中のＣＯ濃度は、０．４≦２次噴出角度θ／θo≦１で最小になり、前記ＮＯｘ濃度は２次噴出角度θ／θoが１を超えると急増する傾向が見られるので前記２次噴出角度θ／θoが０．４以上であって、１以下であることが好ましい。 According to the fourth aspect of the present invention, the CO concentration in the furnace outlet exhaust gas becomes minimum when 0.4 ≦ secondary ejection angle θ / θo ≦ 1, and the NOx concentration is 1 when the secondary ejection angle θ / θo is 1. Since the tendency to increase rapidly is seen when the value exceeds the value, the secondary ejection angle θ / θo is preferably 0.4 or more and preferably 1 or less.

請求項５記載の発明は、同一段の各アフターエアポートに設けられるエア分割部材の中で、各アフターエアポートが設置される一対の火炉壁面の端部同士を接続する一対の火炉側壁に最も近い部位にあるアフターエアポートに取り付けられるエア分割部材は、該エア分割部材からの複数のエア噴出流の噴出方向の中で、前記火炉側壁方向への噴出流の噴出角度および運動量の一方又は両方が他のエア噴出流の噴出角度及び運動量よりも大きく設定されている請求項１から４のいずれか１項に記載のボイラ装置である。 The invention according to claim 5 is a part closest to the pair of furnace side walls connecting the ends of the pair of furnace wall surfaces on which each after-air port is installed among the air dividing members provided in each after-air port of the same stage. The air dividing member attached to the after-air port in the air dividing member has one or both of the jetting angle and momentum of the jet flow toward the furnace side wall among the jet directions of the plurality of air jet flows from the air splitting member. from claim 1 is set larger than the ejection angle and momentum of the air jet flow is boiler apparatus according to any one of 4.

請求項６記載の発明は、一対の火炉側壁に近い部位に位置する火炉壁面に設けられた各段のアフターエアポートに取り付けられるエア分割部材の火炉側壁方向に噴出流を導くエア分割部材の設置数を、同一段の他のアフターエアポートに設けられるエア分割部材より多くした請求項１から５のいずれか１項に記載のボイラ装置である。 The invention according to claim 6 is the number of installed air dividing members that guide the jet flow toward the furnace side wall of the air dividing member attached to the after-air port of each stage provided on the furnace wall surface located near the pair of furnace side walls. and a boiler apparatus according to any one of claims 1-5 which is larger than an air dividing member provided in the other after Airport same stage.

請求項５、６記載の発明によれば、火炉側壁側のエア噴出流の側壁方向への噴出角度および当該噴流の運動量の一方あるいは両方が他のエア噴出流の噴出角度及び運動量よりも大きく設定されていることにより、火炉側壁側に運動量の大きいエア噴出流が流れる。火炉側壁側には未燃ガスの一種であるＣＯ濃度の高い領域が形成され易いが、この領域にエア噴出流が行き届き、空気との混合を促進してＣＯ濃度は低減する。 According to the inventions described in claims 5 and 6 , one or both of the jet angle in the side wall direction of the air jet flow on the side wall of the furnace and the momentum of the jet flow are set larger than the jet angle and momentum of the other air jet flow. By doing so, an air jet flow having a large momentum flows on the side wall of the furnace. A region having a high CO concentration, which is a kind of unburned gas, is likely to be formed on the side wall of the furnace. However, an air jet stream reaches this region, promoting mixing with air and reducing the CO concentration.

請求項７記載の発明は、同一段の各アフターエアポートに設けられるエア分割部材により分割されたエア噴出流の中の一つ以上のエア噴出流の噴出方向が、当該エア分割部材が設置されたアフターエアポートより上流側の火炉内の方向に向かうように構成する請求項１から５のいずれか１項に記載のボイラ装置である。 In the invention according to claim 7, the ejection direction of one or more air ejection flows among the air ejection flows divided by the air division member provided in each after-air port of the same stage is provided with the air division member. It is a boiler apparatus of any one of Claim 1 to 5 comprised so that it may go to the direction in the furnace upstream from an after air port.

請求項７記載の発明によれば、分割されたエア噴流を上流側に向けることによって対向するＡＡＰからの噴流との急速な衝突を避けることができるため、反応領域が拡大するので温度の急激な上昇を抑え、同時に排ガス中のサーマルＮＯｘの生成を抑制することができる。 According to the seventh aspect of the present invention, since the rapid collision with the jet from the facing AAP can be avoided by directing the divided air jet toward the upstream side, the reaction region is expanded, so that the temperature is rapidly increased. It is possible to suppress the rise and simultaneously suppress the generation of thermal NOx in the exhaust gas.

請求項８記載の発明は、最上段の複数のバーナが、対向する火炉壁面でそれぞれ同一水平位置であって、相対向する位置からずれた位置にそれぞれ配置され（千鳥配列ということにする。）、各段の複数のアフターエアポートは、対向する一対の火炉壁面でそれぞれ同一水平位置に配置され、最上段バーナの下流側の同一壁面に設けられる最下段の各アフターエアポートは、前記最上段の複数のバーナの中の隣接する２つのバーナの中間位置の上方に配置される（千鳥配列ということにする。）請求項１から７のいずれか１項に記載のボイラ装置である。 In the invention according to claim 8 , the plurality of burners at the uppermost stage are respectively arranged at the same horizontal position on the opposing furnace wall surfaces and shifted from the opposed positions (referred to as a staggered arrangement). The plurality of after-air ports of each stage are arranged at the same horizontal position on a pair of opposing furnace wall surfaces, and the lowermost after-air ports provided on the same wall surface on the downstream side of the uppermost burner are the plurality of upper-stage air ports. is disposed above the intermediate position between two adjacent burners in the burner (to be referred to as staggered.) is a boiler apparatus according to any one of claims 1 to 7.

請求項８記載の発明によれば、最上段のバーナを対向する火炉壁面に互いに千鳥配列し、最上段バーナの下流側の同一壁面に設けられる最下段のＡＡＰを最上段バーナに対して千鳥配列することにより、最上段バーナからの微粉炭を含んだ噴流は対向壁からのバーナ噴出流と火炉内の中央部では衝突せずに火炉中央部から対向壁側に寄った位置で湾曲上昇する。そこで、対向壁面の最下段のＡＡＰは隣接する最上段バーナの中間位置とは逆の千鳥配列にすることによりアフターエア噴出流が上記バーナからの湾曲上昇噴流を直撃して混合促進する（図１３参照）。 According to the invention described in claim 8 , the uppermost burners are arranged in a staggered manner on the opposing furnace wall surfaces, and the lowermost AAP provided on the same wall surface downstream of the uppermost burner is arranged in a staggered manner with respect to the uppermost burner. By doing so, the jet flow containing the pulverized coal from the uppermost burner does not collide with the burner jet flow from the opposing wall in the central portion of the furnace, and rises in a curved manner at a position close to the opposing wall side from the central portion of the furnace. Therefore, the lowermost AAP on the opposite wall surface has a staggered arrangement opposite to the intermediate position between the adjacent uppermost burners, so that the after-air jet stream directly strikes the curved rising jet stream from the burner to promote mixing (FIG. 13). reference).

請求項９記載の発明は、少なくとも一段の各アフターエアポートは、その上流側の同一壁面に設けられる最上段の複数のバーナの中の隣接する２つのバーナの中間位置の上方に配置されている請求項８記載のボイラ装置である。 The invention of claim 9 wherein at least one stage of the after-Airport, wherein arranged above the intermediate position between two adjacent burners in the multiple burner top which is provided in the same wall surface of the upstream side Item 9. The boiler device according to Item 8 .

請求項９記載の発明によれば、最上段バーナからの微粉炭を含んだ噴流は対向壁からのバーナ噴出流と火炉内の中央部では衝突せずに火炉中央部から対向壁側に寄った位置で湾曲上昇する際に、最上段の複数のバーナの内の隣接バーナの中間位置にある対向壁面のＡＡＰからのアフターエア噴出流が上記バーナからの湾曲上昇噴出流を直撃して混合促進する（図１３参照）。このため未燃焼成分が効果的に燃焼する。 According to the ninth aspect of the present invention, the jet flow containing pulverized coal from the uppermost burner does not collide with the burner jet flow from the opposing wall in the central portion of the furnace, and approaches the opposing wall side from the central portion of the furnace. When the curve rises at the position, the after-air jet flow from the AAP on the opposite wall surface at the intermediate position of the adjacent burners among the plurality of burners at the uppermost stage directly strikes the curve rise jet flow from the burner and promotes mixing. (See FIG. 13). For this reason, an unburned component burns effectively.

請求項１０記載の発明は、各段の各アフターエアポートは、それぞれ互いに上下段で隣接する複数のアフターエアポートの中の隣接する２つのアフターエアポートの中間位置に配置されている請求項８又は９に記載のボイラ装置である。 The invention of claim 1 0 wherein, each after Airport of each stage, according to claim 8 or each of which is arranged in an intermediate position between two adjacent after Airport of a plurality of after-Airport adjacent upper and lower mutually 9 It is a boiler apparatus as described in.

請求項１０記載の発明によれば、複数段のバーナからの微粉炭を含んだ噴出流が対向壁側に寄った位置で湾曲上昇する際に、該対向壁面のいずれかのＡＡＰからのアフターエア噴出流と混合され、このため未燃焼成分が効果的に燃焼する。 According to the invention of claim 1 0, wherein, when the jet stream containing pulverized coal from a plurality of stages of burners is increased curvature at a position close to the opposite wall, after from either AAP of the counter wall It is mixed with the air jet stream so that the unburned components are effectively burned.

請求項１１記載の発明は、前記バーナの下流側であって、かつ前記アフターエアポートの上流側にボイラから排出するボイラ排ガスの一部を供給する混合促進ポートを水平方向の一段毎に複数個、かつ一段以上設けた請求項１から１０のいずれか１項に記載のボイラ装置である。 Invention of claim 1 1, wherein, a downstream side of said burner, and wherein the plurality of mixing promotion port for supplying a part of the boiler exhaust gas discharged from the boiler to the upstream side of the after airport in the horizontal direction of each stage And it is a boiler apparatus of any one of Claim 1 to 10 provided one or more steps | paragraphs .

請求項１１記載の発明によれば、バーナとＡＡＰの間に混合促進ポートを設けることにより、火炉内のバーナで形成された燃焼ガス流領域とその他の未燃焼ガス領域の混合を促進する効果があり、バーナからの燃焼ガス中の未燃分も完全燃焼し、ボイラの燃焼効率が従来より向上する。 According to the invention of claim 1 1, wherein the burner and by providing the mixing acceleration port during AAP, the effect of promoting the mixing of the combustion gas flow region formed by the burner in the furnace and other unburned gas region The unburned portion in the combustion gas from the burner is completely burned, and the combustion efficiency of the boiler is improved as compared with the conventional case.

すなわち、バーナとＡＡＰの間の火炉内の領域は窒素酸化物の還元作用が行われる還元領域であるが、火炉内にはバーナ火炎で形成された高ＮＯｘ濃度領域と、未燃ガス領域の低ＮＯｘ濃度領域が存在し、それらの領域が混合することなく還元作用が働く。そのため、高ＮＯｘ濃度領域においては充分な還元作用が働かず、ＡＡＰから燃焼用エアが混合し、再燃焼領域での再生成ＮＯｘが生じ、炉出口での高ＮＯｘ濃度につながる。そこで、混合促進ポートからバーナ火炎で形成された燃焼ガス領域とその他未燃焼ガス領域が混在する状態で燃焼排ガスを高速で吹き込むことにより、炉内のガスの流動状態を変化させ、燃焼ガスと未燃焼ガスの混合を促進する効果がある。 That is, the region in the furnace between the burner and the AAP is a reduction region in which the reduction action of nitrogen oxide is performed, but the high NOx concentration region formed by the burner flame and the unburned gas region are low in the furnace. There are NOx concentration regions, and these regions work without mixing. Therefore, sufficient reduction action does not work in the high NOx concentration region, and combustion air is mixed from AAP, regenerated NOx is generated in the recombustion region, leading to a high NOx concentration at the furnace outlet. Therefore, by blowing the combustion exhaust gas at a high speed in a state where the combustion gas region formed by the burner flame and other unburned gas regions coexist from the mixing promotion port, the flow state of the gas in the furnace is changed, and the combustion gas and the unburned gas region are changed. It has the effect of promoting the mixing of combustion gases.

また、混合促進ポートから混合促進ガスを吹き込むことで、燃焼ガス領域に残存する一酸化炭素と残存酸素との混合が促進され酸化作用により一酸化炭素が最終生成物である二酸化炭素に変換される。 Further, by blowing the mixing promotion gas from the mixing promotion port, mixing of carbon monoxide remaining in the combustion gas region and residual oxygen is promoted, and carbon monoxide is converted into carbon dioxide, which is the final product, by oxidation. .

請求項１２記載の発明は、混合促進ポートを、最上段バーナでの燃料の燃焼が緩慢になった領域に混合促進ガスを吹き込むことができる箇所の火炉壁に設けた請求項１１記載のボイラ装置である。 The invention of claim 1 wherein the mixing promotion ports, according to claim 1 1, wherein the combustion of the fuel is provided in the furnace wall locations that can be blown to promote mixing gas space made slow at the uppermost stage burner It is a boiler device.

請求項１２記載の発明によれば、最上段バーナでの燃焼が緩慢になった火炉内の部位に混合促進ポートから燃焼排ガスなどを例えば高速な旋回噴出流として吹き込むことにより、炉内の燃焼ガス領域と未燃焼ガス領域の混合が促進され、排ガス中のＮＯｘ濃度が均一となり、ＡＡＰまでの燃料の還元燃焼領域で充分な還元作用が得られ、炉出口では排ガス中のＮＯｘ濃度は著しく低下する。さらに、排ガス中のＣＯ濃度低減にも作用する。理由は、燃焼ガス領域に残存する一酸化炭素が、燃焼ガス領域と未燃ガス領域との混合促進により、未燃ガス領域内の残存酸素と反応して最終生成物である二酸化炭素となるためである。 According to the invention of claim 1 wherein, by blowing, for example, as a high-speed swirling jet flow and flue gas from the mixing acceleration port at the site of combustion furnace became slow in the uppermost stage burner, the combustion in the furnace Mixing of the gas region and unburned gas region is promoted, the NOx concentration in the exhaust gas becomes uniform, and sufficient reduction action is obtained in the reduction combustion region of the fuel up to AAP, and the NOx concentration in the exhaust gas is significantly reduced at the furnace outlet To do. Furthermore, it acts to reduce the CO concentration in the exhaust gas. The reason is that carbon monoxide remaining in the combustion gas region reacts with residual oxygen in the unburned gas region and becomes carbon dioxide, which is the final product, by promoting mixing of the combustion gas region and the unburned gas region. It is.

請求項１３記載の発明は、混合促進ポートを、バーナを設置した火炉壁の両端部側にも設置した請求項１１又は１２に記載のボイラ装置である。 The invention of claim 1 3, wherein the mixing promotion port, a boiler apparatus according to claim 1 1 or 1 2 is also installed in both ends of the furnace wall was installed burners.

請求項１３記載の発明によれば、対向燃焼方式の場合、バーナ部上方の側壁近傍に不完全燃焼しているＣＯ濃度の高い領域が形成されるので、混合促進ポートからは出来るだけ少量の燃焼排ガスなどを吹き込むことで火炉側壁近傍でのＣＯ濃度の低減化が可能となる。 According to claim 1 3 invention described, if the opposing combustion method, since regions with high CO concentrations to the vicinity of the side wall of the burner portion above is incomplete combustion is formed, only a small amount of possible from mixing promotion port By blowing combustion exhaust gas or the like, the CO concentration in the vicinity of the furnace side wall can be reduced.

請求項１記載の発明によれば、ＡＡＰから火炉内に吹き出すエアの方向を水平方向にエアー噴出方向を末広がり状に分割するエア分割部材２１を設けたので、燃焼ガスと未燃焼ガスの混合を促進し、ＣＯを含む未燃ガスのすり抜けを防止でき、火炉内のガス流動が均一化され、火炉出口の排ガス中の低ＮＯｘ濃度化と低ＣＯ濃度化を達成できる。
また、エア分割部材２１によってＡＡＰから火炉内に吹き出すエアの方向を変更できるため、更に燃焼ガス中のサーマルＮＯｘ生成を抑制し、燃焼ガス中のＣＯのすり抜けを防止できる。 According to the first aspect of the present invention, since the air dividing member 21 that divides the direction of the air blown out from the AAP into the furnace in the horizontal direction and the air blowing direction in a divergent form is provided, the mixing of the combustion gas and the unburned gas is performed. It is possible to prevent the unburned gas containing CO from slipping through, uniform the gas flow in the furnace, and achieve low NOx concentration and low CO concentration in the exhaust gas at the furnace outlet.
Moreover, since the direction of the air blown out from the AAP into the furnace can be changed by the air dividing member 21, it is possible to further suppress the generation of thermal NOx in the combustion gas and prevent the CO in the combustion gas from slipping through.

請求項２記載の発明によれば、請求項１記載の発明の効果に加えて、火炉中央部で未燃ガスのすり抜けを防止できる。 According to the invention described in claim 2, in addition to the effect of the invention described in claim 1, unburned gas can be prevented from slipping through the center of the furnace.

請求項３記載の発明によれば、請求項１又は２に記載の発明の効果に加えて、火炉出口排ガス中のＣＯ濃度とＮＯｘ濃度をより一層低減できる。 According to the invention described in claim 3 , in addition to the effect of the invention described in claim 1 or 2 , the CO concentration and NOx concentration in the furnace outlet exhaust gas can be further reduced.

請求項４記載の発明によれば、請求項３に記載の発明の効果に加えて、前記２次噴出角度θ／θoが０．４以上であって、１以下にすることで、火炉出口排ガス中のＣＯ濃度とＮＯｘ濃度をより一層低減できる。 According to the invention of claim 4 , in addition to the effect of the invention of claim 3 , by making the secondary ejection angle θ / θo 0.4 or more and 1 or less, the exhaust gas from the furnace outlet The CO concentration and NOx concentration can be further reduced.

請求項５、６記載の発明によれば、請求項１から４のいずれか１項に記載の発明の効果に加えて、ＣＯを含む未燃ガスのすり抜けを確実に防止するとともに、火炉出口排ガス中のＣＯ濃度とＮＯｘ濃度をより一層低減できる。また、従来必要であった火炉側壁方向へのエア噴出用のサイドＡＡＰが不要となり、設備コストの低減化に貢献できる。 According to claim 5, 6 the invention described, in addition to the effect of the invention according to any one of claims 1 to 4, with reliably prevent slipping of unburned gas containing CO, furnace exit exhaust gas The CO concentration and NOx concentration can be further reduced. Further, the side AAP for blowing air in the direction of the side wall of the furnace, which has been necessary in the past, is no longer necessary, which can contribute to a reduction in equipment costs.

請求項７記載の発明によれば、請求項１から５のいずれか１項に記載の発明の効果に加えて、燃焼反応領域を拡大してガス温度の急激な上昇を抑え、同時に排ガス中のサーマルＮＯｘの生成を抑制することができる。 According to the invention of claim 7, wherein, in addition to the effect of the invention according to any one of claims 1 to 5, suppressing the rapid rise in the gas temperature to expand the combustion reaction zone, in the exhaust gas simultaneously Generation of thermal NOx can be suppressed.

請求項８記載の発明によれば、請求項１から７のいずれか１項に記載の発明の効果に加えて、アフターエア噴出流がバーナからの湾曲上昇噴出流を直撃して燃焼ガスと未燃焼ガスの混合を促進し、より一層の未燃ガスのすり抜け防止効果がある。 According to the invention of claim 8, wherein, in addition to the effect of the invention according to any one of claims 1 to 7, non-combustion gas after-air jet flow is hit the curved rising plume from the burner The mixing of the combustion gas is promoted, and there is a further effect of preventing the unburned gas from slipping through.

請求項９記載の発明によれば、請求項８記載の発明の効果に加えて、より一層の未燃焼ガスを低減できる。 According to the ninth aspect of the invention, in addition to the effect of the eighth aspect of the invention, further unburned gas can be reduced.

請求項１０記載の発明によれば、請求項８又は９に記載の発明の効果に加えて、より一層の未燃焼成分の低減を図ることができる。 According to the invention of claim 1 0, wherein, in addition to the effect of the invention of claim 8 or 9, reduced even more unburned components.

請求項１１記載の発明によれば、請求項１から１０のいずれか１項に記載の発明の効果に加えて、燃焼ガス中の未燃分も完全燃焼し、ボイラの燃焼効率がより一層向上し、排ガス中のＮＯｘ濃度とＣＯ濃度を低減することができる。 According to the invention of claim 1 1, wherein, in addition to the effect of the invention according to any one of claims 1 to 1 0, unburned in the combustion gas is also complete combustion, more combustion efficiency of the boiler Further improvement is possible, and the NOx concentration and CO concentration in the exhaust gas can be reduced.

請求項１２記載の発明によれば、請求項１１記載の発明の効果に加えて、より一層炉内の燃焼ガス領域と未燃焼ガス領域の混合が促進され、炉出口では排ガス中のＮＯｘ濃度とＣＯ濃度が共に従来より低減する。 According to the invention of claim 1 wherein, wherein in addition to the effect of the invention of claim 1 1, wherein, more is further promoted mixing of combustion gas region and unburned gas region in the furnace, NOx in the exhaust gas in the furnace exit Both the concentration and the CO concentration are lower than before.

請求項１３記載の発明によれば、請求項１１又は１２に記載の発明の効果に加えて、火炉側壁近傍の不完全燃焼領域のＣＯ濃度を低減することができる。 According to claim 1 3 invention described can be in addition to the effect of the invention according to claim 11 or 12, to reduce the CO concentration in the incomplete combustion region of the furnace side wall near.

本発明の実施例を図面と共に説明する。
図１には石炭焚きボイラの全体の系統図を示している。バンカ１１から供給する石炭はフィーダ１２で流量調整され、微粉炭製造装置（ミル）２へ一次エアによって搬送される。ミル２で微粉に粉砕された石炭（微粉炭）は送炭管１０を通りバーナ６に供給され、ボイラ火炉１へ投入される。微粉炭を燃焼させる燃焼用エアは、熱交換器４で３００〜４００℃くらいの高温空気となり、風箱５からバーナ６の外周部とＡＡＰ（ＡＡＰ）７から火炉１へ投入される。 Embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows an overall system diagram of a coal fired boiler. The flow rate of coal supplied from the bunker 11 is adjusted by the feeder 12 and conveyed to the pulverized coal production apparatus (mill) 2 by primary air. Coal (pulverized coal) pulverized into fine powder by the mill 2 is supplied to the burner 6 through the coal feeding pipe 10 and is supplied to the boiler furnace 1. Combustion air for burning pulverized coal becomes high-temperature air of about 300 to 400 ° C. in the heat exchanger 4 and is fed from the wind box 5 to the outer peripheral portion of the burner 6 and from the AAP (AAP) 7 to the furnace 1.

ボイラ火炉１で燃焼した排ガスは脱硝装置１３でガス中に含まれる窒素酸化物（ＮＯｘ）が低減され、次いで熱交換器４でガス温度が下げられ、その後、電器集塵機１４で除塵され、さらに脱硫装置１５でガス中に含まれる硫黄酸化物が低減され、煙突１６より大気へ放出される。 The exhaust gas burned in the boiler furnace 1 is reduced in nitrogen oxide (NOx) contained in the gas by the denitration device 13, then the gas temperature is lowered by the heat exchanger 4, and then dedusted by the electric dust collector 14 and further desulfurized. The sulfur oxide contained in the gas is reduced by the device 15 and released from the chimney 16 to the atmosphere.

火炉下方のバーナ６と火炉上方のＡＡＰ７の間に位置する火炉側壁には混合促進ポート８が設けられ、炉内のガス流動の混合を促進するために混合促進ポート８からはＧＲＦ１７で吸引した火炉から排出した燃焼排ガスの一部を高速旋回噴流として炉内へ投入する。 A mixing promotion port 8 is provided in the furnace side wall located between the burner 6 below the furnace and the AAP 7 above the furnace, and the furnace sucked by the GRF 17 from the mixing promotion port 8 in order to promote mixing of gas flow in the furnace. Part of the combustion exhaust gas discharged from the reactor is introduced into the furnace as a high-speed swirling jet.

図２にはＡＡＰ７の一実施例を示す。図２（ａ）にはＡＡＰ７の出口の鉛直方向の断面図を示し、出口形状は円形または矩形である。ＡＡＰ７の出口に近い内部にはエア分割板２１，２１が設置されていて、エア分割板２１の取付角度によって副流Ｓ２のエア噴流の噴出方向は主流Ｓ１とは異なるようにすることができる。図２（ｂ）のＡＡＰ７の水平方向の断面平面図に示すように、ＡＡＰ７内のアフターエアは一対のエア分割板２１，２１により中央主流Ｓ１と左右の副流Ｓ２，Ｓ２に３分割されている。また、３分割された噴流の噴出角度は主流Ｓ１は直進、副流Ｓ２は左右に拡がっていている。 FIG. 2 shows an embodiment of AAP7. FIG. 2A shows a vertical sectional view of the outlet of the AAP 7, and the outlet shape is circular or rectangular. Air dividing plates 21 and 21 are installed in the interior near the outlet of the AAP 7, and the jet direction of the air flow of the secondary flow S <b> 2 can be made different from that of the main flow S <b> 1 depending on the mounting angle of the air dividing plate 21. As shown in the horizontal cross-sectional plan view of the AAP 7 in FIG. 2B, the after air in the AAP 7 is divided into a main main stream S1 and a left and right substreams S2 and S2 by a pair of air dividing plates 21 and 21. Yes. In addition, the jet angle of the three divided jets is straight in the main flow S1 and widened in the left and right directions in the sub flow S2.

ＡＡＰ７には該ＡＡＰ７の中心部に火炉内に向けて２つのエア分割板２１，２１を配置して混合促進ガス流路を３分割しているので、該ＡＡＰ７の中心部を火炉内に向けて流れる中央主流Ｓ１とその両側の副流Ｓ２，Ｓ２が形成される。 Since the AAP 7 has two air dividing plates 21 and 21 arranged in the center of the AAP 7 toward the inside of the furnace to divide the mixing promoting gas flow path into three, the center of the AAP 7 is directed to the inside of the furnace. A flowing central main stream S1 and substreams S2 and S2 on both sides thereof are formed.

また、図３にはＡＡＰ７の他の実施例を示す。図３（ａ）には出口形状は円形であるＡＡＰ７の出口の鉛直方向の断面図を示し、図３（ｂ）には図３（ａ）のＡＡＰ７の水平断面図を示す。ＡＡＰ７の出口に近い内部にはエア分割板２１が設置されていて、エア分割板２１の取付角度を調整することでエア噴流の噴出方向を変えることが出来る。また、図３（ｃ）には出口形状は矩形であるＡＡＰ７の出口の鉛直方向の断面図を示し、図３（ｄ）には図３（ｃ）のＡＡＰ７の水平断面図を示す。 FIG. 3 shows another embodiment of AAP7. FIG. 3A shows a vertical sectional view of the outlet of the AAP 7 having a circular outlet shape, and FIG. 3B shows a horizontal sectional view of the AAP 7 in FIG. An air dividing plate 21 is installed in the interior near the outlet of the AAP 7, and by adjusting the mounting angle of the air dividing plate 21, the jet direction of the air jet can be changed. FIG. 3C shows a vertical sectional view of the outlet of the AAP 7 having a rectangular outlet shape, and FIG. 3D shows a horizontal sectional view of the AAP 7 in FIG.

図２、図３に示すようにＡＡＰ７の出口にエア分割板２１を設置し、ＡＡＰ７からのエア噴流の噴出方向を調整することで対向ＡＡＰ噴流との急速な衝突を避けることができ、燃焼ガス中のサーマルＮＯｘ生成を抑制し、かつＡＡＰ７の水平断面方向に広く噴流を拡散させてＣＯのすり抜け防止にも役立つ。 As shown in FIGS. 2 and 3, an air dividing plate 21 is installed at the outlet of the AAP 7, and by adjusting the jet direction of the air jet from the AAP 7, rapid collision with the opposed AAP jet can be avoided, and the combustion gas It suppresses the generation of thermal NOx in the interior and also diffuses the jet widely in the horizontal cross-sectional direction of the AAP 7 to help prevent CO from slipping through.

また、本実施例ではＡＡＰ７の水平断面方向に末広がり状に噴流を広く拡散させることができるので、特許文献６のようなＡＡＰからのエアーを水平分割しただけで直進流となる噴流に比較して燃焼ガス中のＮＯｘ濃度の抑制とＣＯ濃度の低減効果が大きい。 Further, in this embodiment, the jet can be widely diffused in a divergent shape in the direction of the horizontal cross section of the AAP 7, so that the air from the AAP as in Patent Document 6 is simply divided horizontally and compared with a jet that becomes a straight flow. The effect of suppressing NOx concentration and reducing CO concentration in combustion gas is great.

エア分割板２１のＡＡＰ７への取付角度を変えた場合の火炉出口排ガス中のＮＯｘ濃度、ＣＯ濃度への影響を数値解析プログラムで解析した結果を図４に示す。エア分割板２１のＡＡＰ７への取付角度（ＡＡＰ７の直進流方向に対する水平方向の拡がり角度）が５度近傍で火炉出口排ガス中のＮＯｘ濃度、ＣＯ濃度ともに最低となっている。図５には、図３（ａ）、図３（ｃ）のルーバ型のエア分割板２１をＡＡＰ７に設けた場合の排ガス中のＮＯｘ濃度とＣＯ濃度が同時に低減する燃焼試験結果を示す。従来型であるエア分割板２１をＡＡＰ７に設けない場合の火炉出口ＮＯｘ、ＣＯ濃度に対する低減率を示した。 FIG. 4 shows the result of analyzing the influence on the NOx concentration and CO concentration in the furnace outlet exhaust gas when the mounting angle of the air dividing plate 21 to the AAP 7 is changed with a numerical analysis program. The attachment angle of the air dividing plate 21 to the AAP 7 (the horizontal spreading angle with respect to the straight flow direction of the AAP 7) is around 5 degrees, and both the NOx concentration and the CO concentration in the furnace outlet exhaust gas are minimum. FIG. 5 shows a combustion test result in which the NOx concentration and the CO concentration in the exhaust gas are simultaneously reduced when the louver-type air dividing plate 21 of FIGS. 3A and 3C is provided in the AAP 7. The reduction ratio with respect to the NOx and CO concentration at the furnace outlet when the conventional air dividing plate 21 is not provided in the AAP 7 is shown.

また、図２（ｂ）に示すように、ＡＡＰ７の基部には主流流入孔２４と副流流入孔２５が設けられ、該流入孔２４，２５の開口面積を各流量調節器２６，２７をＡＡＰ７の軸方向にスライドさせることにより調整できる構成を備えている。そのため、流量調整器２６，２７によりＡＡＰ７出口から水平方向に複数個に分割した燃焼用エアの流量を変えることができる。 Further, as shown in FIG. 2B, a main flow inlet hole 24 and a subflow inlet hole 25 are provided at the base of the AAP 7, and the opening areas of the inlet holes 24, 25 are adjusted to the flow rate regulators 26, 27. It can be adjusted by sliding in the axial direction. Therefore, the flow rate of the combustion air divided into a plurality in the horizontal direction from the outlet of the AAP 7 by the flow rate regulators 26 and 27 can be changed.

このようにＡＡＰ７から火炉内に噴出する燃焼用空気（アフターエア）噴流を水平方向に分割することにより、アフターエア噴流がバーナ６からの上昇ガス流に混合して燃料の還元燃焼分（未燃ガス分）を燃焼させることができる。 In this way, by dividing the combustion air (after-air) jet jetted from the AAP 7 into the furnace in the horizontal direction, the after-air jet is mixed with the rising gas flow from the burner 6 to reduce the reduced combustion amount of fuel (unburned) Gas component) can be combusted.

図２に示すように、ＡＡＰ７からの燃焼用エアの噴流を火炉の水平方向に複数分割した各分割噴流の噴出方向は主流Ｓ１が直進、副流Ｓ２が左右に拡がっていて、同一角度にはない。エア分割板２１の設置位置はエア分割板２１のＡＡＰ出口側にある先端部の側面に副流Ｓ２が当たるか又は接するようにＡＡＰ７の中心軸線に対して所定の角度を有するようにＡＡＰ７の出口部に取り付けられる。 As shown in FIG. 2, the jet direction of each of the divided jets obtained by dividing the jet of combustion air from the AAP 7 in the horizontal direction of the furnace is such that the main flow S1 goes straight and the side flow S2 spreads left and right. Absent. The installation position of the air dividing plate 21 is such that the outlet of the AAP 7 has a predetermined angle with respect to the central axis of the AAP 7 so that the side flow S2 hits or contacts the side surface of the tip portion on the AAP outlet side of the air dividing plate 21 Installing in part only be.

このようにＡＡＰ７からの燃焼用エアの噴流を直進する主流Ｓ１と該主流Ｓ１の水平方向左右方向に流れる副流Ｓ２，Ｓ２とに分割することで、対向する火炉壁面にあるＡＡＰの噴流と直接衝突して急速に混合することを避けると共に、火炉内の水平方向に幅広く燃焼用エア噴流を形成することができ、ガスのすり抜け防止も可能にする。 In this way, by dividing the jet of combustion air from the AAP 7 into the main flow S1 that travels straight and the substreams S2 and S2 that flow in the horizontal direction in the horizontal direction of the main flow S1, the jet of the AAP on the opposing furnace wall surface directly While avoiding collision and rapid mixing, a combustion air jet can be formed widely in the horizontal direction in the furnace, and gas can be prevented from slipping through.

また、燃焼用エアを噴出する最も大きい断面積を持つ主流用の出口開口面積がＡＡＰ７の全出口開口面積の６０％以上を占める構成とする。前記主流Ｓ１の流量比については図６で説明する。
図６はＡＡＰ７を流れる全燃焼用エア流量に対する主流Ｓ１の流量比が８０％、７０％及び６０％である場合の数値解析による火炉出口の排ガス中のＮＯｘ濃度とＣＯ濃度を検討した結果である。横軸の流速比は副流／主流流速比であり、流量比６０％では流量比７０％、８０％より火炉出口の排ガス中のＮＯｘ濃度、ＣＯ濃度が共に高めであり、しかも前記流速比＝２ではＣＯ濃度が急増しつつある。これは副流流速が早くなり、主流Ｓ１が副流Ｓ２に引き込まれて貫通力を失い、火炉中央部で未燃ガスのすり抜けの傾向が現れるためである。従って、全燃焼用エア流量に対する主流Ｓ１の流量比は６０％以上必要となる。なお、図６には副流Ｓ２の２次噴出角度θ／θ₀（定義は後述する。）０．７３での解析結果を示している。 The mainstream outlet opening area having the largest cross-sectional area for injecting combustion air occupies 60% or more of the total outlet opening area of AAP7. The flow rate ratio of the main flow S1 will be described with reference to FIG.
FIG. 6 shows the result of examining the NOx concentration and the CO concentration in the exhaust gas at the furnace outlet by numerical analysis when the flow rate ratio of the main flow S1 to the total combustion air flow rate flowing through the AAP 7 is 80%, 70%, and 60%. . The flow rate ratio on the horizontal axis is the side flow / main flow rate ratio. When the flow rate ratio is 60%, the flow rate ratio is 70%, and the NOx concentration and CO concentration in the exhaust gas at the furnace outlet are both higher than 80%. In 2, the CO concentration is increasing rapidly. This is because the sidestream flow velocity is increased, the mainstream S1 is drawn into the sidestream S2, loses the penetration force, and the tendency of the unburned gas to pass through appears in the center of the furnace. Accordingly, the flow rate ratio of the main flow S1 to the total combustion air flow rate is required to be 60% or more. FIG. 6 shows the analysis result of the secondary flow S2 at the secondary ejection angle θ / θ ₀ (definition will be described later) 0.73.

次に、前記全燃焼用エア流量に対する主流流量比とＡＡＰ全断面積に対する主流断面積比の関係をプロットしたグラフを図７に示す。副流／主流流速比は１と１．５の２種類の場合を示す。主流流量比６０％では主流断面積比は０．６（流速比１）となり、流速比１以上及び主流流量比を６０％以上維持するためには主流断面積比０．６以上とすることが必要である。 Next, FIG. 7 is a graph plotting the relationship between the main flow rate ratio with respect to the total combustion air flow rate and the main flow cross sectional area ratio with respect to the AAP total cross sectional area. The side flow / main flow velocity ratio shows two cases of 1 and 1.5. When the main flow rate ratio is 60%, the main flow cross-sectional area ratio is 0.6 (flow velocity ratio 1). In order to maintain the flow velocity ratio 1 or higher and the main flow flow rate ratio 60% or higher, the main flow cross-sectional area ratio may be 0.6 or higher. is necessary.

次にＡＡＰ７から火炉内に噴出させる燃焼用エア噴流の噴出角度について図８と図９に基づいて説明する。図８に示すＡＡＰ７の副流Ｓ２の水平方向の噴出角度θが火炉中央部において隣接する２個ずつで、対向する壁面に設けられる合計４個のＡＡＰ７の中間位置に向かう副流Ｓ２の水平方向の噴出角度θ₀で無次元化した数値を横軸にとり、主流流量比８０％の場合の排ガス中のＮＯｘ濃度、ＣＯ濃度への影響を検討した結果を図９に示す。
なお、前記火炉中央部とは対向する一対の壁面の同一水平面にそれぞれ設けられた一対のＡＡＰ７，７の中間部の位置である。 Next, the jet angle of the combustion air jet jetted from the AAP 7 into the furnace will be described with reference to FIGS. The horizontal jet angle θ of the secondary flow S2 of the AAP 7 shown in FIG. 8 is two adjacent in the center of the furnace, and the horizontal direction of the secondary flow S2 toward the intermediate positions of the four AAPs 7 provided on the opposing wall surfaces. FIG. 9 shows the results of examining the influence on the NOx concentration and CO concentration in the exhaust gas when the horizontal axis represents the dimensionless values at the jet angle θ ₀ of the main flow rate and the main flow rate ratio is 80%.
In addition, the said furnace center part is a position of the intermediate part of a pair of AAP7 and 7 each provided in the same horizontal surface of a pair of wall surface which opposes.

また、図９でいう２次噴出角度は次の通りである。
２次噴出角度＝噴出角度（無次元）θ／θ₀
さらに、図９のＣＯ（−）とＮＯｘ（−）はそれぞれ２次噴出角度θ／θ₀＝０のときの火炉出口排ガス中のＣＯ濃度とＮＯｘ濃度を無次元化して示している。 Further, the secondary ejection angles referred to in FIG. 9 are as follows.
Secondary ejection angle = ejection angle (dimensionless) θ / θ ₀
Further, CO (−) and NOx (−) in FIG. 9 indicate the non-dimensional representation of the CO concentration and NOx concentration in the furnace outlet exhaust gas when the secondary ejection angle θ / θ ₀ = 0, respectively.

主流流量比８０％の条件下で、火炉出口排ガス中のＣＯ濃度（２次噴出角度＝０の時の前記ＣＯ濃度に対する比率で図示している）は
０．４≦２次噴出角度θ／θ₀≦１
の間で最小になり、前記ＮＯｘ濃度に対しては
２次噴出角度θ／θ₀≧１
であると急増する傾向が見られる。即ち、
２次噴出角度θ／θ₀≧１
では当該ＡＡＰ７からの燃料用エアの噴流と隣接するＡＡＰ７からの燃料用エアの噴流とが衝突して急速混合が起こり、サーマルＮＯｘ生成の要因になり得ることを示している。従って前記２次噴出角度θ／θ₀が０．４以上であって、１以下であることが好ましい。 Under the condition of a main flow rate ratio of 80%, the CO concentration in the exhaust gas from the furnace outlet (shown as a ratio to the CO concentration when the secondary injection angle = 0) is 0.4 ≦ secondary injection angle θ / θ ₀ ≦ 1
The secondary ejection angle θ / θ ₀ ≧ 1 for the NOx concentration
A tendency to increase rapidly is seen. That is,
Secondary ejection angle θ / θ ₀ ≧ 1
Shows that the jet of fuel air from the AAP 7 and the jet of fuel air from the adjacent AAP 7 collide with each other and rapid mixing occurs, which can cause thermal NOx generation. Therefore, the secondary ejection angle θ / θ ₀ is preferably 0.4 or more and 1 or less.

図１０には火炉前後壁１ａ，１ｂに配置されるアフターエアポート７の縦断面図（図１０（ａ））と水平方向断面図（図１０（ｂ））を示す。このアフターエアポート７は火炉側壁１ｃ寄りに配置されるエア分割板２１’付きのアフターエアポート７であり、図２に示すエアーを水平方向に拡大させる折れ曲がり状のエア分割板２１，２１の他に火炉側壁１ｃに近い片側により大きな折れ曲がり角度を有するエア分割板２１’を設けている。 FIG. 10 shows a longitudinal sectional view (FIG. 10 (a)) and a horizontal sectional view (FIG. 10 (b)) of the after airport 7 arranged on the front and rear walls 1a and 1b of the furnace. This after-air port 7 is an after-air port 7 with an air dividing plate 21 'disposed near the furnace side wall 1c. In addition to the bent air dividing plates 21 and 21, which expand the air in the horizontal direction shown in FIG. An air dividing plate 21 'having a larger bending angle is provided on one side close to the side wall 1c.

なお、図１５には、従来技術の火炉前後壁１ａ，１ｂに設置される複数のバーナ６とアフターエアポート７の配置例を示す。図１５（ａ）は火炉側壁１ｃ側から見た火炉側面図であり、図１５（ｂ）は火炉前壁１ａ側から見た火炉側面図である。 In addition, in FIG. 15, the example of arrangement | positioning of the some burner 6 and the after-air port 7 installed in the furnace front-and-rear walls 1a and 1b of a prior art is shown. FIG. 15A is a furnace side view seen from the furnace side wall 1c side, and FIG. 15B is a furnace side view seen from the furnace front wall 1a side.

図１５に示す従来技術は、火炉前後壁１ａ，１ｂにはアフターエアポート７の他に側壁１ｃ側に近い箇所にサイドアフターエアポート７’を配置した例である。このサイドアフターエアポート７’は未燃ガスが火炉壁面近くをすり抜けるのを防止するために設置されたエアポートである。しかし図１０に示すアフターエアポート７の構成では、側壁１ｃ側のアフターエアポート７内にエア分割板２１’があるため、当該アフターエアポート７が、図１５のサイドアフターエアポート７’の代りを果たすことができ、サイドアフターエアポート７’の設置を省略できる。 The prior art shown in FIG. 15 is an example in which side after-air ports 7 ′ are disposed on the front and rear walls 1 a and 1 b of the furnace in addition to the after-air ports 7 at positions close to the side wall 1 c side. This side after-air port 7 'is an air port installed to prevent unburned gas from slipping through near the furnace wall surface. However, in the configuration of the after-air port 7 shown in FIG. 10, since the air dividing plate 21 ′ is in the after-air port 7 on the side wall 1c, the after-air port 7 can serve as a substitute for the side after-air port 7 ′ of FIG. The installation of the side after-airport 7 'can be omitted.

なお、本発明は、サイドアフターエアポート７’の本来の趣旨（アフターエアポート７に到達するまでの間に燃焼ガスと未燃ガスとの混合促進と、未燃ガスのすり抜け防止）を踏襲するために側壁１ｃ側に設けたアフターエアポート７からの側壁１ｃ側へエアー噴流を上流に向かって噴出する等の手法へ容易に設計上展開が可能である。 The present invention follows the original purpose of the side after-air port 7 ′ (promotion of mixing of combustion gas and unburned gas and prevention of slipping of unburned gas before reaching the after-air port 7). The design can be easily developed to such a method that an air jet is ejected upstream from the after air port 7 provided on the side wall 1c side to the side wall 1c side.

図１１には水平分散型ＡＡＰ７の一実施例を示す概要図を示している。火炉前後壁１ａ，１ｂに配置されるアフターエアポート７の縦断面図（図１１（ａ））と図１１（ａ）のＡ−Ａ線又はＣ−Ｃ線断面図（図１１（ｂ））及び図１１（ａ）のＢ−Ｂ線又はＤ−Ｄ線断面図（図１１（ｃ））を示す。 FIG. 11 is a schematic diagram showing an embodiment of the horizontal dispersion type AAP 7. A longitudinal sectional view (FIG. 11 (a)) of the after-airport 7 disposed on the furnace front and rear walls 1a, 1b, a sectional view taken along the line AA or CC of FIG. 11 (a) (FIG. 11 (b)), and The BB line or DD line sectional drawing (FIG. 11 (c)) of FIG. 11 (a) is shown.

このアフターエアポート７からのエア噴流は流量が最も多い主流Ｓ１と流量が少ない副流Ｓ２，Ｓ３（Ｓ３−１，Ｓ３−２，Ｓ３−２）に分けられる。エア噴流は縦方向に平面を有する２のエア分割板２１，２１と水平方向に平面を有するエア分割板２２により全部で６分割され、分割された各噴流は火炉内では同一方向に流れない。 The air jet from the after-air port 7 is divided into the main flow S1 having the highest flow rate and the side flows S2 and S3 (S3-1, S3-2, S3-2) having the lowest flow rate. The air jet is divided into six parts in total by two air dividing plates 21 and 21 having a plane in the vertical direction and an air dividing plate 22 having a plane in the horizontal direction, and the divided jets do not flow in the same direction in the furnace.

すなわちエア噴流の中で上側の１つの主流Ｓ１と２つの副流Ｓ２，Ｓ２は水平方向に、下側の３つの副流Ｓ３−１，Ｓ３−２，Ｓ３−２はそれぞれ火炉内のアフターエアポート設置部より上流側の方向に噴出される。上側の３つの噴流Ｓ１，Ｓ２，Ｓ２は図２の水平分散型ＡＡＰ７と同様の作用、効果を奏し、下側の３つの副流Ｓ３−１，Ｓ３−２，Ｓ３−２のうち、左右の２つの副流Ｓ３−２，Ｓ３−２は火炉壁面付近のＣＯすり抜け防止（ＣＯ低減）のために、真中の副流Ｓ３−１は分散型混合促進（ＮＯｘ低減）のために、すり抜け部及び壁面近傍に噴射される。 That is, in the air jet, the upper main flow S1 and the two subflows S2 and S2 are in the horizontal direction, and the lower three subflows S3-1, S3-2 and S3-2 are the after-airports in the furnace. It is ejected in the direction upstream from the installation part. The upper three jets S1, S2, and S2 have the same operations and effects as the horizontal dispersion type AAP7 of FIG. 2, and of the lower three substreams S3-1, S3-2, and S3-2, The two substreams S3-2 and S3-2 are used for preventing CO slipping near the furnace wall surface (CO reduction), and the middle substream S3-1 is used for promoting dispersive mixing (NOx reduction) for passing through and Injected near the wall.

また、図１１（ｂ）に示すように、ＡＡＰ７の基部には主流流入孔２４と副流流入孔２５が設けられ、該流入孔２４，２５の開口面積を各流量調節器２６，２７をＡＡＰ７の軸方向にスライドさせることにより調整できる構成は図２（ｂ）に示した構成と同じである。エア分割板２１，２１とＡＡＰ７の内壁の間にできる副流Ｓ２用の流路はＡＡＰ７の出口部側に向けて狭い通路となるようにエア分割板２１，２１は水平に対する角度αで末広がり状であると共にＡＡＰ７の内周側は出口部側に向けて流路縮流部材２９を配置している。 Further, as shown in FIG. 11B, a main flow inlet hole 24 and a secondary flow inlet hole 25 are provided at the base of the AAP 7, and the opening areas of the inlet holes 24, 25 are adjusted to the flow rate regulators 26, 27. The configuration that can be adjusted by sliding in the axial direction is the same as the configuration shown in FIG. The air dividing plates 21, 21 are divergent at an angle α with respect to the horizontal so that the flow path for the secondary flow S 2 formed between the air dividing plates 21, 21 and the inner wall of the AAP 7 becomes a narrow passage toward the outlet side of the AAP 7. In addition, the flow path contracting member 29 is arranged on the inner peripheral side of the AAP 7 toward the outlet side.

そのため、流量調整器２６，２７によりＡＡＰ７出口から水平方向に複数個に分割した燃焼用エアの噴出流の方向をそれぞれ変えることで、水平方向の火炉内断面に幅広く燃焼用エアの噴流を形成することができ、未燃ガスのすり抜け防止も可能にする。 Therefore, by changing the direction of the jet flow of the combustion air divided into a plurality of parts in the horizontal direction from the outlet of the AAP 7 by the flow rate regulators 26 and 27, a wide jet of the combustion air is formed in the horizontal cross section in the furnace. It is also possible to prevent unburned gas from slipping through.

このようにＡＡＰ７から火炉内に噴出する燃焼用エア（アフターエア）噴流を水平方向に分割することにより、アフターエア噴流がバーナ６からの上昇ガス流に混合して燃料の還元燃焼分（未燃ガス分）を燃焼させることができる。 In this way, by dividing the combustion air (after-air) jet jetted from the AAP 7 into the furnace in the horizontal direction, the after-air jet is mixed with the rising gas flow from the burner 6 to reduce the reduced combustion amount of fuel (unburned) Gas component) can be combusted.

また、図１２には本実施例のバーナ６、アフターエアポート７および混合促進ポート８の配置例を示す。複数段あるバーナ部において火炉前壁１ａ及び後壁１ｂの上下方向に同列に、それぞれバーナ６を対向位置に配置（対向配列という場合がある。）するのではなく、図１２（ａ）の側壁１ｃ側から見た火炉の概略構造図と図１２（ｂ）の火炉前壁１ａの側面図に示すように、少なくとも最上段バーナ６とアフターエアポート７（図１２ではアフタエアーポート７を一段だけ設けた場合を示す）を対向する前壁１ａと後壁１ｂで互いに同一水平面上に千鳥配列とすることで、バーナ部およびアフターエアポート部における未燃粒子を含んだ燃焼ガスを良く混合することができる。 FIG. 12 shows an arrangement example of the burner 6, the after air port 7 and the mixing promoting port 8 of this embodiment. Instead of arranging the burners 6 in opposed positions (sometimes referred to as opposed arrangement) in the vertical direction of the furnace front wall 1a and the rear wall 1b in the burner portion having a plurality of stages, the side walls in FIG. As shown in the schematic structural diagram of the furnace viewed from the 1c side and the side view of the furnace front wall 1a in FIG. 12B, at least the uppermost burner 6 and the after air port 7 (in FIG. 12, only one after air port 7 is provided). In the staggered arrangement of the front wall 1a and the rear wall 1b facing each other on the same horizontal plane, the combustion gas containing unburned particles in the burner part and the after-airport part can be well mixed. .

このとき、バーナ６とアフターエアポート７の間に配置される混合促進ポート８は炉内の流動状態を均一化するために用いられ、出来るだけ少量で吹き込むことが望ましい。そのためには図１２に示すように混合促進ポート８を火炉側壁（前壁１ａ及び後壁１ｂの両端部を接続する一対の側壁）１ｃに設置すれば、側壁１ｃ近傍の炉内ガスの混合を促進することができる。 At this time, the mixing promotion port 8 disposed between the burner 6 and the after air port 7 is used to make the flow state in the furnace uniform, and it is desirable to blow in as little as possible. For that purpose, if the mixing promotion port 8 is installed on the furnace side wall (a pair of side walls connecting both ends of the front wall 1a and the rear wall 1b) 1c as shown in FIG. 12, mixing of the in-furnace gas near the side wall 1c is performed. Can be promoted.

ただし、前壁１ａ又は後壁１ｂの一方の壁面の最上段バーナ６からの微粉炭を含んだ噴流は対向壁からのバーナ噴流と炉内中央で衝突せずに中央部から対向壁側に寄った位置で湾曲しながら上昇する。そこで図１３の火炉１の斜視図に示すように、対向する前壁１ａと後壁１ｂに設けられるアフターエアポート７を最上段バーナ６とは逆の千鳥配列（同一壁面のバーナ６の直上にはアフターエアポート７を配置しないで、該バーナ６からの微粉炭の燃焼ガス流が対向壁面のアフターエアポート７からのエア噴流に当たるようアフターエアポート７を配置する配列）にすることで、対向壁面からのアフターエア噴流が上記バーナ６からの湾曲上昇流に直撃して炉内ガスの混合が促進される。 However, the jet including pulverized coal from the uppermost burner 6 on one wall surface of the front wall 1a or the rear wall 1b does not collide with the burner jet from the opposing wall at the center in the furnace, and approaches the opposing wall from the center. It rises while curving at the position. Therefore, as shown in the perspective view of the furnace 1 in FIG. 13, the after airports 7 provided on the front wall 1a and the rear wall 1b facing each other are arranged in a staggered arrangement opposite to the uppermost burner 6 (immediately above the burner 6 on the same wall surface). By arranging the after-air port 7 so that the combustion gas flow of the pulverized coal from the burner 6 hits the air jet from the after-air port 7 on the opposing wall surface without arranging the after-air port 7, the after-air port from the opposing wall surface is arranged. The air jet strikes the curved upward flow from the burner 6 and the mixing of the in-furnace gas is promoted.

また、図１４に混合促進ポート８を側壁１ｃに設けたときの炉内のガス流れ方向で、それぞれ異なる部位の水平断面内でのガス中のＮＯｘ濃度（平均値）の変化を示す。このように混合促進ポート８を側壁１ｃに設けたことにより、還元領域でのＮＯｘの還元速度が促進され、炉出口での窒素酸化物濃度が低減する。 Further, FIG. 14 shows the change in the NOx concentration (average value) in the gas in the horizontal cross section of each different part in the gas flow direction in the furnace when the mixing promotion port 8 is provided on the side wall 1c. By providing the mixing promotion port 8 on the side wall 1c in this manner, the NOx reduction rate in the reduction region is promoted, and the nitrogen oxide concentration at the furnace outlet is reduced.

排ガス中のＮＯｘ濃度とＣＯ濃度に低下させることができるボイラ装置として産業上の利用可能性が高い。 Industrial applicability is high as a boiler device that can be reduced to NOx concentration and CO concentration in exhaust gas.

本発明の実施例になるボイラ装置システムを示す系統図であるIt is a systematic diagram which shows the boiler apparatus system which becomes an Example of this invention. 本発明の実施例になるボイラ装置のアフターエアポートの鉛直方向の断面図（図２（ａ））と水平方向の断面図（図２（ｂ））である。It is sectional drawing (FIG. 2 (a)) of the vertical direction of the after air port of the boiler apparatus which becomes an Example of this invention, and sectional drawing (FIG.2 (b)) of a horizontal direction. 本発明の実施例になるボイラ装置の円形アフターエアポートの鉛直方向の断面図（図３（ａ））と水平断面図（図３（ｂ））と矩形アフターエアポートの鉛直方向の断面図（図３（ｃ））と水平断面図（図３（ｄ））である。3 is a vertical sectional view (FIG. 3A), a horizontal sectional view (FIG. 3B) of a circular after-air port of a boiler apparatus according to an embodiment of the present invention, and a vertical sectional view of a rectangular after-air port (FIG. 3). (C)) and a horizontal sectional view (FIG. 3 (d)). 図２のアフターエアポートへのエア分割板の取付角度を変えた場合の火炉出口排ガス中のＮＯｘ濃度とＣＯ濃度への影響を数値解析プログラムで解析した結果を示す図である。It is a figure which shows the result of having analyzed with the numerical analysis program the influence on NOx density | concentration and CO density | concentration in furnace exit exhaust gas at the time of changing the attachment angle of the air division board to the after-air port of FIG. 図２（ｂ）のアフターエアポートへエア分割板を設けた場合の排ガス中のＮＯｘ濃度とＣＯ濃度が同時に低減する燃焼試験結果を従来型エア分割板を設けた場合と比較して示す図である。It is a figure which shows the combustion test result in which the NOx density | concentration in exhaust gas at the time of providing an air division board in the after-air port of FIG.2 (b) and CO density | concentration reduces simultaneously with the case where a conventional air division board is provided. . 図２のアフターエアポート内を流れる全燃焼用エア流量に対する主流の流量比を変化させた場合の数値解析による火炉出口の排ガス中のＣＯ濃度とＮＯｘ濃度を示す図である。It is a figure which shows CO density | concentration and NOx density | concentration in the exhaust gas of a furnace exit by the numerical analysis at the time of changing the flow rate ratio of the mainstream with respect to the total combustion air flow volume which flows through the inside of the after-air port of FIG. 図２のアフターエアポート内を流れる全燃焼用エア流量に対する主流流量比とＡＡＰ全断面積に対する主流断面積比の関係をプロットした図である。FIG. 3 is a graph plotting a relationship between a main flow rate ratio with respect to a total combustion air flow rate flowing through the after-air port of FIG. 2 and a main flow cross-sectional area ratio with respect to an AAP total cross-sectional area. 図２のアフターエアポート内から火炉内に噴出させる燃焼用エア噴流の噴出角度を示す図である。It is a figure which shows the ejection angle of the combustion air jet ejected in the furnace from the inside of the after-air port of FIG. 図８に示すＡＡＰの副流の水平方向に対する噴出角度θが火炉中央部において隣接するＡＡＰ７との中間位置に向かう副流の水平方向に対する噴出角度θ₀で無次元化した数値を横軸にとり、主流流量比８０％の場合の排ガス中のＣＯ濃度とＮＯｘ濃度への影響を検討した結果を示す図である。The horizontal axis indicates the dimensionless numerical value of the jet angle θ with respect to the horizontal direction of the side flow of the AAP shown in FIG. 8 at the jet angle θ ₀ with respect to the horizontal direction of the side flow toward the intermediate position with the adjacent AAP 7 in the center of the furnace. It is a figure which shows the result of having examined the influence on CO density | concentration and NOx density | concentration in exhaust gas in the case of 80% of mainstream flow rate ratios. 本発明の実施例になるボイラ装置のアフターエアポートの鉛直方向の断面図（図１０（ａ））と平面図（図１０（ｂ））である。They are a sectional view (Drawing 10 (a)) and a top view (Drawing 10 (b)) of the perpendicular direction of the after air port of the boiler device which becomes an example of the present invention. 本発明の実施例になるボイラ装置のアフターエアポートに３枚のエア分割部材を配置した場合のアフターエアポートの縦断面図（図１１（ａ））と図１１（ａ）のＡ−Ａ線又はＣ−Ｃ線断面図（図１１（ｂ））と図１１（ａ）のＢ−Ｂ線又はＤ−Ｄ線断面図（図１１（ｃ））である。The longitudinal cross-sectional view (FIG. 11 (a)) and the AA line or C of FIG. 11 (a) when three air division members are arrange | positioned at the after-air port of the boiler apparatus which becomes an Example of this invention. FIG. 11 is a cross-sectional view taken along line -C (FIG. 11B) and a cross-sectional view taken along line BB or DD in FIG. 11A (FIG. 11C). 本発明の実施例になるボイラ装置の側壁側から見た火炉の概略構造図（図１２（ａ））と火炉前壁面の側面図（図１２（ｂ））である。It is the schematic structural drawing (FIG. 12 (a)) of the furnace seen from the side wall side of the boiler apparatus which becomes an Example of this invention, and the side view (FIG.12 (b)) of a furnace front wall surface. 図１２のボイラ装置の火炉の斜視図である。It is a perspective view of the furnace of the boiler apparatus of FIG. 本発明の実施例になるボイラ装置の混合促進ポートを火炉側壁に設けたときの炉内のガス流れ方向で、それぞれ異なる部位の水平断面内でのガス中のＮＯｘ濃度（平均値）の変化を示す図である。In the gas flow direction in the furnace when the mixing promotion port of the boiler apparatus according to the embodiment of the present invention is provided on the side wall of the furnace, the change in the NOx concentration (average value) in the gas in the horizontal cross section of each different part FIG. 従来技術の火炉前後壁に配置されるバーナとアフターエアポートを示す火炉側壁側から見た火炉側面図（図１５（ａ））と火炉前壁側から見た火炉側面図（図１５（ｂ））である。A side view of the furnace viewed from the side wall of the furnace showing the burner and the after-airport disposed on the front and rear walls of the prior art (FIG. 15A) and a side view of the furnace viewed from the front side of the furnace (FIG. 15B) It is.

Explanation of symbols

１火炉１ａ前壁
１ｂ後壁１ｃ側壁
２ミル３ＰＡＦ
４熱交換器５風箱
６バーナ７アフターエアポート
７’ サイドアフターエアポート
８混合促進ポート９ＦＤＦ
１０送炭管１１バンカ
１２フィーダ１３脱硝装置
１４電気集塵機１５脱硫装置
１６煙突１７ＧＲＦ
１８レジスタ２１，２１’，２２ガス分割板
２４主流流入孔２５副流流入孔
２６，２７混合促進ガス流量調節器
２９流路縮流部材 1 furnace 1a front wall 1b rear wall 1c side wall 2 mill 3 PAF
4 Heat exchanger 5 Air box 6 Burner 7 After air port 7 'Side after air port 8 Mixing promotion port 9 FDF
DESCRIPTION OF SYMBOLS 10 Coal feeding pipe 11 Bunker 12 Feeder 13 Denitration device 14 Electric dust collector 15 Desulfurization device 16 Chimney 17 GRF
18 Registers 21, 21 ′, 22 Gas dividing plate 24 Main flow inflow hole 25 Subflow inflow holes 26, 27 Mixing promotion gas flow rate regulator 29 Flow path contracting member

Claims

In a boiler device that burns solid fuel containing coal in a furnace,
A plurality of burners for burning solid fuel with a quantity of air equal to or less than the theoretical air ratio are provided on a pair of opposing wall surfaces of the furnace, and one or more burners are provided in the combustion gas flow direction.
A plurality of after-air ports for each stage on the downstream side of the burner of a pair of wall surfaces facing the furnace, and for injecting combustion air insufficient for combustion of solid fuel in the burner into the furnace, and a flow of combustion gas One or more steps in the direction,
In the after-air port, the direction of the combustion air blown out from the after-air port into the furnace is divided into three or more in the horizontal direction, and the air division has a shape such that the directions of the divided air are not the same as each other A member ,
The boiler device characterized in that the air dividing member is provided so as to be able to change the direction of the combustion air blown into the furnace from the after-air port.

The air dividing member is an outlet of a divided jet flow having the largest cross-sectional area for ejecting the combustion air in the central portion, which is the mainstream, among the air divided into three or more divisions from the air dividing member into the furnace The boiler device according to claim 1, wherein the opening area occupies 60% or more of the total outlet opening area of the after-airport.

The jet direction of the air jet flow divided by the air dividing member provided in one after-air port is directed toward the center of the plane formed by a total of four adjacent after-air ports provided on the opposing wall surfaces, and is jetted horizontally. The boiler device according to claim 1 , wherein the boiler device is in a range not exceeding an angle (θo) of the boiler.

A total of four adjacent after-airports of the horizontal jet angle (θ) of the side flow that is a combustion air jet flow other than the main flow among the jet air flow for combustion injected into the furnace from one after- air port The secondary ejection angle (θ / θo), which is the ratio to the horizontal ejection angle (θo), toward the center of the plane made in
0.4 ≦ secondary ejection angle θ / θo ≦ 1
The boiler device according to claim 3 , wherein the boiler device is set to be

Of the air dividing members provided in each after-air port of the same stage, the air attached to the after-air port in the part closest to the pair of furnace side walls connecting the ends of the pair of furnace wall surfaces where each after-air port is installed The dividing member has one or both of the jetting angle and the momentum of the jet flow toward the furnace side wall among the jetting directions of the plurality of air jets from the air dividing member. boiler device according to claim 1 in any one of 4, characterized in that it is set larger than the.

The number of installed air splitting members that guide the jet flow in the direction of the furnace side wall of the air splitting member that is attached to the after-air port of each stage provided on the wall surface of the furnace located near the pair of furnace side walls is set to other after-stages of the same stage. boiler device according to any one of claims 1 5, characterized in that it has more than an air dividing member provided in the airport.

The jet direction of one or more of the air jet flows divided by the air split member provided in each after-air port of the same stage is in the furnace upstream of the after air port where the air split member is installed. boiler device according to any one of claims 1 to 5, characterized in that a configuration toward the direction.

The plurality of burners at the uppermost stage are respectively arranged at the same horizontal position on the opposing furnace wall surfaces and shifted from the opposing positions, and the plurality of after-air ports at each stage are formed by a pair of opposing furnace wall surfaces. Each of the lowermost after-airports arranged at the same horizontal position and provided on the same wall surface on the downstream side of the uppermost burner is arranged above the intermediate position of two adjacent burners in the plurality of uppermost burners. It is boiler apparatus according to any one of claims 1 7, characterized in Rukoto.

At least one stage of the after-Airport, according to claim 8, wherein that you have placed above the intermediate position between two adjacent burners in the uppermost of a plurality of burners provided in the same wall surface of the upstream side Boiler equipment.

10. The boiler according to claim 8 , wherein each after-air port of each stage is arranged at an intermediate position between two adjacent after-air ports among a plurality of after-air ports adjacent to each other in the upper and lower stages. apparatus.

A plurality of mixing promotion ports for supplying a part of boiler exhaust gas discharged from the boiler to the downstream side of the burner and upstream of the after-air port are provided for each horizontal stage, and one or more stages are provided. The boiler device according to any one of claims 1 to 10 .

Mixing promotion port 11. Symbol mounting of the boiler system, characterized in that provided in the furnace wall locations that can be blown to promote mixing gas in a region combustion of fuel in the uppermost stage burner becomes slow.

The boiler device according to claim 11 or 12 , wherein the mixing promotion port is also installed at both ends of the furnace wall where the burner is installed .