JPH1122912A - Device and method for controlling water level in steam separator - Google Patents

Device and method for controlling water level in steam separator

Info

Publication number
JPH1122912A
JPH1122912A JP9176944A JP17694497A JPH1122912A JP H1122912 A JPH1122912 A JP H1122912A JP 9176944 A JP9176944 A JP 9176944A JP 17694497 A JP17694497 A JP 17694497A JP H1122912 A JPH1122912 A JP H1122912A
Authority
JP
Japan
Prior art keywords
water level
steam
steam separator
water
control
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
JP9176944A
Other languages
Japanese (ja)
Inventor
Tadashi Komatsu
正 小松
Makoto Mikami
誠 三上
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Fuji Electric Co Ltd
Original Assignee
Fuji Electric Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Fuji Electric Co Ltd filed Critical Fuji Electric Co Ltd
Priority to JP9176944A priority Critical patent/JPH1122912A/en
Publication of JPH1122912A publication Critical patent/JPH1122912A/en
Pending legal-status Critical Current

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Classifications

    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/30—Hydrogen technology
    • Y02E60/50—Fuel cells

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  • Fuel Cell (AREA)

Abstract

PROBLEM TO BE SOLVED: To enable accurately controlling the flow rate of feedwater and simplify the feedwater flow system. SOLUTION: A cooling water circulation system 20 is equipped with a body of fuel cell 21, a steam separator 22, and a cooling water-circulating pump 23, and by circulating the cooling water eliminates heat evolving from the fuel cell body, evolves steam in the steam separator, which steam is drawn off by a steam-drawing off system 26 and used for reforming or pressure control (release). A feedwater system 25 feeds water to the steam separator. A measuring part 26 takes generated current measurement, generated voltage measurement, water-level measurement, steam flow-rate measurement, feedwater flow- rate, etc., a controller 27 provided with a change-delaying device 28 calculates the respective measurements, and the results are used as control signals for controlling the operation of the fuel cell body, steam separator, steam drawing off system, and feedwater system. Water level is controlled by deciding the controlled set water level of the steam separator in accordance with the calorific value of the fuel cell.

Description

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

【０００１】[0001]

【発明の属する技術分野】この発明は、水蒸気分離器の
水位制御装置および方法に関し、特に燃料電池発電装置
に適用した水蒸気分離器の水位制御装置および方法に関
する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a water level control device and method for a steam separator, and more particularly to a water level control device and method for a steam separator applied to a fuel cell power generator.

【０００２】この発明は、水蒸気分離器が使用される分
野に広く適用可能であり、炭化水素を主成分とする都市
ガス等に蒸気を加えて水素を主成分とするガスに改質
し、この水素と空気中の酸素を原料として電気化学的な
反応で発電を行い、余剰熱を水蒸気分離器を循環する冷
却水循環系にて除去する燃料電池発電装置に利用され
る。また、液体の一部を蒸気として発生する蒸気発生器
とこの蒸気発生器に液体を供給する装置と蒸気発生器か
ら出る液・蒸気の混合物を分離する液・蒸気分離器から
構成され、ボイラなどの蒸気製造装置に利用される。The present invention is widely applicable to the field in which a steam separator is used, and reforms a city gas or the like mainly containing hydrocarbons into a gas mainly containing hydrogen by adding steam. It is used in a fuel cell power generator that generates power by an electrochemical reaction using hydrogen and oxygen in the air as raw materials and removes excess heat in a cooling water circulation system that circulates through a steam separator. It also consists of a steam generator that generates part of the liquid as steam, a device that supplies liquid to the steam generator, and a liquid / steam separator that separates a mixture of liquid and steam from the steam generator. Used for steam production equipment.

【０００３】[0003]

【従来の技術】液・蒸気を扱う蒸気発生器と循環水ポン
プと水蒸気分離器を組み合わせたボイラが一般的に知ら
れているが、燃料電池本体は余剰熱を除去する冷却管が
内部に組み込まれ、ここで除去された熱は蒸気となっ
て、都市ガス等の炭化水素を改質する蒸気原料として利
用する構成を取るのが一般的であり、燃料電池本体は蒸
気発生器に相当する機能を有する。2. Description of the Related Art A boiler combining a steam generator for handling liquid and steam, a circulating water pump and a steam separator is generally known. However, a fuel cell main body has a cooling pipe for removing excess heat therein. In general, the heat removed here becomes steam, which is used as a steam raw material for reforming hydrocarbons such as city gas, and the fuel cell body has a function equivalent to a steam generator. Having.

【０００４】このような、水蒸気分離器で循環水中の蒸
気を分離し利用する装置では、水蒸気分離器は循環水系
統に一定の水量が確保されるようにする水位制御と、安
定して蒸気が発生できるように圧力を一定に保つ圧力制
御が必要である。In such a device that separates and uses steam in the circulating water by the steam separator, the steam separator controls the water level so as to secure a constant amount of water in the circulating water system, and performs stable steam generation. Pressure control is required to keep the pressure constant so that it can be generated.

【０００５】圧力制御は、水蒸気分離器から直接余剰蒸
気を放出するか、循環水系統に熱交換器を設けて余剰熱
を除去し圧力制御を行う方式が一般的である。In general, pressure control is performed by directly discharging excess steam from a steam separator or by providing a heat exchanger in a circulating water system to remove excess heat and control the pressure.

【０００６】水位制御は、出ていく蒸気量と給水量が同
じになるように制御することを基準とし、それに設定水
位と実水位との偏差から給水量を補正する、発生水蒸気
量・給水量・水位の３点制御と呼ばれる方法が用いられ
る。[0006] The water level control is based on the control so that the outgoing steam amount and the water supply amount are the same, and the water supply amount is corrected based on the deviation between the set water level and the actual water level. -A method called three-point control of the water level is used.

【０００７】図６を参照しながら、燃料電池発電装置に
適用した場合の従来の水蒸気分離器の水位制御系を説明
する。燃料電池本体１の発熱を除去する冷却水は、水蒸
気分離器２で水蒸気を発生するのに利用するため冷却水
循環管路３をポンプ４により循環させる。水蒸気分離器
２内の水位は、給水ポンプ５を用い補給水を給水管路６
を通して供給して水位を制御する。水蒸気分離器２で発
生した水蒸気は、改質用蒸気および余剰蒸気として別個
に流量を調節している。すなわち、圧力制御バルブ７、
流量計８を通して改質用の水蒸気として供給し、改質用
水蒸気として用いない残りの水蒸気は圧力制御バルブ
９、流量計１０を通して余剰水蒸気として放出する。こ
の場合、水蒸気分離器２の圧力制御は、圧力計１１にて
測定した圧力測定値と圧力設定値とを比較し、圧力制御
バルブ９の開度を制御することにより行う。また、水蒸
気分離器２の水位制御は、水位計１２により計測した水
位計測値と水位設定値とを比較し、その差に基づいて給
水バルブ１３の開度を調節することによって流量を調節
して行う。１４は流量計である。A water level control system of a conventional steam separator when applied to a fuel cell power generator will be described with reference to FIG. Cooling water for removing heat generated in the fuel cell main body 1 is circulated by a pump 4 through a cooling water circulation pipe 3 for use in generating steam in the steam separator 2. The water level in the steam separator 2 is adjusted by using a water supply pump 5 to supply makeup water to a water supply line 6.
To control the water level. The flow rate of the steam generated by the steam separator 2 is separately adjusted as reforming steam and surplus steam. That is, the pressure control valve 7,
The steam is supplied as reforming steam through the flow meter 8, and the remaining steam not used as the reforming steam is released as surplus steam through the pressure control valve 9 and the flow meter 10. In this case, the pressure control of the steam separator 2 is performed by comparing the measured pressure value measured by the pressure gauge 11 with the set pressure value and controlling the opening of the pressure control valve 9. The water level of the steam separator 2 is controlled by comparing the measured water level measured by the water level gauge 12 with the set water level, and adjusting the flow rate by adjusting the opening of the water supply valve 13 based on the difference. Do. 14 is a flow meter.

【０００８】従来、一般的には、水位制御は図７に示す
方法により行われている。まず、水位をｈ0 ′に設定し
（ステップＳ１）、ついで水位計１２（図６）により水
蒸気分離器２（図６）内の水位ｈ′を計測し（ステップ
Ｓ２）、水位計測値ｈ′と設定水位ｈ0 ′とを比較し、
その差Δｈ′＝ｈ0 ′−ｈ′、すなわち水位偏差（Δ
ｈ′）、から循環水の流量ｆ′を演算する（ステップＳ
３）。流量ｆ′と蒸気流量計測値ｓとに基づいて給水流
量ｆ0 ′＝ｆ′＋ｓを設定する（ステップＳ４）。ここ
に、この蒸気流量計測値ｓは、改質に供する蒸気流量ｓ
1 と圧力制御用に放出する蒸気流量ｓ2 との和である
（ｓ＝ｓ1 ＋ｓ2 ）。ついで、流量計により循環水の流
量を計測して循環水の流量計測値ｆ1 ′を得る（ステッ
プＳ５）。上述の給水量設定値ｆ0 ′と流量計測値ｆ
1 ′を調節器に入力し（ステップＳ６）、ｆ0 ′−ｆ
1 ′に基づいてバルブ特性を変更してｆ0 ′−ｆ1 ′が
０に近づくように流量を調節する（ステップＳ７）。さ
らに、流量を計測し、新しい流量計測値ｆ1 ′から蒸発
による蒸気流量（プロセス量）ｓ3 を差し引いた流量ｆ
2 ′（ｆ2 ′＝ｆ1 ′−ｓ3 ）が水蒸気分離器の給水管
路６（図６）に供給される（ステップＳ８）。このとき
の水位を水位計１２（図６）で計測してステップＳ１〜
Ｓ８の処理を繰り返し、水位を調節している。Conventionally, water level control is generally performed by a method shown in FIG. First, the water level is set to h 0 ′ (step S1), and then the water level h ′ in the steam separator 2 (FIG. 6) is measured by the water level meter 12 (FIG. 6) (step S2), and the water level measurement value h ′ And the set water level h 0 ′,
The difference Δh ′ = h 0 ′ −h ′, that is, the water level deviation (Δ
h ′), the flow rate f ′ of the circulating water is calculated (step S).
3). The water supply flow rate f 0 ′ = f ′ + s is set based on the flow rate f ′ and the measured steam flow value s (step S4). Here, the measured steam flow rate s is the steam flow rate s provided for reforming.
1 and which is the sum of the steam flow s 2 to release for pressure control (s = s 1 + s 2 ). Next, the flow rate of the circulating water is measured by a flow meter to obtain a flow rate measurement value f 1 ′ of the circulating water (step S5). The above-mentioned water supply amount set value f 0 ′ and the measured flow rate f
1 'is input to the controller (step S6), and f 0 ' -f
-F 1 'to adjust the flow rate to be close to 0' f 0 by changing the valve characteristics on the basis of '1 (step S7). Further, the flow rate is measured, and the flow rate f obtained by subtracting the steam flow rate (process quantity) s 3 due to evaporation from the new flow rate measurement value f 1 ′.
2 '(f 2' = f 1 '-s 3) is supplied to the water supply conduit 6 (FIG. 6) of the steam separator (step S8). The water level at this time is measured by the water level meter 12 (FIG. 6), and steps S1 to S1 are performed.
The process of S8 is repeated to adjust the water level.

【０００９】[0009]

【発明が解決しようとする課題】一般に水蒸気分離器
は、発生させる蒸気の圧力の安定性や、蒸気発生器に循
環させる水量を考慮し、大きな容積で設計される。水蒸
気分離器を小さくすれば装置全体の大きさが小さくなり
安価な装置が製作できるが、発生蒸気量を変化させた場
合の圧力の安定性や水位の安定性が損なわれることにな
る。また、水蒸気分離器への給水系は給水流量を測定し
制御するマーイナーループの制御系（図７参照）が組み
込まれるが、この制御系も水位・圧力の安定を考慮して
設定される。Generally, a steam separator is designed with a large volume in consideration of the stability of the pressure of generated steam and the amount of water circulated to the steam generator. If the size of the steam separator is reduced, the size of the entire apparatus is reduced and an inexpensive apparatus can be manufactured. However, the stability of the pressure and the stability of the water level when the amount of generated steam is changed are impaired. The water supply system for the steam separator incorporates a control system of a minor loop (see FIG. 7) for measuring and controlling the flow rate of the water supply, and this control system is also set in consideration of the stability of the water level and pressure.

【００１０】水蒸気分離器を小さくした場合、これら水
位・圧力制御系の安定性を保つことが必要となることを
従来方式での挙動により説明する。The fact that it is necessary to maintain the stability of these water level / pressure control systems when the steam separator is made smaller will be described with reference to the behavior of the conventional system.

【００１１】図８は３点制御を行った従来の制御系（図
７）における水位変動と圧力変動を示すグラフである。FIG. 8 is a graph showing water level fluctuations and pressure fluctuations in a conventional control system (FIG. 7) that performs three-point control.

【００１２】図８は燃料電池の発電負荷を時間ｔ1 で急
激に低下させた場合の諸特性の挙動を示す。線ａで示さ
れるような発電負荷の急激な低下は、燃料電池発電装置
では、電気の出力先に異常が生じた場合に負荷遮断とい
う操作を行うことにより発生する。この場合、燃料電池
発電装置は電気の供給先から電気回路を切り離し、燃料
電池発電装置が熱・電気的に自立する最低負荷の状態に
移行する。FIG. 8 shows the behavior of various characteristics when the power generation load of the fuel cell is rapidly reduced at time t 1 . In the fuel cell power generation device, a sharp decrease in the power generation load as shown by the line a is caused by performing an operation of load shedding when an abnormality occurs in the output destination of electricity. In this case, the fuel cell power generator disconnects the electric circuit from the power supply destination, and shifts to the lowest load state where the fuel cell power generator is thermally and electrically independent.

【００１３】燃料電池発電装置にとって発電負荷の増減
は、燃料電池本体に供給する水素の増減を示す。電池に
供給する水素を増やすには、原燃料の改質に必要な蒸気
量（線ｂ）を増やす必要があり、水蒸気分離器では、発
生蒸気量を増加させると共に、供給する補給水（線ｃ）
を増やすことになる。また、電池の負荷を増やすと電池
の発熱量も増加するので、この発熱量が発生蒸気の熱源
となる。負荷を下げる時は、この逆の熱・物質収支とな
る。そして、時間ｔ1 で発電負荷が急激に低下すると、
発生蒸気量（線ｂ）も給水量（線ｃ）も対応して急激に
低下する。[0013] For the fuel cell power generator, an increase or decrease in the power generation load indicates an increase or decrease in hydrogen supplied to the fuel cell body. In order to increase the amount of hydrogen supplied to the battery, it is necessary to increase the amount of steam (line b) necessary for reforming the raw fuel. In the steam separator, the amount of generated steam is increased and the supply water (line c) is supplied. )
Will increase. Further, when the load of the battery is increased, the calorific value of the battery also increases, and this calorific value becomes a heat source of the generated steam. When the load is reduced, the reverse heat and mass balance results. When the power generation load at time t 1 is rapidly reduced,
Both the amount of generated steam (line b) and the amount of supplied water (line c) decrease correspondingly.

【００１４】ところが、図８では、水蒸気分離器の圧力
（線ｄ）が負荷遮断後、上昇する現象が発生している。
これは、蒸気量を減らすことによって水蒸気分離器系か
ら持ち出される熱量は減少したが、燃料電池からの発熱
は燃料電池を構成する材料の熱容量と冷却水との熱伝導
から決まる熱移動の遅れが発生するために、一時的に循
環水の熱が余るためである。加えて、発生した蒸気の割
合だけ給水量を減らすので、給水による温度低下が少な
くなるためである。However, in FIG. 8, a phenomenon occurs in which the pressure (line d) of the steam separator rises after the load is cut off.
This is because although the amount of heat taken out of the steam separator system was reduced by reducing the amount of steam, the heat generated by the fuel cell was delayed due to the heat transfer determined by the heat capacity of the material constituting the fuel cell and the heat conduction with the cooling water. This is because the heat of the circulating water is temporarily left to be generated. In addition, since the amount of supplied water is reduced by the proportion of the generated steam, the decrease in temperature due to supplied water is reduced.

【００１５】また、図８では水位（線ｅ）が一時的に低
くなりすぎる現象が発生している。水位制御は発生蒸気
量が少なくなることに合わせて、給水量を減らして行っ
ており、本来ならば発生蒸気量と給水量がバランスして
水位は変動しないはずであるが、燃料電池から水蒸気分
離器の間は水と蒸気の混合流であり、負荷の減少によっ
て蒸気の割合が減り、この体積減少によって配管内が水
で満たされるので、水蒸気分離器の水位が低下する。こ
のように、負荷の減少に圧力と水位の調節がすぐ追従せ
ず一時的に大きく変化し、新しい平衡に達するのに時間
Δｔ＝ｔ2 −ｔ1 の遅延が生じる。In FIG. 8, a phenomenon occurs in which the water level (line e) temporarily becomes too low. Water level control is performed by reducing the amount of water supply in accordance with the decrease in the amount of generated steam.While the amount of generated steam and the amount of water supply should normally be balanced and the water level does not fluctuate, the water level is separated from the fuel cell. A mixed flow of water and steam is provided between the vessels, and the reduction in the load reduces the proportion of steam, and this volume reduction fills the pipe with water, thereby lowering the water level of the steam separator. Thus, the pressure and water level adjustments do not immediately follow the decrease in load, but rather temporarily change significantly, causing a delay of time Δt = t 2 −t 1 to reach a new equilibrium.

【００１６】これらの現象は、水蒸気分離器が小さくな
ると顕著に表れ、水位が高くなりすぎて発生蒸気中に水
分が混入する問題や、水位が低くなりすぎて循環ポンプ
が空引きする問題が発生する原因となる。These phenomena become remarkable when the size of the steam separator is reduced. The problem is that the water level is too high and water is mixed in the generated steam, and the water level is too low and the circulation pump is idled. Cause you to

【００１７】また、水位の安定のために給水流量の正確
な制御が必要とされ、給水流量系が簡素化できないとい
う問題がある。Further, there is a problem that accurate control of the feedwater flow rate is required for stabilizing the water level, and the feedwater flow system cannot be simplified.

【００１８】従って、この発明の課題は、給水流量を正
確に制御でき、給水流量系を簡素化し得る水蒸気分離器
の水位制御装置および方法を提供することである。SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a water level control apparatus and method for a steam separator which can accurately control a feedwater flow rate and simplify a feedwater flow system.

【００１９】[0019]

【課題を解決するための手段】上述の課題を解決するた
めに、請求項１記載の水蒸気分離器の水位制御装置は、
燃料電池本体と水蒸気分離器と冷却水循環ポンプとを組
み合わせてなる、燃料電池冷却水循環系と発生蒸気の取
り出し系で、燃料電池の発熱量に応じて水蒸気分離器の
制御設定水位を決める水蒸気分離器の水位制御におい
て、制御設定水位の変化を遅延させる変化遅延手段を設
けたことを特徴とする。In order to solve the above-mentioned problems, a water level control device for a steam separator according to claim 1 is provided.
A fuel cell cooling water circulation system and a system for taking out generated steam that combine a fuel cell body, a water vapor separator, and a cooling water circulation pump.The water vapor separator determines the control set water level of the water vapor separator according to the calorific value of the fuel cell. In the above water level control, a change delay means for delaying a change in the control set water level is provided.

【００２０】請求項２記載の水蒸気分離器の水位制御装
置は、請求項１記載の水蒸気分離器の水位制御装置にお
いて、前記変化遅延手段は、前記制御設定水位の変化に
時間関数の変化率を設けた値を水位調節器の制御設定水
位として前記制御設定水位の変化を遅延させることを特
徴とする。According to a second aspect of the present invention, in the water level control device for a steam separator according to the first aspect, the change delay means includes a time function change rate for a change in the control set water level. The set value is set as a control set water level of a water level adjuster, and a change in the control set water level is delayed.

【００２１】請求項３記載の水蒸気分離器の水位制御装
置は、請求項２記載の水蒸気分離器の水位制御装置にお
いて、前記変化遅延手段は、前記制御設定水位と実測水
位との偏差から水蒸気分離器へ供給する給水量を演算
し、これに水蒸気分離器から発生する蒸気量を加え給水
流量設定値として、水蒸気分離器への給水量で水位を制
御することを特徴とする。According to a third aspect of the present invention, there is provided a water level control device for a steam separator according to the second aspect, wherein the change delay means is configured to separate the water vapor from a deviation between the control set water level and an actually measured water level. The amount of water supplied to the steam separator is calculated, the amount of steam generated from the steam separator is added to the calculated amount, and the water level is controlled by the amount of water supplied to the steam separator as a set value of the amount of feed water flow.

【００２２】請求項４記載の水蒸気分離器の水位制御装
置は、請求項２記載の水蒸気分離器の水位制御装置にお
いて、前記変化遅延手段は、前記制御設定水位と実測水
位との偏差から水蒸気分離器へ供給する給水量を演算
し、これに水蒸気分離器から発生する蒸気量の時間関数
の制限を設けた発生蒸気量補正値を加え給水流量設定値
として、水蒸気分離器への給水量で水位を制御すること
を特徴とする。According to a fourth aspect of the present invention, in the water level control device for a steam separator according to the second aspect, the change delay means is configured to separate the water vapor from a deviation between the control set water level and an actually measured water level. Calculates the amount of water supplied to the steam separator, and adds a generated steam amount correction value that limits the time function of the amount of steam generated from the steam separator to this value. Is controlled.

【００２３】請求項５記載の水蒸気分離器の水位制御装
置は、請求項１ないし４のいずれかに記載の水蒸気分離
器の水位制御装置において、前記給水流量設定値と前記
水蒸気分離器の圧力から、給水流量制御バルブの開度を
直接設定して水位を制御することを特徴とする。According to a fifth aspect of the present invention, there is provided a water level control device for a steam separator according to any one of the first to fourth aspects, wherein the water supply flow rate setting value and the pressure of the steam separator are used. The water level is controlled by directly setting the degree of opening of the water supply flow control valve.

【００２４】請求項６記載の水蒸気分離器の水位制御方
法は、燃料電池本体と水蒸気分離器と冷却水循環ポンプ
とを組み合わせてなる、燃料電池冷却水循環系と発生蒸
気の取り出し系で、燃料電池の発熱量に応じて、水蒸気
分離器の制御設定水位を決める水蒸気分離器の水位制御
において、制御設定水位の変化を遅延させることを特徴
とする。According to a sixth aspect of the present invention, there is provided a water level control method for a fuel cell, comprising: a fuel cell cooling water circulating system and a generated steam taking-out system comprising a fuel cell body, a steam separator and a cooling water circulating pump. In the water level control of the steam separator that determines the control set water level of the steam separator in accordance with the calorific value, a change in the control set water level is delayed.

【００２５】請求項７記載の水蒸気分離器の水位制御方
法は、請求項６記載の水蒸気分離器の水位制御方法にお
いて、前記制御設定水位の変化に時間関数の変化率を設
けた値を水位調節器の制御設定水位とすることを特徴と
する。According to a seventh aspect of the present invention, in the method of controlling a water level of a steam separator according to the sixth aspect, a value in which a change rate of a time function is provided for the change of the control set water level is adjusted. The water level is set to the control setting of the vessel.

【００２６】請求項８記載の水蒸気分離器の水位制御方
法は、請求項７記載の水蒸気分離器の水位制御方法にお
いて、前記制御設定水位と実測水位との偏差から水蒸気
分離器へ供給する給水量を演算し、これに水蒸気分離器
から発生する蒸気量を加え給水流量設定値として、水蒸
気分離器への給水量で水位を制御することを特徴とす
る。According to an eighth aspect of the present invention, there is provided a method for controlling a water level of a steam separator according to the seventh aspect of the present invention, wherein a water supply amount to be supplied to the steam separator based on a deviation between the control set water level and an actually measured water level. Is calculated, and the amount of steam generated from the steam separator is added to the calculated value as a feedwater flow rate set value to control the water level by the amount of water supplied to the steam separator.

【００２７】請求項９記載の水蒸気分離器の水位制御方
法は、請求項７記載の水蒸気分離器の水位制御方法にお
いて、前記制御設定水位と実測水位との偏差から水蒸気
分離器へ供給する給水量を演算し、これに水蒸気分離器
から発生する蒸気量の時間関数の制限を設けた発生蒸気
量補正値を加え給水流量設定値として、水蒸気分離器へ
の給水量で水位を制御することを特徴とする。According to a ninth aspect of the present invention, there is provided a method for controlling a water level of a steam separator according to the seventh aspect, wherein a water supply amount supplied to the steam separator based on a deviation between the control set water level and an actually measured water level. The water level is controlled by the amount of water supplied to the steam separator as a set value of the water supply flow rate by adding a generated steam amount correction value with a time function restriction of the amount of steam generated from the steam separator to the calculated value. And

【００２８】請求項１０記載の水蒸気分離器の水位制御
方法は、請求項６〜９のいずれかに記載の水蒸気分離器
の水位制御方法において、前記給水流量設定値と前記水
蒸気分離器の圧力から、給水流量制御バルブの開度を直
接設定して水位を制御することを特徴とする。A water level control method for a steam separator according to a tenth aspect is the water level control method for a steam separator according to any one of the sixth to ninth aspects, wherein the water supply flow rate set value and the pressure of the steam separator are used. The water level is controlled by directly setting the degree of opening of the water supply flow control valve.

【００２９】[0029]

【発明の実施の形態】図１は、本発明の一実施例による
水位制御装置および方法を燃料電池発電装置に適用した
場合を示す概略ブロック線図である。冷却水循環系２０
は燃料電池本体２１と、水蒸気分離器２２と冷却水循環
ポンプ２３とを備え、燃料電池本体２１の発熱を除去す
る冷却水は冷却水循環ポンプ２３により水蒸気分離器２
２に送られ、水蒸気分離器２２内で水蒸気を発生する。
発生した水蒸気は水蒸気取り出し系２４により取り出さ
れ、改質用に用いるか、または放出して水蒸気分離器２
２内の圧力を調節する。また、水蒸気分離器２２は給水
系２５から給水される。計測部２６は燃料電池本体２１
について燃料電池の運転状況に関するデータ、例えば発
電電流計測値、発電電圧計測値を、水蒸気分離器２２に
ついて水位計測値を、水蒸気取り出し系２４について蒸
気流量計測値を、給水系２５について給水流量をそれぞ
れ計測し、制御部２７にデータ信号を送る。制御部２７
では、ＲＡＭ等の記憶装置（図示しない）にこれらのデ
ータを記憶するとともにこれらのデータを用いて種々の
演算をし、結果を制御信号として燃料電池本体２１、水
蒸気分離器２２、水蒸気取り出し系２４、給水系２５に
送りそれらの働きを制御することにより、燃料電池の発
熱量に応じて水蒸気分離器の制御設定水位を決めること
により水位を制御する。この場合、本発明では、制御部
２７に変化遅延装置２８を設け、負荷の急激な変化に伴
う水位および圧力の一方または双方の激変を生じないよ
うにしている。FIG. 1 is a schematic block diagram showing a case where a water level control device and method according to one embodiment of the present invention are applied to a fuel cell power generator. Cooling water circulation system 20
Is provided with a fuel cell main body 21, a water vapor separator 22 and a cooling water circulation pump 23, and cooling water for removing heat generated in the fuel cell main body 21 is supplied to the water vapor separator 2 by the cooling water circulation pump 23.
2 to generate steam in the steam separator 22.
The generated steam is taken out by a steam taking-out system 24 and used for reforming or released to be used in the steam separator 2.
Adjust the pressure in 2. Further, the steam separator 22 is supplied with water from a water supply system 25. The measuring unit 26 is the fuel cell main body 21
For the data on the operating state of the fuel cell, for example, the measured value of the generated current, the measured value of the generated voltage, the measured water level of the steam separator 22, the measured steam flow rate of the steam extracting system 24, and the measured flow rate of the feed water system 25, respectively. It measures and sends a data signal to the control unit 27. Control unit 27
Then, these data are stored in a storage device (not shown) such as a RAM, and various calculations are performed using these data. The results are used as control signals as a fuel cell main body 21, a steam separator 22, a steam extraction system 24. The water level is controlled by determining the control water level of the steam separator according to the calorific value of the fuel cell by sending the water to the water supply system 25 and controlling the operation thereof. In this case, in the present invention, the control unit 27 is provided with the change delay device 28 so as to prevent a sudden change in one or both of the water level and the pressure due to a sudden change in the load.

【００３０】すなわち、燃料電池の発電負荷によって変
わる、燃料電池から水蒸気分離器の間の水・蒸気量体積
変化に相当する水量を水蒸気分離器の制御設定水位をあ
らかじめ変えておくことで、負荷を変えた時に水位が設
定許容範囲外になることを防止することができるが、そ
の際に、本発明では、この過渡的な負荷変動と制御設定
水位の変更に際して、設定水位を下げる時に給水流量が
少なくならないように、変化遅延装置により設定水位の
変更に時間関数（ランプ関数）を入れ、急激に水位が変
化しなくなるようにしている。That is, the amount of water corresponding to the change in the volume of water and steam between the fuel cell and the steam separator, which varies depending on the power generation load of the fuel cell, is changed in advance by changing the control set water level of the steam separator. Although it is possible to prevent the water level from being outside the allowable setting range when the water level is changed, in the present invention, when the transient load fluctuation and the control set water level are changed, the water supply flow rate is reduced when the set water level is lowered. To prevent the water level from decreasing, a time function (ramp function) is added to the change of the set water level by the change delay device so that the water level does not suddenly change.

【００３１】また、給水量は発生蒸気量にすぐに追従さ
せず、遅れをもたせることで水・蒸気体積変化分を補充
させ、加えて給水による水蒸気分離器系の熱量変化を少
なくしている。これらの水位・圧力系の安定化によっ
て、給水流量制御系のマイナーループを省略し、あらか
じめ測定された給水ポンプ、バルブの特性を使ってバル
ブ開度をプリセットする方式を採用することができる。The amount of supplied water does not immediately follow the amount of generated steam, but is delayed to compensate for the change in water / steam volume, and in addition, the amount of heat in the steam separator system due to the supplied water is reduced. By stabilizing the water level / pressure system, it is possible to omit the minor loop of the feedwater flow control system and adopt a method of presetting the valve opening using the characteristics of the feedwater pump and the valve measured in advance.

【００３２】燃料電池の負荷を上げる時は、燃料電池か
ら水蒸気分離器間の蒸気体積が多くなり水が水蒸気分離
器に押し出され水位が高くなるので、あらかじめ設定水
位を低くしておくことで水位が高くなりすぎるのを防止
することができる。また、燃料電池の負荷が高いときは
水位を高めに設定しておき、負荷を下げた時の水位が低
くなりすぎるのを防止することができる。この設定水位
の変更は時間関数の遅れをもって変更する。例えば水位
を高く設定しておくのは、燃料電池の負荷を下げると
き、水位が下がり過ぎないようにするためなので、給水
量が少なくならないように急に設定水位を下げないよう
にする。When increasing the load of the fuel cell, the vapor volume between the fuel cell and the steam separator increases, and water is pushed out by the steam separator to increase the water level. Can be prevented from becoming too high. In addition, when the load of the fuel cell is high, the water level is set to be higher, and it is possible to prevent the water level when the load is reduced from becoming too low. This change of the set water level changes with a delay of the time function. For example, the water level is set high to prevent the water level from dropping too much when the load on the fuel cell is lowered. Therefore, the water level is not suddenly lowered so that the amount of supplied water does not decrease.

【００３３】水蒸気分離器への給水流量は、燃料電池の
負荷に対応する発生蒸気量に対しランプ関数で遅れをも
って追従させることにより、水位変化を安定させる方向
に制御が働く。たとえば、負荷を上昇させるときは、発
生蒸気により水蒸気分離器系全体から出ていく水の量は
多くなるが、燃料電池本体と水蒸気分離器間の蒸気体積
の増加があるので、水の物質収支を水蒸気分離器の水位
として把握した場合、負荷上昇による発生蒸気量が増加
しても給水量は急に増加させなくても水蒸気分離器の水
位が低下することはない。The flow rate of the water supplied to the steam separator is controlled in a direction to stabilize the water level change by following the generated steam amount corresponding to the load of the fuel cell with a delay by a ramp function. For example, when increasing the load, the amount of water flowing out of the entire steam separator system due to the generated steam increases, but the mass balance of the water increases due to the increase in the steam volume between the fuel cell body and the steam separator. When the water level of the steam separator is grasped, the water level of the steam separator does not decrease even if the amount of steam generated due to an increase in the load increases and the supplied water amount does not suddenly increase.

【００３４】また、負荷上昇時の蒸気量増加によって系
全体の熱量が不足し圧力が一時的に低下する現象が生じ
るが、発生蒸気量の増加にすぐに給水量を追従させない
ことで、給水による温度低下による圧力低下の影響を少
なくすることができる。Also, a phenomenon occurs in which the heat quantity of the entire system becomes insufficient due to the increase in the amount of steam when the load increases, and the pressure temporarily drops. However, the water supply amount is not immediately followed by the increase in the amount of generated steam, so The effect of the pressure drop due to the temperature drop can be reduced.

【００３５】燃料電池の負荷を下げる時は逆の作用によ
って、給水量にランプ関数を設けて流量を少なくするこ
とによって水位・圧力の安定化が図れる。When the load on the fuel cell is reduced, the water level and pressure can be stabilized by providing a ramp function to the water supply amount and reducing the flow rate by the reverse operation.

【００３６】このように、給水流量の変化率を小さくす
ることで、給水流量は、流量によって変わるポンプの吐
出圧力とバルブの開度特性を制御装置に組み込んでお
き、給水設定値に対し水蒸気分離器の測定圧力で補正さ
れたバルブ開度設定値をプリセットすることで決めるこ
とができる。As described above, by reducing the rate of change of the feedwater flow rate, the feedwater flow rate, which varies depending on the flow rate, incorporates the discharge pressure of the pump and the opening degree characteristics of the valve into the control device, and the steam separation with respect to the set feedwater value. Can be determined by presetting the valve opening set value corrected by the measurement pressure of the vessel.

【００３７】[0037]

【実施例】以下、実施例により本発明をさらに詳細に説
明するが、本発明は実施例に限定されないことはもちろ
んである。EXAMPLES Hereinafter, the present invention will be described in more detail by way of examples, but it is needless to say that the present invention is not limited to the examples.

【００３８】（実施例１）図２を参照しながら、燃料電
池発電装置に適用した場合の、本発明の一実施例による
水蒸気分離器の水位制御系を説明する。燃料電池本体１
の発熱を除去する冷却水は、水蒸気分離器２で水蒸気を
発生するのに利用するため冷却水循環系管路３を通りポ
ンプ４により循環させる。燃料電池本体１の発熱量を計
算する基礎データとしての発電電流計測値と発電電圧計
測値が図１の制御部２７に送られ、水位に変換され、さ
らに変化遅延装置２８によりその変化を遅延させる操作
をする。水蒸気分離器２内の水位は、給水ポンプ５を用
い補給水を給水系管路６を通して供給することにより制
御する。この水位は計測部２６としての水位計１２によ
り計測され、データは制御部２７へ送られる。水蒸気分
離器２で発生した水蒸気は、改質用蒸気および余剰蒸気
として別個に流量を調節している。すなわち、圧力制御
バルブ７、流量計８を通して改質用の水蒸気として供給
し、改質用水蒸気として用いない残りの水蒸気は圧力制
御バルブ９、流量計１０を通して余剰水蒸気として放出
する。この場合、水蒸気分離器２の圧力制御は、計測部
２６としての圧力計１１にて測定した圧力測定値を制御
部２７へ送り、圧力設定値と比較し、その差に基づいた
信号を制御部２７より圧力制御バルブ９のアクチュエー
タに送り、その開度を制御することにより行う。また、
水蒸気分離器２の水位制御は、水位計１２の計測した水
位計測値と水位設定値とを制御部２７において比較し、
その差に基づいた信号を制御部２７から給水バルブ１３
のアクチュエータに送って給水バルブ１３の開度を調節
することによって流量を調節して行う。(Embodiment 1) A water level control system of a steam separator according to an embodiment of the present invention when applied to a fuel cell power generator will be described with reference to FIG. Fuel cell body 1
The cooling water for removing the heat generated by the cooling water is circulated by a pump 4 through a cooling water circulating system pipe 3 for use in generating steam in the steam separator 2. The generated current measurement value and the generated voltage measurement value as basic data for calculating the calorific value of the fuel cell main body 1 are sent to the control unit 27 in FIG. 1 and converted into a water level, and the change is delayed by the change delay device 28. Do the operation. The water level in the steam separator 2 is controlled by using a water supply pump 5 to supply makeup water through a water supply line 6. This water level is measured by the water level meter 12 as the measuring unit 26, and the data is sent to the control unit 27. The flow rate of the steam generated by the steam separator 2 is separately adjusted as reforming steam and surplus steam. That is, the steam is supplied as reforming steam through the pressure control valve 7 and the flow meter 8, and the remaining steam not used as the reforming steam is released as surplus steam through the pressure control valve 9 and the flow meter 10. In this case, the pressure control of the steam separator 2 is performed by sending a measured pressure value measured by the pressure gauge 11 as the measuring unit 26 to the control unit 27, comparing the measured pressure value with the set pressure value, and outputting a signal based on the difference. This is performed by sending the pressure control valve 27 to the actuator of the pressure control valve 9 and controlling the opening thereof. Also,
The water level control of the steam separator 2 compares the measured water level measured by the water level meter 12 with the set water level in the control unit 27,
A signal based on the difference is sent from the control unit 27 to the water supply valve 13.
The flow rate is adjusted by adjusting the opening of the water supply valve 13 by sending the water to the actuator.

【００３９】本発明では、水位制御は図３に示す方法に
より行われている。まず、燃料電池本体からの発電電流
計測値（ｉ0 ）と発電電圧計測値（ｖ0 ）とに基づいて
制御部２７（図２）で発熱量が演算され（ステップＳ１
１）、この発熱量に基づいて設定水位ｈ0 が演算により
求められ（ステップＳ１２）、この変換水位ｈ0 に時間
関数（ランプ関数）をかけた水位ｈL を水位として設定
し（ステップＳ１３）、ついで水位計１２（図２）によ
り水蒸気分離器２（図２）内の水位ｈを計測し（ステッ
プＳ１４）、水位計測値ｈと設定水位ｈL とを比較し、
その差Δｈ＝ｈL −ｈ、すなわち水位偏差（Δｈ）、か
ら循環水の流量ｆを演算する（ステップＳ１５）。一
方、蒸気流量計測値ｓに時間関数（ランプ関数）をかけ
て補正値ｓL を得（ステップＳ１６）、流量ｆと蒸気流
量計測値ｓL とに基づいて給水流量ｆ0 ＝ｆ＋ｓL を設
定する（ステップＳ１７）。ここに、この蒸気流量計測
値ｓは改質に供する蒸気流量ｓ1 と圧力制御用に放出す
る蒸気流量ｓ2 との和である（ｓ＝ｓ1 ＋ｓ2 ）。つい
で、流量計により循環水の流量を計測して循環水の流量
を計測して循環水の流量計測値ｆ1 を得る（ステップＳ
１８）。上述の給水量設定値ｆ0 と流量計測値ｆ1 を調
節器に入力し（ステップＳ１９）、ｆ0 −ｆ1に基づい
てバルブ特性を変更してｆ0 −ｆ1 が０に近づくように
流量を調節する（ステップＳ２０）。さらに、流量を計
測し、新しい流量計測値ｆ1 から蒸発による蒸気流量
（プロセス量）ｓ3 を差し引いた流量ｆ2 （ｆ2 ＝ｆ1
−ｓ3 ）が水蒸気分離器の給水管路６（図２）に供給さ
れる（ステップＳ２１）。このときの水位を水位計１２
（図２）で計測してステップＳ１１〜Ｓ２１の処理を繰
り返し、水位を調節している。In the present invention, the water level control is performed by the method shown in FIG. First, the control section 27 (FIG. 2) calculates the heat value based on the measured value of the generated current (i 0 ) and the measured value of the generated voltage (v 0 ) from the fuel cell body (step S1).
1) A set water level h 0 is obtained by calculation based on the calorific value (step S12), and a water level h L obtained by multiplying the converted water level h 0 by a time function (ramp function) is set as a water level (step S13). Then, the water level h in the steam separator 2 (FIG. 2) is measured by the water level meter 12 (FIG. 2) (step S14), and the measured water level h is compared with the set water level h L ,
The circulating water flow rate f is calculated from the difference Δh = h L −h, that is, the water level deviation (Δh) (step S15). On the other hand, the steam flow measurement value s is multiplied by a time function (ramp function) to obtain a correction value s L (step S16), and the water supply flow rate f 0 = f + s L is set based on the flow rate f and the steam flow measurement value s L. (Step S17). Here, the steam flow rate measurement value s is the sum of the steam flow s 2 to release the steam flow s 1 and a pressure control to be subjected to reforming (s = s 1 + s 2). Then, the flow rate of the circulating water is measured by measuring the flow rate of the circulating water with the flow meter to obtain the flow rate measurement value f 1 of the circulating water (step S).
18). Enter the water supply amount set value f 0 and the flow rate measurement value f 1 described above to control (step S19), so as to approach f 0 -f 1 is 0 by changing the valve characteristics on the basis of f 0 -f 1 The flow rate is adjusted (Step S20). Further, the flow rate is measured, the steam flow rate by evaporation from the new flow rate measurement value f 1 (process variable) s 3 obtained by subtracting flow rate f 2 (f 2 = f 1
−s 3 ) is supplied to the water supply line 6 (FIG. 2) of the steam separator (step S21). The water level at this time was
The process of steps S11 to S21 measured in (FIG. 2) is repeated to adjust the water level.

【００４０】なお、本実施例では上述のステップＳ１６
において蒸気流量計測値ｓに時間関数（ランプ関数）を
かけて補正値ｓL を得ているが、場合によっては、これ
を省略してもよい。In this embodiment, the above-described step S16 is performed.
In, the correction value s L is obtained by multiplying the steam flow measurement value s by a time function (ramp function), but this may be omitted in some cases.

【００４１】このように、本実施例では、水蒸気分離器
の水位制御は、燃料電池の発電電流・電圧と改質用に供
する発生蒸気の流量ｓ1 と圧力制御用に放出する蒸気流
量ｓ2 を制御装置に入力して、この改質用蒸気ｓ1 と圧
力制御放出蒸気ｓ2 の和を蒸気流量計測値ｓとする。こ
れらの信号は図１の制御装置２７に入力され、図３に示
すブロック線図に従って演算処理されて、給水バルブ５
に対する開度指令値信号として制御装置２７から出力さ
れ、水蒸気分離器２の水位制御を行う。As described above, in this embodiment, the water level of the steam separator is controlled by the power generation current / voltage of the fuel cell, the flow rate s 1 of generated steam used for reforming, and the steam flow rate s 2 released for pressure control. Is input to the controller, and the sum of the reforming steam s 1 and the pressure-controlled release steam s 2 is defined as a steam flow measurement value s. These signals are input to the control device 27 of FIG. 1 and are subjected to arithmetic processing according to the block diagram shown in FIG.
Is output from the control device 27 as an opening degree command value signal for controlling the water level of the steam separator 2.

【００４２】発熱量は、燃料電池の発電電流と電圧から
下記式により計算される。The calorific value is calculated from the generated current and voltage of the fuel cell by the following equation.

【００４３】[0043]

【数１】発熱量＝発電電流×（１．２６×電池の積層セ
ル数−電池電圧）−放熱量 ここで、係数１．２６は燃料電池の温度から決まる理論
定数であり、放熱量は装置の特性から決まり、定数とし
て制御装置に入力される。Heat generation value = generation current × (1.26 × number of stacked cells of battery−battery voltage) −heat release amount Here, the coefficient 1.26 is a theoretical constant determined by the temperature of the fuel cell, and the heat release amount is determined by the device. And is input to the control device as a constant.

【００４４】発熱量から設定水位への変換は、図５に示
すとおり、発熱量が多い条件では水位を高く、少ない条
件では水位を低く設定され、発熱量演算値が最小から一
定範囲および最大に達する直前の一定範囲においては設
定水位が変化しない。これにより、急変化が避けられ
る。As shown in FIG. 5, the conversion from the calorific value to the set water level is set such that the water level is set high when the calorific value is large, and the water level is set low when the calorific value is small. The set water level does not change in a certain range immediately before reaching. This avoids sudden changes.

【００４５】発熱量から変換された水位と、蒸気流量計
測値は、ランプ関数によって変化速度に制限を設け、従
来の制御方式である図７の３点制御系に組み込むことが
できる。The water level converted from the calorific value and the measured steam flow rate can be limited in the rate of change by a ramp function, and can be incorporated in a three-point control system of FIG. 7 which is a conventional control method.

【００４６】このような構成において、水位の大きな変
動がある負荷遮断時の動作について説明する。燃料電池
本体１を含む燃料電池発電装置の外部負荷を遮断する
と、燃料電池本体１は自立最低負荷まで電流を下げ、原
燃料の改質に必要な蒸気量ｓ1を少なくする。制御部は
電池電流と電圧から発熱量を計算し、負荷が低くなると
水位は低くなる方向に設定される。The operation at the time of load shedding in which the water level greatly fluctuates in such a configuration will be described. When shutting off the external load of the fuel cell power plant comprising a fuel cell body 1, the fuel cell body 1 is lowered current to independence minimum load, to reduce the amount of steam s 1 required for the reforming of the raw fuel. The control unit calculates the calorific value from the battery current and the voltage, and the water level is set to be lower when the load is lower.

【００４７】ここで、燃料電池本体１は、系の熱容量に
よる遅れ分だけ負荷を下げても発熱量は急に下がらない
ので、改質用蒸気ｓ1 を少なくした割合だけ熱が余り水
蒸気分離器２の圧力が上昇する方向に働く。その後燃料
電池本体１からの冷却水中の蒸気量が少なくなリ水位が
低下する方向に働く。Since the calorific value of the fuel cell main body 1 does not drop abruptly even if the load is reduced by the delay due to the heat capacity of the system, the excess amount of heat is reduced by the rate of reducing the reforming steam s 1 . 2 works in the direction of increasing pressure. Thereafter, the amount of steam in the cooling water from the fuel cell main body 1 decreases, and the water level lowers.

【００４８】従来方式ならば、改質用蒸気量ｓ1 が少な
くなることと、負荷が低い時に水位を下げる設定にする
と、補給水量ｆ1 をより少なくする方向に制御が働く
が、補給量ｆ1 を少なくしすぎると、燃料電池本体１−
水蒸気分離器２間の蒸気量変化による水位低下との相乗
効果により水位が低くなりすぎる問題が発生する。そこ
で本発明では、設定水位にランプ関数を入れることによ
り、蒸気量変化による水位低下と設定水位を下げること
とを同調させ、補給水量の変化を少なくしている。In the conventional system, if the reforming steam amount s 1 is reduced and the water level is set to be lower when the load is low, the control works in the direction of reducing the make-up water amount f 1. If 1 is too small, the fuel cell body 1-
There is a problem that the water level becomes too low due to a synergistic effect with the water level drop due to the change in the amount of steam between the steam separators 2. Therefore, in the present invention, the fall of the water level due to the change in the steam amount and the reduction of the set water level are synchronized by inserting a ramp function into the set water level, thereby reducing the change in the makeup water amount.

【００４９】また、発生蒸気量が少なくなることによ
り、３点制御系によって、補給水量の制御設定値を下げ
る方向に働くが、発生蒸気量の変化にランプ関数を入れ
ることにより、補給水量をゆるやかに下げることができ
る。The three-point control system works to lower the control set value of the amount of makeup water by reducing the amount of steam generated. However, by adding a ramp function to the change in the amount of steam generated, the amount of makeup water is gradually reduced. Can be lowered.

【００５０】このように、本発明の水位制御装置および
方法では負荷遮断時の発生蒸気量低下と水蒸気分離器の
設定水位を下げる系において、補給水量はゆるやかに発
生蒸気量とバランスする点まで下げることができる。As described above, in the water level control apparatus and method according to the present invention, in the system for lowering the generated steam amount at the time of load interruption and lowering the set water level of the steam separator, the replenishment water amount is gradually lowered to a point that balances the generated steam amount. be able to.

【００５１】（実施例２）本実施例では、図２に示す装
置構成を用いて、図３に示す制御方法において、マイナ
ーループ系３０を図４に示した制御方法に置き換えて給
水量制御を行う例である。(Embodiment 2) In this embodiment, using the apparatus configuration shown in FIG. 2, in the control method shown in FIG. 3, the minor loop system 30 is replaced with the control method shown in FIG. Here is an example.

【００５２】図４に示すように、給水流量設定値ｆ0 ＝
ｆ＋ｓL を制御部２７へ送り、制御部２７の記憶装置内
に格納されている給水ポンプ特性テーブルから給水ポン
プ特性データを読み出し、給水流量設定ｆ0 ＝ｆ＋ｓL
に基づいてポンプ吐出圧力ｐ1 を計算する（ステップＳ
３１）。一方、図２の圧力計１１により計測された水蒸
気分離器圧力計測値ｐ2 を上述のポンプ吐出圧力ｐ1 と
ともに制御部の記憶装置に入力するとともに、バルブ前
後差圧を計算し、この計算値と制御部２７の記憶装置に
格納されている開度流量特性テーブルから開度流量特性
データを読み出し、バルブ開度指令値ｑを演算する（ス
テップＳ３２）。このバルブ開度指令値信号を給水バル
ブ１３（図２）に送りそのバルブ特性を変更し（ステッ
プＳ３３）、給水流量ｆ1 を得る。As shown in FIG. 4, the water supply flow rate set value f 0 =
f + s L feed to the control unit 27 reads a water supply pump characteristic data from the feedwater pump characteristic table stored in the storage device of the control unit 27, feed water flow setting f 0 = f + s L
Calculating the pump discharge pressure p 1 on the basis of (step S
31). On the other hand, the input to the storage device of the control unit together with the pump discharge pressure p 1 of the above-described water vapor separator pressure measurement values p 2 measured by the pressure gauge 11 in FIG. 2, to calculate the valve differential pressure, the calculated value Then, the opening flow characteristic data is read from the opening flow characteristic table stored in the storage device of the control unit 27, and the valve opening command value q is calculated (step S32). The valve opening command value signal the water supply valve 13 changes its valve characteristic feed in (FIG. 2) (step S33), obtaining a feed water flow f 1.

【００５３】給水量制御のマイナーループ系３０は、図
３に示す点線部分を図４に示す方式で水蒸気分離器の圧
力で補正したバルブ開度を直接出力する方式で行う。給
水量制御のマイナーループは水蒸気分難器の圧力変動な
どの外乱に対して流量を補償するために設けるが、本発
明の制御方式では給水流量は負荷変動時など水位制御系
に対する大きな外乱が発生する場合でも緩やかに給水量
を変化させるので図３に示す本発明の水位制御方式にお
いて、点線で示したマイナーループ系３０の部分を図４
の構成に置き換えて給水流量制御のマイナーループ系を
省略しても、安定した水蒸気分離器の水位制御が可能と
なる。The minor loop system 30 for controlling the water supply amount is configured to directly output the valve opening obtained by correcting the dotted line portion shown in FIG. 3 with the pressure of the steam separator by the method shown in FIG. The water supply flow control minor loop is provided to compensate the flow rate for disturbances such as pressure fluctuations of the water vapor disperser, but with the control method of the present invention, the water supply flow rate causes a large disturbance to the water level control system such as when the load changes. Therefore, in the water level control method of the present invention shown in FIG. 3, the portion of the minor loop system 30 shown by the dotted line in FIG.
Even if the minor loop system for feedwater flow rate control is omitted instead of the above configuration, stable water level control of the steam separator can be achieved.

【００５４】[0054]

【発明の効果】この発明によれば、水蒸気分離器の設定
水位を燃料電池の発電負荷によって変え、その変化にラ
ンプ関数を入れて、さらに、３点制御系の発生蒸気流量
の変化にランプ関数を入れるようにしたので、負荷変動
時に補給水量がゆるやかに発生蒸気流量とバランスする
ように変化する。従って、負荷を上げる時の水位の上が
りすぎや、負荷遮断時の水位の下がりすぎが無くなり、
安定した水位制御が可能となる。According to the present invention, the set water level of the steam separator is changed according to the power generation load of the fuel cell, a ramp function is added to the change, and a ramp function is added to the change of the generated steam flow rate of the three-point control system. , The amount of make-up water changes slowly so as to balance with the generated steam flow rate when the load changes. Therefore, when the load is raised, the water level does not rise too much, and when the load is cut off, the water level does not drop too much.
Stable water level control becomes possible.

【００５５】また、急激に給水量を変化させないこと
で、負荷上昇時の水蒸気分離器の圧力低下や負荷を下げ
る時に圧力上昇が少なくなり安定した圧力制御が行え
る。Further, since the water supply amount is not suddenly changed, the pressure drop of the steam separator at the time of load increase or the pressure increase at the time of load decrease is small, and stable pressure control can be performed.

【００５６】この給水流量の安定化によって、給水流量
の絶対流量は厳密に管理しなくてよいので、給水用流量
計を設置しなくて良い利点がある。By stabilizing the feed water flow, the absolute flow of the feed water does not need to be strictly controlled, so that there is an advantage that it is not necessary to provide a flow meter for the feed water.

【００５７】さらに、冷却水ポンプは、ポンプ入口圧力
が低いとキャビテーションを起こしやすいが水位が低く
なることによって入口圧力が低くなる負荷遮断の条件に
て、水蒸気分離器の温度より低い補給水を連続的に補給
でき、キャビテーションを起こしにくい状態にすること
ができる。Further, in the cooling water pump, when the pump inlet pressure is low, cavitation is apt to occur, but when the water level is lowered, the inlet pressure is lowered. Can be replenished and cavitation hardly occurs.

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

【図１】本発明の一実施例による水位制御装置および方
法を燃料電池発電装置に適用した場合を示す概略ブロッ
ク線図である。FIG. 1 is a schematic block diagram showing a case where a water level control device and method according to one embodiment of the present invention are applied to a fuel cell power generator.

【図２】本発明の一実施例による水位制御装置および方
法を燃料電池発電装置に適用した場合を説明する模式的
構成図である。FIG. 2 is a schematic configuration diagram illustrating a case where the water level control device and method according to one embodiment of the present invention are applied to a fuel cell power generation device.

【図３】本発明の一実施例による水位制御方法を説明す
るブロック線図である。FIG. 3 is a block diagram illustrating a water level control method according to an embodiment of the present invention.

【図４】本発明の一実施例による水位制御方法において
水蒸気分離器の圧力で補正したバルブ開度を直接出力す
る方式を説明するブロック線図である。FIG. 4 is a block diagram illustrating a method of directly outputting a valve opening corrected by the pressure of a steam separator in a water level control method according to an embodiment of the present invention.

【図５】本発明の一実施例による水位制御方法における
発熱量演算値と設定水位との関係を示すグラフである。FIG. 5 is a graph showing a relationship between a calorific value calculation value and a set water level in a water level control method according to one embodiment of the present invention.

【図６】従来の水位制御装置および方法を燃料電池発電
装置に適用した場合を説明する模式的構成図である。FIG. 6 is a schematic configuration diagram illustrating a case where a conventional water level control device and method are applied to a fuel cell power generation device.

【図７】従来の水位制御方法を説明するブロック線図で
ある。FIG. 7 is a block diagram illustrating a conventional water level control method.

【図８】３点制御を行った従来の制御系（図７）におけ
る水位変動と圧力変動を示すグラフであるFIG. 8 is a graph showing water level fluctuation and pressure fluctuation in a conventional control system (FIG. 7) that performed three-point control.

【符号の説明】[Explanation of symbols]

１ 燃料電池本体 ２ 水蒸気分離器 ３ 冷却水循環管路 ４ ポンプ ５ 給水ポンプ ６ 給水管路 ７ 圧力制御バルブ ８ 流量計 ９ 圧力制御バルブ １０ 流量計 １１ 圧力計 １２ 水位計 １３ 給水バルブ ２０ 冷却水循環系 ２１ 燃料電池本体 ２２ 水蒸気分離器 ２３ 冷却水循環ポンプ ２４ 水蒸気取り出し系 ２５ 給水系 ２６ 計測部 ２７ 制御部 ２８ 変化遅延装置（手段） ３０ マイナーループ系 ｆ，ｆ′ 循環水流量 ｆ0 ，ｆ0 ′ 給水流量設定値 ｆ1 ，ｆ1 ′ 流量計測値 ｆ2 ，ｆ2 ′ 流量 ｈ，ｈ′ 水位 ｈ0 ，ｈ0 ′ 設定水位 Δｈ，Δｈ′ 水位偏差 ｐ1 吐出圧力 ｐ2 水蒸気分離器圧力計測値 ｑ バルブ開度指令値 ｓ 蒸気流量計測値 ｓ1 改質用蒸気流量 ｓ2 圧力制御用蒸気流量 ｓ3 蒸気流量（プロセス値）DESCRIPTION OF SYMBOLS 1 Fuel cell main body 2 Steam separator 3 Cooling water circulation line 4 Pump 5 Water supply pump 6 Water supply line 7 Pressure control valve 8 Flow meter 9 Pressure control valve 10 Flow meter 11 Pressure gauge 12 Water level gauge 13 Water supply valve 20 Cooling water circulation system 21 the fuel cell body 22 the steam separator 23 cooling water circulation pump 24 steam extraction system 25 feed water system 26 measuring unit 27 control unit 28 changes the delay unit (means) 30 minor loop system f, f 'circulating water flow rate f 0, f 0' feed water flow Set value f 1 , f 1 ′ Measured flow rate f 2 , f 2 ′ Flow rate h, h ′ Water level h 0 , h 0 ′ Set water level Δh, Δh ′ Water level deviation p 1 discharge pressure p 2 Steam separator pressure measured value q Valve opening command value s Steam flow measurement value s 1 Reforming steam flow s 2 Pressure control steam flow s 3 Steam flow (process value)

Claims (10)

【特許請求の範囲】[Claims] 【請求項１】 燃料電池本体と水蒸気分離器と冷却水循
環ポンプとを組み合わせてなる、燃料電池冷却水循環系
と発生蒸気の取り出し系で、燃料電池の発熱量に応じて
水蒸気分離器の制御設定水位を決める水蒸気分離器の水
位制御において、制御設定水位の変化を遅延させる変化
遅延手段を設けたことを特徴とする水蒸気分離器の水位
制御装置。1. A fuel cell cooling water circulation system and a system for taking out generated steam, comprising a combination of a fuel cell main body, a steam separator and a cooling water circulation pump, wherein a control set water level of the steam separator according to the calorific value of the fuel cell. A water level control device for a steam separator, wherein a change delay means for delaying a change in a control set water level is provided in the water level control of the steam separator for determining the water level. 【請求項２】 前記変化遅延手段は、前記制御設定水位
の変化に時間関数の変化率を設けた値を水位調節器の制
御設定水位として前記制御設定水位の変化を遅延させる
ことを特徴とする請求項１記載の水蒸気分離器の水位制
御装置。2. The method according to claim 1, wherein the change delay unit delays the change in the control set water level as a control set water level of a water level adjuster using a value provided with a time function change rate for the change in the control set water level. The water level control device for a steam separator according to claim 1. 【請求項３】 前記変化遅延手段は、前記制御設定水位
と実測水位との偏差から水蒸気分離器へ供給する給水量
を演算し、これに水蒸気分離器から発生する蒸気量を加
え給水流量設定値として、水蒸気分離器への給水量で水
位を制御することを特徴とする請求項２記載の水蒸気分
離器の水位制御装置。3. The change delay means calculates a water supply amount to be supplied to a steam separator from a deviation between the control set water level and an actually measured water level, and adds a steam amount generated from the steam separator to the water supply amount setting value. 3. The water level control device for a steam separator according to claim 2, wherein the water level is controlled by an amount of water supplied to the steam separator. 【請求項４】 前記変化遅延手段は、前記制御設定水位
と実測水位との偏差から水蒸気分離器へ供給する給水量
を演算し、これに水蒸気分離器から発生する蒸気量の時
間関数の制限を設けた発生蒸気量補正値を加え給水流量
設定値として、水蒸気分離器への給水量で水位を制御す
ることを特徴とする請求項２記載の水蒸気分離器の水位
制御装置。4. The change delay means calculates a water supply amount to be supplied to a steam separator from a deviation between the control set water level and an actually measured water level, and further restricts a time function of a steam amount generated from the steam separator. The water level control device for a steam separator according to claim 2, wherein the water level is controlled by the amount of water supplied to the steam separator as a set value of the feed water flow rate by adding the generated steam amount correction value. 【請求項５】 前記給水流量設定値と前記水蒸気分離器
の圧力から、給水流量制御バルブの開度を直接設定して
水位を制御することを特徴とする請求項１〜４のいずれ
かに記載の水蒸気分離器の水位制御装置。5. The water level is controlled by directly setting an opening of a feedwater flow control valve from the feedwater flow rate set value and the pressure of the steam separator. Water level control device for steam separator. 【請求項６】 燃料電池本体と水蒸気分離器と冷却水循
環ポンプとを組み合わせてなる、燃料電池冷却水循環系
と発生蒸気の取り出し系で、燃料電池の発熱量に応じて
水蒸気分離器の制御設定水位を決める水蒸気分離器の水
位制御において、制御設定水位の変化を遅延させること
を特徴とする水蒸気分離器の水位制御方法。6. A fuel cell cooling water circulating system and a system for taking out generated steam, comprising a fuel cell body, a steam separator and a cooling water circulating pump, wherein a control set water level of the steam separator according to a calorific value of the fuel cell. A method for controlling the water level of a steam separator, comprising delaying a change in a control set water level in controlling the water level of the steam separator. 【請求項７】 前記制御設定水位の変化に時間関数の変
化率を設けた値を水位調節器の制御設定水位とすること
を特徴とする請求項６記載の水蒸気分離器の水位制御方
法。7. The water level control method for a steam separator according to claim 6, wherein a value obtained by providing a change rate of a time function to the change of the control set water level is set as a control set water level of a water level controller. 【請求項８】 前記制御設定水位と実測水位との偏差か
ら水蒸気分離器へ供給する給水量を演算し、これに水蒸
気分離器から発生する蒸気量を加え給水流量設定値とし
て、水蒸気分離器への給水量で水位を制御することを特
徴とする請求項７記載の水蒸気分離器の水位制御方法。8. A water supply amount to be supplied to a steam separator is calculated from a deviation between the control set water level and an actually measured water level, and the amount of steam generated from the steam separator is added to the calculated water supply amount to provide a water supply flow rate set value to the steam separator. The method for controlling the water level of the steam separator according to claim 7, wherein the water level is controlled by the amount of supplied water. 【請求項９】 前記制御設定水位と実測水位との偏差か
ら水蒸気分離器へ供給する給水量を演算し、これに水蒸
気分離器から発生する蒸気量の時間関数の制限を設けた
発生蒸気量補正値を加え給水流量設定値として、水蒸気
分離器への給水量で水位を制御することを特徴とする請
求項７記載の水蒸気分離器の水位制御方法。9. A generated steam amount correction wherein a water supply amount to be supplied to a steam separator is calculated from a deviation between the control set water level and an actually measured water level, and a time function of steam generated from the steam separator is limited. The water level control method for a steam separator according to claim 7, wherein the water level is controlled by a water supply amount to the steam separator as a feedwater flow rate set value by adding the value. 【請求項１０】 前記給水流量設定値と前記水蒸気分離
器の圧力から、給水流量制御バルブの開度を直接設定し
て水位を制御することを特徴とする請求項６〜９のいず
れかに記載の水蒸気分離器の水位制御方法。10. The water level is controlled by directly setting an opening of a feedwater flow control valve based on the feedwater flow rate set value and the pressure of the steam separator. Water level control method of the steam separator.
JP9176944A 1997-07-02 1997-07-02 Device and method for controlling water level in steam separator Pending JPH1122912A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP9176944A JPH1122912A (en) 1997-07-02 1997-07-02 Device and method for controlling water level in steam separator

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP9176944A JPH1122912A (en) 1997-07-02 1997-07-02 Device and method for controlling water level in steam separator

Publications (1)

Publication Number Publication Date
JPH1122912A true JPH1122912A (en) 1999-01-26

Family

ID=16022475

Family Applications (1)

Application Number Title Priority Date Filing Date
JP9176944A Pending JPH1122912A (en) 1997-07-02 1997-07-02 Device and method for controlling water level in steam separator

Country Status (1)

Country Link
JP (1) JPH1122912A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012047439A (en) * 2010-07-27 2012-03-08 Fuji Electric Co Ltd Heat pump steam generator

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2012047439A (en) * 2010-07-27 2012-03-08 Fuji Electric Co Ltd Heat pump steam generator

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