JPH0330044B2 - - Google Patents
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- Publication number
- JPH0330044B2 JPH0330044B2 JP56028697A JP2869781A JPH0330044B2 JP H0330044 B2 JPH0330044 B2 JP H0330044B2 JP 56028697 A JP56028697 A JP 56028697A JP 2869781 A JP2869781 A JP 2869781A JP H0330044 B2 JPH0330044 B2 JP H0330044B2
- Authority
- JP
- Japan
- Prior art keywords
- combustion gas
- steam temperature
- heat flow
- flow rate
- output
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 239000000567 combustion gas Substances 0.000 claims description 62
- 238000006243 chemical reaction Methods 0.000 claims description 14
- 239000000498 cooling water Substances 0.000 claims description 13
- 239000007789 gas Substances 0.000 claims description 10
- 238000001514 detection method Methods 0.000 claims description 9
- 238000010586 diagram Methods 0.000 description 9
- 238000000034 method Methods 0.000 description 4
- 239000000446 fuel Substances 0.000 description 3
- 230000001934 delay Effects 0.000 description 2
- 239000002131 composite material Substances 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000009499 grossing Methods 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 230000008646 thermal stress Effects 0.000 description 1
Description
【発明の詳細な説明】
本発明は、ボイラ過熱器出口蒸気温度を減温器
（過熱低減器）を制御する蒸気温度制御装置に関
する。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a steam temperature control device that controls a boiler superheater outlet steam temperature using a desuperheater.
一般に蒸気温度制御は、過熱器出口蒸気温度を
検出してその目標値と比較して偏差を算出し、そ
の偏差が零になるように温度調節計の出力で減温
器の冷却水量を操作し、フイードバツク制御する
方式が用いられている。 Generally, steam temperature control involves detecting the steam temperature at the outlet of the superheater, calculating the deviation by comparing it with a target value, and controlling the amount of cooling water in the desuperheater using the output of the temperature controller so that the deviation becomes zero. , a feedback control method is used.
しかし、蒸気過熱プロセスの動特性にはむだ時
間を含み大きな遅れがあり、フイードバツク制御
方式だけでは負荷変動時などに、所要の制御性を
達成することができない。 However, the dynamic characteristics of the steam superheating process include dead time and large delays, and the feedback control method alone cannot achieve the required controllability during load fluctuations.
このため、従来
○イ 蒸気流量
○ロ 減温器出口蒸気温度
○ハ 燃料流量と蒸気流量の差
○ニ 空気流量
○ホ 再循環ガスダンパ開度
などの信号を、減温器冷却水量を操作するフイー
ドフオワード制御信号として使用する蒸気温度制
御装置が用いられ、それなりに一応の目的を達成
して来た。 For this reason, conventionally ○A Steam flow rate ○B Steam temperature at the desuperheater outlet ○C Difference between fuel flow rate and steam flow rate ○D Air flow rate ○E Recirculation gas damper opening degree, etc. Steam temperature control devices used as an eid-forward control signal have been used to some extent to some extent.
しかし、近年電力需要の昼夜間格差の増大等に
より、大容量火力発電プラントでも急激に負荷出
力を変えることが必要となつて来た。ところが、
急激に負荷出力を変えると、蒸気温度に大きな変
動をもたらす。他方、高圧・高温ボイラでは過熱
器の材質やタービンの熱応力、さらにプラントの
熱効率の面などから、蒸気温度の変動許容範囲は
厳しく制限されている。 However, in recent years, due to an increase in the day-night difference in power demand, it has become necessary to rapidly change the load output even in large-capacity thermal power plants. However,
Rapid changes in load output cause large fluctuations in steam temperature. On the other hand, in high-pressure/high-temperature boilers, the allowable range of steam temperature fluctuations is severely limited due to factors such as the material of the superheater, the thermal stress of the turbine, and the thermal efficiency of the plant.
したがつて、蒸気温度の変動が火力発電プラン
トを急激な負荷変動に対応させる上での一つの障
害となつており、より制御性の良い蒸気温度制御
装置の出現が望まれている。 Therefore, fluctuations in steam temperature are an obstacle to making a thermal power plant respond to rapid load fluctuations, and there is a desire for a steam temperature control device with better controllability.
この観点から、タービンへ送出される蒸気温度
の変動を考察すると、蒸気温度の変動は蒸気流量
あるいは負荷量の変動と共に、加熱器を通過する
燃焼ガス熱流量の変動と最も高い相関関係がある
ことが分かつた。 From this point of view, considering the fluctuations in the temperature of the steam delivered to the turbine, it can be seen that the fluctuations in the steam temperature have the highest correlation with the fluctuations in the heat flow of the combustion gas passing through the heater, as well as the fluctuations in the steam flow rate or load amount. I understand.
したがつて、減温器の冷却水量を操作するフイ
ードフオワード制御信号としては、蒸気流量（負
荷量）と共に、燃焼ガス熱流量を用いるのが適切
である。 Therefore, it is appropriate to use the combustion gas heat flow rate as well as the steam flow rate (load amount) as a feedforward control signal for controlling the amount of cooling water in the desuperheater.
しかるに、従来、蒸気流量はフイードフオワー
ド制御信号として用いられているが、燃焼ガス熱
流量に関しては、空気流量または再循環ガスダン
パ開度が各々単独でフイードフオワード制御信号
として使用されている場合に、間接的にある程度
考慮されているのにすぎなかつた。 However, conventionally, the steam flow rate has been used as a feedforward control signal, but with regard to the combustion gas heat flow rate, the air flow rate or the recirculation gas damper opening degree has been used independently as a feedforward control signal. In some cases, it has only been indirectly considered to some extent.
本発明は、ボイラ内を流動する燃焼ガス熱流量
に相当する信号を、減温器に対するフイードフオ
ワード制御信号として使用し、負荷変更時の蒸気
温度の変動をより小さくし、急激な負荷変更にも
対応できる蒸気温度制御装置を得ることを目的と
している。 The present invention uses a signal corresponding to the heat flow rate of the combustion gas flowing inside the boiler as a feedforward control signal for the attemperator, thereby making fluctuations in steam temperature smaller when the load changes, and reducing the sudden load change. The aim is to obtain a steam temperature control device that can be used in
火力発電プラント用ボイラでは、タービンへ送
る蒸気の最終過熱は接触型過熱器で行なわれてい
る場合が多い。この場合、蒸気への伝熱量を左右
する最も大きな要因は燃焼ガス熱流量であり、こ
の変動が蒸気温度に対する外乱となる。このた
め、蒸気温度制御の観点からは、燃焼ガス熱流量
をできるだけ一定に保つことが望ましい。 In boilers for thermal power plants, final superheating of steam sent to the turbine is often performed using a contact superheater. In this case, the largest factor influencing the amount of heat transferred to the steam is the heat flow rate of the combustion gas, and this variation becomes a disturbance to the steam temperature. Therefore, from the viewpoint of steam temperature control, it is desirable to keep the combustion gas heat flow as constant as possible.
しかし、負荷変更時には燃料流量したがつて空
気流量が変り、また再熱ボイラでは再熱蒸気温度
の制御のために再循環ガスダンパが操作されて再
循環ガス流量が変り、これらにより燃焼ガス熱流
量が変動し、ボイラ出口主蒸気温度を変動させる
ことになる。 However, when the load changes, the fuel flow rate and therefore the air flow rate change, and in the reheat boiler, the recirculation gas damper is operated to control the reheat steam temperature and the recirculation gas flow rate changes, and the heat flow rate of the combustion gas changes. This will cause the boiler outlet main steam temperature to fluctuate.
このため、この変動を打消すように減温器冷却
水量を操作することが必要となる。この操作制御
方式として、空気流量か燃料流量あるいは再循環
ガスダンパ操作量を、各々単独で減温器冷却水量
を操作するフイードフオワード制御信号として用
いても、ある程度の効果を出すことができるが、
燃焼ガス熱流量に相当する信号をフイードフオワ
ード制御信号として用いた方が、蒸気温度の変動
をより適切に補償できる。 Therefore, it is necessary to manipulate the amount of cooling water in the desuperheater so as to cancel out this fluctuation. As this operation control method, it is possible to achieve some effect by using the air flow rate, fuel flow rate, or recirculation gas damper operation amount as a feedforward control signal that independently controls the desuperheater cooling water amount. ,
Fluctuations in steam temperature can be compensated for more appropriately by using a signal corresponding to the combustion gas heat flow rate as the feedforward control signal.
では、本発明を第１図ａ，ｂに示す概念的特性
ブロツク図で説明する。 The present invention will now be explained with reference to conceptual characteristic block diagrams shown in FIGS. 1a and 1b.
第１図ａは、過熱器入口蒸気温度がフイードバ
ツク制御されていない場合のブロツク図である。 FIG. 1a is a block diagram when the superheater inlet steam temperature is not feedback controlled.
第１図において、１は蒸気温度制御装置、３は
温度フイードバツク調節計で２はその入力で４は
その出力、５は加算器、６は燃焼ガス熱流量（変
化分）ΔFG、７は動特性変換要素（以下単に特
性変換要素という）GF（Ｓ）で８はその出力、９
は加算器５の出力である冷却水操作量（変化分）
ΔFW、１０は伝達特性要素GA（Ｓ）であり１１
はその出力、１２は加算器、１３は伝達特性要素
GB（Ｓ）であり１４はその出力、１５は加算器１
２の出力であり蒸気温度（変化分）ΔT、１００
は減温器と過熱器の合成をそれぞれ示す。 In Fig. 1, 1 is a steam temperature control device, 3 is a temperature feedback controller, 2 is its input, 4 is its output, 5 is an adder, 6 is the combustion gas heat flow rate (variation) ΔFG, and 7 is the dynamic characteristic. In the conversion element (hereinafter simply referred to as characteristic conversion element) G F (S), 8 is its output, 9
is the cooling water operation amount (change amount) which is the output of adder 5
ΔFW, 10 is the transfer characteristic element G A (S) and 11
is its output, 12 is the adder, and 13 is the transfer characteristic element.
G B (S), 14 is its output, 15 is adder 1
2 output and steam temperature (change) ΔT, 100
show the composite of desuperheater and superheater, respectively.
さて、燃焼ガス熱流量変化分（ΔFG）６の過
熱器出口蒸気温度変化分（ΔT）１５への伝達特
性をラプラス関数（Ｓはラプラス演算子）表現で
GB（Ｓ）とする。他方、減温器冷却水操作量変化
分（ΔFW）９の過熱器出口蒸気温度変化分
（ΔT）１５への伝達特性をGA（Ｓ）とする。この
とき、過熱器出口蒸気温度変化分（ΔT）は（１
式）で表わされる。 Now, the transfer characteristic of combustion gas heat flow rate change (ΔFG) 6 to superheater outlet steam temperature change (ΔT) 15 can be expressed as a Laplace function (S is Laplace operator).
Let it be G B (S). On the other hand, the transfer characteristic of the change in the operating amount of the desuperheater cooling water (ΔFW) 9 to the change in the steam temperature at the superheater outlet (ΔT) 15 is defined as G A (S). At this time, the superheater outlet steam temperature change (ΔT) is (1
Expression).
ΔT＝GA（Ｓ）・ΔFW＋GB（Ｓ）・ΔFG
……（１式）
したがつて、燃焼ガス熱流量が変化したとき、
減温器冷却水操作量を（２式）に従つて変化させ
れば、
ΔFW＝GB（Ｓ）／GA（Ｓ）・ΔFG……（２式）
ΔT＝０すなわち、燃焼ガス熱流量が変化しても
過熱器出口蒸気温度を一定に保つことができる。 ΔT=G A (S)・ΔFW+G B (S)・ΔFG
...(Equation 1) Therefore, when the combustion gas heat flow changes,
If the desuperheater cooling water operation amount is changed according to (2 formula), ΔFW=G B (S)/G A (S)・ΔFG...(2 formula) ΔT=0, that is, combustion gas heat flow rate Even if the temperature changes, the superheater outlet steam temperature can be kept constant.
（２式）の特性で冷却水操作量を変化させるた
めには、燃焼ガス熱流量を検出あるいは算出し
て、その変化分６に対して（２式）の特性の特性
変換要素〔GF（Ｓ）〕７で特性変換して、
GF（Ｓ）＝−GB（Ｓ）／GA（Ｓ）……（３式
）
その出力８を温度フイードバツク調節計３の操
作出力４に加算する機構５を持つた蒸気温度制御
装置１を用いればよい。 In order to change the cooling water operation amount according to the characteristics of (Equation 2), the combustion gas heat flow rate is detected or calculated, and the characteristic conversion factor of the characteristics of (Equation 2) [G F ( S )] Convert the characteristics in 7 and add the output 8 to the operation output 4 of the temperature feedback controller 3. A steam temperature control device 1 having a mechanism 5 may be used.
第１図ｂは、減温器出口蒸気温度が、あるいは
減温器と最終過熱器との間に複数個の種類の異な
る過熱器が設置されその出口蒸気温度が、温度フ
イードバツク従調節計で制御されている場合のブ
ロツク図である。 Figure 1b shows that the steam temperature at the outlet of the attemperator, or the outlet steam temperature of multiple different types of superheaters installed between the attemperator and the final superheater, is controlled by a temperature feedback slave controller. FIG.
１６は特性変換要素で１７はその出力、１８は
最終過熱入口蒸気温度目標値（変化分）ΔTS、１
９は減算器、２０は最終過熱器入口蒸気温度（変
化分）ΔT1、２１は減算器１９の出力、２２は温
度フイードバツク従調節計、２３は減温器に前段
過熱器群が加わつたもの、２４は伝達特性要素
G′A（Ｓ）をおのおの示す。 16 is a characteristic conversion element, 17 is its output, 18 is final superheated inlet steam temperature target value (change amount) ΔTS , 1
9 is a subtracter, 20 is the final superheater inlet steam temperature (variation) ΔT 1 , 21 is the output of the subtractor 19, 22 is a temperature feedback slave controller, 23 is a desuperheater plus a pre-superheater group , 24 is the transfer characteristic element
G′ A (S) is shown respectively.
このとき、温度フイードバツク従調節計２２の
目標値変化分ΔTS１８から最終過熱器入口蒸気温
度変化分（ΔT1）２０への伝達特性をGT（Ｓ）と
すれば、最終過熱器出口蒸気温度変化分（ΔT）
１５は、（４式）で表わされる。 At this time, if the transfer characteristic from the target value change ΔT S 18 of the temperature feedback slave controller 22 to the final superheater inlet steam temperature change (ΔT 1 ) 20 is G T (S), then the final superheater outlet steam Temperature change (ΔT)
15 is expressed by (Equation 4).
ΔT＝G′A（Ｓ）・GT（Ｓ）・ΔTS
＋GB（Ｓ）・ΔFG ……（４式）
したがつて、燃焼ガス熱流量が変化したとき、
温度フイードバツク従調節計２２の目標値したが
つて温度フイードバツク主調節計３の出力
（ΔTS）を、（５式）にしたがつて変化されれば
ΔTS＝−GB（Ｓ）／G′A（Ｓ）・GT（Ｓ）・ΔFG
……（５式）
ΔT＝０すなわち、燃焼ガス熱流量が変化しても
最終過熱器出口蒸気温度を一定に保つことができ
る
（５式）の特性で温度フイードバツク従調節計
２２の目標値を変化させるためには、燃焼ガス熱
流量を検出あるいは算出し、その変化分に対して
（６式）の特性の特性変換要素〔G′F（Ｓ）〕１６で
特性変換して
G′F（Ｓ）＝−GB（Ｓ）／G′A（Ｓ）・GT（Ｓ）…
…（６式）
温度フイードバツク主調節計３の出力に加算す
る機構を持つた蒸気温度制御装置１を用いればよ
い。ΔT=G′ A (S)・G T (S)・ΔT S +G B (S)・ΔFG……(Formula 4) Therefore, when the combustion gas heat flow rate changes,
If the target value of the temperature feedback slave controller 22 and the output (ΔT S ) of the temperature feedback master controller 3 are changed according to equation (5), then ΔT S = -G B (S)/G' A (S)・G T (S)・ΔFG ...(Formula 5) ΔT=0 In other words, even if the combustion gas heat flow rate changes, the final superheater outlet steam temperature can be kept constant. In order to change the target value of the temperature feedback slave controller 22 based on the characteristic, the combustion gas heat flow rate is detected or calculated, and the characteristic conversion factor [G' F (S )] Convert the characteristics in 16 and get G′ F (S)=−G B (S)/G′ A (S)・G T (S)…
(Formula 6) A steam temperature control device 1 having a mechanism for adding to the output of the temperature feedback main controller 3 may be used.
では、本発明の実施例を図面を用いて説明す
る。 Embodiments of the present invention will now be described with reference to the drawings.
第２図ａは、本発明の一実施例の概念構成を示
すブロツク図である。 FIG. 2a is a block diagram showing the conceptual configuration of an embodiment of the present invention.
第２図ａにおいて、５１は蒸気温度設定器で５
２はその出力、５３は減算器、５４は蒸気温度検
出器１０５の出力、５５は蒸気流量などのフイー
ドフオワード制御用信号、５０は従来の蒸気温度
制御装置、７０は過熱器１０３へ加わる燃焼ガス
熱流、８０は検出端群８１へ至る燃焼ガス熱流、
８２は燃焼ガス熱流量算出用信号群、８３は燃焼
ガス熱流量入力・算出要素で８４はその出力、８
５は燃焼ガス熱流量基準値発生要素で８６はその
出力、８７は減算器、９０は蒸気流量、１０１は
減温器で１０２はその出力であり１０９はその入
力の冷却水操作信号、１０４は蒸気温度である。 In Figure 2a, 51 is a steam temperature setting device.
2 is its output, 53 is a subtracter, 54 is the output of the steam temperature detector 105, 55 is a feed forward control signal such as steam flow rate, 50 is a conventional steam temperature control device, and 70 is applied to the superheater 103. A combustion gas heat flow 80 is a combustion gas heat flow leading to the detection end group 81.
82 is a group of signals for calculating combustion gas heat flow; 83 is a combustion gas heat flow input/calculation element; 84 is its output;
5 is a combustion gas heat flow reference value generating element, 86 is its output, 87 is a subtracter, 90 is a steam flow rate, 101 is a desuperheater, 102 is its output, 109 is its input cooling water operation signal, 104 is a Steam temperature.
すなわち、蒸気温度設定器５１と減算器５３と
温度フイードバツク調節計３と蒸気流量などによ
るフイードフオワード制御機構を備えた破線で囲
つた従来の蒸気温度制御装置５０に、燃焼ガス熱
流量入力・算出要素８３と減算要素８７と特性変
換要素７と、従来の蒸気温度制御装置の出力ライ
ンに設けられた加算要素５とから、本発明の蒸気
温度制御装置は構成される。なお、特性変換要素
７は燃焼ガス熱流量の変動による主蒸気温度の乱
を打消すタイミングを合わせるために、入力した
偏差信号を進ませたりあるいは遅らせたりするい
わゆる動特性変換要素である。 That is, a conventional steam temperature control device 50 surrounded by a broken line, which is equipped with a steam temperature setter 51, a subtractor 53, a temperature feedback controller 3, and a feedforward control mechanism based on steam flow rate, etc., is connected to a combustion gas heat flow input/output. The steam temperature control device of the present invention is composed of the calculation element 83, the subtraction element 87, the characteristic conversion element 7, and the addition element 5 provided in the output line of the conventional steam temperature control device. Note that the characteristic conversion element 7 is a so-called dynamic characteristic conversion element that advances or delays the input deviation signal in order to adjust the timing of canceling out disturbances in the main steam temperature due to fluctuations in the heat flow rate of the combustion gas.
燃焼ガス熱流量入力・算出要素８３はボイラで
検出された信号を受けて、燃焼ガス熱流量相当信
号８４を発信する。この信号値８４から燃焼ガス
熱流量基準値発生要素８５で発信された基準値８
６を減算要素８７で減算し、基準化された燃焼ガ
ス熱流量相当信号６を発信する。 The combustion gas heat flow input/calculation element 83 receives the signal detected by the boiler and transmits a combustion gas heat flow equivalent signal 84. A reference value 8 is generated from this signal value 84 by a combustion gas heat flow reference value generation element 85.
6 is subtracted by a subtraction element 87, and a signal 6 corresponding to the standardized combustion gas heat flow rate is generated.
この信号６を伝達特性GF（Ｓ）の特性変換要素
７で特性変換し、この出力信号８を加算要素５で
従来の蒸気温度制御装置の操作出力４に加算す
る。この操作量の補正信号による減温器冷却水量
の変化が、燃焼ガス熱流量の変動により過熱器１
０３が生じさせようとする過熱器出口蒸気温度の
変動を打消すように作用する。 This signal 6 is characteristic-converted by a characteristic conversion element 7 of the transfer characteristic G F (S), and this output signal 8 is added to the operation output 4 of the conventional steam temperature control device by an addition element 5. The change in the amount of cooling water in the desuperheater due to the correction signal of this manipulated variable is caused by the fluctuation in the heat flow rate of the combustion gas.
03 acts to cancel out the fluctuations in the superheater outlet steam temperature that would otherwise occur.
第２図ｂは、本発明の他の実施例のブロツク図
であつて、減温器出口蒸気温度あるいは減温器と
最終過熱器の間に別の過熱器が介在し、最終過熱
器入口蒸気温度がフイードバツクされ、温度フイ
ードバツク従調節計で制御されている場合の実施
例の概念構成とその作用を示すものである。 FIG. 2b is a block diagram of another embodiment of the present invention, in which another superheater is interposed between the attemperator outlet steam temperature or the attemperator and the final superheater, and the final superheater inlet steam temperature is This figure shows the conceptual structure and operation of an embodiment in which the temperature is fed back and controlled by a temperature feedback slave controller.
６４は最終過熱器出口蒸気温度検出器１１５か
らの検出値、１１１は最終過熱入口蒸気温度検出
器、１１２は減温器２３の出力、１１４は最終過
熱器１１３の最終過熱器出口蒸気温度である。 64 is the detected value from the final superheater outlet steam temperature detector 115, 111 is the final superheater inlet steam temperature detector, 112 is the output of the desuperheater 23, and 114 is the final superheater outlet steam temperature of the final superheater 113. .
すなわち、破線で囲んだ従来の蒸気温度制御装
置６０は、蒸気温度設定器５１と、この出力信号
５２から最終過熱器出口蒸気温度検出値６４を引
き偏差信号２を算出する減算器５３と、この偏差
信号２を入力しこの偏差が零になるようにPID
（比例・積分・微分）などの制御演算を行ない出
力４を発信する温度フイードバツク主調節計３
と、この出力を減温器出口蒸気温度の目標値もし
くは最終過熱器入口蒸気温度の目標値１８とし
て、この値１８から減温器出口蒸気温度検出値も
しくは最終過熱器入口蒸気温度検出値２０を引き
偏差信号２１を発信する減算器１９と、この偏差
信号２１を入力として偏差が零になるようにPID
などの制御演算を行ない操作信号１０９を発信す
る温度フイードバツク従調節計２２と、蒸気流量
などによるフイードフオワード制御機構とから構
成されている。この従来の蒸気温度制御装置６０
と、燃焼ガス熱流量入力・算出要素８３と、燃焼
ガス熱流量基準値発生要素８５と、減算要素８７
と、特性変換要素１６と、温度フイードバツク主
調節計３の出力部に設けられた加算要素５とか
ら、本発明の蒸気温度制御装置１は構成されてい
る。 That is, the conventional steam temperature control device 60 surrounded by a broken line includes a steam temperature setter 51, a subtracter 53 that calculates a deviation signal 2 by subtracting the final superheater outlet steam temperature detection value 64 from this output signal 52, and this Input the deviation signal 2 and set the PID so that this deviation becomes zero.
Temperature feedback main controller 3 that performs control calculations such as (proportional, integral, differential) and sends output 4
Then, this output is set as the target value 18 of the desuperheater outlet steam temperature or the final superheater inlet steam temperature, and the desuperheater outlet steam temperature detection value or the final superheater inlet steam temperature detection value 20 is calculated from this value 18. A subtracter 19 that transmits a pull deviation signal 21, and a PID that uses this deviation signal 21 as input so that the deviation becomes zero.
It is composed of a temperature feedback slave controller 22 which performs control calculations such as the following and transmits an operation signal 109, and a feedback control mechanism based on steam flow rate and the like. This conventional steam temperature control device 60
, a combustion gas heat flow input/calculation element 83 , a combustion gas heat flow reference value generation element 85 , and a subtraction element 87
The steam temperature control device 1 of the present invention is constituted by the characteristic conversion element 16 and the addition element 5 provided at the output section of the temperature feedback main controller 3.
燃焼ガス熱流量入力・算出要素８３はボイラで
検出された信号８２を受けて、燃焼ガス熱流量相
当信号８４を発信する。この信号値８４から燃焼
ガス熱流量基準値発生要素８５で発信された基準
値８６を減算要素８７で減算し、基準化された燃
焼ガス熱流量相当信号６を発信する。 The combustion gas heat flow input/calculation element 83 receives the signal 82 detected in the boiler and transmits a combustion gas heat flow equivalent signal 84 . A subtraction element 87 subtracts a reference value 86 transmitted by a combustion gas heat flow reference value generation element 85 from this signal value 84, and a standardized combustion gas heat flow equivalent signal 6 is transmitted.
この信号６を伝達特性G′F（Ｓ）の特性変換要素
１６で特性変換し、この出力信号１７を加算要素
５で従来の蒸気温度制御装置６０の温度フイード
バツク主調節計３の出力４したがつて従来の減温
器出口蒸気温度の目標値もしくは最終過熱器入口
蒸気温度の目標値に加算する。この目標値１８の
補正信号２０による減温器出口蒸気温度もしくは
最終過熱器入口蒸気温度の変化が、燃焼ガス熱流
量の変動により最終過熱器１１３が生じさせよう
とする最終過熱器出口蒸気温度１１４の変動を打
消すように作用する。 The characteristics of this signal 6 are converted by the characteristic conversion element 16 of the transfer characteristic G' F (S), and this output signal 17 is converted to the output 4 of the temperature feedback main controller 3 of the conventional steam temperature control device 60 by the addition element 5. Then, it is added to the conventional target value of the steam temperature at the outlet of the desuperheater or the target value of the steam temperature at the final superheater inlet. The change in the desuperheater outlet steam temperature or the final superheater inlet steam temperature due to the correction signal 20 of this target value 18 corresponds to the final superheater outlet steam temperature 114 that the final superheater 113 attempts to generate due to the fluctuation in the combustion gas heat flow rate. acts to cancel out the fluctuations in
第２図ａ，ｂに示した燃焼ガス熱流量入力・算
出要素８３は、プラントで燃焼ガス熱流量が直接
検出できる場合、あるいは燃焼ガス温度の変動が
小さく燃焼ガス流量信号を燃焼ガス熱流量相当信
号と見做せる場合には、単なる信号入力要素であ
る。 The combustion gas heat flow input/calculation element 83 shown in FIGS. 2a and 2b is used when the combustion gas heat flow can be directly detected in the plant, or when the fluctuating combustion gas temperature is small and the combustion gas flow rate signal is equivalent to the combustion gas heat flow. If it can be regarded as a signal, it is simply a signal input element.
燃焼ガス流量とガス温度を検出して燃焼ガス熱
流量を算出する場合には、両者の積を求める乗算
要素を燃焼ガス熱流量入力・算出要素８３内に設
ける。 When calculating the combustion gas heat flow rate by detecting the combustion gas flow rate and gas temperature, a multiplication element for calculating the product of both is provided in the combustion gas heat flow input/calculation element 83.
また、燃焼ガス流量を空気流量と再循環ガス流
量の和として求める場合には、加算要素を燃焼ガ
ス熱流量入力・算出要素の中に備える。 Furthermore, when determining the combustion gas flow rate as the sum of the air flow rate and the recirculation gas flow rate, an addition element is provided in the combustion gas heat flow input/calculation element.
あるいはまた、再循環ガス流量を再循環ガスダ
ンパ操作量から求める場合には、その変換演算要
素を燃焼ガス熱流量入力・算出要素８３の中に設
ける。なお、入力信号にノイズが含まれている場
合には、平滑化するフイルタをこの要素８３の中
に備える。 Alternatively, when the recirculation gas flow rate is determined from the recirculation gas damper operation amount, a conversion calculation element for this is provided in the combustion gas heat flow input/calculation element 83. Note that if the input signal contains noise, a smoothing filter is provided in this element 83.
しかして、燃焼ガス熱流量基準値発生要素８５
の発信する基準値８６は、従来の蒸気温度制御装
置の出力バイアスの状況や、フイードフオワード
制御機構や、温度フイードバツク調節計の積分動
作の有無に左右される。 Therefore, the combustion gas heat flow reference value generation element 85
The reference value 86 transmitted by the steam temperature controller depends on the status of the output bias of the conventional steam temperature control device, the presence or absence of the feedback control mechanism, and the integral operation of the temperature feedback controller.
ある実施例では、冷却水量が50％（標準状態）
のもとで、あるいは蒸気流量もしくは負荷量に対
応した冷却水量のもとで、過熱器出口蒸気温度が
所定の値になる蒸気流量あるいは負荷量に対応し
た燃焼ガス流量を燃焼ガス流量の基準値としてい
る。 In some embodiments, the cooling water volume is 50% (standard condition)
The combustion gas flow rate corresponding to the steam flow rate or load amount at which the superheater outlet steam temperature becomes a predetermined value under the cooling water amount corresponding to the steam flow rate or load amount is the reference value of the combustion gas flow rate. It is said that
さらに、別の実施例では定格運転時あるいは最
低部分負荷運転時の燃焼ガス熱流設計値を用いて
いる。 Furthermore, other embodiments use combustion gas heat flow design values during rated operation or minimum partial load operation.
また、基準値が零でよい場合には、この燃焼ガ
ス熱流量基準値発生要素８５および減算要素８７
は不要である。 In addition, when the reference value may be zero, this combustion gas heat flow reference value generation element 85 and subtraction element 87
is not necessary.
ところで、特性変換要素７および１６の伝達特
性GF（Ｓ）およびG′F（Ｓ）は、各々（３式）およ
び（６式）で定義された特性である。なお、この
特性が物理的に実現不可能な場合や、高次微分特
性となり現実の物理的な系では実現しがたい場合
には、（３式）または（６式）の実現可能な近似
特性を用いる。この場合には、燃焼ガス熱流量の
変動による蒸気温度変動を完全には補償できない
が、この未補償の変動はかなり抑制されており、
温度フイードバツク調節計の制御機能に委ねても
問題はない。 By the way, the transfer characteristics G F (S) and G' F (S) of the characteristic conversion elements 7 and 16 are characteristics defined by (Equation 3) and (Equation 6), respectively. In addition, if this characteristic is physically impossible to realize, or if it becomes a high-order differential characteristic and is difficult to realize in an actual physical system, the approximate characteristic that can be realized by (Equation 3) or (Equation 6) is Use. In this case, although it is not possible to completely compensate for the steam temperature fluctuations due to fluctuations in the combustion gas heat flow rate, this uncompensated fluctuation is considerably suppressed.
There is no problem in leaving it to the control function of the temperature feedback controller.
第３図に、従来の蒸気温度制御装置を使用した
場合と、本発明の蒸気温度制御装置を使用した場
合の、負荷変更時の制御応答の特性図の一例を示
す。 FIG. 3 shows an example of a characteristic diagram of a control response upon load change when using a conventional steam temperature control device and when using the steam temperature control device of the present invention.
第３図において、ａは蒸気流量応答、ｂは燃焼
ガス流量応答、ｃは従来の蒸気温度制御装置を使
用した場合の蒸気温度応答、ｄは本発明の蒸気温
度制御装置を使用した場合の蒸気温度応答であ
る。つまり、本発明の蒸気温度制御装置を使用す
ることにより、負荷変化時の蒸気温度変動を大幅
に抑制できる。 In FIG. 3, a is the steam flow rate response, b is the combustion gas flow rate response, c is the steam temperature response when the conventional steam temperature control device is used, and d is the steam temperature response when the steam temperature control device of the present invention is used. It is a temperature response. In other words, by using the steam temperature control device of the present invention, steam temperature fluctuations during load changes can be significantly suppressed.
この結果、過熱器やタービンの寿命を延ばし、
熱効率の低下を防止でき、かつ電力需要の変化に
よる更に急激な負荷変更にも対応できるようにな
る。 As a result, the lifespan of superheaters and turbines is extended,
It is possible to prevent a decrease in thermal efficiency and also to cope with sudden load changes due to changes in power demand.
第１図ａは本発明の蒸気温度制御装置を用い過
熱器入口蒸気温度をフイードバツク制御しない場
合の蒸気温度系の概念的特性ブロツク図、第１図
ｂはその過熱器入口蒸気温度をフイードバツク制
御する場合の蒸気温度系の概念的特性ブロツク
図、第２図ａは本発明の一実施例の構成を表わし
過熱器入口蒸気温度をフイードバツク制御しない
場合のブロツク図、第２図ｂは本発明の他の実施
例の構成を示し過熱器入口蒸気温度をフイードバ
ツク制御する場合のブロツク図、第３図は本発明
の蒸気温度制御装置の制御応答特性図である。
１……蒸気温度制御装置、３……温度フイード
バツク調節計、５，１２……加算器、７……特性
変換要素、１０，１３……伝達特性要素、１９，
５３，８７……減算器、２２……温度フイードバ
ツク従調節計。
Figure 1a is a conceptual characteristic block diagram of the steam temperature system when the steam temperature control device of the present invention is used and the superheater inlet steam temperature is not feedback controlled, and Figure 1b is the superheater inlet steam temperature that is feedback controlled. Fig. 2a shows the configuration of one embodiment of the present invention, and Fig. 2b shows a block diagram of the case where the superheater inlet steam temperature is not feedback controlled. FIG. 3 is a block diagram showing the configuration of an embodiment of the present invention in which the superheater inlet steam temperature is feedback-controlled, and FIG. 3 is a control response characteristic diagram of the steam temperature control device of the present invention. 1... Steam temperature control device, 3... Temperature feedback controller, 5, 12... Adder, 7... Characteristic conversion element, 10, 13... Transfer characteristic element, 19,
53, 87...Subtractor, 22...Temperature feedback slave controller.
Claims (1)
検出信号を蒸気温度目標値と比較して偏差を求
め、この偏差が零になるように温度フイードバツ
ク調節計の出力で減温器の冷却水量を操作し、ボ
イラ過熱器の蒸気温度をフイードバツク制御する
蒸気温度制御装置において、ボイラ過熱器に加わ
る燃焼ガス熱流量を得るための検出手段と、この
検出手段の出力から燃焼ガス熱流量入力を算出す
る燃焼ガス熱流量入力算出要素と、燃焼ガス熱流
量基準値発生要素と、この基準値発生要素の出力
と前記燃焼ガス熱流量入力算出要素の出力との偏
差信号を入力し、燃焼ガス熱流量の変動による蒸
気温度の変動を打消すタイミングでフイードホワ
ード制御用の操作量修正信号を出力する動特性変
換要素と、この動特性変換要素の出力を前記温度
フイードバツク調節計の操作出力に加算する加算
要素とを備えたことを特徴とする蒸気温度制御装
置。 ２ 特許請求の範囲第１項に記載のものにおい
て、温度フイードバツク調節計は、主調節計と副
調節計とから構成され、この主調節計の後段に前
記加算器を配置したことを特徴とする蒸気温度制
御装置。 ３ 特許請求の範囲第１項あるいは第２項に記載
のものにおいて、燃焼ガス熱流量を燃焼ガス流量
とガス温度とから求めることを特徴とする蒸気温
度制御装置。[Claims] 1. Detect the steam temperature at the outlet of the boiler superheater, compare this detection signal with the steam temperature target value to determine the deviation, and reduce the temperature using the output of the temperature feedback controller so that this deviation becomes zero. A steam temperature control device that operates the amount of cooling water in a heater and feedback-controls the steam temperature of a boiler superheater includes a detection means for obtaining the heat flow rate of combustion gas applied to the boiler superheater, and a detection means for obtaining the heat flow rate of combustion gas applied to the boiler superheater, and a detection means for detecting the combustion gas from the output of this detection means. A combustion gas heat flow input calculation element that calculates the heat flow input, a combustion gas heat flow reference value generation element, and a deviation signal between the output of this reference value generation element and the output of the combustion gas heat flow input calculation element are input. , a dynamic characteristic conversion element that outputs a manipulated variable correction signal for feedforward control at a timing to cancel fluctuations in steam temperature due to fluctuations in combustion gas heat flow rate; and an output of this dynamic characteristic conversion element to be used as the operational output of the temperature feedback controller. A steam temperature control device comprising: an addition element that adds to the temperature of the steam. 2. The temperature feedback controller according to claim 1 is composed of a main controller and a sub-controller, and the adder is arranged after the main controller. Steam temperature control device. 3. A steam temperature control device according to claim 1 or 2, characterized in that the combustion gas heat flow rate is determined from the combustion gas flow rate and the gas temperature.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56028697A JPS57142405A (en) | 1981-02-28 | 1981-02-28 | Steam temperature controller |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP56028697A JPS57142405A (en) | 1981-02-28 | 1981-02-28 | Steam temperature controller |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS57142405A JPS57142405A (en) | 1982-09-03 |
| JPH0330044B2 true JPH0330044B2 (en) | 1991-04-26 |
Family
ID=12255660
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP56028697A Granted JPS57142405A (en) | 1981-02-28 | 1981-02-28 | Steam temperature controller |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS57142405A (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2521670B2 (en) * | 1986-09-05 | 1996-08-07 | 株式会社東芝 | Boiler steam temperature controller |
| JP2001132927A (en) * | 1999-08-26 | 2001-05-18 | Mitsui Eng & Shipbuild Co Ltd | Method and device for controlling temperature of heat exchanger |
| JP6461525B2 (en) * | 2014-09-11 | 2019-01-30 | 株式会社東芝 | Steam temperature control device, steam temperature control method, and power generation system |
| JP6813289B2 (en) * | 2016-06-23 | 2021-01-13 | 株式会社東芝 | Steam temperature controller, steam temperature control method, and power generation system |
Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5447006A (en) * | 1977-09-20 | 1979-04-13 | Kawasaki Heavy Ind Ltd | Controlling of steam temperature of boiler |
| JPS54148902A (en) * | 1978-05-15 | 1979-11-21 | Hitachi Ltd | Temperature control device for miscible burning type boiler |
| JPS55160201A (en) * | 1979-05-30 | 1980-12-13 | Ishikawajima Harima Heavy Ind | Steam temperature controller for boiler |
-
1981
- 1981-02-28 JP JP56028697A patent/JPS57142405A/en active Granted
Patent Citations (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5447006A (en) * | 1977-09-20 | 1979-04-13 | Kawasaki Heavy Ind Ltd | Controlling of steam temperature of boiler |
| JPS54148902A (en) * | 1978-05-15 | 1979-11-21 | Hitachi Ltd | Temperature control device for miscible burning type boiler |
| JPS55160201A (en) * | 1979-05-30 | 1980-12-13 | Ishikawajima Harima Heavy Ind | Steam temperature controller for boiler |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS57142405A (en) | 1982-09-03 |
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