JP3068888B2 - Combustion apparatus and operation method thereof - Google Patents

Combustion apparatus and operation method thereof

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Publication number
JP3068888B2
JP3068888B2 JP3150956A JP15095691A JP3068888B2 JP 3068888 B2 JP3068888 B2 JP 3068888B2 JP 3150956 A JP3150956 A JP 3150956A JP 15095691 A JP15095691 A JP 15095691A JP 3068888 B2 JP3068888 B2 JP 3068888B2
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JP
Japan
Prior art keywords
combustion
gas
carbon dioxide
oxygen
supply system
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.)
Expired - Lifetime
Application number
JP3150956A
Other languages
Japanese (ja)
Other versions
JPH05231609A (en
Inventor
豪 河野
啓信 小林
清 楢戸
茂 小豆畑
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Hitachi Ltd
Mitsubishi Power Ltd
Original Assignee
Babcock Hitachi KK
Hitachi Ltd
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Filing date
Publication date
Application filed by Babcock Hitachi KK, Hitachi Ltd filed Critical Babcock Hitachi KK
Priority to JP3150956A priority Critical patent/JP3068888B2/en
Publication of JPH05231609A publication Critical patent/JPH05231609A/en
Application granted granted Critical
Publication of JP3068888B2 publication Critical patent/JP3068888B2/en
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Expired - Lifetime legal-status Critical Current

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Classifications

    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E20/00—Combustion technologies with mitigation potential
    • Y02E20/32—Direct CO2 mitigation

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  • Chimneys And Flues (AREA)
  • Treating Waste Gases (AREA)

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【０００１】[0001]

【産業上の利用分野】本発明は、燃焼装置に係わり、特
に二酸化炭素を回収し、窒素酸化物を低減させることの
できる燃焼装置とその運転方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a combustion apparatus, and more particularly to a combustion apparatus capable of recovering carbon dioxide and reducing nitrogen oxides, and a method of operating the combustion apparatus.

【０００２】[0002]

【従来の技術】近年、地球温暖化と酸性雨が地球規模的
な環境問題としてあげられている。地球温暖化は大気中
の二酸化炭素の濃度の増加が主要因の一つであり、酸性
雨はＮＯｘ，ＳＯｘ等の酸性ガスに起因する。火力発電
所はこれらの物質の固定排出源として注目されている。
火力発電用燃料としては石油、天然ガス、石炭が使用さ
れており、特に石炭は採掘可能埋蔵量が多く、今後需要
が伸びることが予想される。しかしながら、石炭は天然
ガスと石油に比べて炭素含有量が多く、石油の１０倍の
窒素を含有する。2. Description of the Related Art In recent years, global warming and acid rain have been cited as global environmental problems. One of the main factors of global warming is an increase in the concentration of carbon dioxide in the atmosphere, and acid rain is caused by acid gases such as NOx and SOx. Thermal power plants are attracting attention as a fixed source of these substances.
Petroleum, natural gas, and coal are used as fuel for thermal power generation. Coal is particularly large in minable reserves, and demand is expected to increase in the future. However, coal has a higher carbon content than natural gas and petroleum, and contains ten times as much nitrogen as petroleum.

【０００３】炭酸ガスの排出量削減をエネルギー供給シ
ステムの高効率化で対処できれば、これは最も経済的な
方法であるが、長期的にみれば、経済成長に伴うエネル
ギー消費の伸びに伴う二酸化炭素の排出量増加を抑制で
きるだけの高効率化は不可能であり、発生した二酸化炭
素を除去する技術が必要になる。燃焼排ガス中の二酸化
炭素を回収する方法としては、アミン等の吸収液中に吸
収させる手法や、固体吸着剤に吸着させる吸着法、ある
いは膜分離法等が検討されているが、いずれも変換効率
が低く、これらの装置を稼動させるとシステム全体のエ
ネルギー効率が低下する可能性が高く、まだ実用化には
いたっていない。また燃焼時に発生する窒素酸化物に
は、空気中の窒素が酸素で酸化されて生成するサーマル
ＮＯｘと、燃料中の窒素が酸化されて生成するフューエ
ルＮＯｘとがある。従来、サーマルＮＯｘの低減には火
炎温度を低減する燃焼法が採られ、フューエルＮＯｘの
低減には、燃焼器内にＮＯｘを還元する燃料過剰の領域
を形成する燃焼法が採られてきた。If the reduction of carbon dioxide emissions can be dealt with by increasing the efficiency of the energy supply system, this is the most economical method. However, in the long term, carbon dioxide associated with the increase in energy consumption accompanying economic growth It is impossible to increase the efficiency so as to suppress the increase in the amount of carbon dioxide emissions, and a technique for removing the generated carbon dioxide is required. As a method of recovering carbon dioxide in combustion exhaust gas, a method of absorbing carbon dioxide in an absorbing solution such as an amine, an adsorption method of adsorbing a solid adsorbent, or a membrane separation method have been studied. Therefore, when these devices are operated, there is a high possibility that the energy efficiency of the entire system is reduced, and the devices have not yet been put to practical use. Nitrogen oxides generated during combustion include thermal NOx generated by oxidizing nitrogen in air with oxygen and fuel NOx generated by oxidizing nitrogen in fuel. Conventionally, a combustion method for reducing the flame temperature has been adopted for reducing thermal NOx, and a combustion method for forming a region of excess fuel for reducing NOx in a combustor has been adopted for reducing fuel NOx.

【０００４】炭酸ガスの簡便な分離とサーマルＮＯｘの
抑制の問題を同時に達成する手法として、空気の替わり
に酸素で燃焼する手法が容易に考えられる。酸素で燃焼
すれば、当然サーマルＮＯｘの発生は無くなり、また燃
焼ガスのほとんどが水蒸気と炭酸ガスになり炭酸ガスの
分離が容易になる。しかしながら、酸素で燃焼すると火
炎温度が高くなり、燃焼室を構成する材料の耐熱性や寿
命向上等の技術課題があり、これはエネルギ供給システ
ムの信頼性向上の観点からは大きな課題である。このひ
とつの対策法としては、燃焼炉本体で熱交換を終了した
燃焼排ガスを抽気し、燃焼炉本体外部から燃焼炉に供給
される燃料を燃焼させるために必要な酸素ガスと該抽気
ガスを混合し、燃料の酸化剤として燃焼炉へ供給するよ
うにした燃焼装置において抽気ガス系統もしくは酸化剤
の送気系統に窒素以外の不活性ガスを供給する方法（特
開昭５５−３５２１号公報）が提案されている。As a technique for simultaneously achieving the problems of simple separation of carbon dioxide gas and suppression of thermal NOx, a technique of burning with oxygen instead of air can be easily considered. Burning with oxygen naturally eliminates the generation of thermal NOx, and most of the combustion gas becomes steam and carbon dioxide, which facilitates the separation of carbon dioxide. However, burning with oxygen raises the flame temperature, and there are technical issues such as improvement in heat resistance and life of the material constituting the combustion chamber. This is a major issue from the viewpoint of improving the reliability of the energy supply system. One measure is to extract the flue gas that has undergone heat exchange in the combustion furnace body and mix the extracted gas with the oxygen gas required to burn the fuel supplied from outside the combustion furnace body to the combustion furnace. A method of supplying an inert gas other than nitrogen to a bleed gas system or an oxidant gas supply system in a combustion apparatus in which a fuel is supplied as an oxidant to a combustion furnace (Japanese Patent Laid-Open No. 55-3521). Proposed.

【０００５】また、燃焼排ガスから純粋な二酸化炭素を
回収する方法として、燃焼炉などに設置された酸素燃焼
バーナに炭化水素系燃料と酸素とを導いて燃焼せしめる
酸素燃焼バーナを備えた燃焼装置において、前記燃料及
び酸素のうちの一方もしくは両方に前記燃焼炉で発生す
る排ガスの廃熱を与える熱交換器を設けると共に、前記
排ガスから二酸化炭素を分離、回収するための二酸化炭
素回収手段と、前記燃焼炉で発生する排ガスの一部を前
記酸素燃焼バーナへ返送する燃焼温度調節回路とをそな
えてなることを特徴とする酸素燃焼バーナを用いた燃焼
装置が提案されている（特開昭５９−１６１６０５号公
報）。As a method of recovering pure carbon dioxide from combustion exhaust gas, a combustion apparatus provided with an oxy-fuel burner installed in a combustion furnace or the like and provided with an oxy-fuel burner for guiding hydrocarbon-based fuel and oxygen to burn the fuel. Providing a heat exchanger that gives waste heat of exhaust gas generated in the combustion furnace to one or both of the fuel and oxygen, and separating and recovering carbon dioxide from the exhaust gas, There has been proposed a combustion apparatus using an oxyfuel burner, which comprises a combustion temperature control circuit for returning a part of the exhaust gas generated in the combustion furnace to the oxyfuel burner (Japanese Patent Application Laid-Open No. S59-5959). 161605).

【０００６】[0006]

【発明が解決しようとする課題】上記の公知例で示され
る手法は、炭酸ガス分離を容易にする点では有効である
が、これらの公知例に記載されている手法だけではエネ
ルギ供給システムは稼働しない。たとえば、石炭のよう
な不燃性の灰分や硫黄、窒素を含む燃料を使用した場
合、燃焼排ガス中にＮＯｘ、ＳＯｘ等の酸性ガスおよび
未燃の石炭や灰分からなる粒子が含まれるようになり、
これらを燃焼排ガスと共に循環すると、循環管路内に前
記酸性ガスが高濃度で蓄積し、さらに再循環管路内にお
いて燃焼排ガスに含まれる水蒸気が凝縮した水滴に前記
酸性ガスが溶けて、循環管路の内面を腐食する。また、
前記粒子が再循環燃焼排ガスと共に循環管路内を流れる
と、粒子が管路の内壁に衝突して管路の内面を摩耗した
り、循環管路の内部に堆積して管路の圧損が大きくなる
可能性もある。また装置の初期始動時には燃焼ガスは無
く、酸素だけを初期の酸化剤として使用すると燃焼装置
の耐熱性を高くする必要があり、また燃焼ガス中の炭酸
ガスを必要量だけ回収するにはシステム全体が定常状態
に達するのに長時間要し、これはシステム価格あるいは
効率上大きな問題である。本発明は、上記のような問題
点を解決し、起動時においても酸素濃度が一定で、しか
も効率的な運転ができる燃焼装置とその運転方法及びボ
イラと微粉炭バーナを提供することを目的とする。The methods described in the above-mentioned known examples are effective in facilitating the separation of carbon dioxide gas, but the energy supply system operates only by the methods described in these known examples. do not do. For example, when a fuel containing non-combustible ash, sulfur, and nitrogen such as coal is used, NOx, acid gas such as SOx, and particles composed of unburned coal and ash are contained in the flue gas,
When these are circulated together with the flue gas, the acid gas accumulates at a high concentration in the circulation line, and further, the acid gas dissolves in water droplets in which steam contained in the flue gas is condensed in the recirculation line. Corrodes the inner surface of the road. Also,
When the particles flow in the circulation line together with the recirculated flue gas, the particles collide with the inner wall of the line and wear the inner surface of the line, or accumulate inside the circulation line to cause a large pressure loss in the line. It could be. When the system is initially started, there is no combustion gas, and if only oxygen is used as the initial oxidizing agent, the heat resistance of the combustion system must be increased, and the entire system must be recovered to recover the required amount of carbon dioxide in the combustion gas. Takes a long time to reach a steady state, which is a major problem in terms of system cost or efficiency. An object of the present invention is to solve the above-mentioned problems and to provide a combustion device having a constant oxygen concentration even at the time of start-up and capable of operating efficiently, a method of operating the same, and a boiler and a pulverized coal burner. I do.

【０００７】[0007]

【課題を解決するための手段】上記目的を達成するため
に、本発明では、燃料を供給する配管を含む燃料供給系
と、酸化剤を含む燃焼用気体を供給する燃焼用気体供給
系と、前記燃料供給系を通り搬送された燃料と燃焼用気
体供給系を通ってきた燃焼用気体を燃焼させるバーナ
と、前記バーナを側壁に備えた燃焼室と、前記燃焼室で
発生した燃焼排ガスを前記燃焼室の外部に導く煙道と、
前記煙道に備えられ前記燃焼排ガスを排ガる手段と、前
記燃焼排ガス処理手段によって処理された燃焼排ガスの
一部を前記燃焼用気体供給系に再循環させる手段を備え
た燃焼装置において、前記燃焼排ガス処理手段で処理さ
れた前記燃焼排ガスを二酸化炭素と酸素とに分離する手
段と、前記分離した二酸化炭素と酸素を貯蔵する手段
と、前記貯蔵手段に貯蔵された酸素の一部を前記燃焼用
気体供給系に再循環させる手段を備えたことを特徴とす
る燃焼装置としたものである。In order to achieve the above object, the present invention provides a fuel supply system including a pipe for supplying fuel, a combustion gas supply system for supplying a combustion gas containing an oxidant, a burner for burning a combustion gas having passed through the combustion gas supply system with fuel transported through the fuel supply system, and a combustion chamber provided with the burner on the side wall, the combustion exhaust gas generated in the combustion chamber A flue leading to the outside of the combustion chamber;
Means for exhausting the flue gas provided in the flue, and a combustion device comprising means for recirculating a part of the flue gas treated by the flue gas treatment means to the combustion gas supply system, Means for separating the flue gas treated by the flue gas treatment means into carbon dioxide and oxygen, means for storing the separated carbon dioxide and oxygen, and combustion of a part of the oxygen stored in the storage means. And a means for recirculating the gas into the combustion gas supply system.

【０００８】また、上記の燃焼装置において、前記燃焼
用気体供給系には、空気から酸素を分離する酸素分離装
置と、前記酸素分離装置をバイパスして備えられた空気
供給手段と、該分離装置で分離された酸素を前記バーナ
に供給する手段とを備え、該供給手段の途中に前記燃焼
排ガスから分離した二酸化炭素を再循環させる手段を設
けるのがよい。また、本発明は、上記の燃焼装置の運転
方法において、燃焼装置の起動時に、循環管路内を流れ
るのに十分な量の二酸化炭素が二酸化炭素貯蔵手段に蓄
積されるまでは、燃焼用気体として空気を用いて運転す
るか、あるいは、二酸化炭素貯蔵手段に循環管路を流れ
るのに十分な量の二酸化炭素を供給してから始動するの
がよい。さらに、上記燃焼装置は、二酸化炭素と酸素を
液体状で貯蔵し、使用に際して燃焼排ガスと熱交換して
ガス化しながら運転するのがよいし、また、前記煙道に
ガス濃度検知手段を備えることによって、燃焼排ガス中
の窒素酸化物と灰中未燃分の量が最小となるように前記
燃焼用気体供給系の酸素と再循環二酸化炭素の流量を制
御しながら運転するのがよい。また、上記の燃焼装置に
おいて、前記燃焼排ガスを処理する手段としては脱硫装
置、脱硝装置、脱塵装置の少なくとも一つと乾燥装置を
備えるのがよい。In the above-mentioned combustion apparatus, the combustion gas supply system includes an oxygen separation device for separating oxygen from air, an air supply means provided bypassing the oxygen separation device, and the separation device. And a means for supplying the oxygen separated by the above to the burner, and a means for recirculating the carbon dioxide separated from the flue gas in the supply means. Further, in the method for operating a combustion device according to the present invention, when the combustion device is started, the combustion gas may be supplied until a sufficient amount of carbon dioxide to flow through the circulation pipeline is accumulated in the carbon dioxide storage means. It is preferable to start the operation after supplying the carbon dioxide to the carbon dioxide storage means with a sufficient amount of carbon dioxide to flow through the circulation line. Further, the above-mentioned combustion device preferably stores carbon dioxide and oxygen in a liquid state and operates while exchanging heat with flue gas for gasification during use, and further comprises a gas concentration detecting means in the flue. Therefore, it is preferable to operate while controlling the flow rates of oxygen and recirculated carbon dioxide in the combustion gas supply system so that the amounts of nitrogen oxides in the combustion exhaust gas and unburned components in the ash are minimized. Further, in the above-described combustion device, it is preferable that at least one of a desulfurization device, a denitration device, and a dust removal device and a drying device are provided as means for treating the combustion exhaust gas.

【０００９】また、上記他の目的を達成するために、本
発明では燃料を供給する配管を含む燃料供給系と、酸化
剤を含む燃焼用気体を供給する燃焼用気体供給系と、前
記燃料供給系を通り搬送された燃料と燃焼用気体供給系
を通ってきた燃焼用気体を燃焼させるバーナと、前記バ
ーナを側壁に備えた燃焼室と、前記燃焼室で発生した燃
焼排ガスを前記燃焼室の外部に導く煙道と、前記煙道に
備えられ前記燃焼排ガスを排ガス処理する手段と、前記
燃焼ガス処理手段によって処理された燃焼排ガスの一部
を前記燃焼用気体供給系に再循環させる手段を備えた燃
焼装置において、前記燃焼排ガス処理手段で処理された
燃焼排ガスの残部に燃料と酸素を供給し、燃焼排ガス中
の未燃焼酸素を燃焼させるアフタコンバスタを設けたこ
とを特徴とする燃焼装置としたものである。上記の燃焼
装置において、前記アフタコンバスタの下流に熱交換器
を設け、さらに前記アフタコンバスタの上流で抽気した
燃焼排ガスと、前記熱交換器を通った燃焼排ガスとか
ら、水分と水蒸気を除去する乾燥装置を設け、前記乾燥
装置を通った燃焼排ガスを前記燃焼用気体供給系に再循
環させることとすることができる。 According to another aspect of the present invention, there is provided a fuel supply system including a fuel supply pipe.
A combustion gas supply system for supplying a combustion gas containing an agent,
The fuel conveyed through the fuel supply system and the gas supply system for combustion
A burner for burning the combustion gas passing therethrough;
A combustion chamber having a burner on the side wall;
A flue for directing the flue gas to the outside of the combustion chamber,
Means for exhaust gas treatment of the combustion exhaust gas provided,
Part of the combustion exhaust gas processed by the combustion gas processing means
Having a means for recirculating the gas to the combustion gas supply system.
In the baking apparatus, the waste gas is treated by the combustion exhaust gas treatment means.
Fuel and oxygen are supplied to the rest of the flue gas,
Afterburner that burns unburned oxygen
And a combustion device characterized by the following. Above combustion
A heat exchanger downstream of the after-combustor;
And further bleeding upstream of the after-combustor
Such as flue gas and flue gas passing through the heat exchanger
Provided a drying device for removing moisture and water vapor,
The flue gas that has passed through the device is recycled to the combustion gas supply system.
It can be made to ring.

【００１０】[0010]

【作用】燃焼排ガス中の二酸化炭素を燃焼用気体中の酸
素の希釈気体として用いることは、燃焼用気体が炭素の
化合物である燃料と反応した後の燃焼排ガスの組成をほ
とんど二酸化炭素にする。即ち、従来の空気を用いた燃
焼において燃料として炭化水素系の化合物を用いると燃
料中の炭素と水素はそれぞれ酸素と反応し二酸化炭素と
水蒸気になり、燃料のほとんどが供給された理論的に必
要な量の酸素と反応したとすると、空気中の窒素は反応
に関与しないので燃焼排ガスの組成は主に窒素と二酸化
炭素及び水蒸気の混合物となる。ここで燃焼用気体とし
て燃焼排ガスから分離して得られた二酸化炭素と空気か
ら分離した酸素の混合気体を、前記混合気体中の酸素の
割合を空気中の酸素の割合と等しくして用いると、二酸
化炭素は窒素と同様に反応に関与しないので燃焼排ガス
の組成はほとんど二酸化炭素と水蒸気になる。たとえ
ば、最も環境対策の必要性の高い石炭を前記燃焼用気体
で燃焼させた場合、石炭は炭素だけでなく水素、窒素、
硫黄等の揮発分、無機質である灰を含んでいるので、燃
焼排ガスの組成はほとんどは二酸化炭素となるが、水蒸
気、ＮＯｘ、ＳＯｘ、及び灰分や未燃焼の石炭粒子から
なる塵と酸素が燃焼ガス中に含まれる。そこでこの燃焼
排ガスを脱硫、脱硝、脱塵等の排ガス処理を施した後乾
燥すればほとんど純粋な二酸化炭素を得ることができ、
特別な分離装置なしに、且つ、燃焼システム全体のエネ
ルギー効率を下げることなく容易に二酸化炭素のみを回
収することができる。The use of carbon dioxide in combustion exhaust gas as a diluent gas of oxygen in combustion gas makes the composition of the combustion exhaust gas after the combustion gas has reacted with fuel, which is a compound of carbon, almost carbon dioxide. That is, when a hydrocarbon-based compound is used as a fuel in conventional combustion using air, carbon and hydrogen in the fuel react with oxygen to form carbon dioxide and water vapor, respectively. If it reacts with a certain amount of oxygen, the composition of the flue gas is mainly a mixture of nitrogen, carbon dioxide and water vapor, since nitrogen in the air does not participate in the reaction. Here, when a mixed gas of carbon dioxide and oxygen separated from air obtained by separating from combustion exhaust gas as a combustion gas is used by making the ratio of oxygen in the mixed gas equal to the ratio of oxygen in air, Since carbon dioxide does not participate in the reaction like nitrogen, the composition of the flue gas is almost carbon dioxide and water vapor. For example, when coal with the highest need for environmental measures is burned with the combustion gas, the coal contains not only carbon but also hydrogen, nitrogen,
Since it contains volatile matter such as sulfur and inorganic ash, the composition of flue gas is mostly carbon dioxide, but steam and NOx, SOx, and dust and oxygen consisting of ash and unburned coal particles burn. Contained in gas. Therefore, if this flue gas is subjected to exhaust gas treatment such as desulfurization, denitration, and dust removal and then dried, almost pure carbon dioxide can be obtained.
It is possible to easily recover only carbon dioxide without a special separation device and without lowering the energy efficiency of the entire combustion system.

【００１１】さらにここで得られた二酸化炭素の一部を
回収し、残りを燃焼用気体中の酸素の希釈剤として再循
環させることは、燃焼用空気中の酸素の希釈剤としての
二酸化炭素を外部から連続的に供給する必要をなくし資
源の有効利用を図っている。さらに燃焼用気体として、
前記二酸化炭素と酸素の混合気体を用いることは、燃焼
気体中に窒素が含まれないため、燃焼温度が高温になる
と発生する空気中の窒素の酸化によるサーマルＮＯｘの
発生を皆無にする。また通常、燃料の燃焼率を高めるに
は完全燃焼に必要な理論酸素量以上に酸素を燃焼装置に
供給する。従って燃焼ガス中には酸素が含まれ、これを
水蒸気あるいは炭酸ガスと分離し、再度燃焼に利用する
のは空気中の酸素と窒素とを分離する装置の負荷を軽減
することになり、システムの効率を向上させる。また二
酸化炭素を液体あるいは固体として燃焼ガスから分離貯
蔵すれば、酸素の燃焼ガスからの分離は容易になる。ま
た液体あるいは固体として貯蔵した二酸化炭素を燃焼装
置に供給する際、気化熱を燃焼ガスから供給すれば、二
酸化炭素を液体あるいは固体として分離する二酸化炭素
の燃焼ガスからの分離時に必要な燃焼ガスの冷却が容易
になる。また空気中の酸素を深冷分離法によって分離す
る場合、酸素の気化に必要な熱を燃焼ガスから供給すれ
ば、二酸化炭素の燃焼ガスからの分離も容易になりシス
テムの効率は向上する。Further, by recovering a part of the carbon dioxide obtained here and recirculating the remainder as a diluent of oxygen in the combustion gas, the carbon dioxide as a diluent of oxygen in the combustion air can be removed. This eliminates the need for continuous supply from the outside, and makes effective use of resources. Furthermore, as combustion gas,
The use of the gaseous mixture of carbon dioxide and oxygen eliminates the generation of thermal NOx due to the oxidation of nitrogen in the air, which is generated when the combustion temperature becomes high, because nitrogen is not contained in the combustion gas. Further, usually, in order to increase the combustion rate of the fuel, oxygen is supplied to the combustion device in an amount equal to or more than the theoretical oxygen amount necessary for complete combustion. Therefore, the combustion gas contains oxygen, which is separated from water vapor or carbon dioxide gas, and reused for combustion reduces the load on the device that separates oxygen and nitrogen in the air. Improve efficiency. If carbon dioxide is separated and stored as a liquid or a solid from combustion gas, separation of oxygen from combustion gas becomes easy. In addition, when supplying carbon dioxide stored as a liquid or solid to a combustion device, if the heat of vaporization is supplied from the combustion gas, the combustion gas required to separate carbon dioxide, which separates carbon dioxide as a liquid or a solid, from the combustion gas is removed. Cooling becomes easy. When oxygen in the air is separated by the cryogenic separation method, if the heat required for vaporizing oxygen is supplied from the combustion gas, the separation of carbon dioxide from the combustion gas is facilitated, and the efficiency of the system is improved.

【００１２】またシステムの初期始動時には燃焼ガスか
ら分離された二酸化炭素はなく、始動時には、空気で燃
料を燃焼し、二酸化炭素の再循環管路に設けた二酸化炭
素の貯蔵手段に二酸化炭素を貯蔵する。または、始動時
には、二酸化炭素の貯蔵装置内に、始動に必要な二酸化
炭素として、他の二酸化炭素製造装置より得られたもの
を供給するのも良い。このようにすれば、空気の供給設
備は不要になり、システムとしては簡素化される。しか
しながら、たとえば１００万ｋＷの火力発電所の始動に
必要な二酸化炭素を他の製造装置にて製造するのも容易
では無く、始動法の選択は、発電所の立地条件に依存す
る。At the time of initial startup of the system, there is no carbon dioxide separated from the combustion gas, and at the time of startup, fuel is burned with air and stored in the carbon dioxide storage means provided in the carbon dioxide recirculation line. I do. Alternatively, at the time of starting, carbon dioxide necessary for starting may be supplied to the carbon dioxide storage device from the other carbon dioxide producing device. This eliminates the need for air supply equipment and simplifies the system. However, it is not easy to produce carbon dioxide necessary for starting a 1 MW thermal power plant by another manufacturing apparatus, and the choice of the starting method depends on the location conditions of the power plant.

【００１３】[0013]

【実施例】以下、本発明を実施例により具体的に説明す
るが、本発明はこれらに限定されない。 実施例１ 以下本発明の実施例を図１により説明する。図１は本発
明を微粉炭燃焼装置に適用した一実施例である。燃料で
ある石炭１は粉砕機２で微粉炭３に粉砕された後、貯炭
器４に貯蔵され石炭流量調節機５によって流量を調節し
て供炭機６に供給される。ブロワ１００によって送風さ
れた空気８を、酸素分離装置９によって窒素１０と酸素
１１に分離し、酸素１１は酸素流量調節機１２ａ、１２
ｂによって一次燃焼用気体供給系１４と、二次燃焼用気
体供給系１３に分けられそれぞれ再循環二酸化炭素２６
と管路内で混合され、その後一次燃焼用気体は空気予熱
器２０で燃焼排ガスと熱的に接触して加熱された後、供
炭機６に供給され微粉炭３を乾燥しながら搬送しバーナ
１５の一次側燃焼用気体供給口に供給される。二次燃焼
用気体はそのままバーナ１５の二次側燃焼用気体供給口
に供給される。バーナ１５に供給された燃焼用気体中の
二酸化炭素は燃焼に関与しないが、燃料である微粉炭３
と酸化剤である酸素１１はボイラ１６内で燃焼し、一次
燃焼用気体と二次燃焼気体のトータルの空気比を１以上
で供給ずれば、石炭中の炭素分はほとんど二酸化炭素に
なるが、水んど二酸化炭素になるが、水素、窒素、硫黄
等の揮発分を含む石炭の場合これらが、焼用気体中の酸
素によって酸化され水蒸気及びＮＯｘ、ＳＯｘ等の酸性
ガスが発生する。また燃焼排ガスは、石炭中の灰や未燃
微粉炭粒子が粉塵として含まれている。EXAMPLES Hereinafter, the present invention will be described specifically with reference to Examples, but the present invention is not limited thereto. Embodiment 1 Hereinafter, an embodiment of the present invention will be described with reference to FIG. FIG. 1 shows an embodiment in which the present invention is applied to a pulverized coal combustion apparatus. Coal 1 as a fuel is pulverized into pulverized coal 3 by a pulverizer 2, stored in a coal storage 4 , adjusted in flow rate by a coal flow controller 5, and supplied to a coal feeder 6. The air 8 blown by the blower 100 is separated into nitrogen 10 and oxygen 11 by an oxygen separator 9, and the oxygen 11 is supplied to oxygen flow controllers 12a and 12a.
b, the gas is divided into the primary combustion gas supply system 14 and the secondary combustion gas supply system 13,
And the primary combustion gas is heated by being brought into thermal contact with the combustion exhaust gas in the air preheater 20 and then supplied to the coal supply machine 6 to convey the pulverized coal 3 while drying it and burn it. 15 is supplied to the primary-side combustion gas supply port. The secondary combustion gas is supplied to the secondary combustion gas supply port of the burner 15 as it is. The carbon dioxide in the combustion gas supplied to the burner 15 does not participate in the combustion, but the pulverized coal 3
And the oxygen 11 as an oxidizing agent are burned in the boiler 16 and if the total air ratio of the primary combustion gas and the secondary combustion gas is not supplied at 1 or more, the carbon content in the coal becomes almost carbon dioxide, Although it becomes carbon dioxide, coal containing volatile components such as hydrogen, nitrogen and sulfur is oxidized by oxygen in the burning gas to generate steam and acidic gas such as NOx and SOx. The combustion exhaust gas contains ash in coal and unburned pulverized coal particles as dust.

【００１４】前記二酸化炭素、水蒸気、酸性ガス、粉塵
を含む燃焼灰ガスは煙道１７を通った後、脱硝装置１８
でＮＯｘを除去し、集塵装置１９で脱塵され、さらに空
気予熱器２０で一次燃焼用気体と熱的に接触して冷却さ
れた後、脱硫装置２２でＳ０ｘを除去し、乾燥装置２３
で水蒸気と水分を除去する。乾燥装置２３を通過した燃
焼排ガスはほとんど二酸化炭素と酸素の混合気体２４に
なっており、この混合気体を冷却機３０で−８０℃以下
に冷却して二酸化炭素のみを液化し二酸化炭素と酸素に
分離する。液化された二酸化炭素はポンプ３６ａで二酸
化炭素貯蔵装置３３に送られて貯蔵され、一部は液化二
酸化炭素２５として回収し残りは二酸化炭素送風ブロア
３６ｂによって気化され、一次側及び二次側二酸化炭素
流量調節機２７ａ、２７ｂによってそれぞれ一次燃焼用
気体供給系１４、二次燃焼用気体供給系１３に供給され
る。一方、前記酸素と二酸化炭素の混合気体から分離さ
れた酸素は、圧縮用送風ブロア３７ａによって液化し酸
素貯蔵装置３４に貯蔵された後、気化用酸素送風ブロア
３７ｂによって一次側及び二次側の酸素流量調節機１２
ａ、１２ｂの前段に再循環される。定常運転時において
は、酸化剤としての酸素とその希釈剤としての二酸化炭
素は、それぞれ混合する前に一次燃焼気体用と二次燃焼
気体用に分けられ別々の供給系で混合されるので、一次
燃焼用気体と二次燃焼用気体の空気比を任意にかつ独立
に制御可能となっている。また各燃焼用気体中の二酸化
炭素は、燃焼排ガス中の二酸化炭素を再循環させて用い
ているので、外部から二酸化炭素を供給する必要はな
く、バーナ１５で燃焼した炭素の量に相当する液化二酸
化炭素を回収すれば、再循環二酸化炭素２６の流量は一
定に保たれる。The combustion ash gas containing carbon dioxide, water vapor, acid gas, and dust passes through a flue 17 and then passes through a denitration device 18.
After removing NOx by the dust collector 19 and further cooling by contacting with the primary combustion gas in the air preheater 20, the SOx is removed by the desulfurizer 22 and the drying device 23.
Removes water vapor and moisture. The combustion exhaust gas that has passed through the drying device 23 is almost a mixed gas 24 of carbon dioxide and oxygen, and this mixed gas is cooled to −80 ° C. or less by the cooler 30 to liquefy only carbon dioxide and convert it to carbon dioxide and oxygen. To separate. The liquefied carbon dioxide is sent to and stored in the carbon dioxide storage device 33 by the pump 36a, a part of which is collected as liquefied carbon dioxide 25, and the remainder is vaporized by the carbon dioxide blower 36b, and the primary and secondary carbon dioxide The gas is supplied to the primary combustion gas supply system 14 and the secondary combustion gas supply system 13 by the flow controllers 27a and 27b, respectively. On the other hand, the oxygen separated from the mixed gas of oxygen and carbon dioxide is liquefied by the blowing blower 37a for compression and stored in the oxygen storage device 34, and then the oxygen on the primary side and the secondary side by the blowing blower 37b for vaporization. Flow controller 12
It is recirculated before a and 12b. At the time of steady operation, oxygen as an oxidizing agent and carbon dioxide as a diluent are separated into a primary combustion gas and a secondary combustion gas for mixing before being mixed, and are mixed in separate supply systems. The air ratio between the combustion gas and the secondary combustion gas can be arbitrarily and independently controlled. Further, since the carbon dioxide in each combustion gas is used by recirculating the carbon dioxide in the combustion exhaust gas, there is no need to supply carbon dioxide from outside, and the liquefaction corresponding to the amount of carbon burned by the burner 15 is performed. If the carbon dioxide is recovered, the flow rate of the recirculated carbon dioxide 26 is kept constant.

【００１５】本実施例によれば、ほぼ純粋な液化二酸化
炭素を回収することが可能でありかつ空気中の窒素の酸
化によるサーマルＮＯｘの発生を皆無とすることができ
る。また一次燃焼用気体の予熱を燃焼排ガスと熱交換す
ることによって行っているため装置のエネルギー効率が
よく、燃焼用気体中の二酸化炭素を再循環して用いてい
るので装置の利用効率も高い。また燃焼排ガス中の未燃
焼酸素を回収し再循環させているので、酸素の無駄な消
費がない。さらに、一次側と二次側の空気比を任意に変
化させることができるので、燃焼装置の負荷や石炭の性
状、炭種が変わってもフューエルＮＯｘと灰中未燃分の
量を最小にするような燃焼を行うことができる。According to the present embodiment, it is possible to eradicate almost a pure can be recovered liquefied carbon dioxide and nitrogen evolution by that thermal NOx in oxidation in the air. Further, since the preheating of the primary combustion gas is performed by exchanging heat with the combustion exhaust gas, the energy efficiency of the apparatus is good, and since the carbon dioxide in the combustion gas is recycled and used, the utilization efficiency of the apparatus is high. Further, since unburned oxygen in the combustion exhaust gas is recovered and recycled, there is no wasteful consumption of oxygen. Furthermore, since the air ratio between the primary side and the secondary side can be changed arbitrarily, the amount of fuel NOx and unburned fuel in ash is minimized even if the load on the combustion device, the properties of coal, and the type of coal change. Such combustion can be performed.

【００１６】上記微粉炭燃焼装置の起動方法は、空気流
量調節機３９ａを全閉にし迂回用空気調節機３９ｂを開
け、燃焼用気体として定常運転時の二酸化炭素で希釈さ
れた酸素ではなく空気８を流し、通常の空気による燃焼
を行う。この時再循環二酸化炭素流量調節機２７ａ、２
７ｂと再循環酸素流量調節機３１と液化二酸化炭素流量
調節機２８は閉じ、排ガス流量調節機３５を開けて運転
を行う。空気で燃焼を行うと燃焼排ガス１７の組成は約
７０％が窒素となり、残りは二酸化炭素、水蒸気等にな
る。この燃焼排ガスを定常運転時と同様に脱硝装置１
８、脱塵装置１９、脱硫装置２２で排ガス処理し、乾燥
装置２３で乾燥した後、冷却装置３０で冷却して二酸化
炭素を液体として分離し、二酸化炭素貯蔵装置に貯蔵
し、残りの燃焼排ガスは排ガス流量調節機３５、煙突２
９を通って大気中に放出される。二酸化炭素貯蔵装置に
循環管路内を循環するのに十分な量の二酸化炭素が蓄積
されるまで空気で燃焼を行う。その後、迂回用空気流量
調節機３９ｂを閉じ、空気流量調節機３９ａと再循環二
酸化炭素流量調節機２７ａ、２７ｂを開けて、酸素分離
装置９から得られた酸素１１と、二酸化炭素貯蔵装置３
３に貯蔵されている二酸化炭素を気化用のブロア３６ｂ
で気化して一次側燃焼用気体供給系および二次側燃焼用
気体供給系で混合し、この混合気体を燃焼用気体として
燃焼を行う。すると燃焼用気体である空気に含まれてい
た窒素が供給されなくなるので、燃焼排ガス中の窒素の
濃度は徐々に減少する。燃焼排ガスに残存する窒素がな
くなった後、排ガス流量調節機３５を閉じ回収用酸素流
量調節機３１を開けて定常運転に入る。The starting method of the pulverized coal combustion apparatus is as follows. The air flow regulator 39a is fully closed and the bypass air regulator 39b is opened, and the air 8 is used as the combustion gas instead of oxygen diluted with carbon dioxide during steady operation. And burn with normal air. At this time, the recirculating carbon dioxide flow controller 27a, 2
7b, the recirculation oxygen flow controller 31 and the liquefied carbon dioxide flow controller 28 are closed, and the exhaust gas flow controller 35 is opened to operate. When air is used for combustion, about 70% of the composition of the flue gas 17 is nitrogen, and the remainder is carbon dioxide, water vapor and the like. This combustion exhaust gas is used in the denitration apparatus 1 in the same manner as in the normal operation.
8. Exhaust gas treatment in the dust removal device 19 and the desulfurization device 22, and after drying in the drying device 23, cooled in the cooling device 30 to separate carbon dioxide as a liquid, stored in the carbon dioxide storage device, and the remaining combustion exhaust gas. Is exhaust gas flow controller 35, chimney 2
9 to the atmosphere. Combustion with air is performed until sufficient carbon dioxide is accumulated in the carbon dioxide storage device to circulate in the circulation line. Thereafter, the detour air flow controller 39b is closed, the air flow controller 39a and the recirculating carbon dioxide flow controllers 27a, 27b are opened, and the oxygen 11 obtained from the oxygen separator 9 and the carbon dioxide storage device 3 are opened.
Blower 36b for vaporizing the carbon dioxide stored in 3
And mixed in the primary-side combustion gas supply system and the secondary-side combustion gas supply system, and the mixed gas is burned as the combustion gas. Then, the nitrogen contained in the air as the combustion gas is no longer supplied, so that the concentration of nitrogen in the combustion exhaust gas gradually decreases. After the nitrogen remaining in the combustion exhaust gas has disappeared, the exhaust gas flow controller 35 is closed, the oxygen flow controller 31 for recovery is opened, and a steady operation is started.

【００１７】実施例２ 図２は本発明を微粉炭燃焼装置に適用した一実施例であ
る。石炭１は実施例１と同様にして供炭機６に供給され
る。空気８は空気送風用プロア１００によって深冷分離
装置９に送られて窒素１０と液化酸素１１に分けられ
る。液化酸素１１は交換器１０１で燃焼排ガスと熱的に
接触して気化されたのち一次側および二次側酸素流量調
節機によって分けられ、それぞれ燃焼排ガスから回収し
た二酸化炭素と混合されて燃焼用気体とされ、一次側燃
焼用気体２１は供炭機６で微粉炭を搬送して、二次燃焼
用気体はそのままバーナ１５に供給される。バーナ１５
に供給された微粉炭と酸素はボイラ１６内で燃焼し、そ
の燃焼排ガスは煙道１７を通ったのち脱硝装置１８で脱
硝、脱塵装置１９で脱塵処理されたのち熱交換器１０１
で液化二酸化炭素と液化酸素と熱的に接触して廃熱を回
収される。熱交換器１０１をでた燃焼排ガスはさらに脱
硫装置２２で脱硫、乾燥装置２３で乾燥処理すると、実
施例１と同様に燃焼排ガスはほとんど二酸化炭素と酸素
の混合気体となるので、前記混合気体を冷却装置２４で
−８０℃以下に冷却して二酸化炭素を液体として、酸素
を気体として分離し、液化二酸化炭素は二酸化炭素貯蔵
装置３３に、酸素は酸素貯蔵装置３４に液化して貯蔵す
る。液化二酸化炭素は、二酸化炭素流量調節機２７ａ、
２７ｂによって一次側と、二次側に分けられそれぞれ熱
交換器１０１で燃焼排ガスと熱的に接触して気化され、
一次側は予熱されて、二次側は常温で熱交換器を出たの
ち、それぞれ前記深冷分離によって得られた液化酸素を
気化した酸素と混合される。本実施例によれば、燃焼排
ガスから分離して貯蔵された液化二酸化炭素と深冷分離
によって得られる液化酸素を燃焼排ガスによって気化し
ているので熱効率が良い。Embodiment 2 FIG. 2 shows an embodiment in which the present invention is applied to a pulverized coal combustion apparatus. The coal 1 is supplied to the coal donor 6 in the same manner as in the first embodiment. The air 8 is sent to the cryogenic separation device 9 by the air blower 100 and is separated into nitrogen 10 and liquefied oxygen 11 . The liquefied oxygen 11 is thermally contacted with the combustion exhaust gas in the exchanger 101 and is vaporized, then separated by primary and secondary oxygen flow controllers, and mixed with carbon dioxide recovered from the combustion exhaust gas, respectively, to produce a combustion gas. The primary combustion gas 21 is transported as pulverized coal by the coal supply machine 6, and the secondary combustion gas is supplied to the burner 15 as it is. Burner 15
The pulverized coal and oxygen supplied to the boiler 16 are burned in the boiler 16, and the combustion exhaust gas passes through a flue 17, is denitrated by a denitration device 18, and is dedusted by a dedusting device 19, and then is subjected to a heat exchanger 101
The waste heat is recovered by thermal contact with liquefied carbon dioxide and liquefied oxygen. When the combustion exhaust gas leaving the heat exchanger 101 is further desulfurized by the desulfurization device 22 and dried by the drying device 23, the combustion exhaust gas becomes almost a mixed gas of carbon dioxide and oxygen as in the first embodiment. Cooling is performed at -80 ° C. or lower by the cooling device 24 to separate carbon dioxide into a liquid and oxygen as a gas. The liquefied carbon dioxide is liquefied in the carbon dioxide storage device 33 and the oxygen is liquefied in the oxygen storage device 34 and stored. The liquefied carbon dioxide is a carbon dioxide flow controller 27a,
It is divided into a primary side and a secondary side by 27b, and is thermally contacted with the combustion exhaust gas in the heat exchanger 101 to be vaporized,
After the primary side is preheated and the secondary side exits the heat exchanger at room temperature, the liquefied oxygen obtained by the cryogenic separation is mixed with the vaporized oxygen. According to this embodiment, the liquefied carbon dioxide separated and stored from the flue gas and the liquefied oxygen obtained by cryogenic separation are vaporized by the flue gas, so that the thermal efficiency is high.

【００１８】実施例３ 図３は本発明を微粉炭燃焼ボイラに適用した一実施例で
ある。ボイラ１６の側壁に備えられたバーナ１５には微
粉炭３を搬送した一次燃焼用空気４０を供給する一次燃
焼用気体供給管４１と二次燃焼用空気４２を供給する二
次燃焼用気体供給管４３が備えられており、前記それぞ
れの供給管の途中に一次燃焼気体用二酸化炭素供給管４
４、二次燃焼気体用二酸化炭素供給管４４′が備えられ
ており、それぞれから一次燃焼気体用二酸化炭素４５、
二次燃焼気体用二酸化炭素４５′が供給される。前記燃
料である微粉炭３と前記燃焼用気体がボイラ１６内で燃
焼し、空気比１以上で略完全燃焼を行った場合、燃焼排
ガス４６の組成はほとんど二酸化炭素となり、残りは水
蒸気及び石炭中の揮発分が揮発または燃焼して生じた微
量成分ガスや、石炭中の灰及び未燃焼微粉炭粒子も粉塵
として含まれる。前記燃焼排ガス４６を従来の微粉炭燃
焼装置のように脱硫、脱硝、脱塵等の排ガス処理をした
後、乾燥手段によって水蒸気を分離すれば容易に二酸化
炭素を回収でき、さらに燃焼用気体中に窒素を含まない
ので、空気中の窒素の酸化によるサーマルＮＯｘを皆無
にできる。本実施例によれば、燃焼排ガスを排ガス処理
したのち水蒸気を分離すれば容易に二酸化炭素を回収す
ることができる。さらに燃焼用気体中に窒素をふくまな
いのでサーマルＮＯｘを皆無にできる。また分離した二
酸化炭素の一部を回収した後の残りの二酸化炭素を燃焼
用気体の希釈剤として再循環させて用いれば資源の利用
効率も高くなる。Embodiment 3 FIG. 3 shows an embodiment in which the present invention is applied to a pulverized coal combustion boiler. A primary combustion gas supply pipe 41 for supplying primary combustion air 40 carrying the pulverized coal 3 and a secondary combustion gas supply pipe for supplying secondary combustion air 42 to a burner 15 provided on the side wall of the boiler 16. 43, a carbon dioxide supply pipe 4 for the primary combustion gas is provided in the middle of each of the supply pipes.
4. A secondary combustion gas carbon dioxide supply pipe 44 'is provided, from which the primary combustion gas carbon dioxide 45,
Secondary combustion gas carbon dioxide 45 'is supplied. When the pulverized coal 3 as the fuel and the combustion gas are burned in the boiler 16 and substantially completely burned at an air ratio of 1 or more, the composition of the flue gas 46 is almost carbon dioxide, and the rest is steam and coal. The fine component gas generated by volatilization or combustion of the volatile matter of the above, ash in coal and unburned pulverized coal particles are also included as dust. After subjecting the combustion exhaust gas 46 to desulfurization, denitration, and dust removal as in a conventional pulverized coal combustion device, if the steam is separated by a drying means, carbon dioxide can be easily recovered, and further into the combustion gas. Since it does not contain nitrogen, thermal NOx due to oxidation of nitrogen in the air can be completely eliminated. According to the present embodiment, carbon dioxide can be easily recovered by separating the steam after treating the combustion exhaust gas with the exhaust gas. Further, since nitrogen is not included in the combustion gas, thermal NOx can be completely eliminated. If the remaining carbon dioxide after recovering a part of the separated carbon dioxide is recirculated and used as a diluent for the combustion gas, the utilization efficiency of resources is also increased.

【００１９】実施例４ 図４は本発明を微粉炭燃焼バーナに適用した一実施例で
ある。微粉炭を搬送した一次燃焼用気体５１は一次燃焼
用気体供給口５０から供給され一次燃焼気体用二酸化炭
素５２と混合されて一次燃焼用気体噴出口５５から噴出
する。二次燃焼用気体５３は二次燃焼用気体供給口５４
から供給され二次燃焼気体用二酸化炭素５２’と混合さ
れてエアレジスタ５９で旋回力を与えられ二次燃焼用気
体噴出口５７からバーナ中心軸から外側へ向かって噴出
する。一次燃焼用気体を空気比０・８以下の酸素不足の
条件で、二次燃焼用気体を空気比１．２以上の酸素過剰
の条件で供給すれば、一次側の燃焼では酸素不足のため
燃焼反応の進行が遅くなり燃料中の窒素成分の酸化によ
るフューエルＮＯｘを抑えるが未燃炭素分が増加するの
で、一次燃焼用気体の外側に同心円状に供給された空気
比１．２以上の酸素過剰の二次燃焼用気体によっで未燃
炭素分の燃焼を行い、フューエルＮＯｘと灰中末燃分の
低減を図る二段燃焼を行う。Embodiment 4 FIG. 4 shows an embodiment in which the present invention is applied to a pulverized coal combustion burner. The primary combustion gas 51 carrying the pulverized coal is supplied from the primary combustion gas supply port 50, mixed with the primary combustion gas carbon dioxide 52, and ejected from the primary combustion gas outlet 55. The secondary combustion gas 53 is supplied to the secondary combustion gas supply port 54.
Is mixed with the secondary combustion gas carbon dioxide 52 ′, and is swirled by the air register 59 to be ejected outward from the burner central axis through the secondary combustion gas ejection port 57. If the primary combustion gas is supplied under an oxygen-deficient condition with an air ratio of 0.8 or less and the secondary combustion gas is supplied under an oxygen-excess condition with an air ratio of 1.2 or more, the primary-side combustion burns due to lack of oxygen. because it suppresses the fuel NOx progress of the reaction is slow due to oxidation of nitrogen component in the fuel unburned carbon content is increased, the primary outside the combustion gas supplied to the concentric air ratio of 1.2 or more oxygen excess The combustion of unburned carbon is performed by the secondary combustion gas, and the two-stage combustion for reducing the fuel NOx and the end fuel in ash is performed.

【００２０】一次燃焼用気体と二次燃焼用気体はバーナ
を出た直後は、一次燃焼用気体噴出口５５と二次燃焼用
気体噴出口５７の間にある中空円柱形状の空気分離器５
６によって分けられているので、一次燃焼用気体と二次
燃焼用気体はほとんど混ざりあうことなく前記二段燃焼
は進行する。さらに燃焼用気体として二酸化炭素で希釈
された酸素を用いているので一次側と二次側のトータル
の空気比が１となる条件で前記二段燃焼を行えばバーナ
の燃焼排ガスの組成は、石炭中の揮発分が揮発または燃
焼して生じたガスを除けば、ほとんど燃焼用気体中に存
在していたか、または石炭中の炭素が燃焼した二酸化炭
素となる。この燃焼排ガスを排ガス処理して微量成分ガ
スを除去すればほぼ純粋な二酸化炭素を回収することが
できる。また燃焼用気体として二酸化炭素で希釈された
酸素を用いているので、未燃焼の微粉炭粒子が酸素富化
雰囲気の二次燃焼用気体中の酸素とともに燃焼し高温に
なっている領域においても、空気中の窒素の酸化による
サーマルＮＯｘが発生するとがない。バーナに供給され
る一次側と二次側燃焼用気体及び二酸化炭素の流量を独
立に変化させることにより、燃焼負荷や燃料である石炭
の炭種や性状が変わっても、燃焼排ガス中の窒素酸化物
（フューエルＮＯｘ）と灰中未燃分を低減する空気比で
燃焼用気体を供給し最適な二段燃焼を行うことができ
る。本実施例によれば、微粉炭燃焼用バーナにおいてフ
ューエルＮＯｘとサーマルＮＯｘを同時に低減すること
ができかつ灰中未燃分を減少させる二段燃焼を行うこと
ができる。Immediately after the primary combustion gas and the secondary combustion gas exit the burner, a hollow cylindrical air separator 5 located between the primary combustion gas ejection port 55 and the secondary combustion gas ejection port 57 is provided.
6, the primary combustion gas and the secondary combustion gas hardly mix, and the two-stage combustion proceeds. Furthermore, since oxygen diluted with carbon dioxide is used as a combustion gas, if the two-stage combustion is performed under the condition that the total air ratio of the primary side and the secondary side becomes 1, the composition of the combustion exhaust gas of the burner becomes coal. Except for the gas generated by volatilization or combustion of the volatile components therein, most of the carbon was present in the combustion gas, or the carbon in the coal was converted to the burned carbon dioxide. If this combustion exhaust gas is subjected to exhaust gas treatment to remove trace component gases, almost pure carbon dioxide can be recovered. In addition, since oxygen diluted with carbon dioxide is used as a combustion gas, even in a region where unburned pulverized coal particles are burned with oxygen in the secondary combustion gas in an oxygen-enriched atmosphere and are at a high temperature, There is no generation of thermal NOx due to the oxidation of nitrogen in the air. By independently changing the flow rates of the primary and secondary combustion gases and carbon dioxide supplied to the burner, even if the combustion load or the coal type or properties of coal as fuel changes, the nitrogen oxidation in the combustion exhaust gas Optimum two-stage combustion can be performed by supplying combustion gas at an air ratio that reduces the unburned matter in the ash and fuel (fuel NOx). According to the present embodiment, in the pulverized coal combustion burner, fuel NOx and thermal NOx can be simultaneously reduced, and two-stage combustion for reducing unburned ash in ash can be performed.

【００２１】実施例５ 図５は本発明を水分含有率の高い石炭を燃料とした場合
の微粉炭燃焼装置の一次燃焼用気体供給系に適用した一
実施例である。一次燃焼気体用二酸化炭素６１はヒータ
６０で加熱されて粉砕機２に供給され、ともに粉砕機２
に供給された石炭１は、ヒータ６０で加熱された一次燃
焼気体用二酸化炭素６１によって昇温し、水分を蒸発し
て乾燥されながら微粉炭に粉砕され、粉砕機２を出た後
に酸素１１と混合され一次燃焼用気体７としてバーナ１
５に供給される。二次燃焼用気体は実施例１と同様にし
てバーナ１５に供給される。石炭１の含水率が大きい場
合、高温の燃焼用気体を粉砕機２に供給して乾燥しなけ
ればならないが、空気等の酸素を含んだ気体を加熱して
粉砕機２へ送り石炭１の乾燥を行うと、燃焼用気体中の
酸素が粉砕機内部の石炭とともに燃焼する可能性がある
が、本実施例では石炭１を乾燥させるための予熱用気体
として燃焼排ガスから分離した二酸化炭素を用いるので
粉砕機２の中で石炭１が燃焼することはない。粉砕機２
の中で、石炭１に含まれていた水分が蒸発する際に加熱
された二酸化炭素から蒸発潜熱を奪うので、粉砕機を出
るときには二酸化炭素の温度は下がっており、この時点
で燃料の酸化剤として酸素を供給して一次側燃焼用気体
とすることができる。本実施例によれば、水分含有率の
高い石炭でも粉砕機内で石炭を燃焼させることなく乾燥
することができる。Embodiment 5 FIG. 5 shows an embodiment in which the present invention is applied to a gas supply system for primary combustion of a pulverized coal combustion apparatus using coal having a high water content as a fuel. The carbon dioxide 61 for the primary combustion gas is heated by the heater 60 and supplied to the crusher 2.
Is heated by the carbon dioxide 61 for the primary combustion gas heated by the heater 60, and is pulverized into pulverized coal while being dried by evaporating the water. Burner 1 as mixed primary combustion gas 7
5 is supplied. The secondary combustion gas is supplied to the burner 15 in the same manner as in the first embodiment. When the water content of the coal 1 is high, a high-temperature combustion gas must be supplied to the crusher 2 and dried. However, a gas containing oxygen such as air is heated and sent to the crusher 2 to dry the coal 1. Is performed, oxygen in the combustion gas may be burned together with the coal inside the pulverizer. However, in this embodiment, carbon dioxide separated from the combustion exhaust gas is used as a preheating gas for drying the coal 1. The coal 1 does not burn in the crusher 2. Crusher 2
When the water contained in the coal 1 evaporates, the latent heat of vaporization is removed from the heated carbon dioxide when the water is evaporated, so the temperature of the carbon dioxide drops when leaving the pulverizer. As the primary side combustion gas. According to the present embodiment, even coal having a high moisture content can be dried without burning the coal in the pulverizer.

【００２２】実施例６ 図６は本発明を微粉炭燃焼ボイラに適用した例である。
バーナ１５には微粉炭を搬送した一次燃焼用気体７と二
次燃焼用気体１３が、空気比０．８以下の酸素不足の条
件で送られており、バーナ１５における燃焼ではフュー
エルＮＯｘは減少するが未燃焼炭素が増加するので、バ
ーナ１５上部に備えられた酸素富化燃焼用気体噴出口７
１よりを酸素富化燃焼用気体７０を空気比１．２以上で
供給し未燃焼炭素を燃焼させる。酸素富化雰囲気中で未
燃焼の炭素が燃焼する際、火炉内の火炎温度が上昇し酸
素富化燃焼用気体７０として空気等の窒素を含んだ気体
を供給するとサーマルＮＯｘが発生する可能性がある
が、本発明では燃焼用気体として二酸化炭素で希釈され
た酸素を用いているのでサーマルＮＯｘは発生しない。
従って実施例によれば、ボイラ内二段燃焼によってフュ
ーエルＮＯｘ、サーマルＮＯｘおよび未燃焼炭素を同時
に低減することができる。またバーナ後流で行う二段燃
焼よりも滞留時間を長くとれるのでさらに未燃焼炭素を
低減できる。[0022] Example 6 6 Ru Example der which the present invention is applied to a pulverized coal combustion boiler.
The primary combustion gas 7 and the secondary combustion gas 13 carrying the pulverized coal are sent to the burner 15 under an oxygen-deficient condition with an air ratio of 0.8 or less, and the fuel NOx decreases in the combustion in the burner 15. Since the unburned carbon increases, the gas outlet 7 for oxygen-enriched combustion provided above the burner 15
1 is supplied with an oxygen-enriched combustion gas 70 at an air ratio of 1.2 or more to burn unburned carbon. When unburned carbon is burned in an oxygen-enriched atmosphere, the temperature of the flame in the furnace rises, and if a gas containing nitrogen such as air is supplied as the oxygen-enriched combustion gas 70, thermal NOx may be generated. However, in the present invention, thermal NOx is not generated because oxygen diluted with carbon dioxide is used as the combustion gas.
Therefore, according to the embodiment, the fuel NOx, the thermal NOx, and the unburned carbon can be simultaneously reduced by the two-stage combustion in the boiler. In addition, since the residence time can be set longer than in the two-stage combustion performed downstream of the burner, unburned carbon can be further reduced.

【００２３】実施例７ 図７は本発明を微粉炭燃焼装置の運転方法について適用
した一実施例である。ボイラ１６の側壁に備えられたバ
ーナ１５に供給された微粉炭を搬送した一次燃焼用空気
７と二次燃焼用空気１３はボイラ１６内で燃焼し、その
燃焼排ガスは煙道１７を通って排出されるが、前記煙道
の途中にガス濃度センサ８０を設置して煙道中の燃焼灰
ガス中の酸素と窒素酸化物の濃度を計測し、その結果を
演算装置８１で処理し、前記燃焼排ガス中の窒素酸化物
濃度が最低となるように一次側の酸素流量調節機１２ａ
と再循環二酸化炭素流量調節機２７ａによって一次燃焼
用気体中の酸素濃度を調節し、且つ、前記燃焼排ガス中
の酸素濃度が最低となるように、すなわち灰中未燃分が
最小となるように二次側の酸素流量調節機１２ｂと再循
環二酸化炭素流量調節機２７ｂによって二次燃焼用気体
中の酸素濃度を調節するように、それぞれの流量調節機
にバルプ開度信号を信号伝連手段８２によって伝え、一
次燃焼用気体および二次燃焼用気体中の酸素濃度を調節
する。本実施例によれば、煙道の燃焼排ガス中のガス濃
度を測定することにより、燃焼排ガス中の窒素酸化物を
低減し、且つ、灰中未燃分を最小にした微粉炭燃焼装置
の運転を行うことができる。Embodiment 7 FIG. 7 shows an embodiment in which the present invention is applied to an operation method of a pulverized coal combustion apparatus. The primary combustion air 7 and the secondary combustion air 13 carrying the pulverized coal supplied to the burner 15 provided on the side wall of the boiler 16 are burned in the boiler 16, and the combustion exhaust gas is discharged through a flue 17. However, a gas concentration sensor 80 is installed in the middle of the flue to measure the concentrations of oxygen and nitrogen oxides in the combustion ash gas in the flue, and the result is processed by a computing device 81 to obtain the flue gas. Oxygen flow controller 12a on the primary side so that the concentration of nitrogen oxides in
And the recirculation carbon dioxide flow controller 27a controls the oxygen concentration in the primary combustion gas so that the oxygen concentration in the combustion exhaust gas is minimized, that is, the unburned ash in the ash is minimized. The valv opening signal is transmitted to each of the flow controllers so that the oxygen concentration in the secondary combustion gas is controlled by the secondary oxygen flow controller 12b and the recirculating carbon dioxide flow controller 27b. Control the oxygen concentration in the primary combustion gas and the secondary combustion gas. According to the present embodiment, by measuring the gas concentration in the flue gas of the flue, the operation of the pulverized coal combustion device that reduces the nitrogen oxides in the flue gas and minimizes the unburned portion in the ash It can be performed.

【００２４】実施例８ 図８は本発明をアフタコンバスタ付きの微粉炭燃焼装置
に適用した一実施例である。燃料の酸化剤である酸素１
１は酸素流量調節機１２ａ、１２ｂとアフタコバスター
用酸素流量調節装置１２ｃによって一次燃焼気体用、二
次燃焼気体用、アフタコンバスタ用に分けられる。石炭
１はヒータ６０で加熱された一次燃焼用アフタコンバス
タ用に分けられる。石炭１はヒータ６０で加熱された一
次燃焼用二酸化炭素とともに粉砕機２に供給される。粉
砕機２を出た微粉炭を搬送した一次燃焼用二酸化炭素は
一次燃焼用気体供給系で酸素と混合され、一次燃焼用気
体としてバーナ１５に供給される。二次燃焼用気体は、
実施例１と同様にしてバーナ１５に供給される。バーナ
１５で石炭１と前記燃焼用気体は燃焼し、その燃焼排ガ
スは煙道１７を通過した後、排ガス処理装置９０によっ
て排ガス処理された後、抽気ガス流量調節機９１とアフ
タコンバスタ用流量調節機９２によって流量を調節さ
れ、前記排ガス処理された一部の二酸化炭素は乾燥装置
２３に送られ残りはアフタコンバスタ用酸素９３と燃料
９４としての水素とともにアフタコンバスタ９５に供給
される。前記酸素と燃料はアフタコンバスタ９５内で燃
焼して水蒸気を生成し、供給された二酸化炭素とともに
アフタコンバスタ９５から燃焼排ガスとして排出され、
前記燃焼排ガスの廃熱を熱交換器９６で回収した後、前
記抽気ガスとともに乾燥装置２３へ供給される。前記乾
燥装置２３へ供給された抽気ガス９８とアフタコンバス
タ燃焼廃ガス９７は、水蒸気と水分を除去された後、一
次及び二次燃焼用二酸化炭素流量調節機２７ａ、２７ｂ
および回収用二酸化炭素流量調節機２８によって流量を
調節され、一部は二酸化炭素処理装置２９によって処理
され、残りは一次及び二次燃焼用気体として再循環す
る。[0024] Example 8 FIG. 8 is an example of applying the present invention to pulverized coal combustion apparatus-out after-con with combustor. Oxygen 1 as an oxidizer for fuel
1 is divided into a primary combustion gas, a secondary combustion gas, and an after combuster by the oxygen flow controllers 12a and 12b and the after flow adjuster 12c. The coal 1 is divided into a primary combustion after combustor heated by the heater 60. The coal 1 is supplied to the pulverizer 2 together with the primary combustion carbon dioxide heated by the heater 60. The primary combustion carbon dioxide that has transported the pulverized coal exiting the pulverizer 2 is mixed with oxygen in the primary combustion gas supply system, and supplied to the burner 15 as the primary combustion gas. The secondary combustion gas is
It is supplied to the burner 15 in the same manner as in the first embodiment. The coal 1 and the combustion gas are burned by the burner 15, and the combustion exhaust gas passes through the flue gas 17 and is subjected to exhaust gas treatment by an exhaust gas treatment device 90, and then a bleed gas flow controller 91 and a flow controller for an after combuster flow rate is the regulatory <br/> is by 92, part of the carbon dioxide the exhaust gas treatment and the remaining is sent to the drying device 23 is fed with hydrogen as after-combustor oxygen 93 and fuel 94 to the after-combustor 95 You. The oxygen and the fuel are burned in the after-combustor 95 to generate steam, and are discharged from the after-combustor 95 together with the supplied carbon dioxide as combustion exhaust gas.
After the waste heat of the combustion exhaust gas is recovered by the heat exchanger 96, the waste heat is supplied to the drying device 23 together with the bleed gas. The bleed gas 98 and the after-combustor combustion waste gas 97 supplied to the drying device 23 are subjected to removal of water vapor and moisture, and thereafter, the primary and secondary combustion carbon dioxide flow controllers 27a and 27b.
And the flow rate is adjusted by a carbon dioxide flow controller 28 for recovery, a part is processed by a carbon dioxide treatment device 29, and the rest is recirculated as primary and secondary combustion gases.

【００２５】実施例１において、廃ガス処理のうち燃焼
排ガス中の粉塵を脱塵する装置として電気集塵機を用い
た場合、電気集塵機は燃焼排ガス中の未燃焼の炭素分が
増加すると、石炭の低い誘電率のため捕集効率が著しく
低下する。そこで燃焼用気体を１以上の空気比で供給し
て未燃焼炭素分の低下を図ろうとすると、燃焼排ガス中
の酸素濃度が増加し未燃焼の酸素が燃焼排ガスとともに
再循環する。本実施例は前記燃焼排ガス中の未燃焼酸素
を完全に燃焼させるために、排ガス処理装置の後段にア
フタコンバスタ９５を設けたものであり、前記アフタコ
ンバスタの燃焼排ガス中に含まれる廃熱をも熱交換器で
回収している。本実施例によれば脱塵装置として電気集
塵機を用いた微粉炭燃焼装置において、燃焼排ガス中の
未燃焼炭素を減少させるために、燃焼用気体の空気比を
１以上で供給しボイラの燃焼排ガス中の未燃焼酸素が増
加しても、前記ボイラの後段にアフタコンバスタを備え
ることにより、未燃焼の酸素を完全に燃焼させ、さらに
アフタコンバスタの後段に熱交換器を備えることによっ
て廃熱を回収しているので熱効率も良い。In the first embodiment, when an electric precipitator is used as a device for removing dust in the combustion exhaust gas in the waste gas treatment, when the unburned carbon content in the combustion exhaust gas is increased, the electric precipitator becomes low in coal. The collection efficiency is significantly reduced due to the dielectric constant. Therefore, if an attempt is made to reduce the unburned carbon content by supplying the combustion gas at an air ratio of 1 or more, the oxygen concentration in the flue gas increases, and the unburned oxygen is recirculated together with the flue gas. In this embodiment, in order to completely burn unburned oxygen in the flue gas, an after combustor 95 is provided at a subsequent stage of the flue gas treatment device, and the waste heat contained in the flue gas of the after combustor is also reduced. Collected by heat exchanger. According to this embodiment, in a pulverized coal combustion apparatus using an electric dust collector as a dust removal apparatus, in order to reduce unburned carbon in combustion exhaust gas, the air ratio of combustion gas is supplied at 1 or more, and the combustion exhaust gas of a boiler is used. Even if the unburned oxygen inside increases, the after-combustor is provided at the subsequent stage of the boiler to completely burn unburned oxygen, and the waste heat is recovered by providing the heat exchanger at the later stage of the after-combustor. It has good thermal efficiency.

【００２６】[0026]

【発明の効果】本発明によれば、燃焼用気体中の酸素の
希釈気体として二酸化炭素を用いているので、燃焼排ガ
スを排ガス処理し乾燥した後の燃焼排ガスの組成はほと
んど二酸化炭素となり、燃焼システム全体のエネルギー
効率を下げることなく容易に二酸化炭素を回収すること
ができる。さらに上記のように、燃焼用気体として空気
を用いていないので、空気中の窒素の酸化によるサーマ
ルＮＯｘの生成を皆無にと未燃焼炭素を低減することが
できる。また本発明によれば、燃焼排ガスを排ガス処理
して得た二酸化炭素の一部を燃焼用気体中の酸素の希釈
剤として再循環させているので、装置の利用効率が高く
なる。According to the present invention, since carbon dioxide is used as a diluting gas for oxygen in the combustion gas, the composition of the combustion exhaust gas after exhaust gas treatment and drying of the combustion exhaust gas becomes almost carbon dioxide, Carbon dioxide can be easily recovered without lowering the energy efficiency of the entire system. Further, as described above, is not used the air as combustion gas, it is possible to reduce the unburned carbon and to completely eliminate generation of thermal NOx due to oxidation of nitrogen in the air. Further, according to the present invention, since a part of carbon dioxide obtained by subjecting the combustion exhaust gas to exhaust gas recirculation is used as a diluent for oxygen in the combustion gas, the utilization efficiency of the apparatus is increased.

【図面の簡単な説明】[Brief description of the drawings]

【図１】本発明の微粉炭燃焼装置の一例を示す工程図で
ある。FIG. 1 is a process diagram showing an example of a pulverized coal combustion device of the present invention.

【図２】本発明の微粉炭燃焼装置の他の例を示す工程図
である。FIG. 2 is a process diagram showing another example of the pulverized coal combustion device of the present invention.

【図３】本発明に用いる微粉炭燃焼ボイラの部分拡大図
である。FIG. 3 is a partially enlarged view of a pulverized coal combustion boiler used in the present invention.

【図４】本発明に用いる微粉炭燃焼バーナの部分拡大図
である。FIG. 4 is a partially enlarged view of a pulverized coal combustion burner used in the present invention.

【図５】本発明の微粉炭燃焼装置の燃焼用気体供給系を
示した工程図である。FIG. 5 is a process diagram showing a combustion gas supply system of the pulverized coal combustion device of the present invention.

【図６】本発明に用いる微粉炭燃焼ボイラの部分拡大図
である。FIG. 6 is a partially enlarged view of a pulverized coal combustion boiler used in the present invention.

【図７】本発明の微粉炭燃焼装置の一例を示す部分工程
図である。FIG. 7 is a partial process diagram illustrating an example of the pulverized coal combustion device of the present invention.

【図８】本発明の微粉炭燃焼装置のもう一つの例を示す
工程図である。FIG. 8 is a process diagram showing another example of the pulverized coal combustion device of the present invention.

【符号の説明】[Explanation of symbols]

１…石炭、２…粉砕機、３…微粉炭、４…貯炭器、５…
石炭供給量調節機、６…供炭機、７，４１…一次側燃焼
用気体供給系、８…空気、９…酸素分離装置、１０…窒
素、１１…酸素、１２ａ…一次側酸素流量調節機、１２
ｂ…二次側酸素流量調節機、１３，４３…二次側燃焼用
気体供給系、１４…一次側燃焼用気体供給系、１５…バ
ーナ、１６…ボイラ、１７…煙道、１８…脱硝装置、１
９…脱塵装置、２０…空気予熱機、２１…微粉炭搬送用
気体、２２…脱硫装置、２３…乾燥装置、２４…二酸化
炭素・酸素混合気体、２５…液化二酸化炭素、２６…再
循環二酸化炭素、２７ａ…一次側再循環二酸化炭素流量
調節機、２７ｂ…二次側再循環二酸化炭素流量調節機、
２８…回収用二酸化炭素流量調節機、２９…煙突、３０
…冷却装置、３１…回収用酸素流量計、３２…再循環酸
素、３３…液化二酸化炭素貯蔵装置、３４…液化酸素貯
蔵装置、３５…排ガス流量調節機、３６ａ…液化二酸化
炭素搬送ボンプ、３６ｂ…二酸化炭素送風ブロア（気化
用）、３７ａ…酸素送風ブロア（圧縮用）、３７ｂ…酸
素送風用ブロア、３８…回収用液化酸素、３９ａ…空気
流量調節機、３９ｂ…迂回用空気流量調節機、４０，５
１…一次燃焼用気体、４２，５３…二次燃焼用気体、４
４…一次燃焼気体用二酸化炭素供給系、４４′…二次燃
焼気体用二酸化炭素供給系、４５，５２…一次燃焼気体
用二酸化炭素、４５′，５２′…二次燃焼気体用二酸化
炭素、４６…燃焼排ガス、５０…一次燃焼用気体供給
口、５４…二次燃焼用気体供給口、５５…一次燃焼気体
噴出口、５６…分離器、５７…二次燃焼用気体噴出口、
５８…スロート、５９…エアレジスタ、６０…ヒータ、
７０…酸素富化燃焼用気体、７１…酸素富化燃焼用空気
噴出口、８０…ガス濃度センサ、８１…演算装置、８２
…信号伝達手段、１００…空気送風用ブロア、１０１…
熱交換器1 ... coal, 2 ... pulverizer, 3 ... pulverized coal, 4 ... coal storage, 5 ...
Coal supply amount controller, 6: coal feeder, 7, 41: primary side combustion gas supply system, 8: air, 9: oxygen separator, 10: nitrogen, 11: oxygen, 12a: primary side oxygen flow controller , 12
b: Secondary oxygen flow controller, 13, 43: Secondary combustion gas supply system, 14: Primary combustion gas supply system, 15: Burner, 16: Boiler, 17: Flue, 18: Denitration device , 1
9: dust removal device, 20: air preheater, 21: gas for conveying pulverized coal, 22: desulfurization device, 23: drying device, 24: mixed gas of carbon dioxide and oxygen, 25: liquefied carbon dioxide, 26: recirculated carbon dioxide Carbon, 27a ... primary side recirculating carbon dioxide flow controller, 27b ... secondary side recirculating carbon dioxide flow controller,
28: carbon dioxide flow controller for recovery, 29: chimney, 30
... cooling device, 31 ... recovery oxygen flow meter, 32 ... recirculated oxygen, 33 ... liquefied carbon dioxide storage device, 34 ... liquefied oxygen storage device, 35 ... exhaust gas flow controller, 36a ... liquefied carbon dioxide transport pump, 36b ... Carbon dioxide blowing blower (for vaporization), 37a ... oxygen blowing blower (for compression), 37b ... oxygen blowing blower, 38 ... recovery liquefied oxygen, 39a ... air flow controller, 39b ... detour air flow controller, 40 , 5
1 ... Primary combustion gas, 42, 53 ... Secondary combustion gas, 4
4 ... carbon dioxide supply system for primary combustion gas, 44 '... carbon dioxide supply system for secondary combustion gas, 45, 52 ... carbon dioxide for primary combustion gas, 45', 52 '... carbon dioxide for secondary combustion gas, 46 ... combustion exhaust gas, 50 ... primary combustion gas supply port, 54 ... secondary combustion gas supply port, 55 ... primary combustion gas ejection port, 56 ... separator, 57 ... secondary combustion gas ejection port,
58: throat, 59: air register, 60: heater,
70: oxygen-enriched combustion gas, 71: oxygen-enriched combustion air outlet, 80: gas concentration sensor, 81: arithmetic unit, 82
... Signal transmission means, 100 ... Air blower, 101 ...
Heat exchanger

───────────────────────────────────────────────────── フロントページの続き (72)発明者 楢戸 清 茨城県日立市久慈町4026番地 株式会社 日立製作所 日立研究所内 (72)発明者 小豆畑 茂 茨城県日立市久慈町4026番地 株式会社 日立製作所 日立研究所内 (56)参考文献 「電力中央研究所報告 研究報告：Ｗ 89044 二酸化炭素回収のための火力発 電システムの検討 第２報 石炭火力の 場合」，財団法人電力中央研究所，平成 ２年７月31日，ｐ．７−16 (58)調査した分野(Int.Cl.7，ＤＢ名) F23C 11/00 318 B01D 53/56 F23J 15/00 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kiyoshi Narato 4026 Kuji-cho, Hitachi City, Ibaraki Prefecture Within Hitachi Research Laboratory, Hitachi, Ltd. In-house (56) References “Report of Central Research Institute of Electric Power Industry Research report: W 89044 Study on thermal power generation system for carbon dioxide capture 2nd case of coal-fired power plant”, Central Research Institute of Electric Power Industry, July 1990 31st, p. 7-16 (58) Field surveyed (Int. Cl. 7 , DB name) F23C 11/00 318 B01D 53/56 F23J 15/00

Claims (6)

(57)【特許請求の範囲】(57) [Claims] 【請求項１】 燃料を供給する配管を含む燃料供給系
と、酸化剤を含む燃焼用気体を供給する燃焼用気体供給
系と、前記燃料供給系を通り搬送された燃料と燃焼用気
体供給系を通ってきた燃焼用気体を燃焼させるバーナ
と、前記バーナを側壁に備えた燃焼室と、前記燃焼室で
発生した燃焼排ガスを前記燃焼室の外部に導く煙道と、
前記煙道に備えられ前記燃焼排ガスを排ガス処理する手
段と、前記燃焼排ガス処理手段によって処理された燃焼
排ガスの一部を前記燃焼用気体供給系に再循環させる手
段を備えた燃焼装置において、前記燃焼排ガス処理手段
で処理された前記燃焼排ガスを二酸化炭素と酸素とに分
離する手段と、前記分離した二酸化炭素と酸素を貯蔵す
る手段と、前記貯蔵手段に貯蔵された酸素の一部を前記
燃焼用気体供給系に再循環させる手段を備えたことを特
徴とする燃焼装置。1. A fuel supply system including a pipe for supplying fuel, a combustion gas supply system for supplying a combustion gas containing an oxidant, and a fuel and a combustion gas supply system conveyed through the fuel supply system. A burner that burns the combustion gas that has passed therethrough, a combustion chamber provided with the burner on a side wall, and a flue that guides flue gas generated in the combustion chamber to the outside of the combustion chamber;
Means for exhaust gas treatment of the flue gas provided in the flue, and a combustion device comprising means for recirculating a part of the flue gas treated by the flue gas treatment means to the combustion gas supply system, Means for separating the flue gas treated by the flue gas treatment means into carbon dioxide and oxygen, means for storing the separated carbon dioxide and oxygen, and combustion of a part of the oxygen stored in the storage means. A combustion device comprising means for recirculating the gas to a supply system. 【請求項２】 請求項１記載の燃焼装置において、前記
燃焼用気体供給系には、空気から酸素を分離する酸素分
離装置と、前記酸素分離装置をバイパスして備えられた
空気供給手段と、該分離装置で分離された酸素を前記バ
ーナに供給する手段とを備え、前記酸素分離装置をバイ
パスして備えられた空気供給手段又は前記酸素分離装置
で分離された酸素を前記バーナに供給する手段の途中に
前記燃焼排ガスから分離した二酸化炭素を再循環させる
手段を設けたことを特徴とする燃焼装置。2. The combustion device according to claim 1, wherein the combustion gas supply system includes an oxygen separation device configured to separate oxygen from air, and an air supply unit that bypasses the oxygen separation device. Means for supplying oxygen separated by the separation device to the burner, air supply means provided by bypassing the oxygen separation device or means for supplying oxygen separated by the oxygen separation device to the burner A means for recirculating carbon dioxide separated from the combustion exhaust gas in the middle of the combustion apparatus. 【請求項３】 請求項２記載の燃焼装置の運転方法にお
いて、前記燃焼装置の起動時には循環管路内を流れるの
に十分な量の二酸化炭素が二酸化炭素貯蔵手段に蓄積さ
れるまでは燃焼用気体として空気を用いて運転すること
を特徴とする前記燃焼装置の運転方法。3. The method for operating a combustion device according to claim 2, wherein the combustion device is operated until a sufficient amount of carbon dioxide to flow through the circulation line is accumulated in the carbon dioxide storage means when the combustion device is started. An operation method of the combustion device, wherein the operation is performed using air as a gas. 【請求項４】 請求項２記載の燃焼装置の運転方法にお
いて、前記燃焼装置の初期始動時には、二酸化炭素貯蔵
手段に循環管路内を流れるのに十分な量の二酸化炭素を
供給して始動することを特徴とする前記燃焼装置の運転
方法。4. The method for operating a combustion device according to claim 2, wherein the combustion device is started by supplying a sufficient amount of carbon dioxide to flow in the circulation pipe to the carbon dioxide storage means at an initial start. An operation method of the combustion device, comprising: 【請求項５】 請求項２記載の燃焼装置の運転方法にお
いて、二酸化炭素と酸素を液体状で貯蔵し、使用に際し
て、燃焼排ガスと熱交換してガス化しながら運転するこ
とを特徴とする燃焼装置の運転方法。5. The method for operating a combustion apparatus according to claim 2, wherein carbon dioxide and oxygen are stored in a liquid state, and the apparatus is operated while being gasified by exchanging heat with combustion exhaust gas during use. Driving method. 【請求項６】 請求項２記載の燃焼装置の運転方法にお
いて、前記煙道にガス濃度検知手段を備えることによっ
て、燃焼排ガス中の窒素酸化物と灰中未燃分の量が最小
となるように前記燃焼用気体供給系の酸素と再循環二酸
化炭素の流量を制御することを特徴とした燃焼装置の運
転方法。6. The method for operating a combustion device according to claim 2, wherein the flue is provided with a gas concentration detecting means so that the amounts of nitrogen oxides and unburned ash in the flue gas are minimized. Controlling the flow rates of oxygen and recirculated carbon dioxide in the combustion gas supply system.
JP3150956A 1991-05-28 1991-05-28 Combustion apparatus and operation method thereof Expired - Lifetime JP3068888B2 (en)

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