JP3156227B2 - Pressurized fluidized bed boiler and its control device - Google Patents

Description

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

【０００１】[0001]

【産業上の利用分野】本発明は蒸気発生装置に関わり、
特に蒸気温度制御、空燃比制御に優れた制御装置を備え
た加圧流動層ボイラに関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steam generator,
Particularly, the present invention relates to a pressurized fluidized-bed boiler provided with a control device excellent in steam temperature control and air-fuel ratio control.

【０００２】[0002]

【従来の技術】従来の加圧流動層ボイラで、圧力容器内
に配置される火炉の下部、具体的には層内伝熱管を配置
している場所を二つに分割し、上部はガスが合流する構
造を有する火炉を備えた例はD.Bunthoffらが発表してい
る（「PRESURIZED FLUIDIZED BED COMBUSTION AND FIRS
T EXPERIENCE WITH THE BABCOCK 15MWth PFEBC PIOLOTP
LANT」1989,INTERNATIONAL CONFERENCE ON FLUIDIZED B
ED COMBUSTION（Vol.1,p219））。2. Description of the Related Art In a conventional pressurized fluidized bed boiler, a lower part of a furnace arranged in a pressure vessel, specifically, a place where an in-bed heat transfer tube is arranged is divided into two parts, and an upper part is provided with gas. D. Bunthoff et al. Published an example of a furnace with a converging structure ("PRESURIZED FLUIDIZED BED COMBUSTION AND FIRS
T EXPERIENCE WITH THE BABCOCK 15MWth PFEBC PIOLOTP
LANT '' 1989, INTERNATIONAL CONFERENCE ON FLUIDIZED B
ED COMBUSTION (Vol.1, p219)).

【０００３】また、前記国際会議レポートの例とは異な
るが、図３に示すように、伝熱管配置として片側の火炉
１ａには蒸発器管８と過熱器管９ａが配置され、もう一
方の火炉１ｂには再熱器管１０と一部の過熱器管９ｂが
配置された構成が前記国際会議レポートの開示技術から
容易に考えられる。図３に示す例では、過熱器９の出口
の蒸気温度は、火炉１ａの層内媒体をタンク７ａへ出し
入れして、層高を変えることによって制御される。ま
た、再熱器１０の出口の蒸気温度も火炉１ｂの層内媒体
をタンク７ｂへ出し入れすることで、火炉１ｂの層高を
変化させて制御され、再熱器スプレを使用することなく
プラント効率の低下を防止するものである。なお、再熱
器スプレは本プラントにおいて、再熱器出口蒸気温度が
異常上昇した非常時に使用されるものである。[0003] Further, although different from the example of the report of the international conference, as shown in FIG. 3, an evaporator tube 8 and a superheater tube 9a are arranged in one furnace 1a as a heat transfer tube arrangement, and the other furnace is arranged. The configuration in which the reheater tube 10 and a part of the superheater tube 9b are arranged in 1b can be easily considered from the disclosed technology of the international conference report. In the example shown in FIG. 3, the steam temperature at the outlet of the superheater 9 is controlled by changing the bed height by putting the medium in the bed of the furnace 1a into and out of the tank 7a. Also, the steam temperature at the outlet of the reheater 10 is controlled by changing the bed height of the furnace 1b by moving the medium in the bed of the furnace 1b into and out of the tank 7b, and the plant efficiency is reduced without using a reheater spray. Is to prevent the decrease. The reheater spray is used in this plant in an emergency when the reheater outlet steam temperature rises abnormally.

【０００４】火炉１ａ、１ｂで燃焼した燃料排ガスはそ
れらの上部で合流し、排ガスダクト１３を経てガスター
ビン１５に供給される。そして、ガスタービン１５によ
り駆動される空気圧縮機１６により空気ダクト４内の空
気は加圧され、圧力容器２に供給される。なお、ガスタ
ービン１５から排出した排ガスは排ガスクーラ１７で冷
却された後、煙突１８から大気中に放出される。[0004] Fuel exhaust gases burned in the furnaces 1a and 1b join at their upper portions and are supplied to a gas turbine 15 via an exhaust gas duct 13. Then, the air in the air duct 4 is pressurized by the air compressor 16 driven by the gas turbine 15 and supplied to the pressure vessel 2. Note that the exhaust gas discharged from the gas turbine 15 is cooled by the exhaust gas cooler 17 and then discharged from the chimney 18 into the atmosphere.

【０００５】図３に示す例では、それぞれの火炉１ａ、
１ｂの層高は過熱器９および再熱器１０出口の蒸気温度
に支配されるため、両火炉１ａ、１ｂの層高は必ずしも
等しくはなく、起動停止、負荷変化等プラント運転状態
によって大きく異なる。したがって、両火炉１ａ、１ｂ
の良好な燃焼を維持するに必要な適正な流動化速度およ
び空燃比を維持するために両火炉１ａ、１ｂへ供給され
る空気流量を常に監視し、制御する調整弁が必要であ
る。しかしながら、この場合の図３に示すように、燃焼
用空気ダクト４ａ、４ｂにそれぞれ設けられる空気流量
調整弁３ａ、３ｂは圧力容器２内に設置せざるを得ない
ため、空気流量調整弁３ａ、３ｂの信頼性、保守性に問
題があった。さらに、各火炉１ａ、１ｂの各流動層の出
口の酸素濃度を別々に測定することができないため、空
燃比制御の信頼性の点でも問題があった。In the example shown in FIG. 3, each of the furnaces 1a,
Since the bed height of 1b is governed by the steam temperature at the outlet of the superheater 9 and the reheater 10, the bed heights of the two furnaces 1a and 1b are not necessarily the same, and vary greatly depending on the plant operation state such as start-up / stop and load change. Therefore, both furnaces 1a, 1b
In order to maintain an appropriate fluidization speed and air-fuel ratio necessary for maintaining good combustion of the furnace, a regulating valve for constantly monitoring and controlling the flow rate of air supplied to both furnaces 1a and 1b is required. However, as shown in FIG. 3 in this case, since the air flow control valves 3a and 3b provided respectively in the combustion air ducts 4a and 4b have to be installed in the pressure vessel 2, the air flow control valves 3a and 3b There was a problem in the reliability and maintainability of 3b. Furthermore, since the oxygen concentration at the outlet of each fluidized bed of each of the furnaces 1a and 1b cannot be measured separately, there is a problem in the reliability of the air-fuel ratio control.

【０００６】そこで、上記の問題を解決するために火炉
全体を分割した例を図４に示す（特開平３−１５６２０
１号公報参照）。図４の場合は一つの圧力容器２内に収
納される火炉１を完全に火炉１ａ、１ｂの二つに分割す
ることにより、各火炉１ａ、１ｂの排ガス出口酸素濃度
を監視できるので信頼性ある空燃比制御が可能となる。
しかしながら、図４に示す従来技術では、それぞれの火
炉１ａ、１ｂの空気量の独立した制御という点では、そ
の解決方法について考慮されてなく前述の図３に示す従
来技術と同じ問題があった。もちろん図３の例と同様の
方法を採ることによって火炉１ａ、１ｂごとに独立の空
気流量調整は可能であるが、上記図３の例と同じ理由に
より、空気流量調整弁の信頼性、保守性の点で問題は残
される。FIG. 4 shows an example in which the entire furnace is divided in order to solve the above problem (Japanese Patent Laid-Open Publication No. Hei 3-15620).
No. 1). In the case of FIG. 4, since the furnace 1 accommodated in one pressure vessel 2 is completely divided into two furnaces 1a and 1b, the oxygen concentration at the exhaust gas outlet of each furnace 1a and 1b can be monitored, so that the reliability is high. Air-fuel ratio control becomes possible.
However, in the prior art shown in FIG. 4, in terms of independent control of the amount of air in each of the furnaces 1a and 1b, no solution was taken into consideration, and there was the same problem as the prior art shown in FIG. Of course, it is possible to adjust the air flow independently for each of the furnaces 1a and 1b by adopting the same method as in the example of FIG. 3, but for the same reason as in the example of FIG. The problem remains in the point.

【０００７】また、図５に示すように、圧力容器２の外
から直接に圧力容器２内の火炉１ａ、１ｂへそれぞれ空
気配管４ａ、４ｂを導く方法も考えられるが、この方法
を採用した場合、圧力容器２内を加圧するための加圧空
気源が別に必要になる。加圧空気源用に空気圧縮機１６
から導かれる空気配管設備１９、それに付属する計測制
御設備（弁２０他）を設けることで、全体に設備が複雑
化、コスト増加をもたらす。それだけでなく、一旦圧力
容器２内を加圧した後は、この加圧空気は不要となり、
弁２０を閉めて供給停止されるので、圧力容器２内に空
気が淀み、該空気が火炉１ａ、１ｂの輻射熱を受けて徐
々に圧力容器２内の雰囲気温度を上昇させる。したがっ
て、圧力容器２および圧力容器２内の構造物の設計温度
を上げなければならず、材料の肉厚増加もしくは材料の
グレードアップが必要となり、これもコスト増加を招く
ことになる。Further, as shown in FIG. 5, the furnace 1a in the pressure vessel 2 outside <br/> or RaTadashi contact of the pressure vessel 2, respectively air pipe 4a to 1b, but also conceivable to guide 4b When this method is adopted, a pressurized air source for pressurizing the inside of the pressure vessel 2 is separately required. Air compressor 16 for pressurized air source
By providing the air piping equipment 19 derived from the above and the measurement control equipment (the valve 20 and others) attached thereto, the equipment becomes complicated as a whole and the cost is increased. In addition, once pressurized inside the pressure vessel 2, this pressurized air becomes unnecessary,
Since the supply is stopped by closing the valve 20, air stagnates in the pressure vessel 2, and the air receives the radiant heat of the furnaces 1a and 1b and gradually raises the ambient temperature in the pressure vessel 2. Therefore, the design temperature of the pressure vessel 2 and the structure in the pressure vessel 2 must be increased, and it is necessary to increase the thickness of the material or upgrade the material, which also increases the cost.

【０００８】[0008]

【発明が解決しようとする課題】本発明の目的は、上記
の従来技術の問題点を解決するため、信頼性、保守性に
優れ、圧力容器内の加圧も兼用できる簡素かつ安価な設
備による空気量調整機構を持ち、それによる良好な空燃
比制御が可能な加圧流動層ボイラ装置の提供にある。SUMMARY OF THE INVENTION An object of the present invention is to provide a simple and inexpensive facility which is excellent in reliability and maintainability and can also be used for pressurizing a pressure vessel in order to solve the above-mentioned problems in the prior art. It is an object of the present invention to provide a pressurized fluidized-bed boiler device having an air amount adjusting mechanism and capable of performing good air-fuel ratio control.

【０００９】[0009]

【課題を解決するための手段】本発明の上記目的は次の
構成によって達成される。すなわち、火炉内に蒸発器、
過熱器および再熱器を配置し、層高を変化させることに
よって過熱器出口温度および再熱器出口蒸気温度を制御
する制御手段を持った加圧流動層ボイラにおいて、蒸発
器、過熱器および再熱器のうち、蒸発器を配置した火炉
と再熱器を配置した火炉とをそれぞれ別体とする少なく
とも二つに分割された火炉と、該各火炉を個別に収納す
る少なくとも二つの圧力容器と、各火炉へ送られる燃焼
用空気および各圧力容器の加圧用空気を導くために各圧
力容器に接続される空気配管とを設けた加圧流動層ボイ
ラである。このとき、各圧力容器は最大直径を有する圧
力容器と最小直径を有する圧力容器の直径の比率が１：
１〜１：１．２の範囲の大きさとし、各火炉は各圧力容
器内に収納できるサイズ、形状とすることが望ましい。The above object of the present invention is achieved by the following constitution. That is, the evaporator in the furnace,
In a pressurized fluidized-bed boiler provided with a superheater and a reheater and having control means for controlling the superheater outlet temperature and the reheater outlet steam temperature by changing the bed height, an evaporator, a superheater and a reheater are provided. among heat sink, at least a two to split the furnace to separate evaporator and furnace arranged a furnace and reheater disposed respectively at least housing the respective furnace separately The pressurized fluidized-bed boiler is provided with two pressure vessels and an air pipe connected to each pressure vessel for guiding combustion air sent to each furnace and pressurization air of each pressure vessel. At this time, each pressure vessel has a ratio of the diameter of the pressure vessel having the maximum diameter to the pressure vessel having the minimum diameter of 1:
It is desirable that the size be in the range of 1-1: 1.2, and that each furnace be of a size and shape that can be accommodated in each pressure vessel.

【００１０】また、本発明の上記目的は次の構成によっ
て達成される。すなわち、蒸発器、過熱器および再熱器
のうち、蒸発器を配置した火炉と再熱器を配置した火炉
とをそれぞれ別体とする少なくとも二つに分割された火
炉と、分割された各火炉を個別に収納する少なくとも二
つの圧力容器と、各火炉内の層高を変化させることによ
って過熱器出口温度および再熱器出口蒸気温度を制御す
る制御手段とを備えた加圧流動層ボイラに、各火炉へ送
られる燃焼用空気および各圧力容器の加圧用空気を導く
ために各圧力容器に接続される空気配管に設けられる、
各火炉に導入される空気流量を各々独立して制御できる
ようにした空気流量調整手段と、各火炉の出口の排ガス
中の酸素濃度を検出するために各火炉の排ガス配管に設
けられた酸素濃度検出手段と、各火炉の燃料供給量を検
出する燃料供給量検出手段と、前記酸素濃度検出手段お
よび燃料供給量検出手段の少なくとも一方の検出値に基
づき、前記各空気流量調整手段の空気流量制御を行わせ
る空燃比制御手段とを設けた加圧流動層ボイラ制御装置
である。The above object of the present invention is attained by the following constitution. That is, of the evaporator, the superheater and the reheater, a furnace divided into at least two furnaces each having a furnace in which an evaporator is disposed and a furnace in which a reheater is disposed, Pressurized flow comprising at least two pressure vessels for individually storing each of the fired furnaces, and control means for controlling the superheater outlet temperature and the reheater outlet steam temperature by changing the bed height in each furnace. A bed boiler is provided on an air pipe connected to each pressure vessel to guide combustion air sent to each furnace and pressurized air of each pressure vessel,
Air flow rate adjusting means for independently controlling the flow rate of air introduced into each furnace, and the oxygen concentration provided in the exhaust gas pipe of each furnace to detect the oxygen concentration in the exhaust gas at the outlet of each furnace Detecting means, a fuel supply amount detecting means for detecting a fuel supply amount of each furnace, and an air flow control of each air flow adjusting means based on a detection value of at least one of the oxygen concentration detecting means and the fuel supply amount detecting means. the line Align
That is pressurized Doso boiler control apparatus provided with the air-fuel ratio control means.

【００１１】[0011]

【作用】蒸発器、過熱器および再熱器のうち、蒸発器を
配置した火炉と再熱器を配置した火炉とはそれぞれ別体
とし、各火炉を別々の圧力容器内に収納している。そし
て、各圧力容器に接続された空気配管から空気が圧力容
器内に供給され、この空気は各圧力容器の加圧のために
用いられた後、各火炉下部から炉内に供給されて燃焼用
空気となる。[Action] evaporator of the superheater and reheater, and separately from each other from the furnace arranged a furnace and reheater disposed an evaporator, housed each furnace in a separate pressure vessel are doing. Then, air is supplied from the air pipe connected to each pressure vessel into the pressure vessel, and this air is used for pressurizing each pressure vessel, and then supplied from the lower part of each furnace into the furnace for combustion. It becomes air.

【００１２】また、それぞれの火炉出口の排ガス配管中
の酸素濃度と、各火炉の燃料供給量の少なくとも一方の
値に基づき、各空気配管中に接続される空気流量調整手
段の空気流量制御を行うことで、より正確な空燃比の制
御を各火炉ごとに独立して行うことができる。Further, based on at least one of the oxygen concentration in the exhaust gas pipe at each furnace outlet and the fuel supply amount of each furnace, the air flow rate of the air flow rate adjusting means connected to each air pipe is controlled. Thus, more accurate air-fuel ratio control can be performed independently for each furnace.

【００１３】さらに、蒸気温度変動が生じて、過熱器、
再熱器のそれぞれの出口温度が大きくアンバランスとな
った場合でも、空燃比のアンバランスによる各種ボイラ
性能の低下を心配する事なく各火炉ごとの流動層の層高
調整による各蒸気温度制御が行え、蒸気温度制御幅が大
きくなる。Further, the steam temperature fluctuates, and the superheater
Even when the outlet temperatures of the reheaters are greatly unbalanced, each steam temperature control by adjusting the bed height of the fluidized bed for each furnace can be performed without worrying about the deterioration of various boiler performances due to the air-fuel ratio imbalance. And the steam temperature control range becomes large.

【００１４】また、再熱器１０が蒸発器８と別体の火炉
に分離されて収納されているので、ボイラ起動初期であ
って、蒸気タービン通気前には再熱器収納火炉でなく、
蒸発器収納火炉を起動させ、再熱器を冷却するための蒸
気を十分確保した上で再熱器収納火炉を起動させること
で、再熱器伝熱管の焼損が防止できる。Further, since the reheater 10 is housed separately in a furnace separate from the evaporator 8, it is not in the furnace for storing the reheater at the initial stage of the boiler startup but before ventilating the steam turbine.
By starting the furnace for storing the evaporator and ensuring sufficient steam for cooling the reheater and then starting the furnace for storing the reheater, burning of the reheater heat transfer tube can be prevented.

【００１５】[0015]

【実施例】本発明の実施例を図面と共に説明する。 実施例１ 本実施例の加圧流動層ボイラの概略図を図１に示す。図
１において、二つに分割された火炉１ａ、１ｂの各々は
圧力容器２ａ、２ｂにそれぞれ収納されている。各火炉
１ａ、１ｂには空気流量調整弁３ａ、３ｂを介して空気
ダクト４ａ、４ｂから空気が供給される。また、各火炉
１ａ、１ｂには燃料供給ポンプ電動機６ａ、６ｂで駆動
される燃料供給ポンプ５ａ、５ｂから燃料が供給され
る。火炉１ａ、１ｂの層内媒体はタンク７ａ、７ｂへ出
し入れすることで、媒体の層高を変えることができる。An embodiment of the present invention will be described with reference to the drawings. Embodiment 1 FIG. 1 is a schematic view of a pressurized fluidized-bed boiler of the present embodiment. In FIG. 1, each of the two furnaces 1a and 1b is housed in a pressure vessel 2a or 2b, respectively. Air is supplied to the furnaces 1a and 1b from air ducts 4a and 4b via air flow control valves 3a and 3b. Fuel is supplied to the furnaces 1a and 1b from fuel supply pumps 5a and 5b driven by fuel supply pump motors 6a and 6b. The layer height of the medium can be changed by putting the medium in the furnace 1a, 1b into and out of the tanks 7a, 7b.

【００１６】また、火炉１ａには蒸発器８と過熱器９の
一部９ａを配置し、火炉１ｂには再熱器１０と過熱器９
の残り部分９ｂを配置している。過熱器９を分割配置す
ることによって火炉１ａと火炉１ｂは同じ大きさにして
いる。また、再熱器１０は蒸発器８の火炉１ａへは混在
させてない。そして、過熱器９の出口の蒸気温度は、火
炉１ａの層内媒体をタンク７ａへ出し入れすることで、
また、再熱器１０の出口の蒸気温度は火炉１ｂの層内媒
体を図示しない良く知られた通常の方法でタンク７ｂへ
出し入れすることで制御され、再熱器スプレは不要とな
っている。In the furnace 1a, an evaporator 8 and a part 9a of a superheater 9 are arranged, and in the furnace 1b, a reheater 10 and a superheater 9 are provided.
Is disposed. By arranging the superheaters 9 separately, the furnace 1a and the furnace 1b have the same size. Further, the reheater 10 is not mixed in the furnace 1a of the evaporator 8. Then, the steam temperature at the outlet of the superheater 9 is adjusted by moving the in-layer medium of the furnace 1a into and out of the tank 7a.
Further, the steam temperature at the outlet of the reheater 10 is controlled by putting the medium in the bed of the furnace 1b into and out of the tank 7b by a well-known ordinary method (not shown ), so that the reheater spray is unnecessary.

【００１７】火炉１ａ、１ｂで燃焼した燃料排ガスはそ
れぞれ排ガスダクト１３ａ、１３ｂを経て合流し、ガス
タービン１５に供給される。そして、ガスタービン１５
により駆動される空気圧縮機１６により前記空気ダクト
４ａ、４ｂ内の空気は加圧される。圧力容器２ａ、２ｂ
内に空気ダクト４ａ、４ｂから加圧空気が供給される。
圧力容器２ａ、２ｂ内に供給された加圧空気は各火炉１
ａ、１ｂの下部から炉内に導入され、燃焼用空気として
使用される。こうして、ボイラ運転中は圧力容器２ａ、
２ｂ内の空気は常に流れているために、圧力容器２ａ、
２ｂ内の雰囲気が過度に加熱されることはない。なお、
ガスタービン１５から排出した排ガスは排ガスクーラ１
７で冷却された後、煙突１８から大気中に放出される。The fuel exhaust gases burned in the furnaces 1a and 1b join via exhaust gas ducts 13a and 13b, respectively, and are supplied to a gas turbine 15. And the gas turbine 15
The air in the air ducts 4a and 4b is pressurized by an air compressor 16 driven by the air compressor. Pressure vessels 2a, 2b
Pressurized air is supplied from the air ducts 4a and 4b into the inside.
The pressurized air supplied into the pressure vessels 2a and 2b
a, 1b are introduced into the furnace from below, and used as combustion air. Thus, during the boiler operation, the pressure vessel 2a,
Since the air in 2b is always flowing, the pressure vessel 2a,
The atmosphere in 2b is not excessively heated. In addition,
The exhaust gas discharged from the gas turbine 15 is exhaust gas cooler 1
After being cooled at 7, it is released from the chimney 18 to the atmosphere.

【００１８】次に本実施例のボイラ運転制御装置の構成
を説明する。排ガスダクト１３ａ、１３ｂには火炉１
ａ、１ｂから排出される排ガス中の酸素濃度測定用の酸
素濃度計１２ａ、１２ｂがそれぞれ設けられている。各
圧力容器２ａ、２ｂに備え付けられている制御装置１４
ａ、１４ｂには燃料供給ポンプ電動機６ａ、６ｂの電流
値信号、酸素濃度計１２ａ、１２ｂからの酸素濃度信
号、空気流量調整弁３ａ、３ｂからの空気流量信号が送
信可能となっている。Next, the configuration of the boiler operation control device of this embodiment will be described. Furnace 1 is installed in exhaust gas ducts 13a and 13b.
Oxygen concentration meters 12a and 12b for measuring oxygen concentration in exhaust gas discharged from a and 1b are provided, respectively. Control device 14 provided in each pressure vessel 2a, 2b
The current value signals of the fuel supply pump motors 6a and 6b, the oxygen concentration signals from the oximeters 12a and 12b, and the air flow signals from the air flow control valves 3a and 3b can be transmitted to a and 14b.

【００１９】そして制御装置１４ａ、１４ｂでは、燃料
供給ポンプ電動機６ａ、６ｂの電流値信号から計算され
た燃料供給量に対し、あらかじめ設定された空燃比運転
に必要な空気流量を計算し、それに必要な空気流量調整
弁３ａ、３ｂの弁開度計算し、空気流量が制御されるよ
うになっている。また、制御装置１４ａ、１４ｂは、酸
素濃度計１２ａ、１２ｂの酸素濃度信号に基づき、常に
圧力容器出口の酸素濃度が設定の値になるよう各々の火
炉１ａ、１ｂの空気流量を計算し、空気流量調整弁３
ａ、３ｂの弁開度計算し、適切な空燃比、すなわち適正
な火炉出口酸素濃度になるよう空気流量を制御してもよ
い。The control devices 14a and 14b calculate the air flow required for the air-fuel ratio operation set in advance with respect to the fuel supply amount calculated from the current value signals of the fuel supply pump motors 6a and 6b. The air flow is controlled by calculating the valve opening of the air flow adjusting valves 3a and 3b. Further, the control devices 14a and 14b calculate the air flow rates of the respective furnaces 1a and 1b based on the oxygen concentration signals of the oxygen concentration meters 12a and 12b so that the oxygen concentration at the pressure vessel outlet always becomes a set value. Flow control valve 3
The valve openings a and 3b may be calculated, and the air flow rate may be controlled so as to obtain an appropriate air-fuel ratio, that is, an appropriate furnace outlet oxygen concentration.

【００２０】さらに、前記燃料供給ポンプ電動機６ａ、
６ｂの電流値信号と酸素濃度計１２ａ、１２ｂの酸素濃
度信号との両方の検出信号に基づき空気流量調整弁３
ａ、３ｂの弁開度計算すると、より適切な空燃比を与え
る空気流量を算出でき、その算出結果に基づく空気流量
が制御できる。Further, the fuel supply pump motor 6a,
6b and the oxygen flow rate adjusting valve 3 based on both the detection signals of the oxygen concentration meters 12a and 12b.
By calculating the valve opening degrees a and 3b, the air flow rate that gives a more appropriate air-fuel ratio can be calculated, and the air flow rate based on the calculation result can be controlled.

【００２１】なお、流動層の適正な燃焼を維持するた
め、あるいは伝熱管の摩耗を防止するためには、流動層
内のガス流速を０．８〜１．２ｍ／ｓｅｃ程度の範囲で
運転する必要がある。この流速制御は空気流量の変化に
応じて、上記流速になるように火炉１ａ、１ｂ内の圧力
を制御することにより行われるようになっている。In order to maintain proper combustion of the fluidized bed or to prevent wear of the heat transfer tube, the gas is operated at a gas flow rate in the fluidized bed of about 0.8 to 1.2 m / sec. There is a need. This flow rate control is based on changes in air flow rate.
Accordingly , the pressure is controlled by controlling the pressure in the furnaces 1a and 1b so that the flow velocity is attained.

【００２２】また、再熱器１０と蒸発器８とはそれぞれ
別体の火炉１ａ、１ｂに分離して収納されているので、
ボイラ起動初期であって、蒸気タービン通気前の伝熱管
焼損防止が図れる。なお、各火炉１ａ、１ｂで得られた
過熱蒸気、再熱蒸気は図示しない配管を介して、必要な
負荷装置に供給される。Since the reheater 10 and the evaporator 8 are separately housed in separate furnaces 1a and 1b, respectively.
It is possible to prevent heat transfer tube burnout before the steam turbine is vented in the initial stage of boiler startup. The superheated steam and the reheated steam obtained in each of the furnaces 1a and 1b are supplied to necessary load devices via pipes (not shown).

【００２３】実施例２ 本実施例の加圧流動層ボイラは、二段再熱方式を採用
し、プラント効率の向上を図った例である。この場合、
過熱器出口、第一段再熱器出口、第二段再熱器出口の三
つの蒸気温度をそれぞれ独立に制御する必要がある。そ
こで、図２に示すように火炉１を三分割して、火炉１ａ
は過熱器９ａ出口の蒸気温度制御用、火炉１ｂは第一段
再熱器１０出口蒸気温度制御用および火炉１ｃは第二段
再熱器１１出口の蒸気温度制御用に用いる。ここで、過
熱器９を火炉１ａ〜１ｃ内にそれぞれ分割配置すること
によって、三つの火炉１ａ、１ｂ、１ｃは同じ大きさに
なるようにしている。Embodiment 2 The pressurized fluidized-bed boiler of this embodiment is an example in which a two-stage reheating method is employed to improve plant efficiency. in this case,
It is necessary to independently control the three steam temperatures of the superheater outlet, the first stage reheater outlet, and the second stage reheater outlet. Therefore, the furnace 1 is divided into three parts as shown in FIG.
Is used for controlling the steam temperature at the outlet of the superheater 9a, the furnace 1b is used for controlling the steam temperature at the outlet of the first stage reheater 10, and the furnace 1c is used for controlling the steam temperature at the outlet of the second stage reheater 11. Here, the three heaters 1a, 1b, and 1c have the same size by dividing and arranging the superheater 9 in each of the furnaces 1a to 1c.

【００２４】図２において、三分割された火炉１は、各
々が独立に圧力容器２ａ、２ｂ、２ｃ内に収納されてい
る。このとき、前述のように、過熱器９が三等分され、
かつ再熱器が二等分される。すなわち、火炉１ａには蒸
発器８と過熱器９ａが、火炉１ｂには過熱器９ｂと第一
段再熱器１０が、火炉１ｃには過熱器９ｃと第二段再熱
器１１がそれぞれ収納される。In FIG. 2, furnaces 1 divided into three parts are individually housed in pressure vessels 2a, 2b and 2c. At this time, as described above, the superheater 9 is divided into three equal parts,
And the reheater is bisected. That is, the evaporator 8 and the superheater 9a are stored in the furnace 1a, the superheater 9b and the first-stage reheater 10 are stored in the furnace 1b, and the superheater 9c and the second-stage reheater 11 are stored in the furnace 1c. Is done.

【００２５】各火炉１ａ、１ｂ、１ｃの関連設備は実施
例１に記載したものと同一であるので説明は省略する
が、前記したように過熱器９ａ出口、第一段再熱器１０
出口、第二段再熱器１１出口の三つの蒸気温度をそれぞ
れ独立に制御する必要から制御装置１４も三分割され
る。もちろん、制御装置１４ａ、１４ｂ、１４ｃは単一
のものとして、その装置内部で三つの火炉１ａ、１ｂ、
１ｃの制御をそれぞれ行う構成とすることもできる。ま
た、各火炉１ａ、１ｂ、１ｃからの排ガスは合流されて
ガスタービン１５に供給される。The equipment related to each of the furnaces 1a, 1b, 1c is the same as that described in the first embodiment, and will not be described again. However, as described above, the outlet of the superheater 9a, the first-stage reheater 10
The controller 14 is also divided into three sections because it is necessary to control the three steam temperatures at the outlet and the outlet of the second-stage reheater 11 independently. Of course, the control device 14a, 14b, 14c is a single unit, and three furnaces 1a, 1b,
It is also possible to adopt a configuration in which each control of 1c is performed. The exhaust gases from the furnaces 1a, 1b, 1c are combined and supplied to the gas turbine 15.

【００２６】また、第一段再熱器１０、第二段再熱器１
１ともに、蒸発器８が収納される火炉１ａと別の火炉１
ｂ、１ｃにそれぞれ配置されているので、前述の通りボ
イラ起動初期のタービン通気前の再熱器１０、１１伝熱
管の焼損防止ができる。The first-stage reheater 10 and the second-stage reheater 1
In both cases, the furnace 1a in which the evaporator 8 is stored and another furnace 1
b, since it is arranged to 1c, can prevent burnout of mentioned above the boiler starts early turbine vent before reheater 10, 11 heat transfer tubes.

【００２７】以上のように本発明の上記実施例によれ
ば、次のような効果がある。まず、各々の火炉１への空
気流量を制御するための空気調整弁３を圧力容器２の外
部に設置しているので、信頼性、保守性に優れた空気調
整弁を提供できる。また、複数に分割された火炉１への
燃焼空気は、圧力容器２内を通過した後、火炉１へ入る
ため圧力容器２の加圧だけに使用する空気設備は不要と
なり設備の簡素化が図れるとともに、圧力容器２内の空
気は常時流れているので、火炉１の輻射熱による温度上
昇がなく、圧力容器２内の機器および圧力容器２自身の
設計温度が従来よりも下げられ、材料費の低減が可能と
なる。As described above, according to the above embodiment of the present invention, the following effects can be obtained. First, since the air regulating valve 3 for controlling the air flow rate to each furnace 1 is installed outside the pressure vessel 2, an air regulating valve excellent in reliability and maintainability can be provided. Further, the combustion air into the furnace 1 divided into a plurality of pieces passes through the pressure vessel 2 and then enters the furnace 1, so that the air equipment used only for pressurizing the pressure vessel 2 is unnecessary, and the facility can be simplified. At the same time, since the air in the pressure vessel 2 is constantly flowing, there is no temperature rise due to the radiant heat of the furnace 1, the design temperature of the equipment in the pressure vessel 2 and the design pressure of the pressure vessel 2 itself is lower than before, and the material cost is reduced. Becomes possible.

【００２８】さらに、各々の火炉１の排ガス出口に別々
の酸素濃度計を持ち、その計測値信号と燃料供給量信号
の両者もしくはどちらか一方の信号を取り込んだ制御器
から発信される信号によって、空気調整弁３は開度制御
され、燃焼空気流量が適正に運転できるので、空燃比制
御の信頼性の点においても優れている。Further, a separate oxygen concentration meter is provided at the exhaust gas outlet of each furnace 1 and a signal transmitted from a controller which takes in both or one of the measured value signal and the fuel supply amount signal, The opening degree of the air regulating valve 3 is controlled and the combustion air flow rate can be operated properly, so that the air-fuel ratio control is also excellent in reliability.

【００２９】また、通常運転においても蒸気温度偏差が
生じた場合など様々なプラントの運用を考えた場合、分
割された火炉１の層高は必ずしも互いに等しくはなく、
両者のシステムロスがアンバランスとなる可能性があ
る。さらに火炉内に設けられる空気分散板（図示せ
ず。）の目詰まりなどのトラブル時でもシステムロスは
アンバランスとなる。それによって燃焼空気流量もアン
バランスなことがしばしば発生するが、本発明の上記実
施例によれば、その様な場合でも燃料流量あるいは火炉
１の排ガス出口酸素濃度信号により燃焼空気量が制御さ
れるので、常に適正な空燃比運転が可能となる。When various plant operations are considered, such as when a steam temperature deviation occurs even in normal operation, the bed heights of the divided furnaces 1 are not necessarily equal to each other.
There is a possibility that both system losses will be unbalanced. Further, the system loss becomes unbalanced even when a trouble such as clogging of an air distribution plate (not shown) provided in the furnace occurs. As a result, the combustion air flow rate often becomes unbalanced. According to the above-described embodiment of the present invention, even in such a case, the combustion air flow rate is controlled by the fuel flow rate or the exhaust gas outlet oxygen concentration signal of the furnace 1. Therefore, an appropriate air-fuel ratio operation can always be performed.

【００３０】また、燃料性状の変動、空気流量の誤差な
どが生じた場合でも火炉１の排ガス出口酸素濃度計で、
それを検知するという従来の空燃比制御法が採用できる
ので、信頼性の高い空燃比の運転が維持でき、常に火炉
内の燃焼条件は良好に維持される。それは、高い燃焼効
率、さらにはプラント効率の維持、環境性能の確保、伝
熱管の還元腐食による減肉防止効果がある。Even in the case of fluctuations in fuel properties, errors in air flow rate, etc., the oxygen concentration meter at the exhaust gas outlet of the furnace 1
Since a conventional air-fuel ratio control method of detecting the air-fuel ratio can be employed, a highly reliable operation of the air-fuel ratio can be maintained, and the combustion conditions in the furnace are always maintained in good condition. It has the effect of maintaining high combustion efficiency, maintaining plant efficiency, securing environmental performance, and preventing wall loss due to reduction corrosion of heat transfer tubes.

【００３１】したがって、蒸気温度変動があっても、過
熱器９、再熱器１０（例えば実施例１）、場合によって
は二段式再熱器１０、１１（例えば実施例２）のそれぞ
れの出口温度が大きくアンバランスとなった場合でも、
空燃比のアンバランスによる上記の各種ボイラ性能の低
下を心配する事なく火炉１ごとの流動層の層高調整によ
る各蒸気温度制御が行えるので、蒸気温度制御幅も従来
より大きく拡大できる。Therefore, even if the steam temperature fluctuates, the outlets of the superheater 9, the reheater 10 (for example, the first embodiment) , and in some cases, the two-stage reheaters 10, 11 (for example, the second embodiment) Even if the temperature is greatly unbalanced,
Since each steam temperature can be controlled by adjusting the bed height of the fluidized bed of each furnace 1 without worrying about the above-mentioned various boiler performance deterioration due to the air-fuel ratio imbalance, the steam temperature control width can be greatly expanded as compared with the conventional case.

【００３２】また、上記実施例では再熱器１０がある火
炉１を蒸発器８がある火炉１と分離することで、ボイラ
起動初期であって、タービン通気前は再熱器１０の伝熱
管を焼損させることなく、しかも短時間での起動が可能
となり、起動燃料の節約、起動停止時の発電ロスの低減
となる。また、このような火炉１別に起動タイミングを
ずらすことができるのも火炉１別に空気流量制御を可能
にした効果である。Further, in the above embodiment, the furnace 1 having the reheater 10 is separated from the furnace 1 having the evaporator 8 so that the heat transfer tube of the reheater 10 is used at the initial stage of the boiler startup and before the turbine ventilation. It is possible to start up in a short time without burning out, thereby saving the starting fuel and reducing the power generation loss at the time of starting and stopping. Further, the fact that the start timing can be shifted for each furnace 1 is also an effect of enabling air flow control for each furnace 1.

【００３３】その他、火炉１を複数に分割し、小さくす
ることによって圧力容器２の直径も小さくできる。それ
によって、 （１）圧力容器２の肉厚減少 （２）圧力容器２の溶接部の検査時間の短縮 （３）圧力容器２内機器の重量低減により、大容量ボイ
ラにおいても圧力容器２をモジュール化して輸送もで
き、据付コスト低減となる。In addition, the diameter of the pressure vessel 2 can be reduced by dividing the furnace 1 into a plurality and reducing the size. Thereby, (1) the thickness of the pressure vessel 2 is reduced. (2) the inspection time of the welded portion of the pressure vessel 2 is shortened. (3) The weight of the equipment inside the pressure vessel 2 is reduced, so that the pressure vessel 2 is modularized even in a large-capacity boiler. transportation-out also de <br/> turned into, the installation cost reduction.

【００３４】この場合、複数の各圧力容器２のうち、最
大直径を持つ圧力容器２と最小直径を持つ圧力容器２と
の直径比率が１：１（即ち全ての圧力容器が同一直径）
〜１：１．２の範囲とするように、圧力容器２を構成
し、その中に収納可能なように複数の火炉１のサイズ、
形状を選定することによって、全ての圧力容器２の直径
を最も小さくでき、上記の三つのメリットを最も生かせ
ることになる。[0034] In this case, among the plurality of the pressure vessel 2, the diameter ratio between the pressure vessel 2 having a pressure vessel 2 and the minimum diameter with the largest diameter is 1: 1 (i.e., all of the pressure vessel the same diameter)
The pressure vessel 2 is configured so as to have a range of 1: 1.2, and the sizes of the plurality of furnaces 1 are set so as to be housed therein.
By selecting the shape, the diameters of all the pressure vessels 2 can be minimized, and the above three advantages can be utilized most.

【００３５】[0035]

【発明の効果】本発明によれば、各々の火炉への空気流
量調整弁を各圧力容器の外部に設置しているので、該調
整弁の信頼性、保守性の問題はない。また、複数に分割
された火炉への燃焼空気は、圧力容器内を通過した後、
各火炉へ入るため圧力容器の加圧用の設備が不要であ
り、その空気は常時流れているので火炉の輻射熱による
温度上昇がないことになる。According to the present invention, since the air flow control valve for each furnace is installed outside each pressure vessel, there is no problem in the reliability and maintainability of the control valve. In addition, after the combustion air to the furnace divided into a plurality passes through the pressure vessel,
No equipment for pressurizing the pressure vessel is required to enter each furnace, and since the air flows constantly, there is no temperature rise due to the radiant heat of the furnace.

【００３６】さらに、各々の火炉の出口の排ガス中の酸
素濃度信号と燃料供給量信号の両者もしくはどちらか一
方の信号を取り込んだ空燃比制御手段から発信させる信
号によって各圧力容器に接続する空気流量調整手段は制
御され、燃焼空気流量が適正に運転できる。Further, the air flow rate connected to each pressure vessel is determined by a signal transmitted from the air-fuel ratio control means, which receives the oxygen concentration signal in the exhaust gas at the outlet of each furnace and / or the fuel supply amount signal. The adjusting means is controlled so that the combustion air flow rate can be operated properly.

【００３７】また、蒸気温度変動があっても、過熱器、
再熱器のそれぞれの出口温度が大きくアンバランスとな
った場合でも、空燃比のアンバランスによる各種ボイラ
性能の低下を心配する事なく各火炉ごとの流動層の層高
調整による各蒸気温度制御が行えるので、蒸気温度制御
幅も従来より大きく拡大できる。In addition, even if the steam temperature fluctuates, a superheater,
Even when the outlet temperatures of the reheaters are greatly unbalanced, each steam temperature control by adjusting the bed height of the fluidized bed for each furnace can be performed without worrying about the deterioration of various boiler performances due to the air-fuel ratio imbalance. Since it can be performed, the steam temperature control width can be greatly expanded as compared with the conventional case.

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

【図１】 本発明の実施例１の加圧流動層ボイラを用い
る全体系統図である。FIG. 1 is an overall system diagram using a pressurized fluidized-bed boiler of Embodiment 1 of the present invention.

【図２】 本発明の実施例２の加圧流動層ボイラを用い
る全体系統図である。FIG. 2 is an overall system diagram using a pressurized fluidized bed boiler according to a second embodiment of the present invention.

【図３】 火炉の流動層の部分を分割した従来技術の加
圧流動層ボイラを用いる全体系統図である。FIG. 3 is an overall system diagram using a pressurized fluidized bed boiler of the related art in which a fluidized bed portion of a furnace is divided.

【図４】 火炉に完全に分割した従来技術の加圧流動層
ボイラを用いる全体系統図である。FIG. 4 is an overall system diagram using a pressurized fluidized bed boiler of the prior art completely divided into a furnace.

【図５】 火炉へ直接空気配管を接続した従来技術の加
圧流動層ボイラを用いる全体系統図である。FIG. 5 is an overall system diagram using a pressurized fluidized bed boiler of the related art in which an air pipe is directly connected to a furnace.

【符号の説明】[Explanation of symbols]

１ａ，１ｂ，１ｃ…火炉、２ａ，２ｂ，２ｃ…圧力容
器、３ａ，３ｂ，３ｃ…空気流量調整弁、４ａ，４ｂ，
４ｃ…空気ダクト、５ａ，５ｂ，５ｃ…燃料供給ポン
プ、６ａ，６ｂ，６ｃ…燃料供給ポンプ電動機、７ａ，
７ｂ，７ｃ…媒体貯蔵タンク、８…蒸発器、９ａ，９ｂ
…過熱器管、１０…第一段再熱器、１１…第二段再熱
器、１２ａ，１２ｂ，１２ｃ…酸素濃度計、１３ａ，１
３ｂ，１３ｃ…排ガスダクト、１４ａ，１４ｂ，１４ｃ
…制御器、１５…ガスタービン、１６…空気圧縮機、１
７…排ガスクーラ、１８…煙突、１９…圧力容器加圧空
気配管、２０…圧力容器加圧空気弁1a, 1b, 1c: furnace, 2a, 2b, 2c: pressure vessel, 3a, 3b, 3c: air flow regulating valve, 4a, 4b,
4c: air duct, 5a, 5b, 5c: fuel supply pump, 6a, 6b, 6c: fuel supply pump motor, 7a,
7b, 7c: medium storage tank, 8: evaporator, 9a, 9b
... superheater tube, 10 ... first stage reheater, 11 ... second stage reheater, 12a, 12b, 12c ... oxygen concentration meter, 13a, 1
3b, 13c: exhaust gas duct, 14a, 14b, 14c
... Controller, 15 ... Gas turbine, 16 ... Air compressor, 1
7 exhaust gas cooler, 18 chimney, 19 pressure vessel pressurized air piping, 20 pressure vessel pressurized air valve

───────────────────────────────────────────────────── フロントページの続き (72)発明者 東川 謙示 広島県呉市宝町６番９号 バブコック日 立株式会社 呉工場内 (72)発明者 野中 公大 広島県呉市宝町６番９号 バブコック日 立株式会社 呉工場内 (72)発明者 坂田 太郎 広島県呉市宝町６番９号 バブコック日 立株式会社 呉工場内 審査官 豊島 唯 (56)参考文献 特開 平４−36503（ＪＰ，Ａ) 特開 昭56−113906（ＪＰ，Ａ) 特開 平４−309702（ＪＰ，Ａ) (58)調査した分野(Int.Cl.⁷，ＤＢ名) F22B 1/02 F23C 10/16 F23C 10/28 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Kenji Higashikawa 6-9 Takaracho, Kure City, Hiroshima Prefecture Inside the Kure Plant, Babcock Hitachi Ltd. (72) Inventor Kodai Nonaka 6-9 Takaracho Kure City, Hiroshima Prefecture Babcock Inside the Kure Plant, Hitachi Ltd. (72) Inventor Taro Sakata 6-9 Takara-cho, Kure City, Hiroshima Pref. Examiner in the Kure Plant, Hitachi Co., Ltd. Yui Toshima (56) JP-A-56-113906 (JP, A) JP-A-4-309702 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) F22B 1/02 F23C 10/16 F23C 10 / 28

Claims (3)

(57)【特許請求の範囲】(57) [Claims] 【請求項１】 火炉内に蒸発器、過熱器および再熱器を
配置し、層高を変化させることによって過熱器出口温度
および再熱器出口蒸気温度を制御する制御手段を持った
加圧流動層ボイラにおいて、 蒸発器、過熱器および再熱器のうち、蒸発器を配置した
火炉と再熱器を配置した火炉とをそれぞれ別体とする少
なくとも二つに分割された火炉と、 分割された各火炉を個別に収納する少なくとも二つの圧
力容器と、 各火炉へ送られる燃焼用空気および各圧力容器の加圧用
空気を導くために各圧力容器に接続される空気配管と、 を設けたことを特徴とする加圧流動層ボイラ。1. A pressurized flow having a control means for disposing an evaporator, a superheater and a reheater in a furnace and controlling a superheater outlet temperature and a reheater outlet steam temperature by changing a bed height. In the bed boiler, the evaporator was installed among the evaporator, superheater and reheater .
A furnace divided into at least two separate furnaces each including a furnace and a furnace in which a reheater is arranged; at least two pressure vessels for individually storing the divided furnaces; A pressurized fluidized-bed boiler, comprising: an air pipe connected to each pressure vessel for guiding the combustion air and the pressurized air of each pressure vessel. 【請求項２】 各圧力容器は最大直径を有する圧力容器
と最小直径を有する圧力容器の直径の比率が１：１〜
１：１．２の範囲の大きさとし、各火炉は各圧力容器内
に収納できるサイズ、形状とすることを特徴とする請求
項１記載の加圧流動層ボイラ。2. The pressure vessel according to claim 1, wherein the ratio of the diameter of the pressure vessel having the largest diameter to that of the pressure vessel having the smallest diameter is 1: 1 to 1: 1.
2. A pressurized fluidized bed boiler according to claim 1, wherein the size is in the range of 1: 1.2, and each furnace has a size and a shape that can be stored in each pressure vessel. 【請求項３】 蒸発器、過熱器および再熱器のうち、蒸
発器を配置した火炉と再熱器を配置した火炉とをそれぞ
れ別体とする少なくとも二つに分割された火炉と、分割
された各火炉を個別に収納する少なくとも二つの圧力容
器と、各火炉内の層高を変化させることによって過熱器
出口温度および再熱器出口蒸気温度を制御する制御手段
とを備えた加圧流動層ボイラに、 各火炉へ送られる燃焼用空気および各圧力容器の加圧用
空気を導くために各圧力容器に接続される空気配管に設
けられる、各火炉に導入される空気流量を各々独立して
制御できるようにした空気流量調整手段と、 各火炉の出口の排ガス中の酸素濃度を検出するために各
火炉の排ガス配管に設けられた酸素濃度検出手段と、 各火炉の燃料供給量を検出する燃料供給量検出手段と、 前記酸素濃度検出手段および燃料供給量検出手段の少な
くとも一方の検出値に基づき、前記各空気流量調整手段
の空気流量制御を行わせる空燃比制御手段と、を設けた
ことを特徴とする加圧流動層ボイラの制御装置。Wherein the evaporator, of the superheater and reheater, furnace divided at least into two to the evaporator and the furnace arranged a furnace and reheater placing the separate bodies respectively And at least two pressure vessels for individually storing the divided furnaces, and control means for controlling the superheater outlet temperature and the reheater outlet steam temperature by changing the bed height in each furnace. In the pressurized fluidized bed boiler, the air flow introduced into each furnace, which is provided in an air pipe connected to each pressure vessel to guide the combustion air sent to each furnace and the pressurized air of each pressure vessel, Air flow rate adjusting means which can be controlled independently; oxygen concentration detecting means provided in an exhaust gas pipe of each furnace for detecting oxygen concentration in exhaust gas at an outlet of each furnace; fuel supply amount of each furnace Fuel supply amount detecting means for detecting Based on at least one of the detected value of the oxygen concentration detecting means and the fuel supply quantity detecting means, characterized in that said air-fuel ratio control means to I line of air flow rate control of the air flow rate adjusting means, the provided pressure Control device for pressure fluidized bed boiler.