JPH0646083B2 - Boiler boost controller - Google Patents
Boiler boost controllerInfo
- Publication number
- JPH0646083B2 JPH0646083B2 JP59205499A JP20549984A JPH0646083B2 JP H0646083 B2 JPH0646083 B2 JP H0646083B2 JP 59205499 A JP59205499 A JP 59205499A JP 20549984 A JP20549984 A JP 20549984A JP H0646083 B2 JPH0646083 B2 JP H0646083B2
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- pressure
- stress
- boiler
- steam
- main steam
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Description
【発明の詳細な説明】 〔発明の利用分野〕 本発明はボイラ昇圧制御装置に係り、特に過熱器の出口
ヘツダのコーナ部に発生する熱応力を減少させて寿命消
費量を低減するボイラ昇圧制御装置に関するものであ
る。Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a boiler boost control device, and more particularly to a boiler boost control that reduces thermal stress generated at a corner of an outlet header of a superheater to reduce life consumption. It relates to the device.
近年急増する電力需要に応えるための大容量の火力発電
所が建設されているが、これらのボイラは部分負荷時に
おいても高い発電効率を得るために、超臨界圧から亜臨
界圧へ変圧運転を行なうことが要求されている。Large-capacity thermal power plants have been constructed to meet the rapidly increasing demand for electric power in recent years.However, these boilers must be transformed from supercritical pressure to subcritical pressure in order to obtain high power generation efficiency even under partial load. You are required to do it.
これは最近の電力需要の特徴として、原子力発電の伸び
と共に、負荷の最大と最小の差も増大し、火力発電はベ
ースロード用から負荷調整用へと移行する傾向にあるか
らである。This is because, as a feature of recent electric power demand, the difference between the maximum and minimum loads increases along with the growth of nuclear power generation, and thermal power generation tends to shift from base load use to load adjustment use.
つまり、火力発電は、ボイラ負荷が常に全負荷で運転さ
れるものは少なく、負荷を８０％負荷、５０％負荷、２
５％負荷へと負荷を上げ、下げして運転したり、運転を
停止するなど、いわゆる高頻度起動停止（Daily Start
Stop以下単にＤＳＳという）運転を行なって中間負荷を
担うのである。In other words, in thermal power generation, few boiler loads are always operated at full load, and 80% load, 50% load, 2
The so-called high-frequency start / stop (Daily Start), such as increasing or decreasing the load to 5% to start or stop the operation.
It carries out an intermediate load by performing an operation (hereinafter simply referred to as DSS) from Stop.
このように火力発電は部分負荷での運転が増えた場合、
負荷に応じて圧力を変化させて運転する、いわゆる全負
荷では超臨界圧域、部分負荷では亜臨界圧域で運転する
ＤＳＳ運転を行なうことによって、部分負荷での発電効
率を数％向上させることができる。In this way, in thermal power generation, when the operation at partial load increases,
Improve the power generation efficiency in partial load by performing DSS operation in which pressure is changed according to load, that is, so-called full-load supercritical pressure region and partial load subcritical pressure region. You can
第２図は変圧運転強制貫流ボイラの概略系統図である。FIG. 2 is a schematic system diagram of a variable pressure operation once-through boiler.
給水ポンプ１で昇圧された給水は給水管路２で給水加熱
器３で加熱された後、節炭器４に入り、予熱されて火炉
水冷壁５，６で熱吸収し、天井壁７、ケージ壁８で再び
熱吸収されて蒸発し、気水分離器９に流入する。The water supply pressurized by the water supply pump 1 is heated by the water supply heater 3 in the water supply pipe 2, then enters the economizer 4, is preheated and is absorbed by the water cooling walls 5 and 6 of the furnace, the ceiling wall 7 and the cage. The wall 8 absorbs heat again, evaporates, and flows into the steam separator 9.
気水分離器９で分離された給水は循環管路１０の再循環
ポンプ１１で昇圧され、再循環流量調整弁１２により火
炉水冷壁５，６を冷却するために必要な流量に調整さ
れ、給水管路２の給水と合流する。The feed water separated by the steam separator 9 is boosted by the recirculation pump 11 of the circulation line 10, adjusted by the recirculation flow rate adjusting valve 12 to a flow rate necessary for cooling the furnace water cooling walls 5, 6, and the feed water is supplied. It joins with the water supply in pipeline 2.
一方、気水分離器９のレベルは気水分離器水位制御弁１
３により調整され、気水分離器９で分離された蒸気は一
次過熱器バイパス管路１４、一次過熱器バイパス弁１５
を経てフラツシユタンク１６に導かれる。On the other hand, the level of the steam separator 9 is the water separator water level control valve 1
The steam which is adjusted by 3 and separated by the steam separator 9 is connected to the primary superheater bypass pipe line 14 and the primary superheater bypass valve 15.
After that, it is guided to the flash tank 16.
この導かれた流体はフラツシユタンク１６で気水分離さ
れ、液状流体はフラツシユタンクドレン弁１７を有する
液体戻し管路１８より復水器１９の液側に供給され、蒸
気状流体はフラツシユタンク蒸気ダンプ弁２０を有する
蒸気戻し管路２１より復水器１９の蒸気側に供給されそ
れぞれ回収される。The guided fluid is separated into steam and water in the flash tank 16, the liquid fluid is supplied to the liquid side of the condenser 19 from the liquid return pipe 18 having the flash tank drain valve 17, and the vaporous fluid is flashed. It is supplied to the steam side of the condenser 19 from the steam return pipe line 21 having the tank steam dump valve 20, and collected respectively.
この復水器１９で回収された復水は給水となって復水管
路２２より復水ポンプ２３で圧送されて脱気器２４に導
かれて、ここで脱気されその後再び給水管路２に導かれ
る。The condensate recovered by the condenser 19 becomes feed water, which is pumped from the condensate conduit 22 by the condensate pump 23 and guided to the deaerator 24, where it is deaerated and then again supplied to the water supply conduit 2. Be guided.
他方、ケージ壁８の蒸気温度及び蒸気圧力が上昇するに
つれて発生蒸気の一部は蒸気供給管路２５を経て一次過
熱器２６に供給され、ここでさらに過熱された蒸気は二
次過熱器バイパス管路２７、二次過熱器バイパス弁２９
を経てフラツシユタンク１６へ導かれる。On the other hand, as the steam temperature and the steam pressure of the cage wall 8 increase, a part of the generated steam is supplied to the primary superheater 26 via the steam supply pipeline 25, and the steam further superheated therein is the secondary superheater bypass pipe. Passage 27, secondary superheater bypass valve 29
After that, it is led to the flash tank 16.
また一次過熱器２６で加熱された蒸気は過熱器減圧弁２
９を経て二次過熱器３０で過熱され主蒸気管路３１へ供
給される。Further, the steam heated by the primary superheater 26 is used as the superheater pressure reducing valve 2
After being heated by 9 and superheated in the secondary superheater 30, it is supplied to the main steam line 31.
この様に主蒸気管路３１が暖まるまでは絞り弁３２が閉
じられて蒸気はタービンバイパス管路３３、タービンバ
イパス弁３４を経てフラツシユタンク１６へ導かれる。As described above, the throttle valve 32 is closed until the main steam pipe 31 is warmed, and the steam is guided to the flash tank 16 through the turbine bypass pipe 33 and the turbine bypass valve 34.
その後に主蒸気管路３１が暖まると絞り弁３２をやや開
いてタービンバイパス弁３４を閉じて高圧タービン３５
へ蒸気を供給しタービン暖機運転に入る。After that, when the main steam line 31 becomes warm, the throttle valve 32 is slightly opened and the turbine bypass valve 34 is closed to close the high pressure turbine 35.
Supply steam to the turbine to start warming up.
高圧タービン３５を出た蒸気は再熱器３６によって加熱
され、低圧タービン３７を経て排気管路３８より復水器
１９に導かれる。３９は脱気器加熱蒸気弁、４０はバー
ナ、４１は燃料調節弁である。The steam leaving the high-pressure turbine 35 is heated by the reheater 36, and is led to the condenser 19 from the exhaust pipe 38 through the low-pressure turbine 37. Reference numeral 39 is a deaerator heating steam valve, 40 is a burner, and 41 is a fuel control valve.
一方、二次過熱器３０の出口には第３図に示す様な出口
ヘツダ４２が取付けられ、ノズルコーナ部４３を有す
る。On the other hand, an outlet header 42 as shown in FIG. 3 is attached to the outlet of the secondary superheater 30 and has a nozzle corner portion 43.
ところが、火力発電用ボイラの中間負荷運用化に伴ない
ＤＳＳ運転を行なうと、ボイラ耐圧部の厚肉管（二次過
熱器３０の出口ヘツダ４２のノズルコーナ部４３）に発
生する応力、およびこの応力に伴なう寿命消費が問題と
なる。However, when the DSS operation is performed along with the operation of the intermediate load of the boiler for thermal power generation, the stress generated in the thick-walled pipe (the nozzle corner portion 43 of the outlet header 42 of the secondary superheater 30) of the pressure resistant portion of the boiler, and this stress Lifetime consumption associated with is a problem.
特に、高温で高圧の蒸気にさらされる最終過熱器３０の
出口ヘツダ４２のノズルコーナ部４３に発生する応力、
寿命消費はボイラプラントが要求される運用期間を信頼
性高く運用できるか否かの重要な評価基準になってい
る。In particular, the stress generated in the nozzle corner portion 43 of the outlet header 42 of the final superheater 30, which is exposed to high temperature and high pressure steam,
Lifespan consumption is an important evaluation criterion for reliable operation of boiler plants during the required operation period.
最終過熱器３０の出口ヘツダ４２で消費される寿命の大
部分はクリープ損傷によるものである。以下このクリー
プ損傷評価法を第４図を用いて簡単に説明する。Most of the life consumed at the outlet header 42 of the final superheater 30 is due to creep damage. The creep damage evaluation method will be briefly described below with reference to FIG.
第４図は横軸に時間、縦軸に応力に示したボイラ起動時
の発生応力模式図である。FIG. 4 is a schematic diagram of generated stress at the time of starting the boiler, in which the horizontal axis represents time and the vertical axis represents stress.
ボイラをコールドスタートで運転して停止したり、ある
いはウオームスタートで運転して停止したりの様に、運
転、停止を繰り返すと第３図の出口ヘツダ４２の中で最
も発生応力の大きいノズルコーナ部４３の応力は第４図
に示す様に変化する。それは、ボイラ点火後、出口ヘツ
ダ４２の流体温度上昇とともに第４図のＡ点からＢ点で
は圧縮応力が発生し、定常運転に移行するに従って第４
図のＢ点からＣ点では引張応力が発生する。この現象
は、Ａ点からＢ点間では熱応力、Ｂ点からＤ点間では熱
応力に対して内圧応力が優勢になっていることを表わし
ている。When the boiler is operated by cold start and stopped, or is operated by warm start and then stopped, the nozzle corner portion 43 having the largest stress in the outlet header 42 of the outlet header 42 of FIG. Stress changes as shown in FIG. After the boiler is ignited, a compressive stress is generated at points A to B in FIG.
Tensile stress occurs at points B to C in the figure. This phenomenon indicates that the thermal stress is dominant between the points A and B and the internal pressure stress is dominant over the thermal stress between the points B and D.
ここで、蒸気温度が出口ヘツダ４２の材質により決まる
クリープ温度領域を越える所で、応力を保持していると
クリープ損傷による寿命を消費することになる。Here, if the steam temperature exceeds the creep temperature region determined by the material of the outlet header 42, if stress is retained, the life due to creep damage is consumed.
第５図は縦軸に第４図の応力を示し、横軸にひずみを示
した応力、ひずみ特性曲線図で、第５図中のＡ，Ｂ，
Ｃ，Ｄ点は第４図のＡ，Ｂ，Ｃ，Ｄ点と同一のものを示
す。FIG. 5 is a stress-strain curve diagram in which the vertical axis represents the stress of FIG. 4 and the horizontal axis represents the strain, and A, B, and S in FIG.
Points C and D are the same as points A, B, C and D in FIG.
クリープ損傷は、第４図、第５図の初期応力σ とクリ
ープ保持時間により決まるが、第４図、第５図の初期応
力σ は、下式(1)で得られる。Creep damage is caused by the initial stress σ in Figs. 4 and 5. And chestnut
Although it depends on the loop holding time, the initial response in Figs. 4 and 5
Force σ Is obtained by the following equation (1).
ここに、σｐτ：定格運転時相当応力 στ：圧縮時最大相当応力 （マイナスは圧縮応力、プラスは引張応力） Ｅ，Ｆ：材質、温度により決る定数 Ｙ1：降状応力 初期応力σ を抑えて、クリープ損傷を小さくしようと
すれば(1)式のうち圧縮最大相当応力στ（第４図、第
５図のＢ点）の絶対値を抑えることが必要になる。すな
わち、前記(1)式で、定格運転時相当応力σｐτは設計
条件により一定であり、降状応力Ｙ1、材質、温度によ
る決る定数（F/E−１）は、材質、温度により決まるの
で直接制御することはできないからである。 Where σpτ: Equivalent stress during rated operation στ: Maximum equivalent stress during compression (minus is compressive stress, plus is tensile stress) E, F: Constant determined by material and temperature Y1: Yield stress Initial stress σ To reduce creep damage
Then, the maximum equivalent compression stress σ in Eq. (1)τ(Fig. 4, Fig.
It is necessary to suppress the absolute value of point B in Fig. 5). sand
That is, the stress equivalent to the rated operation σpτIs design
The yield stress Y is constant depending on the conditions.1, Material, temperature
The constant (F / E-1) is determined by the material and temperature.
This is because it cannot be controlled directly with.
第６図はボイラの連続運転時間（保持時間）を一定とし
たときの圧縮最大相当応力δξと寿命消費率φの特性曲
線図で、目盛は両対数表示である。FIG. 6 is a characteristic curve diagram of the maximum compressive equivalent stress δ ξ and the life consumption rate φ when the continuous operation time (holding time) of the boiler is constant, and the scale is a logarithmic display.
この第６図からクリープ損傷は圧縮最大相当応力δξに
依存している。From FIG. 6, the creep damage depends on the maximum compression equivalent stress δ ξ .
第７図は縦軸に蒸気圧力、蒸気温度を示し、横軸に時間
を示した起動時の蒸気圧力、蒸気温度の時間変化を示す
特性曲線図、第８図は縦軸に応力、横軸に時間を示し、
第７図の流体条件における過熱器３０における出口ヘツ
ダ４２のノズルコーナ部４３に発生する熱応力、内圧応
力の変化を示す特性曲線図である。Fig. 7 is a characteristic curve showing steam pressure and steam temperature on the vertical axis, and steam pressure at start-up with time on the horizontal axis, and steam temperature at startup, and Fig. 8 is stress on the vertical axis, horizontal axis Indicates the time
9 is a characteristic curve diagram showing changes in thermal stress and internal pressure stress generated in the nozzle corner portion 43 of the outlet header 42 in the superheater 30 under the fluid condition of FIG. 7. FIG.
なお、第７図において曲線Ｇは蒸気温度、曲線Ｈは蒸気
圧力、第８図において、曲線Ｉは内圧応力、曲線Ｊは熱
応力を示し、Ｔ1〜Ｔ5は時間を示す。Curve G in FIG. 7 indicates steam temperature, curve H indicates steam pressure, curve I in FIG. 8 indicates internal pressure stress, curve J indicates thermal stress, and T 1 to T 5 indicate time.
従来のボイラ起動時におけるタービン通気（第７図、第
８図のＴ2）後、ボイラが再循環運転されている間（第
７図、第８図のＴ3）の昇圧制御は主蒸気圧力一定の目
標設定を行ない第２図に示すタービンバイパス弁３４を
閉じるか、あるいは燃料調節弁４１を開いて第７図の曲
線Ｈ上に示すＫ，Ｌ，Ｍ，Ｎ点の様に主蒸気圧力を上げ
て制御していた。After the conventional turbine ventilation (T 2 in FIGS. 7 and 8) at boiler startup, the boost control is performed while the boiler is in recirculation operation (T 3 in FIGS. 7 and 8). A certain target is set and the turbine bypass valve 34 shown in FIG. 2 is closed, or the fuel control valve 41 is opened and the main steam pressure is changed to points K, L, M and N shown on the curve H in FIG. Was raised and controlled.
従って、変圧ベンソンボイラの最終過熱器３０の出口ヘ
ツダ４２に発生する応力を実運転データより解析すると
通気時Ｔ2から低負荷時（循環運転時）Ｔ3間においては
第８図の曲線Ｊで示す如く最大の圧縮相当応力δξが発
生している。Therefore, when the stress generated in the outlet header 42 of the final superheater 30 of the transformer Benson boiler is analyzed from the actual operation data, the curve J of FIG. 8 is obtained between the ventilation time T 2 and the low load time (circulation operation) T 3 . As shown, the maximum compressive equivalent stress δ ξ is generated.
この様にＴ2からＴ3においては第８図の曲線Ｊでは圧縮
応力がピークになり、曲線Ｉでは引張応力が一定であ
り、圧縮最大相当応力δξを低下させてクリープ損傷に
よる寿命消費を低減することはできない。Thus, from T 2 to T 3 , the compressive stress peaks in the curve J of FIG. 8 and the tensile stress is constant in the curve I, and the maximum compressive equivalent stress δ ξ is reduced to reduce the life consumption due to creep damage. It cannot be reduced.
本発明はかかる従来の欠点を解消しようとするもので、
その目的とするところは、ボイラ起動時に過熱器の出口
ヘツダに発生する熱応力を減少して発生応力、寿命消費
を低減し、ボイラにおける信頼性の向上を計ることがで
きるボイラ昇圧制御装置を得ようとするものである。The present invention is intended to eliminate such conventional drawbacks,
The purpose is to reduce the thermal stress generated at the outlet header of the superheater at the time of boiler startup to reduce the generated stress and life consumption, and to obtain a boiler boost control device that can improve reliability in the boiler. It is something to try.
本発明は前述の目的を達成するために、 ボイラ起動時にボイラ耐圧部の蒸気接触部に圧縮応力が
発生することを予測する圧縮応力予測手段と、 その圧縮応力予測手段での圧縮応力の予測に基づいて、
前記ボイラ耐圧部の蒸気接触部に発生する圧縮応力を減
少するように引張応力を発生させるために主蒸気圧を設
定する主蒸気圧設定手段と、 主蒸気圧を検出する主蒸気圧検出手段とを備え、 前記主蒸気圧設定手段によつて設定された主蒸気圧設定
値と、前記主蒸気圧検出手段によつて検出された主蒸気
圧検出値との偏差によつて、ボイラ耐圧部の内圧を高め
る手段を制御することを特徴とするものである。In order to achieve the above-mentioned object, the present invention provides a compressive stress predicting means for predicting that a compressive stress is generated in a steam contact part of a boiler pressure resistant part at the time of starting a boiler, and a compressive stress predicting means by the compressive stress predicting means. On the basis of,
Main steam pressure setting means for setting a main steam pressure to generate a tensile stress so as to reduce the compressive stress generated in the steam contact portion of the boiler pressure resistant portion, and a main steam pressure detecting means for detecting the main steam pressure. The main steam pressure setting value set by the main steam pressure setting means, and the deviation between the main steam pressure detection value detected by the main steam pressure detecting means, the boiler pressure resistant portion of the It is characterized by controlling a means for increasing the internal pressure.
以下本発明の実施例を図面を用いて説明する。 Embodiments of the present invention will be described below with reference to the drawings.
第１図は本発明の実施例に係るボイラの昇圧制御装置の
概略系統図である。FIG. 1 is a schematic system diagram of a booster control device for a boiler according to an embodiment of the present invention.
第１図において蒸気温度検出器４４により蒸気温度実測
値４５、蒸気圧力検出器４６により蒸気圧力実測値４
７、蒸気流量検出器４８により蒸気流量実測値４９を検
出する。検出した実測値４５，４７，４９をもとに、統
計モデルにより区間（第７図、第８図のＴ2〜Ｔ3間）内
の時刻における流体条件を予測する。すなわち、蒸気温
度予測器５０において蒸気温度予測値５１、蒸気圧力予
測器５２において蒸気圧力予測値５３、蒸気流量予測器
５４において蒸気流量予測値５５が得られる。これら予
測値５１，５３，５５の流体条件から流体から熱伝達率
演算器５６においてメタルへの熱伝達率演算値５７を求
める。これをもとに、非定常熱伝導方程式を解いて管寄
板厚方向温度分布を求める。In FIG. 1, the steam temperature actually measured value 45 by the steam temperature detector 44 and the steam pressure actually measured value 4 by the steam pressure detector 46
7. The actual steam flow rate value 49 is detected by the steam flow rate detector 48. Based on the detected measured values 45, 47, 49, the fluid condition at the time within the section (between T 2 and T 3 in FIGS. 7 and 8) is predicted by a statistical model. That is, the steam temperature predictor 50 obtains the steam temperature predictive value 51, the steam pressure predictor 52 obtains the steam pressure predictive value 53, and the steam flow predictor 54 obtains the steam flow predictive value 55. From the fluid conditions of these predicted values 51, 53 and 55, the heat transfer coefficient calculator 56 from the fluid to the metal calculates the heat transfer coefficient calculation value 57 to the metal. Based on this, the unsteady heat conduction equation is solved to obtain the temperature distribution in the pipe plate thickness direction.
例えば円筒の熱伝達方程式(2)および境界条件(3),(4)を
解くことにより求める。For example, it is obtained by solving the heat transfer equation (2) and boundary conditions (3) and (4) of a cylinder.
α：メタル温度伝導度Ｔ：メタル温度 ｔ：時間γ：円筒中心からの距離 Ｔf：流体温度Ｔo：メタル内面温度 この方程式(2),(3),(4)を解いて求められた熱伝達率演
算値５７を基に温度分布演算器５８によって温度分布演
算値５９を求める。 alpha: metal temperature Conductivity T: metal temperature t: time gamma: distance from the cylindrical center T f: fluid temperature T o: Metal inner surface temperature This equation (2), (3), obtained by solving (4) Based on the calculated heat transfer coefficient 57, the temperature distribution calculator 58 calculates the temperature distribution calculated value 59.
この温度分布演算値５９より、熱応力演算器６０におい
て熱応力演算値６１を求める。つぎに、熱応力演算値６
１を基に熱応力ポーク時刻予測器６２において、区間内
で最大の圧縮熱応力が発生する時刻を予測する。From the temperature distribution calculation value 59, a thermal stress calculation value 61 is obtained in the thermal stress calculator 60. Next, thermal stress calculation value 6
Based on 1, the thermal stress poke time predictor 62 predicts the time at which the maximum compressive thermal stress occurs in the section.
この様に蒸気温度予測器５０、蒸気圧力予測器５２、蒸
気流量予測器５４、熱伝達率演算器５６、温度分布演算
器５８、熱応力演算器６０および熱応力ピーク時刻予測
器６２によって熱応力ピーク予測器６３が構成されてい
る。In this way, the steam temperature predictor 50, the steam pressure predictor 52, the steam flow rate predictor 54, the heat transfer coefficient calculator 56, the temperature distribution calculator 58, the thermal stress calculator 60, and the thermal stress peak time predictor 62 are used for the thermal stress. The peak predictor 63 is configured.
この熱応力ピーク予測器６３からの熱応力ピーク予測値
６４に基いて主蒸気圧力設定器６５において、その区間
（第７図、第８図のＴ1〜Ｔ5）での昇圧が、熱応力ピー
ク発生時刻に一致するよう、主蒸気圧力設定を行なう。Based on the thermal stress peak predicted value 64 from the thermal stress peak predictor 63, in the main steam pressure setter 65, the pressure increase in that section (T 1 to T 5 in FIGS. 7 and 8) is the thermal stress. Set the main steam pressure so that it coincides with the peak occurrence time.
この主蒸気圧力設定器６５で設定した主蒸気圧力設定値
６６と、蒸気圧力検出器４６で検出された蒸気圧力実測
値４７を一致させるために演算器６７によって偏差６８
を求め、この偏差６８を比例積分演算器６９に入れ、出
力信号７０を弁開度調節器７１に与える制御信号７２に
よってタービンバイパス弁３４を閉じるか、あるいは燃
料調節弁４１を開いて昇圧するのである。A deviation 68 is calculated by the calculator 67 in order to match the main steam pressure set value 66 set by the main steam pressure setter 65 with the steam pressure actual measurement value 47 detected by the steam pressure detector 46.
This deviation 68 is input to the proportional-plus-integral calculator 69, and the turbine bypass valve 34 is closed or the fuel control valve 41 is opened to raise the pressure by the control signal 72 that gives the output signal 70 to the valve opening regulator 71. is there.
従来のボイラ起動時における昇圧制御は、前述した様に
タービンバイパス弁３４、燃料調節弁４１の弁操作はプ
ログラム制御により行なわれ、その目標圧力の設定は計
画時に決めたものを用い変更されるものではなく第７図
の曲線Ｈで示す様にＫ，Ｌ，Ｍ点へと昇圧していた。In the conventional booster control at the time of starting the boiler, as described above, the valve operation of the turbine bypass valve 34 and the fuel control valve 41 is performed by program control, and the setting of the target pressure is changed by using the one determined at the time of planning. Instead, the pressure was increased to points K, L, and M as shown by the curve H in FIG.
ところが、本発明においては、高温、高圧の蒸気にさら
される過熱器出口ヘツダ３０等のクリープ損傷による寿
命消費に大きく寄与する起動時の圧縮応力δτに注目
し、目標圧力設定を行なうものでタービン通気時（第
７，８図のＴ2）からボイラの再循環運転時（第７，８
図のＴ3）間に第７図の破線Ｏで示す如く内圧をＫ，
Ｐ，Ｍへと高くし、第８図の曲線Ｊで示す圧縮熱応力の
ピークに一致するように昇圧するのである。However, in the present invention, the target pressure is set by paying attention to the compressive stress δ τ at the time of startup, which greatly contributes to the lifetime consumption due to the creep damage of the superheater outlet header 30 exposed to high temperature and high pressure steam. From ventilation (T 2 in FIGS. 7 and 8) to boiler recirculation operation (7 and 8)
During T 3 ) in the figure, as shown by the broken line O in FIG.
The pressure is increased to P and M, and the pressure is increased so as to coincide with the peak of the compressive thermal stress shown by the curve J in FIG.
第８図で昇圧時、圧縮熱応力ピークに昇圧を一致させた
場合、蒸気圧力は第７図の破線Ｏで示すように高くなる
が、内圧応力は第８図の破線Ｑで示すように低くなる。When the compression thermal stress peak is made to coincide with the pressure increase in FIG. 8, the vapor pressure becomes high as shown by the broken line O in FIG. 7, but the internal pressure stress becomes low as shown by the broken line Q in FIG. Become.
つまり、従来の昇圧装置では内圧応力は第８図の曲線Ｉ
（実線）で示す如く大きくなり、この時の昇圧による熱
応力への影響は小さく、熱応力は第８図の曲線Ｊで示す
如く変らない。That is, in the conventional booster, the internal pressure stress is equal to the curve I in FIG.
It becomes large as shown by (solid line), and the influence on the thermal stress due to pressurization at this time is small, and the thermal stress does not change as shown by the curve J in FIG.
つぎに、過熱器３０における出口ヘツダ４２ノズル内面
コーナ部４３でのトータルの発生応力を見ると、本発明
のように昇圧させると圧縮の熱応力を引張の内圧応力で
相殺することになり、第４図および第５図における従来
の点Ａ，Ｂ，Ｃ，Ｄの実線は、本発明の点Ａ，Ｒ，Ｓ，
Ｔの破線の様になる。Next, looking at the total generated stress at the outlet header 42 nozzle inner surface corner portion 43 of the superheater 30, when the pressure is increased as in the present invention, the compressive thermal stress is canceled by the tensile internal pressure stress. The solid lines of the conventional points A, B, C, D in FIGS. 4 and 5 are the points A, R, S,
It becomes like the broken line of T.
従って、結果的には圧縮応力の絶対値を小さくすること
になり、クリープ寿命消費をそれだけ小さくすることが
できる。Therefore, as a result, the absolute value of the compressive stress is reduced, and the creep life consumption can be reduced accordingly.
なお第６図において、材質、設計圧力にもよるが、例え
ば、保持時間１００時間で圧縮時最大相当応力δτを１
６kg/mm2から１５kg/mm2に抑えることができれば、寿命
消費率φは約０．００００７から約０．００００６にな
り寿命消費を約１４％低減することができる。In FIG. 6, although depending on the material and the design pressure, for example, the maximum equivalent stress δ τ during compression at a holding time of 100 hours is 1
If it can be suppressed from 6 kg / mm 2 to 15 kg / mm 2 , the life consumption rate φ can be reduced from about 0.00007 to about 0.00006, and the life consumption can be reduced by about 14%.
本発明は、ボイラ起動時にボイラ耐圧部の蒸気接触部に
圧縮応力が発生することを予測する圧縮応力予測手段
と、その圧縮応力予測手段での圧縮応力の予測に基づい
て、前記ボイラ耐圧部の蒸気接触部に発生する圧縮応力
を減少するように引張応力を発生させるために主蒸気圧
を設定する主蒸気圧設定手段と、主蒸気圧を検出する主
蒸気圧検出手段とを備え、 前記主蒸気圧設定手段によつて設定された主蒸気圧設定
値と、前記主蒸気圧検出手段によつて検出された主蒸気
圧検出値との偏差によつて、ボイラ耐圧部の内圧を高め
る手段を制御するので、ボイラ起動時に発生する熱応力
を減少して寿命消費を低減することができ、しかもＤＳ
Ｓ運転を行なうものにおいては特に有効である。The present invention, based on the compressive stress predicting means for predicting that compressive stress is generated in the steam contact part of the boiler pressure resistant part at the time of starting the boiler, and the prediction of the compressive stress in the compressive stress predicting means, A main steam pressure setting means for setting a main steam pressure for generating a tensile stress so as to reduce a compressive stress generated in the steam contact portion; and a main steam pressure detecting means for detecting a main steam pressure. By means of the deviation between the main steam pressure set value set by the steam pressure setting means and the main steam pressure detection value detected by the main steam pressure detection means, means for increasing the internal pressure of the boiler pressure resistant portion is provided. Since it is controlled, it is possible to reduce the thermal stress generated at the time of starting the boiler and reduce the life consumption.
It is particularly effective for those performing S operation.
第１図は本発明の実施例に係るボイラ昇圧制御装置の概
略系統図、第２図は変圧運転強制貫流ボイラの概略系統
図、第３図は出口ヘツダのノズルコーナ部を示す拡大断
面図、第４図はボイラ起動時の発生応力模式図、第５図
は第４図の応力とひずみの特性曲線図、第６図は圧縮最
大相当応力と寿命消費率の特性曲線図、第７図は起動時
の蒸気圧力、蒸気温度の時間変化を示す特性曲線図、第
８図は熱応力、内圧応力の時間変化を示す特性曲線図で
ある。 ３４……タービンバイパス弁、４１……燃料調節弁、４
２……出口ヘツダ、４３……ノズルコーナ部、４５……
蒸気温度実測値、４６……蒸気圧力検出器、４７……蒸
気圧力実測値、４９……蒸気流量実測値、６３……熱応
力ピーク予測器、６４……熱応力ピーク予測値、６５…
…主蒸気圧力設定器、６６……主蒸気圧力設定値、６７
……演算器、６８……偏差、７１……弁開度調節器。FIG. 1 is a schematic system diagram of a boiler boosting control device according to an embodiment of the present invention, FIG. 2 is a schematic system diagram of a variable pressure operation once-through boiler, and FIG. 3 is an enlarged sectional view showing a nozzle corner portion of an outlet header, Fig. 4 is a schematic diagram of stress generated at boiler startup, Fig. 5 is a characteristic curve diagram of stress and strain of Fig. 4, Fig. 6 is a characteristic curve diagram of compression maximum equivalent stress and life consumption rate, and Fig. 7 is start-up. FIG. 8 is a characteristic curve diagram showing time changes of steam pressure and steam temperature, and FIG. 8 is a characteristic curve diagram showing time changes of thermal stress and internal pressure stress. 34 ... Turbine bypass valve, 41 ... Fuel control valve, 4
2 ... Exit header, 43 ... Nozzle corner, 45 ...
Steam temperature actual measurement value, 46 ... Steam pressure detector, 47 ... Steam pressure actual measurement value, 49 ... Steam flow rate actual measurement value, 63 ... Thermal stress peak predictor, 64 ... Thermal stress peak prediction value, 65 ...
… Main steam pressure setter, 66 …… Main steam pressure set value, 67
…… Calculator, 68 …… Deviation, 71 …… Valve opening regulator.
Claims (1)
に圧縮応力が発生することを予測する圧縮応力予測手段
と、 その圧縮応力予測手段での圧縮応力の予測に基づいて、
前記ボイラ耐圧部の蒸気接触部に発生する圧縮応力を減
少するように引張応力を発生させるために主蒸気圧を設
定する主蒸気圧設定手段と、 主蒸気圧を検出する主蒸気圧検出手段とを備え、 前記主蒸気圧設定手段によつて設定された主蒸気圧設定
値と、前記主蒸気圧検出手段によつて検出された主蒸気
圧検出値との偏差によつて、ボイラ耐圧部の内圧を高め
る手段を制御することを特徴とするボイラ昇圧制御装
置。1. A compressive stress predicting means for predicting that a compressive stress is generated in a steam contact portion of a boiler pressure-resistant portion at the time of starting the boiler, and a compressive stress predicting means for predicting compressive stress,
Main steam pressure setting means for setting a main steam pressure to generate a tensile stress so as to reduce the compressive stress generated in the steam contact portion of the boiler pressure resistant portion, and a main steam pressure detecting means for detecting the main steam pressure. The main steam pressure setting value set by the main steam pressure setting means, and the deviation between the main steam pressure detection value detected by the main steam pressure detecting means, the boiler pressure resistant portion of the A boiler booster control device characterized by controlling a means for increasing an internal pressure.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59205499A JPH0646083B2 (en) | 1984-10-02 | 1984-10-02 | Boiler boost controller |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP59205499A JPH0646083B2 (en) | 1984-10-02 | 1984-10-02 | Boiler boost controller |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6183802A JPS6183802A (en) | 1986-04-28 |
| JPH0646083B2 true JPH0646083B2 (en) | 1994-06-15 |
Family
ID=16507868
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP59205499A Expired - Fee Related JPH0646083B2 (en) | 1984-10-02 | 1984-10-02 | Boiler boost controller |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0646083B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5388884B2 (en) * | 2010-01-29 | 2014-01-15 | 中国電力株式会社 | Heat recovery apparatus and heat recovery method for turbine in power generation equipment |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS59219604A (en) * | 1983-05-26 | 1984-12-11 | 株式会社日立製作所 | Controller for warm air in steam piping |
-
1984
- 1984-10-02 JP JP59205499A patent/JPH0646083B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6183802A (en) | 1986-04-28 |
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