JP2014070772A - Combustion apparatus provided with solid fuel burner and operation method of the same - Google Patents

Combustion apparatus provided with solid fuel burner and operation method of the same Download PDF

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JP2014070772A
JP2014070772A JP2012216192A JP2012216192A JP2014070772A JP 2014070772 A JP2014070772 A JP 2014070772A JP 2012216192 A JP2012216192 A JP 2012216192A JP 2012216192 A JP2012216192 A JP 2012216192A JP 2014070772 A JP2014070772 A JP 2014070772A
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gas
nozzle
combustion
primary
oxygen
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JP5979668B2 (en
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Satoshi Tadakuma
聡 多田隈
Satohiko Mine
聡彦 嶺
Hitoshi Wakamatsu
仁 若松
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Mitsubishi Power Ltd
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Babcock Hitachi KK
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Abstract

PROBLEM TO BE SOLVED: To provide an oxygen combustion apparatus capable of retaining stable burner flame even when making the oxygen concentration of fuel carrier gas extremely low, and to provide an operation method of the oxygen combustion apparatus.SOLUTION: A combustion apparatus provided with a solid fuel burner includes: an oxygen generation device 6; an oxygen line 26 for combustion gas for supplying high oxygen concentration gas which is obtained by the device 6 to the solid fuel burner 15; and the solid fuel burner in which the oxygen concentration of a gas mixture consisting of a primary additional gas 52 to be supplied to a primary additional nozzle 43, a high oxygen concentration gas of the line 26 and exhaust gas (recirculation gas) of the boiler 1 is adjusted to 50 to 80 vol.%, the oxygen concentration of a gas mixture consisting of fuel to be supplied to a primary nozzle 40 and carrier gas of the fuel is adjusted to 4 to 21 vol.%, the oxygen concentration of a gas mixture consisting of combustion gas to be supplied to a secondary nozzle 45 and a cubic nozzle 46, oxygen gas and the recirculation gas is adjusted to 30 to 50 vol.% and an average oxygen concentration of the gas to be supplied as the whole through the primary nozzle 40, the secondary nozzle 45 and the cubic nozzle 46 is adjusted to 26 to 28 vol.%, is operated.

Description

本発明は、固体燃料バーナを備えた燃焼装置及びその運転方法に係り、特に、固体燃料バーナにおける燃焼用ガスとして空気を主体とする気体を用いる空気燃焼モードと、高酸素濃度ガスと再循環ガスとの混合ガスを主体とする気体を用いる酸素燃焼モードとを切り替え可能に構成された固体燃料バーナを備えた燃焼装置とその運転方法に関する。   The present invention relates to a combustion apparatus equipped with a solid fuel burner and a method for operating the same, and more particularly to an air combustion mode using a gas mainly composed of air as a combustion gas in the solid fuel burner, a high oxygen concentration gas, and a recirculation gas. The present invention relates to a combustion apparatus including a solid fuel burner configured to be switchable between an oxyfuel combustion mode using a gas mainly composed of a mixed gas and an operating method thereof.

火力発電等に用いられるボイラプラントから化石燃料の燃焼に伴って排出する炭酸ガス（ＣＯ２）を低減するため、空気から窒素分を除去した高酸素濃度ガスを用いて燃料を燃焼させ、燃焼排ガス中のＣＯ２濃度を高めてその分離回収を容易にする酸素燃焼式ボイラプラントシステム（以下、酸素燃焼システムと称すこともある。）が研究・開発されている。 In order to reduce carbon dioxide (CO 2 ) emitted from combustion of fossil fuels from boiler plants used for thermal power generation, etc., the fuel is burned using high oxygen concentration gas from which nitrogen content has been removed from the air, and combustion exhaust gas its oxyfuel combustion boiler plant system that facilitates separation and recovery by increasing the CO 2 concentration in (hereinafter sometimes referred to as oxyfuel combustion system.) have been studied and developed.

酸素燃焼システムは種々のものが知られているが、燃焼用ガスとして前述の高酸素濃度ガスと燃焼排ガスを再循環させたものを用いるものが多い。   Various types of oxyfuel combustion systems are known, but many of them use a recirculation of the above-mentioned high oxygen concentration gas and combustion exhaust gas as a combustion gas.

特開２００７−１４７１６２号公報JP 2007-147162 A 特開２０１１−７５１７５号公報JP 2011-75175 A

既存の空気燃焼式のボイラを用いて酸素燃焼システムを構築しようとする場合には、燃料の搬送用ガスを含めた燃焼用ガス全体の酸素濃度を空気と同等の約２１％にすると、燃焼用ガス組成のうち、酸素を除いた組成の違いから、ボイラ内部の熱交換器における熱吸収特性が大幅に変化する。したがって、熱交換器の配置や伝熱面積の変更を伴う大掛かりな改造が必要となって、設備費・改造の労力が多大となる。   When an oxyfuel combustion system is to be constructed using an existing air-fired boiler, if the oxygen concentration of the entire combustion gas including the fuel transfer gas is about 21% equivalent to air, Among the gas compositions, the heat absorption characteristics in the heat exchanger inside the boiler are greatly changed due to the difference in the composition excluding oxygen. Therefore, a large-scale remodeling accompanied with the change of the heat exchanger arrangement and heat transfer area is required, and the facility cost and the labor for the remodeling become great.

ボイラの大掛かりな改造を回避するため、熱交換器の配置や伝熱面積の変更をできるだけ少なくするには、燃料の搬送用ガスを含めた燃焼用ガス全体の酸素濃度を空気よりも高め、例えば約２７％とする必要がある。   In order to avoid major modifications of the boiler, in order to minimize the change of the heat exchanger arrangement and heat transfer area, the oxygen concentration of the entire combustion gas including the fuel transfer gas is made higher than air, for example, It needs to be about 27%.

一方、燃料と燃料搬送ガスからなる混合流体をバーナの燃料ノズルから火炉内に噴出させる場合に、燃料搬送用ガスの酸素濃度が高ければ高いほど、固体燃料を粉砕する粉砕装置内では粉塵爆発の危険性が増すため、その安全対策を強化する必要性が生ずる。   On the other hand, when a mixed fluid composed of fuel and fuel carrier gas is ejected from the fuel nozzle of the burner into the furnace, the higher the oxygen concentration of the fuel carrier gas, the higher the concentration of dust in the pulverizer that pulverizes solid fuel. As the danger increases, there is a need to strengthen its safety measures.

燃料搬送用ガスの酸素濃度を極力低くすれば、その安全対策に要する時間、労力及びコストを削減することができる。特に、燃料搬送用ガスに酸素を供給せず、燃料搬送用ガスとして燃料装置出口の排ガスを主要成分として再循環させるシステムが理想的である。しかし、燃料搬送用ガスの酸素濃度を極力低くすると、バーナの着火性が低下し、燃焼が不安定となる。   If the oxygen concentration of the fuel carrier gas is made as low as possible, the time, labor and cost required for the safety measures can be reduced. In particular, a system that does not supply oxygen to the fuel transfer gas and recirculates the exhaust gas at the outlet of the fuel device as the main component as the fuel transfer gas is ideal. However, if the oxygen concentration of the fuel transfer gas is reduced as much as possible, the ignitability of the burner is lowered and the combustion becomes unstable.

本発明の課題は、上記問題点を克服し、燃料搬送用ガスの酸素濃度を極力低くしても、安定したバーナ火炎を保持できる酸素燃焼装置とその運転方法を提供することである。   An object of the present invention is to provide an oxyfuel combustion apparatus capable of maintaining a stable burner flame and a method of operating the oxyfuel combustion apparatus even when the above problems are overcome and the oxygen concentration of the fuel transfer gas is as low as possible.

上記本発明の課題は、次の解決手段により解決される。
請求項１記載の発明は、円筒状のノズルが中心軸まわりに同心状に多重に形成され、中心軸側より、燃料とその搬送気体からなる混合ガスを噴出させ、混合ガス噴出口に保炎器（６０）を設けた１次ノズル（４０）、該１次ノズル（４０）の外周側に燃焼用ガスを噴出させる２次ノズル（４５）、該２次ノズル（４５）の外周側に２次ノズル（４５）と共通の燃焼用ガスを噴出させる３次ノズル（４６）及び前記１次ノズル（４０）と２次ノズル（４５）の隔壁の内周面側に追加燃焼用ガスを噴出させる１次追加ノズル（４３）を設けた固体燃料バーナ（１５）と、１次ノズル（４０）に接続する燃料とその搬送気体からなる混合流体を供給する１次ガスライン（１７）と、２次ノズル（４５）及び３次ノズル（４６）の両方に燃焼用ガスを供給する燃焼用ガスライン（１８）と、空気から窒素を分離して高酸素濃度ガスを得る酸素発生装置（６）と、該酸素発生装置（６）で得られた高酸素濃度ガスを前記固体燃料バーナ（１５）に供給する燃焼用ガス用酸素ライン（２６）を備えた燃焼装置（１）において、
燃焼装置（１）から排出された燃焼排ガスを１次ガスライン（１７）に接続する再循環ガスライン（３）を設け、燃焼用ガスライン（１８）に燃焼用ガス用酸素ライン（２６）及び再循環ガスライン（３）をそれぞれ接続し、２次ノズル（４５）及び３次ノズル（４６）の両方に燃焼用ガスを供給する燃焼用ガスライン（１８）から分岐して燃焼用ガスと酸素ガスと再循環ガスを１次追加ノズル（４３）に供給する分岐燃焼用ガスライン（３４）と、燃料とその搬送気体からなる混合流体の供給量を調整する１次ガス量調整手段（２１）を１次ガスライン（１７）に設け、燃焼用ガスと酸素ガスと再循環ガスからなる混合ガスの供給量を調整する燃焼用ガス量調整手段（２２）を燃焼用ガスライン（１８）に設け、再循環ガスの供給量を調整する再循環ガス入口ガス量調整手段（１１）と再循環ガス量調整手段（２５）を再循環ガスライン（３）の上流側と下流側にそれぞれ設け、高酸素濃度ガスの供給量を調整する燃焼用ガス用酸素量調整手段（９）を燃焼用ガス用酸素ライン（２６）に設け、燃焼用ガスと酸素ガスと再循環ガスからなる混合ガスの供給量を調整する分岐燃焼用ガス供給量調整手段（３５）を分岐燃焼用ガスライン（３４）に設けたことを特徴とする固体燃料バーナを備えた燃焼装置である。 The problems of the present invention are solved by the following means.
In the first aspect of the present invention, cylindrical nozzles are formed concentrically around the central axis, and a mixed gas composed of fuel and its carrier gas is ejected from the central axis side, and a flame holding is performed at the mixed gas outlet. A primary nozzle (40) provided with a vessel (60), a secondary nozzle (45) for injecting combustion gas to the outer peripheral side of the primary nozzle (40), and 2 on the outer peripheral side of the secondary nozzle (45). A combustion gas common to the secondary nozzle (45) is ejected, and an additional combustion gas is ejected to the inner peripheral surface of the partition wall of the primary nozzle (40) and the secondary nozzle (45). A solid fuel burner (15) provided with a primary additional nozzle (43), a primary gas line (17) for supplying a mixed fluid comprising fuel connected to the primary nozzle (40) and its carrier gas, and a secondary Combustion gas to both nozzle (45) and tertiary nozzle (46) A combustion gas line (18) to be supplied, an oxygen generator (6) for separating nitrogen from air to obtain a high oxygen concentration gas, and the high oxygen concentration gas obtained by the oxygen generator (6) In a combustion apparatus (1) provided with an oxygen line (26) for combustion gas supplied to a fuel burner (15),
A recirculation gas line (3) for connecting the combustion exhaust gas discharged from the combustion device (1) to the primary gas line (17) is provided, and the combustion gas oxygen line (26) and the combustion gas line (18) are connected to the combustion gas line (18). Recirculation gas lines (3) are connected to each other and branched from a combustion gas line (18) for supplying combustion gas to both the secondary nozzle (45) and the tertiary nozzle (46), and combustion gas and oxygen Branch combustion gas line (34) for supplying gas and recirculated gas to the primary additional nozzle (43), and primary gas amount adjusting means (21) for adjusting the supply amount of the mixed fluid comprising fuel and its carrier gas Is provided in the primary gas line (17), and a combustion gas amount adjusting means (22) for adjusting the supply amount of the mixed gas comprising combustion gas, oxygen gas and recirculation gas is provided in the combustion gas line (18). Adjust the supply amount of recirculation gas The recirculation gas inlet gas amount adjusting means (11) and the recirculation gas amount adjusting means (25) are respectively provided on the upstream side and the downstream side of the recirculation gas line (3) to adjust the supply amount of the high oxygen concentration gas. Combustion gas oxygen amount adjusting means (9) is provided in the combustion gas oxygen line (26) to adjust the supply amount of the mixed gas composed of the combustion gas, oxygen gas and recirculation gas. A combustion apparatus equipped with a solid fuel burner, characterized in that the adjusting means (35) is provided in the branch combustion gas line (34).

請求項２記載の発明は、燃焼用ガスライン（１８）に燃焼用ガス用酸素濃度測定手段（２９）と、分岐燃焼用ガスライン（３４）に分岐燃焼ガス用酸素濃度測定手段（３０）とを備えていることを特徴とする請求項１に記載の固体燃料バーナを備えた燃焼装置である。   According to the second aspect of the present invention, the combustion gas oxygen concentration measuring means (29) is provided in the combustion gas line (18), and the branch combustion gas oxygen concentration measuring means (30) is provided in the branch combustion gas line (34). The combustion apparatus having a solid fuel burner according to claim 1.

請求項３記載の発明は、請求項２に記載の固体燃料バーナを備えた燃焼装置の運転方法であって、１次追加ノズル（４３）に供給される燃焼用ガスと酸素ガスと再循環ガスからなる混合ガスの酸素濃度を５０〜８０vol.％に調節し、前記１次ノズル（４０）に供給される燃料とその搬送気体からなる混合流体の酸素濃度を４〜２１vol.％に調節し、２次ノズル（４５）及び３次ノズル（４６）に供給される燃焼用ガスと酸素ガスと再循環ガスからなる混合ガスの酸素濃度を３０〜５０vol.％に調節し、前記１次ノズル（４０）、２次ノズル（４５）および３次ノズル（４６）を通じて固体燃料バーナ全体として供給されるガスの平均酸素濃度を２６〜２８vol.％に調節することを特徴とする固体燃料バーナを備えた燃焼装置の運転方法である。   A third aspect of the present invention is a method of operating a combustion apparatus including the solid fuel burner according to the second aspect, wherein combustion gas, oxygen gas, and recirculation gas supplied to the primary additional nozzle (43) are provided. Adjusting the oxygen concentration of the mixed gas consisting of 50 to 80 vol.%, Adjusting the oxygen concentration of the mixed fluid consisting of the fuel supplied to the primary nozzle (40) and its carrier gas to 4 to 21 vol.%, The oxygen concentration of the mixed gas composed of combustion gas, oxygen gas, and recirculation gas supplied to the secondary nozzle (45) and the tertiary nozzle (46) is adjusted to 30 to 50 vol.%, And the primary nozzle (40 ) Combustion with a solid fuel burner characterized in that the average oxygen concentration of the gas supplied as a whole of the solid fuel burner through the secondary nozzle (45) and the tertiary nozzle (46) is adjusted to 26-28 vol.%. It is the operation method of an apparatus.

請求項４記載の発明は、酸素発生装置（６）の運転の停止と燃焼用ガス用酸素量調整手段（９）及び分岐燃焼ガス用酸素量調整手段（２０）の閉鎖及び再循環ガスの供給量を調整する再循環ガス入口ガス量調整手段（１１）及び／又は再循環ガス量調整手段（２５）の閉鎖により１次ガスライン（１７）の１次ガス量調整手段（２１）と燃焼用ガスライン（１８）の燃焼用ガス量調整手段（２２）と分岐燃焼用ガスライン（３４）の分岐燃焼ガス量調整手段（３５）を調節して、固体燃料バーナ（１５）における燃焼用ガスとして空気を主体とする気体を用いる空気燃焼モードと、燃焼用ガス用酸素ライン（２６）に供給する高酸素濃度ガスの供給量と再循環ガスライン（３）に供給する再循環ガス量と分岐燃焼用ガスライン（３４）に供給する酸素濃度ガスの供給量を調整して、固体燃料バーナ（１５）における燃焼用ガスとして高酸素濃度ガスと再循環ガスを混合する気体を用いる酸素燃焼モードとを切り替える固体燃料バーナを備えた燃焼装置の運転方法である。   The invention according to claim 4 stops the operation of the oxygen generator (6), closes the oxygen amount adjusting means for combustion gas (9) and the oxygen amount adjusting means for branch combustion gas (20), and supplies recirculation gas. By closing the recirculation gas inlet gas amount adjusting means (11) and / or the recirculating gas amount adjusting means (25) for adjusting the amount, the primary gas amount adjusting means (21) of the primary gas line (17) and the combustion gas are adjusted. By adjusting the combustion gas amount adjusting means (22) of the gas line (18) and the branch combustion gas amount adjusting means (35) of the branch combustion gas line (34), the combustion gas in the solid fuel burner (15) is adjusted. Air combustion mode using gas mainly composed of air, supply amount of high oxygen concentration gas supplied to combustion gas oxygen line (26), recirculation gas amount supplied to recirculation gas line (3), and branch combustion Supply to gas line (34) Combustion provided with a solid fuel burner that adjusts the supply amount of oxygen concentration gas to switch between oxygen combustion modes using a gas that mixes high oxygen concentration gas and recirculation gas as combustion gas in the solid fuel burner (15) It is the operation method of an apparatus.

請求項５記載の発明は、高酸素濃度ガスと再循環ガスとの混合ガスを主体とする気体を用いる酸素燃焼モードにおいて、前記１次ノズル（４０）と２次ノズル（４５）と３次ノズル（４６）と１次追加ノズル（４３）の各ノズルに供給される気体の酸素濃度が、１次追加ノズル（４３）＞２次ノズル（４５）及び３次ノズル（４６）＞１次ノズル（４０）となるように前記ノズル（４３，４５、４６、４０）へ供給するガス量調整手段（３５，２２、２１）を調節することを特徴とする請求項４記載の固体燃料バーナを備えた燃焼装置の運転方法である。   According to a fifth aspect of the present invention, the primary nozzle (40), the secondary nozzle (45) and the tertiary nozzle are used in an oxyfuel combustion mode using a gas mainly composed of a mixed gas of a high oxygen concentration gas and a recirculation gas. (46) and the oxygen concentration of the gas supplied to each nozzle of the primary additional nozzle (43) are as follows: primary additional nozzle (43)> secondary nozzle (45) and tertiary nozzle (46)> primary nozzle ( The solid fuel burner according to claim 4, wherein the gas amount adjusting means (35, 22, 21) supplied to the nozzle (43, 45, 46, 40) is adjusted so as to be 40). This is a method for operating a combustion apparatus.

請求項６記載の発明は、１次追加ノズル（４３）から噴出する燃焼用ガスの流速（Ｂ）が固体燃料を吹き飛ばす流速の上限値（Ｂ0）を超えないよう（Ｂ≦Ｂ0）にし、保炎器（６０）の周りの酸素濃度（Ａ）を、その下限値（Ａ0）を上回り、保炎器（６０）が焼損しないようにその上限値（Ａ1％）を下回るように（Ａ1≧Ａ≧Ａ0）にし、１次ノズル（４０）から噴出する燃料とその搬送ガスの混合ガスの流速（Ｃ）を、バーナ火炎を吹き飛ばす流速の上限値（Ｃ0）を超えないよう（Ｃ≦Ｃ0）にし、前記ノズル（４３，４５、４６、４０）へ供給するガス量調整手段（３５，２２、２１）を調節することを特徴とする請求項５記載の固体燃料バーナを備えた燃焼装置の運転方法である。 The invention described in claim 6 is such that the flow velocity (B) of the combustion gas ejected from the primary additional nozzle (43) does not exceed the upper limit (B 0 ) of the flow velocity at which the solid fuel is blown away (B ≦ B 0 ). The oxygen concentration (A) around the flame holder (60) exceeds its lower limit (A 0 ) and falls below its upper limit (A 1 %) so that the flame holder (60) does not burn out. (A 1 ≧ A ≧ A 0 ), and the flow velocity (C) of the mixed gas of the fuel ejected from the primary nozzle (40) and its carrier gas does not exceed the upper limit value (C 0 ) of the flow velocity for blowing off the burner flame. The solid fuel burner according to claim 5, characterized in that the gas amount adjusting means (35, 22, 21) supplied to the nozzle (43, 45, 46, 40) is adjusted in such a manner (C ≦ C 0 ). Is a method of operating a combustion apparatus equipped with

ここで、例えばＡ0は２５％、Ｂ0は４０〜５０ｍ／ｓ、Ｃ0は２０ｍ／ｓである。
（作用）
本発明では、１次追加ノズル４３が、燃焼用ガスを供給する２次ノズル４５および３次ノズル４６と独立して構成されており、１次追加ノズル４３にのみ高濃度の酸素を供給することが可能である。 Here, for example, A0 is 25%, B0 is 40 to 50 m / s, and C0 is 20 m / s.
(Function)
In the present invention, the primary additional nozzle 43 is configured independently of the secondary nozzle 45 and the tertiary nozzle 46 that supply combustion gas, and supplies high concentration oxygen only to the primary additional nozzle 43. Is possible.

そのため、保炎器６０の周りに十分な酸素を供給した状態であっても、１次追加ノズル４３から噴出する１次追加ガス５２の流速（Ｂ）は、その上限値（Ｂ0）を超えないことと、さらに、１次ノズル４０から噴出する燃料搬送用ガスの流速（Ｃ）は、その上限値（Ｃ0）を超えないことが必要である。 For this reason, even when sufficient oxygen is supplied around the flame holder 60, the flow velocity (B) of the primary additional gas 52 ejected from the primary additional nozzle 43 exceeds the upper limit (B 0 ). In addition, it is necessary that the flow velocity (C) of the fuel carrier gas ejected from the primary nozzle 40 does not exceed the upper limit (C 0 ).

すなわち、保炎器６０の周りの酸素濃度をＡ％、その流速をＢｍ／ｓ、１次ノズル４０から噴出する燃料搬送用ガスの流速をＣｍ／ｓとすると、
Ａ≧Ａ0 かつＢ≦Ｂ0 かつＣ≦Ｃ0
が成立する。 That is, assuming that the oxygen concentration around the flame holder 60 is A%, the flow rate is Bm / s, and the flow rate of the fuel carrier gas ejected from the primary nozzle 40 is Cm / s.
A ≧ A 0 and B ≦ B 0 and C ≦ C 0
Is established.

また、本発明では、１次追加ノズル４３から噴出する１次追加ガス５２の酸素濃度が高すぎる場合、保炎器６０が焼損してしまうため、保炎器６０の周りの酸素濃度（Ａ％）を、酸素濃度の実測上限値（Ａ1％＝４０％）以内となるように１次追加ノズル４３から噴出する１次追加ガス５２の酸素濃度を調整する必要がある。 Further, in the present invention, when the oxygen concentration of the primary additional gas 52 ejected from the primary additional nozzle 43 is too high, the flame holder 60 is burned out, so that the oxygen concentration around the flame holder 60 (A%). ) Needs to be adjusted so that the oxygen concentration of the primary additional gas 52 ejected from the primary additional nozzle 43 is within the upper limit of actual measurement of oxygen concentration (A 1 % = 40%).

請求項１、２記載の装置発明によれば、前記１次ノズル４０と２次ノズル４５と３次ノズル４６と１次追加ノズル４３に供給する燃料用ガスと高酸素濃度ガスと再循環ガスの供給量をそれぞれ調整する各ガス供給量調整手段３５，２２、２１を設けたことにより、１次ノズル４０のガス噴出口に設けた保炎器６０の部分で燃料の着火・安定燃焼が可能となる。   According to the first and second aspects of the invention, the fuel gas, the high oxygen concentration gas, and the recirculation gas supplied to the primary nozzle 40, the secondary nozzle 45, the tertiary nozzle 46, and the primary additional nozzle 43 are provided. By providing each gas supply amount adjusting means 35, 22, 21 for adjusting the supply amount, fuel can be ignited and stably burned at the portion of the flame holder 60 provided at the gas outlet of the primary nozzle 40. Become.

請求項３記載の発明によれば、分岐燃焼ガス用酸素量調整手段２０の開度を調整することで、１次追加ノズル４３に供給される前記混合ガスの酸素濃度を５０〜１００vol.％、送風ファン出口手段１０の開度を調整することで、１次ノズル４０に供給される前記混合ガスの酸素濃度を４〜２１vol.％、燃焼用ガス用酸素量調整手段９の開度を調整することで、２次ノズル４５及び３次ノズル４６に供給される前記混合ガスの酸素濃度を３０〜５０vol.％に調節することができ、保炎器６０の部分で燃料の着火・安定燃焼が可能となる。   According to invention of Claim 3, the oxygen concentration of the said mixed gas supplied to the primary additional nozzle 43 is 50-100 vol.% By adjusting the opening degree of the oxygen amount adjustment means 20 for branch combustion gas, By adjusting the opening degree of the blower fan outlet means 10, the oxygen concentration of the mixed gas supplied to the primary nozzle 40 is adjusted to 4 to 21 vol.%, And the opening degree of the combustion gas oxygen amount adjusting means 9 is adjusted. Thus, the oxygen concentration of the mixed gas supplied to the secondary nozzle 45 and the tertiary nozzle 46 can be adjusted to 30 to 50 vol.%, And the ignition and stable combustion of the fuel can be performed in the flame holder 60 portion. It becomes.

請求項４記載の発明によれば、請求項３記載の発明の効果に加えて、燃焼装置を高酸素濃度ガスと再循環ガスを用いない空気燃焼モードで運転することができるだけでなく、高酸素濃度ガスと再循環ガスを用いる酸素燃焼モードで運転することができる。   According to the invention described in claim 4, in addition to the effect of the invention described in claim 3, not only can the combustion apparatus be operated in an air combustion mode that does not use a high oxygen concentration gas and a recirculation gas, It is possible to operate in an oxygen combustion mode using a concentration gas and a recirculation gas.

請求項５記載の発明によれば、請求項４記載の発明の効果に加えて、高酸素濃度ガスと再循環ガスを用いる酸素燃焼モードで運転する場合において、各ノズルに供給される気体の酸素濃度が
１次追加ノズル４３＞２次ノズル４５及び３次ノズル４６＞１次ノズル４０
となるよう調節可能にしたので、保炎器６０の部分で燃料の着火性と安定燃焼性が得られる。 According to the invention described in claim 5, in addition to the effect of the invention described in claim 4, in the case of operating in the oxygen combustion mode using the high oxygen concentration gas and the recirculation gas, the oxygen of the gas supplied to each nozzle The density is the primary additional nozzle 43> secondary nozzle 45 and tertiary nozzle 46> primary nozzle 40.
Therefore, fuel ignitability and stable combustibility can be obtained in the flame holder 60.

請求項６記載の発明によれば、請求項５記載の発明の効果に加えて、例えば、各ノズルに供給される気体の酸素濃度を１次追加ノズル４３＝２次ノズル４５及び３次ノズル４６＞１次ノズル４０としても燃料搬送用ガスの酸素濃度を極力低くすることは可能であり、保炎器６０の部分で着火・安定燃焼のために必要な最低限の酸素濃度（Ａ0）と流速の上限値（Ｂ0）とを満足させることができる。 According to the invention described in claim 6, in addition to the effect of the invention described in claim 5, for example, the oxygen concentration of the gas supplied to each nozzle is set to the primary additional nozzle 43 = the secondary nozzle 45 and the tertiary nozzle 46. > Even with the primary nozzle 40, it is possible to reduce the oxygen concentration of the gas for transporting the fuel as much as possible, and the minimum oxygen concentration (A 0 ) required for ignition and stable combustion in the flame holder 60 The upper limit (B 0 ) of the flow velocity can be satisfied.

その場合、保炎器６０の周りの酸素濃度（Ａ％）を、酸素濃度の上限値（Ａ1％）以内となるように１次追加ノズル４３から噴出する１次追加ガス５２の酸素濃度を調整する必要がある。 In this case, the oxygen concentration of the primary additional gas 52 ejected from the primary additional nozzle 43 is set so that the oxygen concentration (A%) around the flame holder 60 is within the upper limit (A 1 %) of the oxygen concentration. It needs to be adjusted.

本発明になる一実施例の酸素燃焼ボイラシステムの系統図である。1 is a system diagram of an oxyfuel boiler system according to an embodiment of the present invention. 本発明になる一実施例の酸素燃焼ボイラシステムの系統図である。1 is a system diagram of an oxyfuel boiler system according to an embodiment of the present invention. 本発明になる一実施例のバーナの概略断面図である。It is a schematic sectional drawing of the burner of one Example which becomes this invention. 本発明になる一実施例のバーナ出口付近の酸素濃度及び流速の分布を説明する図である。It is a figure explaining distribution of oxygen concentration and flow velocity near the burner exit of one example used as the present invention.

以下、本発明の実施例を図面とともに説明する。
ただし、本実施例では燃料搬送用ガスの酸素濃度を極力低くするために、燃料搬送用ガスに酸素を供給しない構成としているが、以下に述べる実施例において、酸素発生装置６から生成した酸素を１次ガスライン１７に追加投入しても構わない。 Embodiments of the present invention will be described below with reference to the drawings.
However, in this embodiment, in order to make the oxygen concentration of the fuel transfer gas as low as possible, oxygen is not supplied to the fuel transfer gas. However, in the embodiment described below, oxygen generated from the oxygen generator 6 is not used. It may be added to the primary gas line 17 additionally.

なお、固体燃料として微粉炭を用いるバーナを例として説明しているが、本発明の対象は、燃料の種類により限定されるものではなく、石炭以外にも褐炭や植物由来の固体燃料を微粉化したものやそれらの混合物にも適用できる。   In addition, although the burner using pulverized coal as a solid fuel is described as an example, the object of the present invention is not limited by the type of fuel, and pulverized coal or plant-derived solid fuel other than coal is pulverized. It can also be applied to those prepared and mixtures thereof.

図１は本発明の一実施例の酸素燃焼ボイラシステムの系統図である。
本システムは、石炭（微粉炭）を燃料とするボイラ１からの排ガスを処理する排ガス処理系統２と、該排ガス処理系統２から排出された排ガスをボイラ１に循環させるための再循環ガスライン３と、ミル１６を通して燃料（本実施例では微粉炭）と燃料用ガス（本実施例では空気）をボイラ１に供給する１次ガスライン１７と、ウインドボックス１２を通してボイラ１内に燃焼用ガスを供給する燃焼用ガスライン１８と、該燃焼用ガスライン１８から分岐して、燃焼用ガスと酸素発生装置６からの酸素をウインドボックス１２内部でなく、直接一次追加ノズル４３に供給する分岐燃焼用ガスライン３４と、酸素発生装置６で生成した酸素を燃焼用ガスライン１８へ供給する燃焼用ガス用酸素ライン２６と、酸素発生装置６で生成した酸素を分岐燃焼用ガスライン３４へ供給する分岐燃焼ガス用酸素ライン１９等から構成される。 FIG. 1 is a system diagram of an oxyfuel boiler system according to an embodiment of the present invention.
This system includes an exhaust gas treatment system 2 that processes exhaust gas from a boiler 1 that uses coal (pulverized coal) as fuel, and a recirculation gas line 3 that circulates the exhaust gas discharged from the exhaust gas treatment system 2 to the boiler 1. And a primary gas line 17 for supplying fuel (pulverized coal in the present embodiment) and fuel gas (air in the present embodiment) to the boiler 1 through the mill 16, and combustion gas in the boiler 1 through the wind box 12. A combustion gas line 18 to be supplied, and a branch combustion for branching from the combustion gas line 18 to supply the combustion gas and oxygen from the oxygen generator 6 directly to the primary additional nozzle 43 instead of the inside of the wind box 12. The gas line 34, the combustion gas oxygen line 26 that supplies the oxygen generated by the oxygen generator 6 to the combustion gas line 18, and the oxygen generated by the oxygen generator 6 are separated. Composed of branched combustion gas oxygen line 19, etc. supplied to the combustion gas line 34.

ミル１６は、燃料供給装置として石炭を粉砕し、微粉砕された石炭（微粉炭）は空気送風ファン７からの空気と再循環ガスファン８で送風される再循環ガスライン３からのボイラ排ガスからなる再循環ガスとの混合ガス（１次ガス）に搬送されて１次ガスライン１７からボイラ１のバーナ１５に供給される。   The mill 16 pulverizes coal as a fuel supply device, and finely pulverized coal (pulverized coal) is generated from the air from the air blowing fan 7 and the boiler exhaust gas from the recirculation gas line 3 blown by the recirculation gas fan 8. It is conveyed to a mixed gas (primary gas) with the recirculated gas and supplied from the primary gas line 17 to the burner 15 of the boiler 1.

なお、燃焼用ガスライン１８には空気送風ファン７により空気が導入され、その量が送風ファン出口バルブ１０により調整される。また燃焼用ガスライン１８に燃焼用ガス用酸素ライン２６が接続する接続部より上流側の燃焼用ガスライン１８に１次ガスライン１７の基部が接続されているので１次ガスライン１７を流れる微粉炭搬送用ガスはボイラ排ガスを含むガスであり、搬送中の微粉炭が発火する危険性はない。   Air is introduced into the combustion gas line 18 by the air blower fan 7, and the amount thereof is adjusted by the blower fan outlet valve 10. Further, since the base of the primary gas line 17 is connected to the combustion gas line 18 upstream of the connection portion where the combustion gas oxygen line 26 is connected to the combustion gas line 18, fine powder flowing through the primary gas line 17. The charcoal transport gas is a gas containing boiler exhaust gas, and there is no risk that the pulverized coal being transported will ignite.

また、ボイラ１の１次ノズル４０（図３）の出口部手前の内周壁面に出口がある１次追加ノズル４３に分岐燃焼用ガスライン３４から直接、酸素濃度の高い燃焼用ガス（１次追加ガス５２）が供給される。また、分岐燃焼用ガスライン３４には、分岐燃焼ガス用酸素ライン１９から酸素が供給されるが、その酸素供給量は分岐燃焼ガス用酸素ライン１９に設けた分岐燃焼ガス用酸素量調整バルブ２０で調整される。   Further, a combustion gas having a high oxygen concentration (primary) is directly supplied from the branch combustion gas line 34 to the primary additional nozzle 43 having an outlet on the inner peripheral wall surface in front of the outlet portion of the primary nozzle 40 (FIG. 3) of the boiler 1. Additional gas 52) is supplied. The branch combustion gas line 34 is supplied with oxygen from the branch combustion gas oxygen line 19. The oxygen supply amount of the branch combustion gas oxygen line 19 is provided in the branch combustion gas oxygen line 19. It is adjusted with.

また、燃焼用ガス用酸素ライン２６に設けられた燃焼用ガス用酸素量調整バルブ９により燃焼用ガスライン１８に供給される酸素量が調整される。燃焼用ガス用酸素ライン２６は１次ガスライン１７が燃焼用ガスライン１８に接続する箇所より後流側の燃焼用ガスライン１８に接続しているので、微粉炭流が流れる１次ガスライン１７内での酸素による発火のおそれはない。   Further, the amount of oxygen supplied to the combustion gas line 18 is adjusted by the combustion gas oxygen amount adjusting valve 9 provided in the combustion gas oxygen line 26. Since the combustion gas oxygen line 26 is connected to the combustion gas line 18 on the downstream side of the location where the primary gas line 17 is connected to the combustion gas line 18, the primary gas line 17 through which the pulverized coal flow flows. There is no risk of ignition due to oxygen inside.

さらに、燃焼用ガスライン１８からウインドボックス１２に供給される燃焼用ガス量は燃焼用ガス用酸素濃度測定装置２９の酸素濃度の測定値に基づき燃焼用ガス量調整バルブ２２で調整される。また、再循環ガスライン３から燃焼用ガスライン１８へ供給される再循環ガス量は排ガス処理系統２の出口に接続するＣＯ２回収・放出ライン２８から分岐する再循環ガスライン３に設けられた再循環ガス入口ガス量調整バルブ１１と燃焼用ガスライン１８への再循環ガスライン３の接続部近くの再循環ガス量調整バルブ２５により調整される。 Further, the amount of combustion gas supplied from the combustion gas line 18 to the wind box 12 is adjusted by the combustion gas amount adjusting valve 22 based on the measured value of the oxygen concentration of the combustion gas oxygen concentration measuring device 29. The amount of recirculation gas supplied from the recirculation gas line 3 to the combustion gas line 18 is provided in the recirculation gas line 3 branched from the CO 2 recovery / release line 28 connected to the outlet of the exhaust gas treatment system 2. The recirculation gas inlet gas amount adjustment valve 11 and the recirculation gas amount adjustment valve 25 near the connection portion of the recirculation gas line 3 to the combustion gas line 18 are adjusted.

さらに、１次ガスライン１７内には石炭バンカ１４から石炭フィーダ１３を通じて微粉炭が供給されるが、該１次ガスライン１７内の微粉炭搬送用ガス量は石炭フィーダ１３の前流側に設けられた１次ガス量調整バルブ２１で調整される。   Furthermore, pulverized coal is supplied into the primary gas line 17 from the coal bunker 14 through the coal feeder 13. The amount of pulverized coal transport gas in the primary gas line 17 is provided on the upstream side of the coal feeder 13. The primary gas amount adjusting valve 21 is adjusted.

また、分岐燃焼用ガスライン３４は燃焼用ガス用酸素ライン２６が燃焼用ガスライン１８に接続する箇所より後流側の燃焼用ガスライン１８から分岐してウインドボックス１２内の１次追加ノズル４３に酸素などを供給するが、その酸素供給量は分岐燃焼用ガスライン３４に設けられた分岐燃焼用ガス供給量調整バルブ３５と分岐燃焼用酸素濃度測定装置３０で容易に調整される。   Further, the branch combustion gas line 34 branches from the combustion gas line 18 on the downstream side of the location where the combustion gas oxygen line 26 is connected to the combustion gas line 18, and the primary additional nozzle 43 in the wind box 12. The oxygen supply amount is easily adjusted by the branch combustion gas supply amount adjusting valve 35 provided in the branch combustion gas line 34 and the branch combustion oxygen concentration measuring device 30.

なお、分岐燃焼用ガスライン３４には分岐燃焼ガス用酸素ライン１９からの酸素に加えて燃焼用ガスライン１８からの燃焼用ガス（空気）と再循環ガスと酸素の混合ガスが供給されるので１次追加ノズル４３に供給される１次追加ガス５２中の酸素濃度が分岐燃焼用酸素濃度測定装置３０で計測され、分岐燃焼用ガス供給量調整バルブ３５で酸素供給量が正確に制御できる。   In addition to the oxygen from the branch combustion gas oxygen line 19, the branch combustion gas line 34 is supplied with a mixed gas of combustion gas (air), recirculation gas and oxygen from the combustion gas line 18. The oxygen concentration in the primary additional gas 52 supplied to the primary additional nozzle 43 is measured by the branch combustion oxygen concentration measuring device 30, and the oxygen supply amount can be accurately controlled by the branch combustion gas supply amount adjustment valve 35.

図２は図１とは別の実施例である酸素燃焼ボイラシステムの系統図を示す。本システムが図１に示すシステムと異なる所は次の通りである。
（１）図１のシステムにある酸素発生装置６から生成した酸素を分岐燃焼用ガスライン３４へ供給する分岐燃焼ガス用酸素ライン１９を設けていない。
（２）再循環ガスライン３からの再循環ガスを燃焼用ガスライン１８の最上流部（燃焼用ガス用酸素ライン２６との接続部より上流部）と図１のシステムに無い燃焼用ガスライン１８の最下流部（分岐燃焼用ガスライン３４との接続部より下流部）の２箇所から供給する構成を設けている。 FIG. 2 shows a system diagram of an oxyfuel boiler system which is an embodiment different from FIG. The difference between this system and the system shown in FIG. 1 is as follows.
(1) The branch combustion gas oxygen line 19 for supplying oxygen generated from the oxygen generator 6 in the system of FIG. 1 to the branch combustion gas line 34 is not provided.
(2) The recirculation gas from the recirculation gas line 3 is supplied to the most upstream portion of the combustion gas line 18 (upstream from the connection with the combustion gas oxygen line 26) and the combustion gas line not in the system of FIG. 18 is provided from two locations in the most downstream portion (downstream portion from the connection portion with the branch combustion gas line 34).

上記図２のシステムにおける、図１に示すシステムとの相違点（１）、（２）により、純酸素ラインの一本化（簡略化）によるシステムの安全性向上（純酸素ラインを極力少なくすれば、その安全対策に要する時間、労力及びコストを削減できる。）が図れるという作用効果がある。   The system shown in FIG. 2 differs from the system shown in FIG. 1 (1) and (2) by improving the system safety by simplifying the pure oxygen line (the pure oxygen line can be reduced as much as possible). For example, the time, labor and cost required for the safety measures can be reduced.)

図１、図２に示す燃焼システムのいずれの場合でも、図３に示す１次追加ノズル４３に供給される燃焼用ガス（１次追加ガス５２）は、バーナ１５の上流側の流路、即ち分岐燃焼用ガスライン３４上で酸素濃度を正確に調節して供給できる。また、高酸素濃度ガスを高温となるバーナ１５の近傍まで導く必要が無いので安全性の点で都合が良い。   In either case of the combustion system shown in FIGS. 1 and 2, the combustion gas (primary additional gas 52) supplied to the primary additional nozzle 43 shown in FIG. The oxygen concentration can be accurately adjusted and supplied on the branch combustion gas line 34. Further, there is no need to guide the high oxygen concentration gas to the vicinity of the burner 15 that is at a high temperature, which is convenient in terms of safety.

図３には本実施例に係るバーナ１５とその周辺の概略構成例を示す。
火炉壁面５５の開口部（スロート部）に配置されるバーナ１５は、起動時に液体燃料（例えば重油）を燃焼させるために燃料を供給する液体燃料ライン５０をバーナ中心軸に配置し、その外周に１次ノズル４０を配置し、１次ノズル４０のさらに外周に燃焼用ガスが流れる２次ノズル４５を配置し、２次ノズル４５のさらに外周に燃焼用ガスが流れる３次ノズル４６を配置している。 FIG. 3 shows a schematic configuration example of the burner 15 and its periphery according to the present embodiment.
The burner 15 disposed at the opening (throat portion) of the furnace wall surface 55 has a liquid fuel line 50 for supplying fuel to burn liquid fuel (for example, heavy oil) at the time of start-up disposed on the burner central axis and on the outer periphery thereof. The primary nozzle 40 is disposed, the secondary nozzle 45 through which the combustion gas flows is further disposed on the outer periphery of the primary nozzle 40, and the tertiary nozzle 46 through which the combustion gas flows is disposed further on the outer periphery of the secondary nozzle 45. Yes.

１次ノズル４０内には上流側から順に、１次ノズル４０の隔壁の内側に流路縮小部材４２、バーナ中心軸の周りに微粉炭の流れを該１次ノズル４０の隔壁の内側に比較的重い微粉炭を偏流させる濃縮器４１、１次ノズル４０の先端部に保炎器６０を配置している。また、濃縮器４１と保炎器６０の間の１次ノズル４０の隔壁の内側に１次追加ノズル４３の出口部４９を設けている。１次追加ノズル４３は１次ノズル４０の隔壁の外周面に沿って１次ノズル４０の先端部よりノズル４０の隔壁の内周面側に設けられた出口部４９に接続している。   In the primary nozzle 40, in order from the upstream side, the flow path reducing member 42 is disposed inside the partition wall of the primary nozzle 40, and the flow of pulverized coal around the central axis of the burner is relatively distributed inside the partition wall of the primary nozzle 40. A flame holder 60 is disposed at the tip of the concentrator 41 and the primary nozzle 40 for drifting heavy pulverized coal. Further, an outlet 49 of the primary additional nozzle 43 is provided inside the partition wall of the primary nozzle 40 between the concentrator 41 and the flame holder 60. The primary additional nozzle 43 is connected to an outlet 49 provided on the inner peripheral surface side of the partition wall of the nozzle 40 from the tip of the primary nozzle 40 along the outer peripheral surface of the partition wall of the primary nozzle 40.

１次ノズル４０には１次ガス(燃料搬送用ガス）５１が、２次ノズル４５には２次ガス４７、３次ノズル４６には３次ガス４８が、また１次追加ノズル４３には１次追加ガス５２がそれぞれ供給される。   The primary nozzle 40 has a primary gas (fuel transfer gas) 51, the secondary nozzle 45 has a secondary gas 47, the tertiary nozzle 46 has a tertiary gas 48, and the primary additional nozzle 43 has 1 Next, additional gas 52 is supplied.

ここで、考慮すべき課題として以下の事項がある。
（ａ）１次ノズル４０の隔壁の内周側出口に位置する保炎器６０に十分な酸素を供給するために、１次追加ノズル４３から噴出する１次追加ガス５２の流速を大きくし過ぎると、１次ノズル４０の隔壁の内周側へ濃縮された微粉炭が乱れてしまい、保炎器６０の周りに微粉炭を効果的に集めることができない。
（ｂ）上記（ａ）において１次追加ノズル４３から噴出する１次追加ガス５２の流速を、上限値以下に抑えた場合、保炎器６０の周りに十分な酸素を供給できない。
（ｃ）上記（ａ）において１次追加ノズル４３から噴出する１次追加ガス５２の酸素濃度を上昇させることで、保炎器６０に十分な酸素を供給した場合、燃料搬送用ガスの流速は大きくなり、バーナ火炎が吹き飛ぶ。 Here, there are the following matters as issues to be considered.
(A) To supply sufficient oxygen to the flame holder 60 located at the inner peripheral outlet of the partition wall of the primary nozzle 40, the flow rate of the primary additional gas 52 ejected from the primary additional nozzle 43 is excessively increased. And the pulverized coal concentrated to the inner peripheral side of the partition wall of the primary nozzle 40 is disturbed, and the pulverized coal cannot be effectively collected around the flame holder 60.
(B) When the flow rate of the primary additional gas 52 ejected from the primary additional nozzle 43 in (a) is suppressed to the upper limit value or less, sufficient oxygen cannot be supplied around the flame holder 60.
(C) When sufficient oxygen is supplied to the flame holder 60 by increasing the oxygen concentration of the primary additional gas 52 ejected from the primary additional nozzle 43 in (a) above, the flow rate of the fuel carrier gas is It grows and the burner flame blows away.

図１、図２に示す実施例では次のような構成を採用している。
すなわち、図３に示す２次ノズル４５と３次ノズル４６を、ウインドボックス１２を介して燃焼用ガスライン１８と接続し、１次追加ノズル４３に分岐燃焼用ガスライン３４を接続して、分岐燃焼用ガスライン３４から１次追加ノズル４３に１次追加ガス５２を供給できるようにする。 The embodiment shown in FIGS. 1 and 2 employs the following configuration.
That is, the secondary nozzle 45 and the tertiary nozzle 46 shown in FIG. 3 are connected to the combustion gas line 18 via the wind box 12, and the branch combustion gas line 34 is connected to the primary additional nozzle 43 to branch. The primary additional gas 52 can be supplied from the combustion gas line 34 to the primary additional nozzle 43.

また、分岐燃焼用ガスライン３４に供給される燃焼用ガスの酸素濃度は図１では分岐燃焼ガス用酸素量調整バルブ２０によって調整する。
また、図２では燃焼用ガス用酸素量調整バルブ９によって調整する。 Further, the oxygen concentration of the combustion gas supplied to the branch combustion gas line 34 is adjusted by the branch combustion gas oxygen amount adjusting valve 20 in FIG.
Moreover, in FIG. 2, it adjusts with the oxygen amount adjustment valve 9 for combustion gases.

さらに、１次ガスライン１７、燃焼用ガスライン１８、分岐燃焼用ガスライン３４には、各々酸素濃度測定のためのガス採取ラインが接続されており、各ガス採取ラインによって採取された各ガスライン１７、１８及び３４の配管中の酸素濃度は、それぞれ酸素濃度測定装置２９、３０及び３１によって、常時測定することができる。   Further, a gas sampling line for measuring the oxygen concentration is connected to the primary gas line 17, the combustion gas line 18, and the branch combustion gas line 34, and each gas line sampled by each gas sampling line is connected. The oxygen concentrations in the pipes 17, 18 and 34 can be constantly measured by the oxygen concentration measuring devices 29, 30 and 31, respectively.

上記構成要素により、安定したバーナ１５での火炎を保持できる仕組みを以下、図３及び図４を用いて説明する。
図３に示すように、１次ノズル４０の中心軸側には、濃縮器４１が設置されており、１次ガスライン１７内の微粉炭と燃料搬送用ガスからなる混合流体の流れの中で微粉炭は１次ノズル４０の隔壁内壁面側へ濃縮される。前記隔壁内壁面側へ濃縮された微粉炭の流れは、１次ノズル４０の隔壁内壁面に接続する１次追加ノズル４３から噴出する高酸素濃度の燃焼用ガス（１次追加ガス）５２によって、安定して微粉炭が燃焼する。 A mechanism that can maintain a stable flame in the burner 15 using the above-described components will be described below with reference to FIGS.
As shown in FIG. 3, a concentrator 41 is installed on the central axis side of the primary nozzle 40, and in the flow of the mixed fluid composed of pulverized coal and fuel transport gas in the primary gas line 17. The pulverized coal is concentrated on the inner wall surface side of the partition wall of the primary nozzle 40. The flow of the pulverized coal concentrated on the inner wall surface side of the partition wall is caused by a high oxygen concentration combustion gas (primary additional gas) 52 ejected from the primary additional nozzle 43 connected to the partition wall inner wall surface of the primary nozzle 40. Pulverized coal burns stably.

図４は、バーナ１５の１次ノズル４０、２次ノズル４５及び３次ノズル４６の各流路の先端部付近の横断面図（図４（ａ））と、上記図４（ａ）に示すバーナ１５の１次ノズル４０の隔壁内壁面側における水平方向の各位置での酸素濃度の変化を示す図（図４（ｂ））と図４（ａ）に示すバーナ１５の１次ノズル４０の隔壁内壁面側における水平方向の各位置でのガス流速（図４（ｃ））を表したものである。   FIG. 4 is a cross-sectional view (FIG. 4A) near the tip of each flow path of the primary nozzle 40, the secondary nozzle 45, and the tertiary nozzle 46 of the burner 15, and FIG. 4A above. FIG. 4B shows the change in oxygen concentration at each position in the horizontal direction on the inner wall surface of the partition wall of the primary nozzle 40 of the burner 15 and FIG. 4A shows the primary nozzle 40 of the burner 15 shown in FIG. The gas flow velocity (FIG.4 (c)) in each position of the horizontal direction in the partition inner wall surface side is represented.

バーナ１５の燃焼性は、１次ノズル４０の先端の隔壁内壁面側に位置する保炎器６０に十分な酸素を供給できるかどうかがポイントとなる。このときの保炎器６０周りの最低酸素濃度はＡ0％（例えば２５％）である。 The point of flammability of the burner 15 is whether sufficient oxygen can be supplied to the flame holder 60 located on the inner wall surface side of the partition wall at the tip of the primary nozzle 40. At this time, the minimum oxygen concentration around the flame holder 60 is A 0 % (for example, 25%).

前述の３つの考慮すべき事項（ａ）、（ｂ）及び（ｃ）について、仮に、１次追加ノズル４３から噴出する１次追加ガス５２を、２次ノズル４５と３次ノズル４６に共通するウインドボックス１２から供給するように構成した場合、即ち１次追加ノズル４３から噴出する１次追加ガス５２の酸素濃度を２次ノズル４５と３次ノズル４６と同じにすると次のような問題が生じる。
（１）１次追加ノズル４３から噴出する１次追加ガス５２の流量を増やすことによって、保炎器６０に十分な酸素を供給しようとすると、その燃焼用ガスの流速（Ｂ）は、微粉炭を吹き飛ばす流速の上限値（Ｂ0）を超える。すなわち、Ｂ≧Ｂ0となる（比較例１）。
（２）反対に、１次追加ノズル４３から噴出する１次追加ガス５２の流速（Ｂ）を、前記上限値以下(Ｂ≦Ｂ0)に抑えようとすると、保炎器６０の周りに十分な酸素を供給できず、保炎器６０の周りの酸素濃度（Ａ）は、その下限値（Ａ0）を下回る。すなわち、Ａ≦Ａ0となる（比較例２）。 As for the above three considerations (a), (b), and (c), the primary additional gas 52 ejected from the primary additional nozzle 43 is common to the secondary nozzle 45 and the tertiary nozzle 46. When configured to supply from the wind box 12, that is, when the oxygen concentration of the primary additional gas 52 ejected from the primary additional nozzle 43 is the same as that of the secondary nozzle 45 and the tertiary nozzle 46, the following problem occurs. .
(1) When sufficient oxygen is supplied to the flame holder 60 by increasing the flow rate of the primary additional gas 52 ejected from the primary additional nozzle 43, the flow velocity (B) of the combustion gas is pulverized coal. Exceeds the upper limit (B 0 ) of the flow velocity at which the air is blown away. That is, B ≧ B 0 (Comparative Example 1).
(2) On the contrary, if the flow velocity (B) of the primary additional gas 52 ejected from the primary additional nozzle 43 is to be kept below the upper limit (B ≦ B 0 ), the flame holder 60 is sufficiently around Oxygen cannot be supplied, and the oxygen concentration (A) around the flame holder 60 is lower than the lower limit (A 0 ). That is, A ≦ A 0 (Comparative Example 2).

また、１次追加ノズル４３から噴出する１次追加ガス５２の酸素濃度が高すぎる場合、保炎器６０が焼損してしまうため、保炎器６０の周りの酸素濃度（Ａ％）を、酸素濃度の上限値（Ａ1％）以内となるように１次追加ノズル４３から噴出する１次追加ガス５２の酸素濃度を調整する必要がある。
（３）そこで、１次追加ノズル４３から噴出する１次追加ガス５２の流速（Ｂ）を、上限値（Ｂ0）以下（Ｂ≦Ｂ0）に抑えつつ、酸素濃度（Ａ）を上昇させることで、保炎器６０に十分な酸素を供給しようとすると、１次ノズル４０から噴出する燃料搬送用ガス（１次ガス）５１の流速（Ｃ）は、バーナ火炎を吹き飛ばす流速の上限値（Ｃ0）を超える。すなわち、Ｃ≧Ｃ0となる。 In addition, if the oxygen concentration of the primary additional gas 52 ejected from the primary additional nozzle 43 is too high, the flame holder 60 is burned out, so the oxygen concentration (A%) around the flame holder 60 is reduced to oxygen. It is necessary to adjust the oxygen concentration of the primary additional gas 52 ejected from the primary additional nozzle 43 so as to be within the upper limit value (A 1 %) of the concentration.
(3) Therefore, the oxygen concentration (A) is increased while suppressing the flow velocity (B) of the primary additional gas 52 ejected from the primary additional nozzle 43 to the upper limit (B 0 ) or less (B ≦ B 0 ). Thus, when sufficient oxygen is supplied to the flame holder 60, the flow velocity (C) of the fuel carrier gas (primary gas) 51 ejected from the primary nozzle 40 is the upper limit value of the flow velocity at which the burner flame is blown away ( C 0 ) is exceeded. That is, C ≧ C 0 .

そのため、保炎器６０に十分な酸素を供給し、かつ、１次追加ノズル４３から噴出する１次追加ガス５２の流速（Ｂ）を、微粉炭を吹き飛ばす流速の上限値（Ｂ0）以下とし、かつ、１次ノズル４０から噴出する燃料搬送用ガス５１の流速（Ｃ）を、火炎を吹き飛ばす流速の上限値（Ｃ0）以下にできるシステム及びバーナ構造にする必要がある。 Therefore, sufficient oxygen is supplied to the flame holder 60, and the flow rate (B) of the primary additional gas 52 ejected from the primary additional nozzle 43 is set to be equal to or less than the upper limit value (B 0 ) of the flow rate at which the pulverized coal is blown off. In addition, it is necessary to provide a system and burner structure in which the flow velocity (C) of the fuel transfer gas 51 ejected from the primary nozzle 40 can be made equal to or lower than the upper limit value (C 0 ) of the flow velocity for blowing off the flame.

本実施例では、１次追加ノズル４３がウインドボックス１２と独立して構成されており、１次追加ノズル４３にのみ高濃度の酸素を供給することが可能である。
そのため、保炎器６０の周りに十分な酸素を供給した状態であっても、１次追加ノズル４３から噴出する１次追加ガス５２の流速（Ｂ）は、その上限値（Ｂ0）を超えないことと、さらに、１次ノズル４０から噴出する燃料搬送用ガス（１次ガス５１）のの流速（Ｃ）は、その上限値（Ｃ0）を超えないことが必要である。 In the present embodiment, the primary additional nozzle 43 is configured independently of the window box 12, and high concentration oxygen can be supplied only to the primary additional nozzle 43.
For this reason, even when sufficient oxygen is supplied around the flame holder 60, the flow velocity (B) of the primary additional gas 52 ejected from the primary additional nozzle 43 exceeds the upper limit (B 0 ). In addition, the flow velocity (C) of the fuel carrier gas (primary gas 51) ejected from the primary nozzle 40 must not exceed the upper limit (C 0 ).

すなわち、保炎器６０の周りの酸素濃度をＡ％、その流速をＢｍ／ｓ、１次ノズル４０から噴出する燃料搬送用ガスの流速をＣｍ／ｓとすると、
Ａ≧Ａ0 かつＢ≦Ｂ0 かつＣ≦Ｃ0
が成立する。 That is, assuming that the oxygen concentration around the flame holder 60 is A%, the flow rate is Bm / s, and the flow rate of the fuel carrier gas ejected from the primary nozzle 40 is Cm / s.
A ≧ A 0 and B ≦ B 0 and C ≦ C 0
Is established.

ここで、例えばＡ０＝２５％、Ｂ０＝４０〜５０ｍ／ｓ、Ｃ０＝２０ｍ／ｓである。
表１に本発明の実施例のガスラインでの流量の比率及び酸素濃度の例を示す。また、比較例も併せて表１に示した。 Here, for example, A0 = 25%, B0 = 40 to 50 m / s, and C0 = 20 m / s.
Table 1 shows an example of the flow rate ratio and oxygen concentration in the gas line of the embodiment of the present invention. The comparative examples are also shown in Table 1.

Figure 2014070772
全体の酸素濃度は、空気燃焼と同負荷とするために、全体のノズル（１次ノズル４０＋２次ノズル４５＋３次ノズル４６＋１次追加ノズル４３）の酸素濃度を２７％とした。
Figure 2014070772
 In order to make the total oxygen concentration the same load as that of air combustion, the oxygen concentration of the entire nozzles (primary nozzle 40 + secondary nozzle 45 + tertiary nozzle 46 + primary additional nozzle 43) was set to 27%.

ここでは、本発明の実施例１〜３では、それぞれ１次追加ノズル４３から噴出する１次追加ガス５２中の酸素濃度の上限（＝８０vol.％）と下限（＝５０vol.％）とした場合を示している。   Here, in Examples 1 to 3 of the present invention, the upper limit (= 80 vol.%) And lower limit (= 50 vol.%) Of the oxygen concentration in the primary additional gas 52 ejected from the primary additional nozzle 43 are used. Is shown.

また、比較例１は、上記（ａ）で示したＡ≧Ａ0かつＢ≧Ｂ0かつＣ≦Ｃ0、比較例２は、上記（ｂ）で示したＡ≦Ａ0かつＢ≦Ｂ0かつＣ≦Ｃ0、比較例３は、上記（ｃ）で示したＡ≦Ａ0かつＢ≦Ｂ0かつＣ≧Ｃ0の条件を満たした一例を示している。なお前記比較例１〜３のＡ（酸素濃度）、Ｂ（ガス流速）、Ｃ（ガス流速）についての上記下線部の条件が本発明と相違する部分である。 In Comparative Example 1, A ≧ A 0 and B ≧ B 0 and C ≦ C 0 shown in (a) above, and in Comparative Example 2, A ≦ A 0 and B ≦ B 0 shown in (b) above. And C ≦ C 0 , Comparative Example 3 shows an example satisfying the conditions of A ≦ A 0 , B ≦ B 0 and C ≧ C 0 shown in (c) above. The underlined conditions for A (oxygen concentration), B (gas flow rate), and C (gas flow rate) of Comparative Examples 1 to 3 are different from the present invention.

本発明の実施例と比較例１〜３におけるバーナ１５の出口付近の酸素濃度及び流速の分布を図４（ｂ）、（ｃ）に示す。図４（ｂ）の縦軸は酸素濃度、横軸は１次ノズル４０の内周壁側における水平方向距離であり、図４（ｃ）の縦軸はガス流速、横軸は１次ノズル４０の内周壁側における水平方向距離である。   FIGS. 4B and 4C show the oxygen concentration and flow velocity distribution in the vicinity of the outlet of the burner 15 in the examples of the present invention and Comparative Examples 1-3. 4B, the vertical axis represents the oxygen concentration, the horizontal axis represents the horizontal distance on the inner peripheral wall side of the primary nozzle 40, the vertical axis in FIG. 4C represents the gas flow velocity, and the horizontal axis represents the primary nozzle 40. This is the horizontal distance on the inner peripheral wall side.

図４（ｂ）、（ｃ）から分かるように、比較例１では、バーナ１５の１次追加ノズル４３から１次ノズル４０内に噴出する高酸素濃度（約４３％）の１次追加ガス５２の流速を大きくし、保炎器６０に十分な酸素を供給している。このとき、１次追加ノズル４３から供給される燃焼用ガス（１次追加ガス５２）の酸素濃度は約４３％であり、保炎器６０の周りの酸素濃度は約３０％である。保炎器６０の周りの酸素濃度は問題ないが、１次追加ガス５２の流量比率が３０％となり、Ｂ≧Ｂ0となる。これにより、１次ノズル４０の内周壁側へ濃縮された微粉炭が吹き飛んでしまい、保炎器６０の周りの燃料濃度の希薄化により、着火性及び保炎性の悪化を引き起こし、良好な保炎を維持することはできない。 As can be seen from FIGS. 4B and 4C, in Comparative Example 1, the primary additional gas 52 having a high oxygen concentration (about 43%) ejected from the primary additional nozzle 43 of the burner 15 into the primary nozzle 40. Is increased in flow rate, and sufficient oxygen is supplied to the flame holder 60. At this time, the oxygen concentration of the combustion gas (primary additional gas 52) supplied from the primary additional nozzle 43 is about 43%, and the oxygen concentration around the flame holder 60 is about 30%. Although the oxygen concentration around the flame stabilizer 60 is no problem, next the flow rate ratio of the primary additional gas 52 is 30%, the B ≧ B 0. As a result, the concentrated pulverized coal blows off to the inner peripheral wall side of the primary nozzle 40, and the dilution of the fuel concentration around the flame holder 60 causes deterioration of ignitability and flame holding performance, and good holding performance. The flame cannot be maintained.

比較例２では、１次追加ノズル４３から噴出する１次追加ガス５２の流量を１０％に抑え、流速の上限値（Ｂ0）を超えないようにしている。このとき、１次追加ノズル４３から供給される１次追加ガス５２中の酸素濃度は約４３％であり、保炎器６０の周りの酸素濃度は約２０％である。この条件では、１次ノズル４０の内周壁側出口に位置する保炎器６０に酸素を十分に供給できず、安定したバーナ火炎を保持できない。 In Comparative Example 2, the flow rate of the primary additional gas 52 ejected from the primary additional nozzle 43 is suppressed to 10% so as not to exceed the upper limit value (B 0 ) of the flow velocity. At this time, the oxygen concentration in the primary additional gas 52 supplied from the primary additional nozzle 43 is about 43%, and the oxygen concentration around the flame holder 60 is about 20%. Under this condition, oxygen cannot be sufficiently supplied to the flame holder 60 located at the inner peripheral wall side outlet of the primary nozzle 40, and a stable burner flame cannot be maintained.

比較例３では、１次追加ノズル４３から噴出する１次追加ガス５２の流量を１０％に抑え、その酸素濃度を上昇させ、保炎器６０に十分な酸素を供給している。１次追加ノズル４３から供給される１次追加ガス５２中の酸素濃度は、約７０％であり、保炎器６０の周りの酸素濃度は約３０％となる。１次追加ノズル４３から噴出する１次追加ガス５２の流速及び保炎器６０の周りのガス中の酸素濃度は問題ないが、１次ノズル４０から噴出する燃料搬送用ガス（１次ガス５１）の流量が６５％となり、燃料搬送用ガスの流速が、上限値（Ｃ0）を超える。１次ノズル４０の出口の１次ガス５１の流速が大きくなることで、バーナ火炎が吹き飛んでしまい、良好な保炎を維持することはできない。 In Comparative Example 3, the flow rate of the primary additional gas 52 ejected from the primary additional nozzle 43 is suppressed to 10%, the oxygen concentration is increased, and sufficient oxygen is supplied to the flame holder 60. The oxygen concentration in the primary additional gas 52 supplied from the primary additional nozzle 43 is about 70%, and the oxygen concentration around the flame holder 60 is about 30%. There is no problem with the flow rate of the primary additional gas 52 ejected from the primary additional nozzle 43 and the oxygen concentration in the gas around the flame holder 60, but the fuel carrier gas ejected from the primary nozzle 40 (primary gas 51). And the flow rate of the fuel transfer gas exceeds the upper limit (C 0 ). When the flow velocity of the primary gas 51 at the outlet of the primary nozzle 40 is increased, the burner flame is blown out, and good flame holding cannot be maintained.

一方、本発明の実施例１では、１次追加ノズル４３から供給される１次追加ガス５２の流量比率は１０％であり、その流速（Ｂ）は上限値（Ｂ0＝４０〜５０ｍ／ｓ）を下回る(Ｂ≦Ｂ0)。また、１次追加ガス５２の酸素濃度は約６０％であり、保炎器６０の周りの酸素濃度は約３０％であり、これは、保炎器６０の周りに必要な最低酸素濃度２５％（１次ガス５１の酸素濃度を５０％以下にすると、保炎器６０周りの酸素濃度が２５％以下となり失火する。）を上回る(Ａ≧Ａ0)。また、保炎器６０の焼損を防止する最高酸素濃度４０％（１次ガス５１の酸素濃度を８０％以上にすると、保炎器６０周りの酸素濃度が４０％以上となり保炎器６０が焼損するため。）下回る(Ａ≦Ａ1)。また、１次ガス５１の流量比率が４０％であり、その流速（Ｃ)は上限値（Ｃ0）を下回る(Ｃ≦Ｃ0)。 On the other hand, in Example 1 of the present invention, the flow rate ratio of the primary additional gas 52 supplied from the primary additional nozzle 43 is 10%, and the flow velocity (B) is the upper limit (B 0 = 40 to 50 m / s). ) (B ≦ B 0 ). Further, the oxygen concentration of the primary additional gas 52 is about 60%, and the oxygen concentration around the flame holder 60 is about 30%, which is the minimum oxygen concentration required around the flame holder 60 is 25%. (If the oxygen concentration of the primary gas 51 is 50% or less, the oxygen concentration around the flame holder 60 is 25% or less and misfire occurs.) (A ≧ A 0 ). Further, the maximum oxygen concentration 40% that prevents the flame holder 60 from burning out (if the oxygen concentration of the primary gas 51 is 80% or higher, the oxygen concentration around the flame holder 60 becomes 40% or higher and the flame holder 60 burns out. To be less than) (A ≦ A 1 ). The flow rate ratio of the primary gas 51 is 40%, and the flow velocity (C) is lower than the upper limit value (C 0 ) (C ≦ C 0 ).

また、本発明では、固体燃料バーナ１５における燃焼用ガスとして空気を主体とする気体を用いる空気燃焼モードでも運転可能である。
この場合、燃焼用ガス用酸素量調整バルブ９及び分岐燃焼ガス用酸素量調整バルブ２０を徐々に閉じて酸素発生装置６から供給する酸素を減らしつつ、空気送風ファン７の出口バルブ１０を徐々に開いて空気送風ファン７から供給する酸素を増やし、ボイラ１内の酸素量が過剰状態、または不足状態にならないように調整しながら、同時に、再循環ガス入口ガス量調整バルブ１１または再循環ガス量調整バルブ２５を徐々に閉じることで、ボイラ１内を再循環ガスによるＣＯ２主体ガスから空気によるＮ２主体ガスへと切り替える運転が行われる。 Further, in the present invention, operation is possible even in an air combustion mode using a gas mainly composed of air as a combustion gas in the solid fuel burner 15.
In this case, the outlet valve 10 of the air blowing fan 7 is gradually closed while the oxygen amount adjusting valve 9 for combustion gas and the oxygen amount adjusting valve 20 for branch combustion gas are gradually closed to reduce the oxygen supplied from the oxygen generator 6. The oxygen supplied from the air blower fan 7 is increased and adjusted so that the amount of oxygen in the boiler 1 does not become excessive or insufficient. At the same time, the recirculation gas inlet gas amount adjustment valve 11 or the recirculation gas amount is adjusted. By gradually closing the adjustment valve 25, an operation of switching the inside of the boiler 1 from the CO2 main gas by recirculation gas to the N2 main gas by air is performed.

以上より、本発明は、燃料搬送用ガスの酸素濃度を極力低くしても、良好なバーナ火炎を形成することができる。   As described above, the present invention can form a good burner flame even if the oxygen concentration of the fuel carrier gas is as low as possible.

１・・・ボイラ ２・・・排ガス処理系統
３・・・再循環ガスライン ５・・・窒素ライン
６・・・酸素発生装置 ７・・・空気送風ファン
８・・・再循環ガスファン ９・・・燃焼用ガス用酸素量調整バルブ
１０・・・送風ファン出口バルブ
１１・・・再循環ガス入口ガス量調整バルブ
１２・・・ウインドボックス １３・・・フィーダ
１４・・・バンカ １５・・・バーナ
１６・・・ミル １７・・・１次ガスライン
１８・・・燃焼用ガスライン １９・・・分岐燃焼ガス用酸素ライン
２０・・・分岐燃焼ガス用酸素量調整バルブ
２１・・・１次ガス量調整バルブ
２２・・・燃焼用ガス量調整バルブ
２３・・・分岐再循環ガス用酸素ライン
２４・・・分岐再循環ガス用酸素量調整バルブ
２５・・・再循環ガス量調整バルブ
２６・・・燃焼用ガス用酸素ライン
２７・・・排ガスライン ２８・・・ＣＯ２回収・放出ライン
２９・・・燃焼用ガス用酸素濃度測定装置
３０・・・分岐燃焼ガス用酸素濃度測定装置
３１・・・燃焼用ガス用酸素濃度測定装置
３２・・・バイパス再循環ガス量調整バルブ
３３・・・バイパス再循環ガスライン
３４・・・分岐燃焼用ガスライン
３５・・・分岐燃焼用ガス供給量調整バルブ
４０・・・１次ノズル ４１・・・濃縮器
４２・・・流路縮小部材（ヘ゛ンチュリ）
４３・・・１次追加ノズル ４４・・・１次ガス酸素ライン
４５・・・２次ノズル ４６・・・３次ノズル
４７・・・２次ガス ４８・・・３次ガス
４９・・・１次追加ノズル出口
５０・・・液体燃料ライン(燃料)
５１・・・１次ガス(燃料搬送用ガス)
５２・・・１次追加ガス ５３・・・燃焼用ガス
６０・・・保炎器 DESCRIPTION OF SYMBOLS 1 ... Boiler 2 ... Exhaust gas treatment system 3 ... Recirculation gas line 5 ... Nitrogen line 6 ... Oxygen generator 7 ... Air ventilation fan 8 ... Recirculation gas fan 9. ··· Combustion gas oxygen amount adjustment valve 10 ··· Blower fan outlet valve 11 ··· Recirculation gas inlet gas amount adjustment valve 12 ··· Wind box 13 ··· Feeder 14 · · · Bunker 15 ··· Burner 16 ... Mill 17 ... Primary gas line 18 ... Combustion gas line 19 ... Branch combustion gas oxygen line 20 ... Branch combustion gas oxygen amount adjustment valve
21 ... Primary gas amount adjusting valve 22 ... Combustion gas amount adjusting valve 23 ... Branch recirculation gas oxygen line
24 ... Branch recirculation gas oxygen amount adjustment valve 25 ... Recirculation gas amount adjustment valve 26 ... Combustion gas oxygen line 27 ... Exhaust gas line 28 ... CO2 recovery / release line 29 ..Oxygen concentration measuring device 30 for combustion gas ... Oxygen concentration measuring device 31 for branched combustion gas ... Oxygen concentration measuring device 32 for combustion gas ... Bypass recirculation gas amount adjusting valve 33 ... Bypass Recirculation gas line 34 ... Branch combustion gas line 35 ... Branch combustion gas supply adjustment valve 40 ... Primary nozzle 41 ... Concentrator 42 ... Flow path reducing member (venturi)
43 ... Primary additional nozzle 44 ... Primary gas oxygen line 45 ... Secondary nozzle 46 ... Third nozzle 47 ... Secondary gas 48 ... Third gas 49 ... 1 Next additional nozzle outlet 50 ... Liquid fuel line (fuel)
51 ... Primary gas (fuel transfer gas)
52 ... Primary additional gas 53 ... Combustion gas 60 ... Flame holder

Claims (6)

円筒状のノズルが中心軸まわりに同心状に多重に形成され、中心軸側より、燃料とその搬送気体からなる混合ガスを噴出させ、混合ガス噴出口に保炎器（６０）を設けた１次ノズル（４０）、該１次ノズル（４０）の外周側に燃焼用ガスを噴出させる２次ノズル（４５）、該２次ノズル（４５）の外周側に２次ノズル（４５）と共通の燃焼用ガスを噴出させる３次ノズル（４６）及び前記１次ノズル（４０）と２次ノズル（４５）の隔壁の内周面側に追加燃焼用ガスを噴出させる１次追加ノズル（４３）を設けた固体燃料バーナ（１５）と、
１次ノズル（４０）に接続する燃料とその搬送気体からなる混合流体を供給する１次ガスライン（１７）と、
２次ノズル（４５）及び３次ノズル（４６）の両方に燃焼用ガスを供給する燃焼用ガスライン（１８）と、
空気から窒素を分離して高酸素濃度ガスを得る酸素発生装置（６）と、
該酸素発生装置（６）で得られた高酸素濃度ガスを前記固体燃料バーナ（１５）に供給する燃焼用ガス用酸素ライン（２６）
を備えた燃焼装置（１）において、
該燃焼装置（１）から排出された燃焼排ガスを１次ガスライン（１７）に接続する再循環ガスライン（３）を設け、
燃焼用ガスライン（１８）に燃焼用ガス用酸素ライン（２６）及び再循環ガスライン（３）をそれぞれ接続し、
２次ノズル（４５）及び３次ノズル（４６）の両方に燃焼用ガスを供給する燃焼用ガスライン（１８）から分岐して燃焼用ガスと酸素ガスと再循環ガスを１次追加ノズル（４３）に供給する分岐燃焼用ガスライン（３４）と、
燃料とその搬送気体からなる混合流体の供給量を調整する１次ガス量調整手段（２１）を１次ガスライン（１７）に設け、
燃焼用ガスと酸素ガスと再循環ガスからなる混合ガスの供給量を調整する燃焼用ガス量調整手段（２２）を燃焼用ガスライン（１８）に設け、
再循環ガスの供給量を調整する再循環ガス入口ガス量調整手段（１１）と再循環ガス量調整手段（２５）を再循環ガスライン（３）の上流側と下流側にそれぞれ設け、
高酸素濃度ガスの供給量を調整する燃焼用ガス用酸素量調整手段（９）を燃焼用ガス用酸素ライン（２６）に設け、
燃焼用ガスと酸素ガスと再循環ガスからなる混合ガスの供給量を調整する分岐燃焼用ガス供給量調整手段（３５）を分岐燃焼用ガスライン（３４）に設けた
ことを特徴とする固体燃料バーナを備えた燃焼装置。 A cylindrical nozzle is formed concentrically around the central axis, and a mixed gas composed of fuel and its carrier gas is ejected from the central axis side, and a flame stabilizer (60) is provided at the mixed gas outlet 1 The secondary nozzle (40), the secondary nozzle (45) for injecting combustion gas to the outer peripheral side of the primary nozzle (40), and the secondary nozzle (45) common to the outer peripheral side of the secondary nozzle (45) A tertiary nozzle (46) for ejecting combustion gas and a primary additional nozzle (43) for ejecting additional combustion gas to the inner peripheral surface side of the partition wall of the primary nozzle (40) and the secondary nozzle (45). A provided solid fuel burner (15);
A primary gas line (17) for supplying a mixed fluid comprising a fuel connected to the primary nozzle (40) and its carrier gas;
A combustion gas line (18) for supplying combustion gas to both the secondary nozzle (45) and the tertiary nozzle (46);
An oxygen generator (6) for separating nitrogen from air to obtain a high oxygen concentration gas;
Combustion gas oxygen line (26) for supplying a high oxygen concentration gas obtained by the oxygen generator (6) to the solid fuel burner (15)
In a combustion apparatus (1) comprising:
Providing a recirculation gas line (3) for connecting the combustion exhaust gas discharged from the combustion device (1) to the primary gas line (17);
The combustion gas oxygen line (26) and the recirculation gas line (3) are connected to the combustion gas line (18),
Branching from the combustion gas line (18) for supplying combustion gas to both the secondary nozzle (45) and the tertiary nozzle (46), the combustion gas, oxygen gas and recirculation gas are supplied to the primary additional nozzle (43). Branch combustion gas line (34) supplied to
A primary gas amount adjusting means (21) for adjusting a supply amount of a mixed fluid composed of fuel and its carrier gas is provided in the primary gas line (17),
Combustion gas amount adjusting means (22) for adjusting the supply amount of the mixed gas composed of combustion gas, oxygen gas and recirculation gas is provided in the combustion gas line (18),
Recirculation gas inlet gas amount adjustment means (11) and recirculation gas amount adjustment means (25) for adjusting the supply amount of the recirculation gas are provided on the upstream side and the downstream side of the recirculation gas line (3), respectively.
Combustion gas oxygen amount adjusting means (9) for adjusting the supply amount of the high oxygen concentration gas is provided in the combustion gas oxygen line (26),
Solid fuel characterized in that a branch combustion gas supply amount adjusting means (35) for adjusting a supply amount of a mixed gas comprising combustion gas, oxygen gas and recirculation gas is provided in the branch combustion gas line (34). Combustion device with burner. 燃焼用ガスライン（１８）に燃焼用ガス用酸素濃度測定手段（２９）と、分岐燃焼用ガスライン（３４）に分岐燃焼ガス用酸素濃度測定手段（３０）とを備えていることを特徴とする請求項１に記載の固体燃料バーナを備えた燃焼装置。   The combustion gas line (18) includes combustion gas oxygen concentration measuring means (29), and the branch combustion gas line (34) includes branch combustion gas oxygen concentration measuring means (30). A combustion apparatus comprising the solid fuel burner according to claim 1. 請求項２に記載の固体燃料バーナを備えた燃焼装置の運転方法であって、
１次追加ノズル（４３）に供給される燃焼用ガスと酸素ガスと再循環ガスからなる混合ガスの酸素濃度を５０〜８０vol.％に調節し、前記１次ノズル（４０）に供給される燃料とその搬送気体からなる混合流体の酸素濃度を４〜２１vol.％に調節し、２次ノズル（４５）及び３次ノズル（４６）に供給される燃焼用ガスと酸素ガスと再循環ガスからなる混合ガスの酸素濃度を３０〜５０vol.％に調節し、前記１次ノズル（４０）、２次ノズル（４５）および３次ノズル（４６）を通じて、全体として供給されるガスの平均酸素濃度を２６〜２８vol.％に調節することを特徴とする固体燃料バーナを備えた燃焼装置の運転方法。 A method for operating a combustion apparatus comprising the solid fuel burner according to claim 2,
Fuel supplied to the primary nozzle (40) by adjusting the oxygen concentration of the mixed gas consisting of combustion gas, oxygen gas and recirculation gas supplied to the primary additional nozzle (43) to 50-80 vol.%. And the oxygen concentration of the mixed fluid composed of the carrier gas is adjusted to 4 to 21 vol.%, And consists of combustion gas, oxygen gas and recirculation gas supplied to the secondary nozzle (45) and the tertiary nozzle (46). The oxygen concentration of the mixed gas is adjusted to 30 to 50 vol.%, And the average oxygen concentration of the gas supplied as a whole through the primary nozzle (40), the secondary nozzle (45) and the tertiary nozzle (46) is 26. The operating method of the combustion apparatus provided with the solid fuel burner characterized by adjusting to -28 vol.%. 酸素発生装置（６）の運転の停止と燃焼用ガス用酸素量調整手段（９）及び分岐燃焼ガス用酸素量調整手段（２０）の閉鎖及び再循環ガスの供給量を調整する再循環ガス入口ガス量調整手段（１１）及び／又は再循環ガス量調整手段（２５）の閉鎖により１次ガスライン（１７）の１次ガス量調整手段（２１）と燃焼用ガスライン（１８）の燃焼用ガス量調整手段（２２）と分岐燃焼用ガスライン（３４）の分岐燃焼用ガス供給量調整手段（３５）を調節して、固体燃料バーナ（１５）における燃焼用ガスとして空気を主体とする気体を用いる空気燃焼モードと、燃焼用ガス用酸素ライン（２６）に供給する高酸素濃度ガスの供給量と再循環ガスライン（３）に供給する再循環ガス量と分岐燃焼用ガスライン（３４）に供給する酸素濃度ガスの供給量を調整して、固体燃料バーナ（１５）における燃焼用ガスとして高酸素濃度ガスと再循環ガスを混合する気体を用いる酸素燃焼モードとを切り替える固体燃料バーナを備えた燃焼装置の運転方法。   Stopping the operation of the oxygen generator (6), closing the oxygen amount adjusting means for combustion gas (9) and the oxygen amount adjusting means for branch combustion gas (20), and the recirculation gas inlet for adjusting the supply amount of the recirculation gas By closing the gas amount adjusting means (11) and / or the recirculation gas amount adjusting means (25), the primary gas amount adjusting means (21) of the primary gas line (17) and the combustion gas line (18) are used for combustion. A gas mainly composed of air as a combustion gas in the solid fuel burner (15) by adjusting the gas amount adjusting means (22) and the branch combustion gas supply amount adjusting means (35) of the branch combustion gas line (34). An air combustion mode, a supply amount of high oxygen concentration gas supplied to the combustion gas oxygen line (26), a recirculation gas amount supplied to the recirculation gas line (3), and a branch combustion gas line (34) Oxygen concentration gas supplied to By adjusting the supply amount, operating method of the combustion apparatus having a solid fuel burner for switching between oxyfuel combustion mode using a gas mixing high oxygen concentration gas and recycle gas as combustion gas in the solid fuel burner (15). 高酸素濃度ガスと再循環ガスとの混合ガスを主体とする気体を用いる酸素燃焼モードにおいて、前記１次ノズル（４０）と２次ノズル（４５）と３次ノズル（４６）と１次追加ノズル（４３）の各ノズルに供給される気体の酸素濃度が
１次追加ノズル（４３）＞２次ノズル（４５）及び３次ノズル（４６）＞１次ノズル（４０）
となるように前記ノズル（４３，４５、４６、４０）へ供給するガス量調整手段（３５，２２、２１）を調節する
ことを特徴とする請求項４記載の固体燃料バーナを備えた燃焼装置の運転方法。 The primary nozzle (40), the secondary nozzle (45), the tertiary nozzle (46), and the primary additional nozzle in the oxyfuel combustion mode using a gas mainly composed of a mixed gas of high oxygen concentration gas and recirculation gas. The oxygen concentration of the gas supplied to each nozzle of (43) is: primary additional nozzle (43)> secondary nozzle (45) and tertiary nozzle (46)> primary nozzle (40)
The combustion apparatus having a solid fuel burner according to claim 4, wherein the gas amount adjusting means (35, 22, 21) supplied to the nozzle (43, 45, 46, 40) is adjusted so as to satisfy Driving method. １次追加ノズル（４３）から噴出する燃焼用ガスの流速（Ｂ）が固体燃料を吹き飛ばす流速の上限値（Ｂ0）を超えないよう（Ｂ≦Ｂ0）にし、保炎器（６０）の周りの酸素濃度（Ａ）を、その下限値（Ａ0）を上回り、その上限値（Ａ1％）を下回るように（Ａ1≧Ａ≧Ａ0）にし、１次ノズル（４０）から噴出する燃料とその搬送ガスの混合ガスの流速（Ｃ）を、バーナ火炎を吹き飛ばす流速の上限値（Ｃ0）超えないよう（Ｃ≦Ｃ0）にし、前記ノズル（４３，４５、４６、４０）へ供給するガス量調整手段（３５，２２、２１）を調節することを特徴とする請求項５記載の固体燃料バーナを備えた燃焼装置の運転方法。 The flow velocity (B) of the combustion gas ejected from the primary additional nozzle (43) does not exceed the upper limit (B 0 ) of the flow velocity at which the solid fuel is blown off (B ≦ B 0 ), and the flame holder (60) The surrounding oxygen concentration (A) is set so that it exceeds the lower limit value (A 0 ) and falls below the upper limit value (A 1 %) (A 1 ≧ A ≧ A 0 ), and is ejected from the primary nozzle (40). The flow rate (C) of the mixed gas of the fuel to be transported and the carrier gas is set so as not to exceed the upper limit value (C 0 ) of the flow rate for blowing off the burner flame (C ≦ C 0 ), and the nozzles (43, 45, 46, 40) 6. A method for operating a combustion apparatus equipped with a solid fuel burner according to claim 5, wherein gas amount adjusting means (35, 22, 21) supplied to the fuel is adjusted.
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