JPS58164909A - Reduction and combustion method for nitrogen oxide - Google Patents
Reduction and combustion method for nitrogen oxideInfo
- Publication number
- JPS58164909A JPS58164909A JP4565682A JP4565682A JPS58164909A JP S58164909 A JPS58164909 A JP S58164909A JP 4565682 A JP4565682 A JP 4565682A JP 4565682 A JP4565682 A JP 4565682A JP S58164909 A JPS58164909 A JP S58164909A
- Authority
- JP
- Japan
- Prior art keywords
- burner
- air
- stage burner
- fuel injected
- fuel
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
Classifications
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23C—METHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN A CARRIER GAS OR AIR
- F23C6/00—Combustion apparatus characterised by the combination of two or more combustion chambers or combustion zones, e.g. for staged combustion
- F23C6/04—Combustion apparatus characterised by the combination of two or more combustion chambers or combustion zones, e.g. for staged combustion in series connection
- F23C6/045—Combustion apparatus characterised by the combination of two or more combustion chambers or combustion zones, e.g. for staged combustion in series connection with staged combustion in a single enclosure
- F23C6/047—Combustion apparatus characterised by the combination of two or more combustion chambers or combustion zones, e.g. for staged combustion in series connection with staged combustion in a single enclosure with fuel supply in stages
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
- F23C—METHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN A CARRIER GAS OR AIR
- F23C2201/00—Staged combustion
- F23C2201/10—Furnace staging
- F23C2201/101—Furnace staging in vertical direction, e.g. alternating lean and rich zones
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Combustion & Propulsion (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
Abstract
Description
【発明の詳細な説明】
本発明は窒素酸化物還元燃焼方法に係り、特にボイラ装
置のような竪型燃焼装置における排ガス中の窒素酸化物
を低減させる燃焼法に関する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a nitrogen oxide reduction combustion method, and particularly to a combustion method for reducing nitrogen oxides in exhaust gas in a vertical combustion device such as a boiler device.
従来、この種の燃焼装置の排ガス中の窒素酸化物を低減
させる方法としては、（１）排ガス再循環法、（２）二
段燃焼法、（３）水噴射法、および（４）脱硝燃焼法な
どが知られている。このうち、脱硝燃焼法は空気比１以
下の還元雰囲気下で燃料（炭化水素）を燃焼させ、生成
したラジカル生成物で窒素酸化物の還元を行なうもので
、還元剤を用いずに燃料自体によって炉内脱硝を行なう
ことができるので有利である。Conventionally, methods for reducing nitrogen oxides in the exhaust gas of this type of combustion equipment include (1) exhaust gas recirculation method, (2) two-stage combustion method, (3) water injection method, and (4) denitrification combustion. The law is known. Among these, the denitrification combustion method burns fuel (hydrocarbons) in a reducing atmosphere with an air ratio of less than 1, and reduces nitrogen oxides with the generated radical products, using the fuel itself without using a reducing agent. This is advantageous because denitrification can be carried out within the furnace.
第１図および第２図は、このような脱硝燃焼法に用いら
れる火炉１の断面図、およびその人視図を示すもので、
火炉１内の前部に下段、（−す２、中段バーナ３、およ
び上段バーナ４が配置され、さらにその上方に前部アフ
タエアポート５、およびこれに対向して後部アフタエア
ポート６が配置されている。また火炉１の下方にはホツ
ノくロアが設けられ、その下段のホツノく導管８かち空
気または排ガスと空気との混合ガスが導入されるように
なっている。なお、上記火炉ｌ内の燃焼ガスは上方の過
熱器９で一部吸熱されて高温ガス１０となり、この高温
ガスは、その後、図示されない再熱器や節炭器を通して
熱交換される。ボイラ装置の場合にはその負荷に応じて
伝熱割合が調節される。Figures 1 and 2 show a cross-sectional view of a furnace 1 used in such a denitrification combustion method and a human view thereof.
A lower stage burner 2, a middle stage burner 3, and an upper stage burner 4 are arranged at the front part of the furnace 1, and a front after air port 5 is arranged above it, and a rear after air port 6 is arranged opposite thereto. In addition, a hot lower is provided below the furnace 1, and air or a mixed gas of exhaust gas and air is introduced through 8 hot conduits at the bottom. Part of the combustion gas is absorbed by the upper superheater 9 to become high-temperature gas 10, and this high-temperature gas is then heat-exchanged through a reheater and an economizer (not shown). The heat transfer rate is adjusted accordingly.
上記装置を用いて還元燃焼を行なう場合には、各バーナ
の空気比（理論燃焼空気量に対する割合）を１以下にし
、一方、最上段のアフタエアポート５．６からは未燃分
を完全燃焼させるための空気が供給される。この場合ア
フターエアが上段バーナ４へ巻き込まれ、このため上段
バーナ４で生成した、窒素酸化物を還元するための燃焼
中間生成物（以下、ラジカルと称する）が一部酸化され
る埃象が見出された。When performing reductive combustion using the above device, the air ratio (ratio to the theoretical combustion air amount) of each burner is set to 1 or less, while unburned matter is completely combusted from the after air port 5.6 at the top stage. Air is supplied for the purpose. In this case, the after air is drawn into the upper burner 4, and a dust phenomenon is observed in which combustion intermediate products (hereinafter referred to as radicals) generated in the upper burner 4 for reducing nitrogen oxides are partially oxidized. Served.
本発明の目的は、このような窒素酸化物還元燃焼法の欠
点をなくし、最上段のアフターエアボートから供給され
る空気に影醤、されずに排ガス中の：、：
窒素酸化物を効率よく低減することができる燃焼・ｊ１
゛
法を提供することにある。、１さ
上記目的を達成するため、本発明者らは、脱硝反応を起
こさせるための各段のバーナの動作条件について極々の
実験を行なった。その結果、各バーすの空気比（理論燃
焼空気量に対する割合）は下段バーナでは０．８〜１．
０、中段バーナでは０．６〜０．８、および上段バーナ
では０．４〜０．６の組み合わせ条件下で排ガス中の窒
素酸化物濃度が最低となることがわかった。しかし、さ
らに検討したところ、このような条件下においても、前
部アフターエア５から上段バーナ４の火炎内に空気が巻
き込まれ、該上段バーナ４の火炎の上半分の領域のラジ
カルが酸化され、窒素酸化物の還元反応を半減している
ことがわかった。The purpose of the present invention is to eliminate such drawbacks of the nitrogen oxide reduction combustion method, and to efficiently reduce nitrogen oxides in exhaust gas without affecting the air supplied from the after air boat on the top stage. Combustion that can be done
The goal is to provide a method. , 1. In order to achieve the above object, the present inventors conducted extensive experiments regarding the operating conditions of the burners in each stage for causing the denitrification reaction. As a result, the air ratio (ratio to the theoretical combustion air amount) of each bar was 0.8 to 1.
It was found that the nitrogen oxide concentration in the exhaust gas was lowest under the combination of 0.0, 0.6 to 0.8 for the middle burner, and 0.4 to 0.6 for the upper burner. However, further investigation revealed that even under such conditions, air is drawn into the flame of the upper burner 4 from the front after-air 5, and radicals in the upper half of the flame of the upper burner 4 are oxidized. It was found that the reduction reaction of nitrogen oxides was halved.
第３図は、第１図の拡大部１１０Ｂ方向矢視図であり、
前部アフターエア５からの空気の巻き込み状況を示した
ものである。炉下部の下段／（−す２および中段バーナ
３で燃焼が行なわれる結果、火炉１には上昇、流１２が
誘起する。この上昇流１２は、上段バーナ、：１ｌｌｌ
１１．４からの噴出流により部分的に阻：：１゜
止され、下部巻ぎ、込み流１３および前部アフターエア
５からの上部巻き込み流１４（１種のカルマ □ン
渦）が誘起され、上段バーナ４へ一部のアフターエアが
供給される。このため、上段ノく−ナ４の空気比を仮り
に０．４としても、上段バーナ（マルチバーナ）４の上
半分の燃焼条件は０．６、場合によっては０．８程度に
なり、上段バーナ４の上半部で生成したラジカルが酸化
され、脱硝反応が阻害されることになる。この上部巻き
込み流１４は、上昇流速や上段バーナ４と前部アフター
エア５間の距離によって変化し、上昇流速が大きい場合
は上部巻き込み流１４は増加し、また上段バーナ４と前
部アフターエア５間の距離が小さい程、上部巻き込み流
１４が増加することが分った。FIG. 3 is a view taken in the direction of the enlarged portion 110B in FIG.
This shows how air is drawn in from the front after-air 5. As a result of combustion occurring in the lower stage burner 2 and the middle stage burner 3 in the lower part of the furnace, an upward flow 12 is induced in the furnace 1.
It is partially blocked by the jet flow from 11.4, and the lower winding, inrush flow 13 and upper winding flow 14 (a kind of Karma vortex) from the front afterair 5 are induced. , some after air is supplied to the upper stage burner 4. Therefore, even if the air ratio of the upper stage burner 4 is assumed to be 0.4, the combustion condition in the upper half of the upper stage burner (multi-burner) 4 will be 0.6, or in some cases about 0.8, Radicals generated in the upper half of the burner 4 are oxidized and the denitrification reaction is inhibited. This upper entrainment flow 14 changes depending on the upward flow velocity and the distance between the upper stage burner 4 and the front afterair 5. When the upward flow velocity is large, the upper entrainment flow 14 increases, and the upper stage burner 4 and the front afterair 5 It has been found that the smaller the distance between the two, the more the upper entrainment flow 14 increases.
本発明は、前述のように上段バーナ４では空気比を０．
４より以下に低下させることができず、また上記アフタ
ーエアによる上記巻き込み流１４を避けることができな
いことに鑑み、第４図に模式的に示すように、アフター
エアポート５の直下の燃焼噴射量、この場合は上段バー
ナ（マルチツク−す）の上部噴射燃料１５を下部よりも
多くシ、上段バーナ４のラジカル生成量を増加させ、脱
硝反応を効果的に行なうものである。In the present invention, as described above, the air ratio in the upper stage burner 4 is set to 0.
4, and in view of the fact that the entrainment flow 14 caused by the after air cannot be avoided, as schematically shown in FIG. 4, the combustion injection amount directly below the after air port 5, In this case, more fuel 15 is injected into the upper part of the upper stage burner (multiple combustion chamber) than the lower part, thereby increasing the amount of radicals produced in the upper stage burner 4 and effectively carrying out the denitrification reaction.
典型的には、本発明は、前記第１図にお（・て、前部ア
フターエア５からの巻き込み空気を勘案して上段バーナ
４の上方向への燃料噴射量を多くし、下方向の燃料噴射
量を少な（することにより、上段バーナ４でのラジカル
発生量を多くするものである。すなわち、上段バーナ４
の上下方向に燃料噴射１のバイアスをもたせることによ
り、効果的な脱硝反応を行なわせるものである。Typically, in the present invention, as shown in FIG. By reducing the amount of fuel injection, the amount of radicals generated in the upper burner 4 is increased.
By biasing the fuel injection 1 in the vertical direction, an effective denitrification reaction can be carried out.
本発明において、アフターエアポート直下に供給する燃
料は、第４図に示すように上段バーナ（マルチバーナ）
４の上半部の燃料噴射量を多くし、一方、下半部の燃料
噴射量を相対的に小さくしてもよいし、また上段バーナ
４とアフターエアポート５０間のプラネットバーナを設
けてこのバーナの燃料噴射量を多くしてもよい。いずれ
の場合も上段バーナ、またはこれに相当するバーナの空
気比は脱硝反応に好適な０．４〜ｏ、６ｉすることが好
ましい。なお、上段バーナ（マルチバーナ）の空気比は
上半分と下半分でほぼ等しくすることができるので、上
半分の燃料噴射量を増加してもＣＯや煤塵の発生は抑制
することができる。In the present invention, the fuel supplied directly below the after-airport is supplied to the upper stage burner (multi-burner) as shown in Fig. 4.
The amount of fuel injected in the upper half of 4 may be increased, while the amount of fuel injected in the lower half of 4 may be relatively small, or a planet burner may be provided between the upper stage burner 4 and the after air port 50 to The fuel injection amount may be increased. In either case, the air ratio of the upper stage burner or a burner equivalent thereto is preferably 0.4 to 6, which is suitable for the denitrification reaction. Note that since the air ratio of the upper stage burner (multi-burner) can be made almost equal between the upper half and the lower half, the generation of CO and soot can be suppressed even if the fuel injection amount in the upper half is increased.
本発明は、第１図のように、炉前面にバーナを配置した
フロントファイアリング方式の燃焼装置（典型的にはボ
イラ）のみならず、炉両面にバーナを配置した対向燃焼
方式や、炉のコーナにバーナな配置するコーナファイア
リング方式（またはタンゼンシャル方式）でも全く同様
に適用することができる。なお、本発明は、ガス、石油
、石炭等、いずれの燃料にも適用可能である。As shown in Fig. 1, the present invention applies not only to a front-firing type combustion device (typically a boiler) in which burners are placed in front of the furnace, but also in a facing combustion type combustion device in which burners are placed on both sides of the furnace, and in a furnace. A corner firing method (or tangential method) in which burners are arranged at corners can be applied in exactly the same manner. Note that the present invention is applicable to any fuel such as gas, oil, and coal.
以上、本発明によれば、アフターエアの巻き込みの影響
な少なくし、上段バーナ４で発生するラジカル量を増加
させ、中、下段バーナで発生した窒素酸化物を効果的に
還元させることができる。As described above, according to the present invention, the influence of after air entrainment can be reduced, the amount of radicals generated in the upper burner 4 can be increased, and nitrogen oxides generated in the middle and lower burners can be effectively reduced.
第１図は、マルチバーナを具備した火炉の断面図、第２
図は第１図の拡大部分１１のＡ夜回、第３図は、拡大部
分１１０Ｂ視図で、炉内のガス流れを説明する図、第４
図は、本発明による上段バーナの燃料噴射状況を模式的
に示す図である。
ｌ・・・火炉、２・・・下段バーナ、３・・・中段バー
ナ、４・・・上段バーナ、５・・・前部アフターエ、７
＄−）ａ第１図 第２図
第３図 第４図
弓Figure 1 is a cross-sectional view of a furnace equipped with a multi-burner;
The figure shows the A night view of the enlarged portion 11 in FIG.
The figure is a diagram schematically showing the fuel injection situation of the upper stage burner according to the present invention. l...Furnace, 2...Lower burner, 3...Middle burner, 4...Upper burner, 5...Front after-burner, 7
$-)a Fig. 1 Fig. 2 Fig. 3 Fig. 4 Bow
Claims (1)
段に配置し、かつその上部にアフターエアポートを備え
た燃焼装置の燃焼法において、上記各バーナの空気比を
１以下にして還元燃焼を行なうと共に前記アフターエア
ポート直下の燃料噴射量を相対的に増大させ、その部分
のラジカル生成物の酸化を抑制することを特徴とする窒
素酸化物還元燃焼方法。 （２、特許請求の範囲第１項において、前記多段バーナ
の空気比を下段バーナで１．０〜０．８、中段バーナで
０．８〜０．６、および上段バーナで０．６〜０．４と
することを特徴とする窒素酸化物還元燃焼方法。(1) In the combustion method of a combustion device in which a plurality of burners are arranged in upper and lower stages in the direction of air flow in a furnace and equipped with an after-air port at the top, the air ratio of each burner is set to 1 or less to perform reductive combustion. A nitrogen oxide reduction combustion method characterized in that the amount of fuel injected directly below the after-air port is relatively increased to suppress oxidation of radical products in that portion. (2. In claim 1, the air ratio of the multi-stage burner is 1.0 to 0.8 for the lower stage burner, 0.8 to 0.6 for the middle stage burner, and 0.6 to 0 for the upper stage burner. A nitrogen oxide reduction combustion method characterized by: .4.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4565682A JPS58164909A (en) | 1982-03-24 | 1982-03-24 | Reduction and combustion method for nitrogen oxide |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP4565682A JPS58164909A (en) | 1982-03-24 | 1982-03-24 | Reduction and combustion method for nitrogen oxide |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS58164909A true JPS58164909A (en) | 1983-09-29 |
Family
ID=12725417
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP4565682A Pending JPS58164909A (en) | 1982-03-24 | 1982-03-24 | Reduction and combustion method for nitrogen oxide |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS58164909A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6193311A (en) * | 1984-10-15 | 1986-05-12 | Hitachi Ltd | Monitoring method of combustion state and device thereof |
| US4881753A (en) * | 1987-11-30 | 1989-11-21 | Toyota Jidosha Kabushiki Kaisha | Air suspension system with an air drier |
-
1982
- 1982-03-24 JP JP4565682A patent/JPS58164909A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6193311A (en) * | 1984-10-15 | 1986-05-12 | Hitachi Ltd | Monitoring method of combustion state and device thereof |
| US4881753A (en) * | 1987-11-30 | 1989-11-21 | Toyota Jidosha Kabushiki Kaisha | Air suspension system with an air drier |
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