JP7043382B2 - Thermal power plant - Google Patents

Thermal power plant Download PDF

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JP7043382B2
JP7043382B2 JP2018184502A JP2018184502A JP7043382B2 JP 7043382 B2 JP7043382 B2 JP 7043382B2 JP 2018184502 A JP2018184502 A JP 2018184502A JP 2018184502 A JP2018184502 A JP 2018184502A JP 7043382 B2 JP7043382 B2 JP 7043382B2
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throttle valve
pressure
feed water
opening degree
water heater
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JP2020051416A (en
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太久磨 野添
佳子 清水
豊 田代
勇太 中林
英丈 高橋
光平 岩本
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Toshiba Corp
Toshiba Energy Systems and Solutions Corp
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/62—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light
    • G01N21/63—Systems in which the material investigated is excited whereby it emits light or causes a change in wavelength of the incident light optically excited
    • G01N21/64—Fluorescence; Phosphorescence
    • G01N21/6428—Measuring fluorescence of fluorescent products of reactions or of fluorochrome labelled reactive substances, e.g. measuring quenching effects, using measuring "optrodes"
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N33/00—Investigating or analysing materials by specific methods not covered by groups G01N1/00 - G01N31/00
    • G01N33/48—Biological material, e.g. blood, urine; Haemocytometers
    • G01N33/50—Chemical analysis of biological material, e.g. blood, urine; Testing involving biospecific ligand binding methods; Immunological testing
    • G01N33/52—Use of compounds or compositions for colorimetric, spectrophotometric or fluorometric investigation, e.g. use of reagent paper and including single- and multilayer analytical elements
    • G01N33/525—Multi-layer analytical elements
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N21/00—Investigating or analysing materials by the use of optical means, i.e. using sub-millimetre waves, infrared, visible or ultraviolet light
    • G01N21/75—Systems in which material is subjected to a chemical reaction, the progress or the result of the reaction being investigated
    • G01N2021/755—Comparing readings with/without reagents, or before/after reaction

Description

本発明の実施形態は、火力発電プラントに関する。 Embodiments of the present invention relate to a thermal power plant.

自然エネルギーによる発電の増加により発電量の急変が起こり、電力系統において系統周波数が急減する場合がある。具体的には、図１５に示すように、たとえば、１０秒程度の短時間で、１％程度の系統周波数の減少が発生する場合がある（系統周波数が５０Ｈｚである電力系統では、０．５Ｈｚ分、系統周波数が減少。系統周波数が６０Ｈｚである電力系統では、０．６Ｈｚ分、系統周波数が減少）。 An increase in power generation from natural energy may cause a sudden change in the amount of power generation, resulting in a sudden decrease in the system frequency in the power system. Specifically, as shown in FIG. 15, for example, a decrease in the system frequency of about 1% may occur in a short time of about 10 seconds (0.5 Hz in a power system having a system frequency of 50 Hz). The system frequency is reduced by the minute. In the power system where the system frequency is 60 Hz, the system frequency is reduced by 0.6 Hz).

上記のように電力系統において系統周波数が急激に減少したとき、火力発電プラントでは、系統周波数の安定化のために、発電出力を急速に増加させることが要求され、出力増大運転を実行する場合がある。 When the grid frequency in the power system decreases sharply as described above, the thermal power plant is required to rapidly increase the power generation output in order to stabilize the grid frequency, and may execute the output increase operation. be.

一般的な出力増大運転に関して、図１６Ａから図１６Ｃを用いて説明する。図１６Ａから図１６Ｃでは、系統周波数の減少を検出した時点における発電出力（初期出力）が９５％ＭＷである場合を示している。図１６Ａにおいては、蒸気加減弁の開度(ＭＣＶ開度)を実線で示している。図１６Ｂにおいては、高圧タービン（ＨＰ ＳＴ）に流入する蒸気の流量を実線で示し、中圧タービン（ＩＰ ＳＴ）に流入する蒸気の流量を一点鎖線で示すと共に、高圧タービン（ＨＰ ＳＴ）に流入する蒸気の制限値を破線で示し、中圧タービン（ＩＰ ＳＴ）に流入する蒸気の制限値を二点鎖線で示している。図１６Ｃにおいては、発電出力を実線で示している。 A general output increasing operation will be described with reference to FIGS. 16A to 16C. 16A to 16C show a case where the power generation output (initial output) at the time when the decrease in the system frequency is detected is 95% MW. In FIG. 16A, the opening degree (MCV opening degree) of the steam control valve is shown by a solid line. In FIG. 16B, the flow rate of steam flowing into the high-pressure turbine (HP ST) is shown by a solid line, the flow rate of steam flowing into the medium-pressure turbine (IP ST) is shown by a alternate long and short dash line, and the flow rate of steam flows into the high-pressure turbine (HP ST). The limit value of the steam to be used is shown by a broken line, and the limit value of the steam flowing into the medium pressure turbine (IPST) is shown by a two-dot chain line. In FIG. 16C, the power generation output is shown by a solid line.

出力増大運転を実行する際には、一般的に、通常運転（系統周波数が安定している時に行われる運転）の際に開度を絞る運用（絞り運用）が行われている蒸気加減弁を、系統周波数の低下に応じた開度まで開く。図１６Ａに示すように、たとえば、９４％の開度から１００％の開度になるように、蒸気加減弁の動作を制御する。これにより、図１６Ｂに示すように、蒸気タービン（図では、高圧タービン（ＨＰ ＳＴ）、中圧タービン（ＩＰ ＳＴ））に作動媒体として供給される蒸気の流量を増加させる。その結果、発電出力（負荷）を増加させる。図１６Ｃに示すように、たとえば、発電出力が９５％ＭＷから９８％ＭＷに増加する。 When executing the output increase operation, generally, the steam control valve that is operated to narrow the opening (throttle operation) during the normal operation (operation performed when the system frequency is stable) is used. , Open to the opening according to the decrease of the system frequency. As shown in FIG. 16A, for example, the operation of the steam control valve is controlled so as to change from an opening of 94% to an opening of 100%. As a result, as shown in FIG. 16B, the flow rate of steam supplied as a working medium to the steam turbine (in the figure, the high pressure turbine (HP ST) and the medium pressure turbine (IP ST)) is increased. As a result, the power generation output (load) is increased. As shown in FIG. 16C, for example, the power generation output increases from 95% MW to 98% MW.

発電プラントにおいては、通常運転時のプラント熱効率を高くするために、主蒸気加減弁の開度をほぼ全開に近い状態で通常運転を実行するものがある。このような発電プラントにおいて出力増大運転を実行する際には、主蒸気加減弁の開度を大きくする余地が小さいので、発電出力の増加が不十分になる場合がある。その結果、系統周波数を十分に回復させることが困難な場合がある。 In some power plants, in order to increase the plant thermal efficiency during normal operation, normal operation is performed with the opening of the main steam control valve almost fully open. When the output increasing operation is executed in such a power plant, there is little room for increasing the opening degree of the main steam control valve, so that the increase in the power generation output may be insufficient. As a result, it may be difficult to sufficiently recover the system frequency.

このような課題に対応するために、さまざまな技術が提案されている。たとえば、出力増大運転を実行する際には、給水加熱器に接続するタービン抽気配管に設置された抽気弁を全閉状態または半閉状態にし、給水加熱器に熱媒として供給する抽気蒸気の流量を低減させる。その結果、蒸気タービンに作動媒体として供給される蒸気の流量が増加するので、発電出力の増加を実現できる。 Various techniques have been proposed to deal with such problems. For example, when executing the output increase operation, the bleed air valve installed in the turbine bleed air pipe connected to the feed water heater is fully closed or semi-closed, and the flow rate of the bleed steam supplied to the feed water heater as a heat medium. To reduce. As a result, the flow rate of steam supplied to the steam turbine as an operating medium increases, so that an increase in power generation output can be realized.

特開２０１４－６６１８８号公報Japanese Unexamined Patent Publication No. 2014-666188

The Grid code (http://www2.nationalgrid.com/UK/Industry-information/Electricity-codes/Grid-Code/)The Grid code (http://www2.nationalgrid.com/UK/Industry-information/Electricity-codes/Grid-Code/)

しかしながら、上記方法では、脱気器へ送られる復水を十分に加熱できずに、脱気器へ入る水の温度が低下して脱気器の圧力が低下するので、脱気蒸気が多く必要になる。このとき、脱気蒸気の増加量は、低圧給水加熱器の抽気カット分よりも多くなる。その結果、発電出力が低下する場合がある。脱気蒸気の増加を防ぐためには、復水流量を低下させると共に、復水および給水を貯蔵するための容器が必要となる。長期間にわたって発電出力を増加させる場合には、現実的ではないほど、その容器の容量を大きくする必要がある。 However, in the above method, the condensate sent to the deaerator cannot be sufficiently heated, the temperature of the water entering the deaerator decreases, and the pressure of the deaerator decreases, so that a large amount of degassed steam is required. become. At this time, the amount of increase in degassed steam is larger than the amount of bleed air cut in the low-pressure feed water heater. As a result, the power generation output may decrease. In order to prevent the increase of degassed steam, a container for condensate and water supply is required as well as reducing the condensate flow rate. When increasing the power generation output over a long period of time, it is necessary to increase the capacity of the container so that it is not realistic.

また、上記方法において、発電出力が高い高負荷の運転を実行しているときに出力増大運転を行う際に、上記のように給水加熱器に熱媒として供給する抽気蒸気の流量を大幅に低減させた場合には、蒸気タービンを作動媒体として通過する蒸気の流量が上限許容値よりも大きくなる場合がある。その結果、蒸気タービンにおいて損傷が発生する可能性が高まる。 Further, in the above method, the flow rate of the bleed steam supplied as a heat medium to the feed water heater as described above is significantly reduced when the output increase operation is performed while the high load operation with high power generation output is being executed. In this case, the flow rate of steam passing through the steam turbine as an operating medium may be larger than the upper limit allowable value. As a result, there is an increased likelihood of damage to the steam turbine.

上記のような事情により、発電出力を十分に増加させると共に、蒸気タービンを作動媒体として通過する蒸気の流量が上限許容値以下になるように、出力増大運転を行うことが容易でない場合がある。 Due to the above circumstances, it may not be easy to sufficiently increase the power generation output and to increase the output so that the flow rate of steam passing through the steam turbine as an operating medium becomes equal to or less than the upper limit allowable value.

したがって、本発明が解決しようとする課題は、発電出力を十分に増加させると共に、蒸気タービンを作動媒体として通過する蒸気の流量が上限許容値以下になるように、出力増大運転を容易に実行可能な、火力発電プラントを提供することである。 Therefore, the problem to be solved by the present invention is that the power generation output can be sufficiently increased and the output increasing operation can be easily executed so that the flow rate of steam passing through the steam turbine as a working medium is equal to or less than the upper limit allowable value. It is to provide a thermal power plant.

実施形態の火力発電プラントは、蒸気タービンと、蒸気タービンから排気された蒸気を冷却して凝縮させる復水器と、蒸気タービンから抽気された蒸気を加熱媒体として用いて、復水器において凝縮された水を加熱する給水加熱部と、給水加熱部において加熱された水を加熱することによって蒸気を生成するボイラと、ボイラで生成された蒸気が蒸気タービンに供給されることによって蒸気タービンが回転し、その駆動力によって発電を行う発電機とを備え、抽気絞り弁を介して加熱媒体が供給される給水加熱器を給水加熱部が複数備えている。実施形態の火力発電プラントは、電力系統における系統周波数の減少を検出した際に発電機の発電出力を増加させる出力増大運転を行う場合に、系統周波数の減少を検出した時点における発電機の発電出力に基づいて、複数の抽気絞り弁のそれぞれに関して、開度を小さくする動作と開度を保持させる動作とのいずれか一方を行うように制御する制御装置を有する。 The thermal power plant of the embodiment is condensed in the water condensing device by using the steam turbine, the water condensing device that cools and condenses the steam exhausted from the steam turbine, and the steam extracted from the steam turbine as a heating medium. A water supply heating unit that heats the water, a boiler that generates steam by heating the water heated in the water supply heating unit, and a steam turbine that rotates by supplying the steam generated by the boiler to the steam turbine. The water supply heating unit is provided with a generator that generates power by the driving force thereof, and a water supply heater to which a heating medium is supplied via an bleeding throttle valve. In the thermal power plant of the embodiment, when the output increase operation for increasing the power generation output of the generator when the decrease in the system frequency in the power system is detected, the power generation output of the generator at the time when the decrease in the system frequency is detected is performed. Based on the above, there is a control device that controls each of the plurality of bleeding throttle valves to perform either an operation of reducing the opening degree or an operation of maintaining the opening degree .

図１は、第１実施形態に係る火力発電プラントの要部を模式的に示す図である。FIG. 1 is a diagram schematically showing a main part of a thermal power plant according to a first embodiment. 図２は、第１実施形態に係る火力発電プラントにおいて、「出力増大運転」を実行する場合に、系統周波数の減少を検出した時点で発電機１４が電力系統に出力していた電力の値と、抽気絞り弁Ｖ３１～Ｖ３３の開閉動作との関係を示す図である。FIG. 2 shows the value of the electric power output to the electric power system by the generator 14 at the time when the decrease in the system frequency is detected when the “output increasing operation” is executed in the thermal power plant according to the first embodiment. , Is a diagram showing the relationship with the opening / closing operation of the bleeding throttle valves V31 to V33. 図３は、第１実施形態において、実施例１および比較例の条件を示す図である。FIG. 3 is a diagram showing the conditions of Example 1 and Comparative Example in the first embodiment. 図４Ａは、実施例１の条件１において、各高圧抽気絞り弁Ｖ３１～Ｖ３３の開度を示す図である。FIG. 4A is a diagram showing the opening degrees of the high-pressure bleeding throttle valves V31 to V33 under the condition 1 of the first embodiment. 図４Ｂは、実施例１の条件１において、高圧タービン部１１（ＨＰ ＳＴ）に流入する蒸気の流量、中圧タービン部１２（ＩＰ ＳＴ）に流入する蒸気の流量を示す図である。FIG. 4B is a diagram showing the flow rate of steam flowing into the high pressure turbine section 11 (HP ST) and the flow rate of steam flowing into the medium pressure turbine section 12 (IP ST) under the condition 1 of the first embodiment. 図４Ｃは、実施例１の条件１において、発電出力を示す図である。FIG. 4C is a diagram showing the power generation output under the condition 1 of the first embodiment. 図５Ａは、実施例１の条件２において、各高圧抽気絞り弁Ｖ３１～Ｖ３３の開度を示す図である。FIG. 5A is a diagram showing the opening degrees of the high-pressure bleeding throttle valves V31 to V33 under the condition 2 of the first embodiment. 図５Ｂは、実施例１の条件２において、高圧タービン部１１（ＨＰ ＳＴ）に流入する蒸気の流量、中圧タービン部１２（ＩＰ ＳＴ）に流入する蒸気の流量を示す図である。FIG. 5B is a diagram showing the flow rate of steam flowing into the high pressure turbine section 11 (HP ST) and the flow rate of steam flowing into the medium pressure turbine section 12 (IP ST) under the condition 2 of the first embodiment. 図５Ｃは、実施例１の条件２において、発電出力を示す図である。FIG. 5C is a diagram showing the power generation output under the condition 2 of the first embodiment. 図６Ａは、実施例１の条件３において、各高圧抽気絞り弁Ｖ３１～Ｖ３３の開度を示す図である。FIG. 6A is a diagram showing the opening degrees of the high-pressure bleeding throttle valves V31 to V33 under the condition 3 of the first embodiment. 図６Ｂは、実施例１の条件３において、高圧タービン部１１（ＨＰ ＳＴ）に流入する蒸気の流量、中圧タービン部１２（ＩＰ ＳＴ）に流入する蒸気の流量を示す図である。FIG. 6B is a diagram showing the flow rate of steam flowing into the high pressure turbine section 11 (HP ST) and the flow rate of steam flowing into the medium pressure turbine section 12 (IP ST) under the condition 3 of the first embodiment. 図６Ｃは、実施例１の条件３において、発電出力を示す図である。FIG. 6C is a diagram showing the power generation output under the condition 3 of the first embodiment. 図７Ａは、実施例１の条件４において、各高圧抽気絞り弁Ｖ３１～Ｖ３３の開度を示す図である。FIG. 7A is a diagram showing the opening degrees of the high-pressure bleeding throttle valves V31 to V33 under the condition 4 of the first embodiment. 図７Ｂは、実施例１の条件４において、高圧タービン部１１（ＨＰ ＳＴ）に流入する蒸気の流量、中圧タービン部１２（ＩＰ ＳＴ）に流入する蒸気の流量を示す図である。FIG. 7B is a diagram showing the flow rate of steam flowing into the high pressure turbine section 11 (HP ST) and the flow rate of steam flowing into the medium pressure turbine section 12 (IP ST) under the condition 4 of the first embodiment. 図７Ｃは、実施例１の条件４において、発電出力を示す図である。FIG. 7C is a diagram showing the power generation output under the condition 4 of the first embodiment. 図８Ａは、比較例の条件１において、各高圧抽気絞り弁Ｖ３１～Ｖ３３の開度を示す図である。FIG. 8A is a diagram showing the opening degrees of the high-pressure bleeding throttle valves V31 to V33 under the condition 1 of the comparative example. 図８Ｂは、比較例の条件１において、高圧タービン部１１（ＨＰ ＳＴ）に流入する蒸気の流量、中圧タービン部１２（ＩＰ ＳＴ）に流入する蒸気の流量を示す図である。FIG. 8B is a diagram showing the flow rate of steam flowing into the high pressure turbine section 11 (HP ST) and the flow rate of steam flowing into the medium pressure turbine section 12 (IP ST) under condition 1 of the comparative example. 図８Ｃは、比較例の条件１において、発電出力を示す図である。FIG. 8C is a diagram showing the power generation output under the condition 1 of the comparative example. 図９Ａは、比較例の条件２において、各高圧抽気絞り弁Ｖ３１～Ｖ３３の開度を示す図である。FIG. 9A is a diagram showing the opening degrees of the high-pressure bleeding throttle valves V31 to V33 under the condition 2 of the comparative example. 図９Ｂは、比較例の条件２において、高圧タービン部１１（ＨＰ ＳＴ）に流入する蒸気の流量、中圧タービン部１２（ＩＰ ＳＴ）に流入する蒸気の流量を示す図である。FIG. 9B is a diagram showing the flow rate of steam flowing into the high pressure turbine section 11 (HP ST) and the flow rate of steam flowing into the medium pressure turbine section 12 (IP ST) under the condition 2 of the comparative example. 図９Ｃは、比較例の条件２において、発電出力を示す図である。FIG. 9C is a diagram showing the power generation output under the condition 2 of the comparative example. 図１０Ａは、比較例の条件３において、各高圧抽気絞り弁Ｖ３１～Ｖ３３の開度を示す図である。FIG. 10A is a diagram showing the opening degrees of the high-pressure bleeding throttle valves V31 to V33 under the condition 3 of the comparative example. 図１０Ｂは、比較例の条件３において、高圧タービン部１１（ＨＰ ＳＴ）に流入する蒸気の流量、中圧タービン部１２（ＩＰ ＳＴ）に流入する蒸気の流量を示す図である。FIG. 10B is a diagram showing the flow rate of steam flowing into the high pressure turbine section 11 (HP ST) and the flow rate of steam flowing into the medium pressure turbine section 12 (IP ST) under the condition 3 of the comparative example. 図１０Ｃは、比較例の条件３において、発電出力を示す図である。FIG. 10C is a diagram showing the power generation output under the condition 3 of the comparative example. 図１１は、第２実施形態に係る火力発電プラントにおいて、「出力増大運転」を実行する場合に、系統周波数の減少を検出した時点で発電機１４が電力系統に出力していた電力の値と、抽気絞り弁Ｖ３１～Ｖ３３の開閉動作との関係を示す図である。FIG. 11 shows the value of the electric power output to the electric power system by the generator 14 at the time when the decrease in the system frequency is detected when the “output increasing operation” is executed in the thermal power plant according to the second embodiment. , Is a diagram showing the relationship with the opening / closing operation of the bleeding throttle valves V31 to V33. 図１２は、第２実施形態に係る火力発電プラントにおいて、系統周波数の減少を検出した時点で発電機１４から電力系統に出力された電力（発電出力Ｌ）が９５％ＭＷを超えた値である場合（９５＜Ｌの場合）に実行する「絞り動作」の一例を示す図である。FIG. 12 shows a value in which the electric power (power generation output L) output from the generator 14 to the electric power system at the time when the decrease in the system frequency is detected in the thermal power plant according to the second embodiment exceeds 95% MW. It is a figure which shows an example of the "squeezing operation" to execute in the case (the case of 95 <L). 図１３は、第２実施形態に係る実施例２について、条件を示す図である。FIG. 13 is a diagram showing conditions for Example 2 according to the second embodiment. 図１４Ａは、実施例２の条件１において、各高圧抽気絞り弁Ｖ３１～Ｖ３３の開度を示す図である。FIG. 14A is a diagram showing the opening degrees of the high-pressure bleeding throttle valves V31 to V33 under the condition 1 of the second embodiment. 図１４Ｂは、実施例２の条件１において、高圧タービン部１１（ＨＰ ＳＴ）に流入する蒸気の流量、中圧タービン部１２（ＩＰ ＳＴ）に流入する蒸気の流量を示す図である。FIG. 14B is a diagram showing the flow rate of steam flowing into the high pressure turbine section 11 (HP ST) and the flow rate of steam flowing into the medium pressure turbine section 12 (IP ST) under the condition 1 of the second embodiment. 図１４Ｃは、実施例２の条件１において、発電出力を示す図である。FIG. 14C is a diagram showing the power generation output under the condition 1 of the second embodiment. 図１５は、関連技術において、電力系統で系統周波数が急激に減少したときの様子を示す図である。FIG. 15 is a diagram showing a state when the system frequency suddenly decreases in the power system in the related technique. 図１６Ａは、関連技術において出力増大運転を実行す場合における蒸気加減弁（ＭＣＶ）の開度を示す図である。FIG. 16A is a diagram showing the opening degree of the steam control valve (MCV) when the output increasing operation is executed in the related technique. 図１６Ｂは、関連技術において出力増大運転を実行する際に、高圧タービン部１１（ＨＰ ＳＴ）に流入する蒸気の流量、中圧タービン部１２（ＩＰ ＳＴ）に流入する蒸気の流量を示す図である。FIG. 16B is a diagram showing the flow rate of steam flowing into the high pressure turbine section 11 (HP ST) and the flow rate of steam flowing into the medium pressure turbine section 12 (IP ST) when the output increasing operation is executed in the related technique. be. 図１６Ｃは、関連技術において出力増大運転を実行する場合における発電出力を示す図である。FIG. 16C is a diagram showing the power generation output when the output increasing operation is executed in the related technique.

＜第１実施形態＞
［全体構成］
第１実施形態に係る火力発電プラントの要部について、図１を用いて説明する。 <First Embodiment>
[overall structure]
The main part of the thermal power plant according to the first embodiment will be described with reference to FIG.

図１に示すように、本実施形態の火力発電プラントでは、蒸気タービン１から排気された蒸気Ｆ１（排気蒸気）が、復水器２で冷却されて凝縮する。復水器２において凝縮した水Ｆ２（復水）は、給水加熱部３で加熱される。そして、給水加熱部３において加熱された水Ｆ３（給水）は、ボイラ４で加熱され、蒸気Ｆ４（主蒸気）が生成される。ボイラ４で生成された蒸気Ｆ４が蒸気タービン１に作動媒体として供給される。これにより、蒸気タービン１が発電機１４を駆動して、発電が行われる。 As shown in FIG. 1, in the thermal power generation plant of the present embodiment, the steam F1 (exhaust steam) exhausted from the steam turbine 1 is cooled by the condenser 2 and condensed. The condensed water F2 (condensed water) in the condenser 2 is heated by the water supply heating unit 3. Then, the water F3 (water supply) heated in the water supply heating unit 3 is heated by the boiler 4, and steam F4 (main steam) is generated. The steam F4 generated by the boiler 4 is supplied to the steam turbine 1 as an operating medium. As a result, the steam turbine 1 drives the generator 14 to generate electricity.

本実施形態において、火力発電プラントは、再生サイクルおよび再熱サイクルを構成するように、蒸気タービン１と復水器２と給水加熱部３とボイラ４との各部が構成されている。以下より、火力発電プラントを構成する各部の詳細について順次説明する。 In the present embodiment, the thermal power plant is composed of a steam turbine 1, a condenser 2, a water supply heating unit 3, and a boiler 4 so as to constitute a regeneration cycle and a reheat cycle. The details of each part constituting the thermal power plant will be described below in order.

本実施形態において、蒸気タービン１は、高圧タービン部１１、中圧タービン部１２、および、低圧タービン部１３によって構成されている。蒸気タービン１は、高圧タービン部１１と中圧タービン部１２と低圧タービン部１３とにおいて、タービンロータが回転することで、発電機１４を駆動する。発電機１４の駆動によって生じた電力は、電力系統（図示省略）に出力される。 In the present embodiment, the steam turbine 1 is composed of a high-pressure turbine section 11, a medium-pressure turbine section 12, and a low-pressure turbine section 13. The steam turbine 1 drives the generator 14 by rotating the turbine rotor in the high-pressure turbine section 11, the medium-pressure turbine section 12, and the low-pressure turbine section 13. The electric power generated by driving the generator 14 is output to the electric power system (not shown).

具体的には、蒸気タービン１のうち、高圧タービン部１１は、ボイラ４から蒸気Ｆ４が作動媒体として供給口Ａ１１から流入し、排気口Ａ１１ｂから蒸気Ｂ１ｂが流出する。ここでは、ボイラ４で生成された蒸気Ｆ４は、主蒸気加減弁ＶＦ４を経由して、高圧タービン部１１に導入される。そして、高圧タービン部１１の排気口Ａ１１ｂから流出した蒸気Ｂ１ｂのうち、大部分の蒸気Ｂ１ｂ＿１は、ボイラ４に流れ、ボイラ４で再び加熱される。これに対して、排気口Ａ１１ｂから流出した蒸気Ｂ１ｂのうち、残りの蒸気Ｂ１ｂ＿２は、給水加熱部３に流れる。この他に、高圧タービン部１１は、抽気口Ａ１１ａが形成されており、抽気口Ａ１１ａから蒸気Ｂ１ａが流出し、その蒸気Ｂ１ａが給水加熱部３へ流れる。 Specifically, in the high-pressure turbine section 11 of the steam turbine 1, steam F4 flows in from the boiler 4 as an operating medium from the supply port A11, and steam B1b flows out from the exhaust port A11b. Here, the steam F4 generated by the boiler 4 is introduced into the high-pressure turbine section 11 via the main steam control valve VF4. Then, of the steam B1b flowing out from the exhaust port A11b of the high-pressure turbine section 11, most of the steam B1b_1 flows to the boiler 4 and is heated again by the boiler 4. On the other hand, of the steam B1b flowing out from the exhaust port A11b, the remaining steam B1b_2 flows to the water supply heating unit 3. In addition to this, the high-pressure turbine unit 11 is formed with an air extraction port A11a, steam B1a flows out from the air extraction port A11a, and the steam B1a flows to the water supply heating unit 3.

蒸気タービン１のうち、中圧タービン部１２は、ボイラ４において再度加熱された蒸気Ｂ４（再熱蒸気）が作動媒体として供給口Ａ１２から流入し、排気口Ａ１２ｂ，Ａ１２ｃから蒸気Ｂ１ｄ，Ｂ１２が流出する。ここでは、ボイラ４において再度加熱された蒸気Ｂ４は、インターセプト弁ＶＢ４を経由して、中圧タービン部１２に導入される。中圧タービン部１２の排気口Ａ１２ｂから流出した蒸気Ｂ１ｄは、給水加熱部３へ流れる。また、中圧タービン部１２の排気口Ａ１２ｃから流出した蒸気Ｂ１２は、低圧タービン部１３へ流れる。この他に、中圧タービン部１２は、抽気口Ａ１２ａが形成されており、抽気口Ａ１２ａから蒸気Ｂ１ｃが流出し、その蒸気Ｂ１ｃが給水加熱部３へ流れる。 Of the steam turbine 1, in the medium pressure turbine section 12, steam B4 (reheated steam) reheated in the boiler 4 flows in from the supply port A12 as an operating medium, and steam B1d and B12 flow out from the exhaust ports A12b and A12c. do. Here, the steam B4 reheated in the boiler 4 is introduced into the medium pressure turbine section 12 via the intercept valve VB4. The steam B1d flowing out from the exhaust port A12b of the medium pressure turbine section 12 flows to the water supply heating section 3. Further, the steam B12 flowing out from the exhaust port A12c of the medium pressure turbine section 12 flows to the low pressure turbine section 13. In addition to this, the medium pressure turbine unit 12 is formed with an air extraction port A12a, steam B1c flows out from the air extraction port A12a, and the steam B1c flows to the water supply heating unit 3.

蒸気タービン１のうち、低圧タービン部１３は、供給口Ａ１３から作動流体として流入した蒸気Ｂ１２が流れ、排気口Ａ１３ｅから蒸気Ｆ１が流出する。排気口Ａ１３ｅから流出した蒸気Ｆ１は、復水器２へ流れる。この他に、低圧タービン部１３は、１つ以上の抽気口Ａ１３ａが形成されている。抽気口Ａ１３ａから流出した蒸気Ｂ１ｅ（抽気蒸気）は、給水加熱部３へ流れる。 Of the steam turbine 1, the low-pressure turbine section 13 has steam B12 flowing in as a working fluid from the supply port A13, and steam F1 flowing out from the exhaust port A13e. The steam F1 flowing out from the exhaust port A13e flows to the condenser 2. In addition to this, the low pressure turbine section 13 is formed with one or more bleed air ports A13a. The steam B1e (bleed steam) flowing out from the bleed air port A13a flows to the water supply heating unit 3.

復水器２は、蒸気タービン１から排気された蒸気Ｆ１（排気蒸気）を冷却して凝縮させるために設置されている。具体的には、復水器２は、蒸気タービン１を構成する低圧タービン部１３の排気口Ａ１３ｃから排出された蒸気Ｆ１を冷却し凝縮させる。ここでは、復水器２は、たとえば、海水や大気を冷却媒体として用いて、蒸気Ｆ１の冷却を行う。復水器２で凝縮した水Ｆ２は、復水ポンプＰ２によって加圧されて、給水加熱部３に移送される。 The condenser 2 is installed to cool and condense the steam F1 (exhaust steam) exhausted from the steam turbine 1. Specifically, the condenser 2 cools and condenses the steam F1 discharged from the exhaust port A13c of the low-pressure turbine unit 13 constituting the steam turbine 1. Here, the condenser 2 cools the steam F1 by using, for example, seawater or the atmosphere as a cooling medium. The water F2 condensed by the condenser 2 is pressurized by the condenser pump P2 and transferred to the water supply heating unit 3.

給水加熱部３は、蒸気タービン１から抽気された蒸気Ｂ１ａ，Ｂ１ｂ＿２，Ｂ１ｃ～Ｂ１ｅを用いて、復水器２で凝縮した水Ｆ２を加熱し、その加熱した水Ｆ３をボイラ４に供給するために設置されている。つまり、本実施形態の火力発電プラントは、再生サイクルを構成している。 The water supply heating unit 3 uses steam B1a, B1b_2, B1c to B1e extracted from the steam turbine 1 to heat the water F2 condensed by the condenser 2, and supplies the heated water F3 to the boiler 4. It is installed in. That is, the thermal power plant of the present embodiment constitutes a regeneration cycle.

給水加熱部３は、高圧給水加熱部３Ａと低圧給水加熱部３Ｂとを含む。高圧給水加熱部３Ａは、複数の給水加熱器３１～３３を備えている。複数の給水加熱器３１～３３のそれぞれは、たとえば、シェルの内部にチューブが収容されているシェル＆チューブ式の熱交換器である。高圧給水加熱部３Ａにおいては、第１高圧給水加熱器３１、第２高圧給水加熱器３２、および、第３高圧給水加熱器３３が給水加熱器として設置されている。 The water supply heating unit 3 includes a high-pressure water supply heating unit 3A and a low-pressure water supply heating unit 3B. The high-pressure feed water heater 3A includes a plurality of feed water heaters 31 to 33. Each of the plurality of feed water heaters 31 to 33 is, for example, a shell-and-tube heat exchanger in which a tube is housed inside the shell. In the high-pressure feed water heater 3A, a first high-pressure feed water heater 31, a second high-pressure feed water heater 32, and a third high-pressure feed water heater 33 are installed as feed water heaters.

給水加熱部３においては、さらに、脱気器３１１が設けられている。脱気器３１１は、たとえば、直接接触式の熱交換器である。 In the water supply heating unit 3, a deaerator 311 is further provided. The deaerator 311 is, for example, a direct contact heat exchanger.

給水加熱部３において、低圧給水加熱部３Ｂ、脱気器３１１、および、高圧給水加熱部３Ａのそれぞれに加熱媒体として供給される蒸気Ｂ１ａ，Ｂ１ｂ＿２，Ｂ１ｃ～Ｂ１ｅ（抽気蒸気）のそれぞれは、復水器２で凝縮した水Ｆ２の流れに沿って、圧力が順次高くなっている。すなわち、蒸気Ｂ１ａの圧力が最も高く、蒸気Ｂ１ｂ＿２，Ｂ１ｃ、Ｂ１ｄの順に圧力が下がり、蒸気Ｂ１ｅの圧力が最も低い。そして、給水加熱部３において、復水器２で凝縮した水Ｆ２は、低圧給水加熱部３Ｂ、脱気器３１１、高圧給水加熱部３Ａ（第３高圧給水加熱器３３、第２高圧給水加熱器３２、および、第１高圧給水加熱器３１）を順次流れるときに、蒸気Ｂ１ａ，Ｂ１ｂ＿２，Ｂ１ｃ～Ｂ１ｅの熱によって加熱されて、温度が上昇する。 In the water supply heating unit 3, the steams B1a, B1b_2, B1c to B1e (bleed air steam) supplied as heating media to each of the low pressure water supply heating unit 3B, the deaerator 311, and the high pressure water supply heating unit 3A are restored. The pressure is gradually increased along the flow of the water F2 condensed by the condenser 2. That is, the pressure of the steam B1a is the highest, the pressures of the steams B1b_2, B1c, and B1d decrease in this order, and the pressure of the steam B1e is the lowest. Then, in the feed water heater 3, the water F2 condensed by the feed water heater 2 is the low pressure feed water heater 3B, the deaerator 311 and the high pressure feed water heater 3A (third high pressure feed water heater 33, second high pressure feed water heater). 32 and the first high-pressure feed water heater 31) are sequentially heated by the heat of the steams B1a, B1b_2, B1c to B1e, and the temperature rises.

給水加熱部３を構成する各部について更に詳細に説明する。 Each part constituting the water supply heating part 3 will be described in more detail.

高圧給水加熱部３Ａのうち、第１高圧給水加熱器３１は、高圧タービン部１１の抽気口Ａ１１ａから供給される蒸気Ｂ１ａと、第２高圧給水加熱器３２から供給される水Ｆ３２との間において、熱交換が行われる。この熱交換により、第２高圧給水加熱器３２から流出した水Ｆ３２は、第１高圧給水加熱器３１で加熱される。この一方で、高圧タービン部１１の抽気口Ａ１１ａから流出した蒸気Ｂ１ａは、第１高圧給水加熱器３１での熱交換により冷却されて凝縮し、ドレン水Ｂ３１として第２高圧給水加熱器３２へ流出する。 Among the high-pressure feed water heaters 3A, the first high-pressure feed water heater 31 is between the steam B1a supplied from the extraction port A11a of the high-pressure turbine section 11 and the water F32 supplied from the second high-pressure feed water heater 32. , Heat exchange takes place. Due to this heat exchange, the water F32 flowing out of the second high-pressure feed water heater 32 is heated by the first high-pressure feed water heater 31. On the other hand, the steam B1a flowing out from the bleed air port A11a of the high-pressure turbine section 11 is cooled and condensed by heat exchange in the first high-pressure feed water heater 31, and flows out to the second high-pressure feed water heater 32 as drain water B31. do.

高圧給水加熱部３Ａのうち、第２高圧給水加熱器３２は、高圧タービン部１１の排気口Ａ１１ｂから供給される蒸気Ｂ１ｂ＿２と、第３高圧給水加熱器３３から供給される水Ｆ３３との間において、熱交換が行われる。この熱交換により、第３高圧給水加熱器３３から流出した水Ｆ３３は、第２高圧給水加熱器３２で加熱される。この一方で、高圧タービン部１１の排気口Ａ１１ｂから流出した蒸気Ｂ１ｂ＿２は、第２高圧給水加熱器３２での熱交換により冷却されて凝縮し、ドレン水Ｂ３２として第３高圧給水加熱器３３へ流出する。 Among the high-pressure feed water heaters 3A, the second high-pressure feed water heater 32 is between the steam B1b_2 supplied from the exhaust port A11b of the high-pressure turbine section 11 and the water F33 supplied from the third high-pressure feed water heater 33. , Heat exchange takes place. Due to this heat exchange, the water F33 flowing out of the third high-pressure feed water heater 33 is heated by the second high-pressure feed water heater 32. On the other hand, the steam B1b_2 flowing out from the exhaust port A11b of the high-pressure turbine section 11 is cooled and condensed by heat exchange in the second high-pressure feed water heater 32, and flows out to the third high-pressure feed water heater 33 as drain water B32. do.

高圧給水加熱部３Ａのうち、第３高圧給水加熱器３３は、中圧タービン部１２の抽気口Ａ１２ａから供給される蒸気Ｂ１ｃと、脱気器３１１から供給される水Ｆ３１１との間において、熱交換が行われる。この熱交換により、脱気器３１１から流出した水Ｆ３１１は、第３高圧給水加熱器３３で加熱される。この一方で、中圧タービン部１２の抽気口Ａ１２ａから流出した蒸気Ｂ１ｃは、第３高圧給水加熱器３３での熱交換により冷却されて凝縮し、ドレン水Ｂ３３として脱気器３１１へ流出する。 Of the high-pressure feed water heaters 3A, the third high-pressure feed water heater 33 heats between the steam B1c supplied from the bleed air port A12a of the medium-pressure turbine section 12 and the water F311 supplied from the deaerator 311. The exchange will take place. Due to this heat exchange, the water F311 flowing out of the deaerator 311 is heated by the third high-pressure feed water heater 33. On the other hand, the steam B1c flowing out from the bleed air port A12a of the medium pressure turbine section 12 is cooled and condensed by heat exchange in the third high-pressure feed water heater 33, and flows out to the deaerator 311 as drain water B33.

高圧給水加熱部３Ａのうち、脱気器３１１は、中圧タービン部１２の排気口Ａ１２ｂから供給される蒸気Ｂ１ｄが、低圧給水加熱部３Ｂから供給される水Ｆ３４に混合されて加熱されることによって、その水Ｆ３４について脱気を行う。脱気器３１１は、広義には給水加熱器の一種であって、低圧給水加熱部３Ｂから供給された水Ｆ３４に溶解している気体を取り除くと共に、加熱を行う。脱気器３１１で脱気された水Ｆ３１１は、給水ポンプＰ３１１によって加圧された後に、第３高圧給水加熱器３３に移送される。 Of the high-pressure water supply heating unit 3A, the deaerator 311 is heated by mixing steam B1d supplied from the exhaust port A12b of the medium-pressure turbine unit 12 with water F34 supplied from the low-pressure water supply heating unit 3B. Degass the water F34. The deaerator 311 is a kind of feed water heater in a broad sense, and removes the gas dissolved in the water F34 supplied from the low-pressure feed water heater 3B and heats the heater. The water F311 degassed by the deaerator 311 is pressurized by the water supply pump P311 and then transferred to the third high-pressure feed water heater 33.

低圧給水加熱部３Ｂは、低圧タービン部１３の抽気口Ａ１３ａから供給される蒸気Ｂ１ｅと、復水器２から復水ポンプＰ２を介して供給される水Ｆ２との間において、熱交換が行われる。この熱交換により、復水器２から復水ポンプＰ２を介して供給される水Ｆ２は、加熱される。この一方で、低圧タービン部１３の抽気口Ａ１３ａから流出した蒸気Ｂ１ｅは、低圧給水加熱部３Ｂでの熱交換により冷却されて凝縮する。 The low-pressure water supply heating unit 3B exchanges heat between the steam B1e supplied from the bleed air port A13a of the low-pressure turbine unit 13 and the water F2 supplied from the condenser 2 via the condensate pump P2. .. By this heat exchange, the water F2 supplied from the condenser 2 via the condenser pump P2 is heated. On the other hand, the steam B1e flowing out from the bleed air port A13a of the low-pressure turbine section 13 is cooled and condensed by heat exchange in the low-pressure water supply heating section 3B.

本実施形態の給水加熱部３においては、複数の抽気絞り弁Ｖ３１～Ｖ３３が設けられている。 In the water supply heating unit 3 of the present embodiment, a plurality of bleed air throttle valves V31 to V33 are provided.

具体的には、第１の高圧抽気絞り弁Ｖ３１は、第１高圧給水加熱器３１に加熱媒体として供給する蒸気Ｂ１ａの流量を調整するために設置されている。第２の高圧抽気絞り弁Ｖ３２は、第２高圧給水加熱器３２に加熱媒体として供給する蒸気Ｂ１ｂ＿２の流量を調整するために設置されている。そして、第３の高圧抽気絞り弁Ｖ３３は、第３高圧給水加熱器３３に加熱媒体として供給する蒸気Ｂ１ｃの流量を調整するために設置されている。 Specifically, the first high-pressure bleed air throttle valve V31 is installed to adjust the flow rate of the steam B1a supplied to the first high-pressure feed water heater 31 as a heating medium. The second high-pressure bleed air throttle valve V32 is installed to adjust the flow rate of the steam B1b_2 supplied to the second high-pressure feed water heater 32 as a heating medium. The third high-pressure bleed throttle valve V33 is installed to adjust the flow rate of the steam B1c supplied to the third high-pressure feed water heater 33 as a heating medium.

ボイラ４は、給水加熱部３で加熱された水Ｆ３（給水）を加熱することによって蒸気Ｆ４，Ｂ４（主蒸気，過熱蒸気）を生成するために設置されている。具体的には、ボイラ４は、給水加熱部３において第１高圧給水加熱器３１で加熱された水Ｆ３が被加熱媒体として供給される。そして、ボイラ４は、たとえば、燃焼により発生する熱を用いて、その給水加熱部３から供給された水Ｆ３を加熱して蒸発させる。ボイラ４で生じた蒸気Ｆ４は、蒸気タービン１を構成する高圧タービン部１１に作動媒体として供給される。 The boiler 4 is installed to generate steams F4 and B4 (main steam, superheated steam) by heating the water F3 (water supply) heated by the water supply heating unit 3. Specifically, in the boiler 4, the water F3 heated by the first high-pressure feed water heater 31 in the feed water heating unit 3 is supplied as a medium to be heated. Then, the boiler 4 uses, for example, the heat generated by combustion to heat and evaporate the water F3 supplied from the water supply heating unit 3. The steam F4 generated in the boiler 4 is supplied as an operating medium to the high-pressure turbine section 11 constituting the steam turbine 1.

この他に、ボイラ４は、高圧タービン部１１の排気口Ａ１１ｂから流出した蒸気Ｂ１ｂのうち大部分の蒸気Ｂ１ｂ＿１が流入し、その蒸気Ｂ１ｂ＿１を再度加熱する。ボイラ４で再度加熱された蒸気Ｂ４は、蒸気タービン１を構成する中圧タービン部１２に作動媒体として供給される。このように、本実施形態の火力発電プラントは、ボイラ４で蒸気を再熱する再熱サイクルで構成されている。 In addition to this, in the boiler 4, most of the steam B1b_1 out of the steam B1b flowing out from the exhaust port A11b of the high-pressure turbine section 11 flows in, and the steam B1b_1 is heated again. The steam B4 reheated by the boiler 4 is supplied as an operating medium to the medium pressure turbine section 12 constituting the steam turbine 1. As described above, the thermal power plant of the present embodiment is composed of a reheat cycle in which steam is reheated by the boiler 4.

本実施形態の火力発電プラントは、更に、制御装置８００を備えている。制御装置８００は、演算器（図示省略）とメモリ装置（図示省略）とを含み、メモリ装置が記憶しているプログラムを用いて演算器が演算処理を行うことによって、各部の制御を行うように構成されている。 The thermal power plant of the present embodiment further includes a control device 800. The control device 800 includes an arithmetic unit (not shown) and a memory device (not shown), and the arithmetic unit performs arithmetic processing using a program stored in the memory device so as to control each part. It is configured.

ここでは、制御装置８００は、操作指令や検出データなどが入力信号として入力される。そして、制御装置８００は、その入力された入力信号に基づいて演算処理を行い、制御信号ＣＴＬを出力信号として各部に出力することで、各部の動作を制御する。 Here, the control device 800 inputs operation commands, detection data, and the like as input signals. Then, the control device 800 performs arithmetic processing based on the input input signal and outputs the control signal CTL as an output signal to each unit to control the operation of each unit.

本実施形態において、制御装置８００は、電力系統において系統周波数が急速に減少したことを検知した場合には、系統周波数を回復させるために、系統周波数の減少を検知した時点よりも発電機１４の出力を増加させる「出力増大運転」を行う。「出力増大運転」は、たとえば、１０秒程度の短時間で、１％程度の系統周波数の減少が発生した場合に実行される。「出力増大運転」では、発電機１４の出力を「通常運転」の場合よりも急速に増加させる。 In the present embodiment, when the control device 800 detects that the system frequency has decreased rapidly in the power system, in order to recover the system frequency, the controller 14 of the generator 14 has more than the time when the decrease of the system frequency is detected. Perform "output increase operation" to increase the output. The "output increasing operation" is executed, for example, when a system frequency decrease of about 1% occurs in a short time of about 10 seconds. In the "output increasing operation", the output of the generator 14 is increased more rapidly than in the "normal operation".

詳細については後述するが、本実施形態において「出力増大運転」を実行する場合には、制御装置８００は、系統周波数の減少を検出した時点で発電機１４から電力系統に出力していた電力（発電出力）に基づいて、抽気絞り弁Ｖ３１～Ｖ３３の開度を小さくする動作（絞り動作）を制御する。 Although the details will be described later, when the "output increasing operation" is executed in the present embodiment, the control device 800 outputs the electric power (output) output from the generator 14 to the electric power system when the decrease in the system frequency is detected. Based on the power generation output), the operation of reducing the opening degree of the bleed air throttle valves V31 to V33 (throttle operation) is controlled.

ここでは、制御装置８００は、系統周波数の減少を検出した時点で発電機１４から電力系統に出力された電力（発電出力）が低くなるに伴って、給水加熱器３１～３３において加熱媒体の圧力が高い側から低い側に向けて加熱媒体が供給される流量を低減させる給水加熱器３１～３３の数が増加するように、抽気絞り弁Ｖ３１～Ｖ３３の制御を行う。これにより、系統周波数の減少を検出した時点よりも給水加熱部３に供給する加熱媒体の流量を低減させることで、発電機１４の出力を増加させる。 Here, as the power output from the generator 14 to the power system (power generation output) decreases when the control device 800 detects a decrease in the system frequency, the pressure of the heating medium in the feed water heaters 31 to 33 becomes low. The bleeding throttle valves V31 to V33 are controlled so that the number of feed water heaters 31 to 33 that reduce the flow rate of the heating medium supplied from the high side to the low side increases. As a result, the output of the generator 14 is increased by reducing the flow rate of the heating medium supplied to the water supply heating unit 3 from the time when the decrease in the system frequency is detected.

［動作］
以下より、本実施形態の火力発電プラントの動作に関して、「通常運転」を行う場合と、「出力増大運転」を行う場合とに分けて説明を行う。 [motion]
Hereinafter, the operation of the thermal power plant of the present embodiment will be described separately for the case of performing "normal operation" and the case of performing "output increasing operation".

（通常運転）
本実施形態の火力発電プラントにおいて「通常運転」を行うときの動作の一例に関して説明する。 (Normal operation)
An example of the operation when performing "normal operation" in the thermal power plant of the present embodiment will be described.

上記の火力発電プラントにおいて「通常運転」が行われる場合には、ボイラ４から蒸気Ｆ４が蒸気タービン１に供給され、蒸気タービン１で仕事を行う。蒸気タービン１においては、蒸気Ｆ４が主蒸気加減弁ＶＦ４を介して高圧タービン部１１に作動媒体として供給されて仕事を行う。そして、高圧タービン部１１から排気された蒸気Ｂ１ｂのうち、大部分の蒸気Ｂ１ｂ＿１がボイラ４で再度加熱された後に、そのボイラ４で再度加熱された蒸気Ｂ４がインターセプト弁ＶＢ４を介して中圧タービン部１２に作動媒体として供給されて仕事を行う。その後、中圧タービン部１２から排出された蒸気Ｂ１２が低圧タービン部１３に作動媒体として供給されて仕事を行う。低圧タービン部１３から排出された蒸気Ｆ１は、復水器２において凝縮され、その復水器２で凝縮された水Ｆ２が給水加熱部３で加熱される。給水加熱部３において、復水器２で凝縮された水Ｆ２は、蒸気タービン１から抽気された蒸気Ｂ１ａ，Ｂ１ｂ＿２，Ｂ１ｃ，Ｂ１ｄ，Ｂ１ｅの熱によって加熱される。そして、給水加熱部３において加熱された水Ｆ３がボイラ４で加熱されることによって、ボイラ４で蒸気Ｆ４が生成される。その後、ボイラ４で生成された蒸気Ｆ４は、上述したように、蒸気タービン１に作動媒体として供給される。 When "normal operation" is performed in the above-mentioned thermal power generation plant, steam F4 is supplied from the boiler 4 to the steam turbine 1 to perform work in the steam turbine 1. In the steam turbine 1, the steam F4 is supplied to the high-pressure turbine section 11 as an operating medium via the main steam control valve VF4 to perform work. Then, of the steam B1b exhausted from the high-pressure turbine section 11, most of the steam B1b_1 is reheated by the boiler 4, and then the steam B4 reheated by the boiler 4 passes through the intercept valve VB4 to the medium-pressure turbine. It is supplied to the unit 12 as a working medium to perform work. After that, the steam B12 discharged from the medium pressure turbine unit 12 is supplied to the low pressure turbine unit 13 as an operating medium to perform work. The steam F1 discharged from the low-pressure turbine section 13 is condensed in the condenser 2, and the water F2 condensed in the condenser 2 is heated in the water supply heating section 3. In the water supply heating unit 3, the water F2 condensed by the condenser 2 is heated by the heat of the steams B1a, B1b_2, B1c, B1d, and B1e extracted from the steam turbine 1. Then, the water F3 heated in the water supply heating unit 3 is heated by the boiler 4, and the steam F4 is generated by the boiler 4. After that, the steam F4 generated in the boiler 4 is supplied to the steam turbine 1 as a working medium as described above.

給水加熱部３では、蒸気タービン１から抽気された蒸気Ｂ１ａ，Ｂ１ｂ＿２，Ｂ１ｃが、抽気絞り弁Ｖ３１～Ｖ３３を介して、加熱媒体として供給される。「通常運転」を行う場合において一定の発電出力（定格出力）で火力発電プラントが安定的に稼働している状態では、発電効率を最大に保持するために、制御装置８００は、抽気絞り弁Ｖ３１～Ｖ３３を、たとえば、全開状態にしている。 In the water supply heating unit 3, the steams B1a, B1b_2, and B1c extracted from the steam turbine 1 are supplied as a heating medium via the bleeding throttle valves V31 to V33. In the state where the thermal power plant is operating stably at a constant power generation output (rated output) in the case of "normal operation", in order to maintain the maximum power generation efficiency, the control device 800 is the bleed air throttle valve V31. ~ V33 is set to the fully open state, for example.

（出力増大運転）
本実施形態の火力発電プラントにおいて「出力増大運転」を行うときの動作の一例に関して、図２を用いて説明する。 (Output increase operation)
An example of the operation when performing the “output increasing operation” in the thermal power plant of the present embodiment will be described with reference to FIG.

図２では、本実施形態において「出力増大運転」を実行する場合に、系統周波数の減少を検出した時点で発電機１４が電力系統に出力していた値Ｌ（％）と、抽気絞り弁Ｖ３１～Ｖ３３の動作との関係を例示している。図２では、抽気絞り弁Ｖ３１～Ｖ３３について開度を小さくする「絞り動作」を実行する場合を「有」と示し、「絞り動作」を実行しない場合を「無」と示している。 In FIG. 2, when the “output increasing operation” is executed in the present embodiment, the value L (%) output to the power system by the generator 14 at the time when the decrease in the system frequency is detected and the bleed air throttle valve V31. -The relationship with the operation of V33 is illustrated. In FIG. 2, the case where the “throttle operation” for reducing the opening degree of the bleed air throttle valves V31 to V33 is executed is shown as “yes”, and the case where the “throttle operation” is not executed is shown as “no”.

図２に示すように、本実施形態では、系統周波数の減少を検出した時点で発電機１４から電力系統に出力された電力（発電出力）が低くなるに伴って、「絞り動作」を実行する抽気絞り弁Ｖ３１～Ｖ３３の数が増加している。ここでは、上述したように、抽気絞り弁Ｖ３１～Ｖ３３の「絞り動作」は、系統周波数の減少を検出した時点で発電機１４から電力系統に出力された電力（発電出力）が低くなるに伴って、給水加熱器３１～３３において加熱媒体の圧力が高い側から低い側に向けて加熱媒体が供給される流量を低減させる給水加熱器３１～３３の数が増加するように制御される。以下より、抽気絞り弁Ｖ３１～Ｖ３３の「絞り動作」について、具体的に説明する。 As shown in FIG. 2, in the present embodiment, when the decrease in the system frequency is detected, the power output from the generator 14 to the power system (power generation output) becomes low, and the “throttle operation” is executed. The number of bleeding throttle valves V31 to V33 is increasing. Here, as described above, in the "throttle operation" of the bleed-out throttle valves V31 to V33, the power (power generation output) output from the generator 14 to the power system at the time when the decrease in the system frequency is detected becomes lower. Therefore, in the feed water heaters 31 to 33, the number of feed water heaters 31 to 33 that reduce the flow rate at which the heating medium is supplied is controlled to increase from the side where the pressure of the heating medium is high to the side where the pressure is low. Hereinafter, the "throttle operation" of the bleed air throttle valves V31 to V33 will be specifically described.

（９５＜Ｌの場合）
図２に示すように、系統周波数の減少を検出した時点で発電機１４から電力系統に出力された電力（発電出力Ｌ）が９５％ＭＷ（第１の閾値Ｌ１）を超えた値である場合（９５＜Ｌの場合）には、制御装置８００は、第１の高圧抽気絞り弁Ｖ３１、第２の高圧抽気絞り弁Ｖ３２、および、第３の高圧抽気絞り弁Ｖ３３について、「絞り動作」を実行しない。つまり、第１の高圧抽気絞り弁Ｖ３１の開度、第２の高圧抽気絞り弁Ｖ３２の開度、および、第３の高圧抽気絞り弁Ｖ３３の開度を保持させた状態で出力増大運転を行う。 (When 95 <L)
As shown in FIG. 2, when the power (power generation output L) output from the generator 14 to the power system at the time when the decrease in the system frequency is detected exceeds 95% MW (first threshold L1). (In the case of 95 <L), the control device 800 performs a "squeezing operation" for the first high-pressure bleeding throttle valve V31, the second high-pressure bleeding throttle valve V32, and the third high-pressure bleeding throttle valve V33. Do not execute. That is, the output increasing operation is performed while maintaining the opening degree of the first high-pressure bleeding throttle valve V31, the opening degree of the second high-pressure bleeding throttle valve V32, and the opening degree of the third high-pressure bleeding throttle valve V33. ..

（９０＜Ｌ≦９５の場合）
系統周波数の減少を検出した時点で発電機１４から電力系統に出力された電力が９５％ＭＷ（第１の閾値Ｌ１）以下であって９０％ＭＷ（第２の閾値Ｌ２）を超えた値である場合（９０＜Ｌ≦９５の場合）には、制御装置８００は、第１の高圧抽気絞り弁Ｖ３１については、「絞り動作」を実行するのに対して、第２の高圧抽気絞り弁Ｖ３２および第３の高圧抽気絞り弁Ｖ３３については、「絞り動作」を実行しない。つまり、第１の高圧抽気絞り弁Ｖ３１の開度を小さくし、かつ、第２の高圧抽気絞り弁Ｖ３２の開度および第３の高圧抽気絞り弁Ｖ３３の開度を保持させた状態で、出力増大運転を行う。 (When 90 <L ≦ 95)
When the decrease in the system frequency is detected, the power output from the generator 14 to the power system is 95% MW (first threshold L1) or less and exceeds 90% MW (second threshold L2). In some cases (when 90 <L ≦ 95), the control device 800 executes the “drawing operation” for the first high-pressure bleeding throttle valve V31, while the second high-pressure bleeding throttle valve V32. And for the third high pressure bleeding throttle valve V33, the "throttle operation" is not executed. That is, the output is performed in a state where the opening degree of the first high-pressure bleeding throttle valve V31 is reduced and the opening degree of the second high-pressure bleeding throttle valve V32 and the opening degree of the third high-pressure bleeding throttle valve V33 are maintained. Perform augmented operation.

（８５＜Ｌ≦９０の場合）
系統周波数の減少を検出した時点で発電機１４から電力系統に出力された電力が９０％ＭＷ（第２の閾値Ｌ２）以下であって８５％ＭＷ（第３の閾値Ｌ３）を超えた値である場合（８５＜Ｌ≦９０の場合）には、制御装置８００は、第１の高圧抽気絞り弁Ｖ３１および第２の高圧抽気絞り弁Ｖ３２については、「絞り動作」を実行するのに対して、第３の高圧抽気絞り弁Ｖ３３については、「絞り動作」を実行しない。つまり、第１の高圧抽気絞り弁Ｖ３１の開度および第２の高圧抽気絞り弁Ｖ３２の開度を小さくし、かつ、第３の高圧抽気絞り弁Ｖ３３の開度を保持させた状態で、出力増大運転を行う。 (When 85 <L ≤ 90)
When the decrease in the system frequency is detected, the power output from the generator 14 to the power system is 90% MW (second threshold L2) or less and exceeds 85% MW (third threshold L3). In certain cases (in the case of 85 <L ≦ 90), the control device 800 performs a “squeezing operation” for the first high pressure bleeding throttle valve V31 and the second high pressure bleeding throttle valve V32. , The "throttle operation" is not executed for the third high-pressure bleeding throttle valve V33. That is, the output is in a state where the opening degree of the first high-pressure bleeding throttle valve V31 and the opening degree of the second high-pressure bleeding throttle valve V32 are reduced and the opening degree of the third high-pressure bleeding throttle valve V33 is maintained. Perform augmented operation.

（８５≦Ｌの場合）
系統周波数の減少を検出した時点で発電機１４から電力系統に出力された電力が８５％ＭＷ（第３の閾値Ｌ３）以下である場合（８５≦Ｌの場合）には、制御装置８００は、第１の高圧抽気絞り弁Ｖ３１、第２の高圧抽気絞り弁Ｖ３２、および、第３の高圧抽気絞り弁Ｖ３３について、「絞り動作」を実行する。つまり、第１の高圧抽気絞り弁Ｖ３１の開度、第２の高圧抽気絞り弁Ｖ３２の開度、および、第３の高圧抽気絞り弁Ｖ３３の開度を小さくした状態で、出力増大運転を行う。 (When 85 ≤ L)
When the power output from the generator 14 to the power system at the time when the decrease in the system frequency is detected is 85% MW (third threshold L3) or less (when 85 ≦ L), the control device 800 determines. A "squeezing operation" is executed for the first high-pressure bleeding squeezing valve V31, the second high-pressure bleeding squeezing valve V32, and the third high-pressure bleeding squeezing valve V33. That is, the output increasing operation is performed with the opening degree of the first high-pressure bleeding throttle valve V31, the opening degree of the second high-pressure bleeding throttle valve V32, and the opening degree of the third high-pressure bleeding throttle valve V33 reduced. ..

［実施例］
以下より、本実施形態の火力発電プラントで実行する出力増大運転に関する実施例および比較例について説明する。 [Example]
Hereinafter, examples and comparative examples relating to the output increase operation executed in the thermal power plant of the present embodiment will be described.

図３は、第１実施形態において、実施例１および比較例の条件を示す図である。 FIG. 3 is a diagram showing the conditions of Example 1 and Comparative Example in the first embodiment.

図４Ａから図４Ｃは、実施例１の条件１の場合について示す図である。図５Ａから図５Ｃは、実施例１の条件２の場合について示す図である。図６Ａから図６Ｃは、実施例１の条件３の場合について示す図である。図７Ａから図７Ｃは、実施例１の条件４の場合について示す図である。図８Ａから図８Ｃは、比較例の条件１の場合について示す図である。図９Ａから図９Ｃは、比較例の条件２の場合について示す図である。図１０Ａから図１０Ｃは、比較例の条件３の場合について示す図である。 4A to 4C are diagrams showing the case of condition 1 of the first embodiment. 5A to 5C are diagrams showing the case of condition 2 of the first embodiment. 6A to 6C are diagrams showing the case of condition 3 of the first embodiment. 7A to 7C are diagrams showing the case of condition 4 of the first embodiment. 8A to 8C are diagrams showing the case of condition 1 of the comparative example. 9A to 9C are diagrams showing the case of condition 2 of the comparative example. 10A to 10C are diagrams showing the case of condition 3 of the comparative example.

ここで、図４Ａから図１０Ａにおいては、各高圧抽気絞り弁Ｖ３１～Ｖ３３の開度を示している。図４Ｂから図１０Ｂにおいては、高圧タービン部１１（ＨＰ ＳＴ）に流入する蒸気の流量と、中圧タービン部１２（ＩＰ ＳＴ）に流入する蒸気の流量とを実線で示すと共に、高圧タービン部１１（ＨＰ ＳＴ）に流入する蒸気の制限値、および、中圧タービン部１２（ＩＰ ＳＴ）に流入する蒸気の制限値を破線で示している。図４Ｃから図１０Ｃにおいては、発電出力を実線で示している。 Here, in FIGS. 4A to 10A, the opening degrees of the high-pressure bleed throttle valves V31 to V33 are shown. In FIGS. 4B to 10B, the flow rate of steam flowing into the high-pressure turbine section 11 (HP ST) and the flow rate of steam flowing into the medium-pressure turbine section 12 (IP ST) are shown by solid lines, and the high-pressure turbine section 11 is shown. The limit value of the steam flowing into (HP ST) and the limit value of the steam flowing into the medium pressure turbine unit 12 (IP ST) are shown by a broken line. In FIGS. 4C to 10C, the power generation output is shown by a solid line.

（実施例１の条件１の場合）
実施例１の条件１の場合では、図３に示すように、発電出力Ｌが１００％ＭＷである状態で通常運転を実行しているときに、系統周波数の減少（図１５参照）を検出し、出力増大運転を行う場合に関して示している。つまり、図２に示したように、系統周波数の減少を検出した時点で発電機１４から電力系統に出力された電力（発電出力Ｌ）が９５％ＭＷ（第１の閾値Ｌ１）を超えた値である場合（９５＜Ｌの場合）において、出力増大運転を行う場合に関して例示している。 (In the case of condition 1 of Example 1)
In the case of condition 1 of the first embodiment, as shown in FIG. 3, a decrease in the system frequency (see FIG. 15) is detected during normal operation in a state where the power generation output L is 100% MW. , The case where the output increase operation is performed is shown. That is, as shown in FIG. 2, the value of the power (power generation output L) output from the generator 14 to the power system when the decrease in the system frequency is detected exceeds 95% MW (first threshold value L1). In the case where (95 <L), the case where the output increasing operation is performed is illustrated.

上記の場合において、実施例１の条件１の場合では、図４Ａに示すように、第１の高圧抽気絞り弁Ｖ３１、第２の高圧抽気絞り弁Ｖ３２、および、第３の高圧抽気絞り弁Ｖ３３について、「絞り動作」を実行しない。すなわち、第１の高圧抽気絞り弁Ｖ３１の開度、第２の高圧抽気絞り弁Ｖ３２の開度、および、第３の高圧抽気絞り弁Ｖ３３の開度を、通常運転のときの開度に保持させた状態で出力増大運転を行う。具体的には、第１の高圧抽気絞り弁Ｖ３１の開度、第２の高圧抽気絞り弁Ｖ３２の開度、および、第３の高圧抽気絞り弁Ｖ３３の開度を、全開状態の開度（１００％）に保持する。そして、主蒸気加減弁ＶＦ４の開度は、従来技術と同様に増加され、場合によっては全開する。 In the above case, in the case of the condition 1 of the first embodiment, as shown in FIG. 4A, the first high-pressure bleed throttle valve V31, the second high-pressure bleed throttle valve V32, and the third high-pressure bleed throttle valve V33. Does not execute the "aperture operation". That is, the opening degree of the first high-pressure bleeding throttle valve V31, the opening degree of the second high-pressure bleeding throttle valve V32, and the opening degree of the third high-pressure bleeding throttle valve V33 are maintained at the opening degree during normal operation. The output increase operation is performed in the state where the output is increased. Specifically, the opening degree of the first high-pressure bleeding throttle valve V31, the opening degree of the second high-pressure bleeding throttle valve V32, and the opening degree of the third high-pressure bleeding throttle valve V33 are set to the opening degree in the fully open state. Hold at 100%). Then, the opening degree of the main steam control valve VF4 is increased as in the prior art, and in some cases, it is fully opened.

これにより、図４Ｂに示すように、高圧タービン部１１に流入する蒸気の流量、および、中圧タービン部１２に流入する蒸気の流量が増加する。その結果、図４Ｃに示すように、発電出力が増加する。実施例１の条件１の場合では、高圧タービン部１１に流入する蒸気の流量が制限値以下の状態であると共に、中圧タービン部１２に流入する蒸気の流量が制限値以下の状態で（図４Ｂ参照）、約１．８％ＭＷ程度、発電出力が増加する（図４Ｃ参照）。 As a result, as shown in FIG. 4B, the flow rate of the steam flowing into the high-pressure turbine section 11 and the flow rate of the steam flowing into the medium-pressure turbine section 12 increase. As a result, as shown in FIG. 4C, the power generation output increases. In the case of condition 1 of the first embodiment, the flow rate of the steam flowing into the high-pressure turbine section 11 is below the limit value, and the flow rate of the steam flowing into the medium-pressure turbine section 12 is below the limit value (FIG. 4B), the power generation output increases by about 1.8% MW (see FIG. 4C).

（実施例１の条件２の場合）
実施例１の条件２の場合では、図３に示すように、発電出力Ｌが９５％ＭＷである状態で通常運転を実行しているときに、系統周波数の減少（図１５参照）を検出し、出力増大運転を行う場合に関して示している。つまり、図２に示したように、系統周波数の減少を検出した時点で発電機１４から電力系統に出力された電力が９５％ＭＷ（第１の閾値Ｌ１）以下であって９０％ＭＷ（第２の閾値Ｌ２）を超えた値である場合（９０＜Ｌ≦９５の場合）において、出力増大運転を行う場合に関して例示している。 (In the case of condition 2 of Example 1)
In the case of condition 2 of the first embodiment, as shown in FIG. 3, a decrease in the system frequency (see FIG. 15) is detected during normal operation in a state where the power generation output L is 95% MW. , The case where the output increase operation is performed is shown. That is, as shown in FIG. 2, the power output from the generator 14 to the power system at the time when the decrease in the system frequency is detected is 95% MW (first threshold value L1) or less and 90% MW (first threshold value L1) or less. When the value exceeds the threshold value L2) of 2 (when 90 <L ≦ 95), the case where the output increasing operation is performed is illustrated.

上記の場合において、実施例１の条件２の場合では、図５Ａに示すように、第１の高圧抽気絞り弁Ｖ３１については、「絞り動作」を実行するのに対して、第２の高圧抽気絞り弁Ｖ３２および第３の高圧抽気絞り弁Ｖ３３については、「絞り動作」を実行しない。すなわち、第１の高圧抽気絞り弁Ｖ３１の開度を小さくし、かつ、第２の高圧抽気絞り弁Ｖ３２の開度および第３の高圧抽気絞り弁Ｖ３３の開度を保持させた状態で、出力増大運転を行う。ここでは、全開状態の開度（１００％）から、たとえば、５％の開度になるように、第１の高圧抽気絞り弁Ｖ３１の開度を小さくする。その後、第１の高圧抽気絞り弁Ｖ３１の開度を徐々に大きくする。そして、主蒸気加減弁ＶＦ４の開度は、従来技術と同様に増加され、場合によっては全開する。 In the above case, in the case of the condition 2 of the first embodiment, as shown in FIG. 5A, the first high-pressure bleed air throttle valve V31 executes the "drawing operation", whereas the second high-pressure bleed air is drawn. For the throttle valve V32 and the third high-pressure bleed throttle valve V33, the "throttle operation" is not executed. That is, the output is in a state where the opening degree of the first high-pressure bleeding throttle valve V31 is reduced and the opening degree of the second high-pressure bleeding throttle valve V32 and the opening degree of the third high-pressure bleeding throttle valve V33 are maintained. Perform augmented operation. Here, the opening degree of the first high-pressure bleeding throttle valve V31 is reduced so that the opening degree is, for example, 5% from the opening degree (100%) in the fully opened state. After that, the opening degree of the first high-pressure bleeding throttle valve V31 is gradually increased. Then, the opening degree of the main steam control valve VF4 is increased as in the prior art, and in some cases, it is fully opened.

これにより、図５Ｂに示すように、高圧タービン部１１に流入する蒸気の流量、および、中圧タービン部１２に流入する蒸気の流量が増加する。その結果、図５Ｃに示すように、発電出力が増加する。実施例１の条件２の場合では、高圧タービン部１１に流入する蒸気の流量が制限値以下の状態であると共に、中圧タービン部１２に流入する蒸気の流量が制限値以下の状態で（図５Ｂ参照）、発電出力が約５％ＭＷ増加する（図５Ｃ参照）。 As a result, as shown in FIG. 5B, the flow rate of the steam flowing into the high-pressure turbine section 11 and the flow rate of the steam flowing into the medium-pressure turbine section 12 increase. As a result, as shown in FIG. 5C, the power generation output increases. In the case of condition 2 of the first embodiment, the flow rate of the steam flowing into the high-pressure turbine section 11 is below the limit value, and the flow rate of the steam flowing into the medium-pressure turbine section 12 is below the limit value (FIG. (See 5B), the power generation output increases by about 5% MW (see FIG. 5C).

（実施例１の条件３の場合）
実施例１の条件３の場合では、図３に示すように、発電出力Ｌが９０％ＭＷである状態で通常運転を実行しているときに、系統周波数の減少（図１５参照）を検出し、出力増大運転を行う場合に関して示している。つまり、図２に示したように、系統周波数の減少を検出した時点で発電機１４から電力系統に出力された電力が９０％ＭＷ（第２の閾値Ｌ２）以下であって８５％ＭＷ（第３の閾値Ｌ３）を超えた値である場合（８５＜Ｌ≦９０の場合）において、出力増大運転を行う場合に関して例示している。 (In the case of condition 3 of Example 1)
In the case of condition 3 of the first embodiment, as shown in FIG. 3, a decrease in the system frequency (see FIG. 15) is detected during normal operation in a state where the power generation output L is 90% MW. , The case where the output increase operation is performed is shown. That is, as shown in FIG. 2, the power output from the generator 14 to the power system at the time when the decrease in the system frequency is detected is 90% MW (second threshold value L2) or less and 85% MW (second threshold value L2). In the case where the value exceeds the threshold value L3) of 3 (when 85 <L ≦ 90), the case where the output increasing operation is performed is illustrated.

上記の場合において、実施例１の条件３の場合では、図６Ａに示すように、第１の高圧抽気絞り弁Ｖ３１および第２の高圧抽気絞り弁Ｖ３２については、「絞り動作」を実行するのに対して、第３の高圧抽気絞り弁Ｖ３３については、「絞り動作」を実行しない。すなわち、第１の高圧抽気絞り弁Ｖ３１の開度および第２の高圧抽気絞り弁Ｖ３２の開度を小さくし、かつ、第３の高圧抽気絞り弁Ｖ３３の開度を保持させた状態で、出力増大運転を行う。ここでは、全開状態の開度（１００％）から、たとえば、５％の開度になるように、第１の高圧抽気絞り弁Ｖ３１の開度および第２の高圧抽気絞り弁Ｖ３２の開度の両者を同じ割合で小さくする。その後、第１の高圧抽気絞り弁Ｖ３１の開度および第２の高圧抽気絞り弁Ｖ３２の開度の両者を同じ割合で徐々に大きくする。そして、主蒸気加減弁ＶＦ４の開度は、従来技術と同様に増加され、場合によっては全開する。 In the above case, in the case of the condition 3 of the first embodiment, as shown in FIG. 6A, the "drawing operation" is executed for the first high-pressure bleed throttle valve V31 and the second high-pressure bleed throttle valve V32. On the other hand, the "throttle operation" is not executed for the third high-pressure bleed air throttle valve V33. That is, the output is in a state where the opening degree of the first high-pressure bleeding throttle valve V31 and the opening degree of the second high-pressure bleeding throttle valve V32 are reduced and the opening degree of the third high-pressure bleeding throttle valve V33 is maintained. Perform augmented operation. Here, the opening degree of the first high-pressure bleeding throttle valve V31 and the opening degree of the second high-pressure bleeding throttle valve V32 are set so as to be, for example, 5% from the opening degree in the fully opened state (100%). Make both smaller at the same rate. After that, both the opening degree of the first high-pressure bleeding throttle valve V31 and the opening degree of the second high-pressure bleeding throttle valve V32 are gradually increased at the same ratio. Then, the opening degree of the main steam control valve VF4 is increased as in the prior art, and in some cases, it is fully opened.

これにより、図６Ｂに示すように、高圧タービン部１１に流入する蒸気の流量、および、中圧タービン部１２に流入する蒸気の流量が増加する。その結果、図６Ｃに示すように、発電出力が増加する。実施例１の条件３の場合では、高圧タービン部１１に流入する蒸気の流量が制限値以下の状態であると共に、中圧タービン部１２に流入する蒸気の流量が制限値以下の状態で（図６Ｂ参照）、発電出力が約７％ＭＷ増加する（図６Ｃ参照）。 As a result, as shown in FIG. 6B, the flow rate of the steam flowing into the high-pressure turbine section 11 and the flow rate of the steam flowing into the medium-pressure turbine section 12 increase. As a result, as shown in FIG. 6C, the power generation output increases. In the case of condition 3 of the first embodiment, the flow rate of the steam flowing into the high-pressure turbine section 11 is below the limit value, and the flow rate of the steam flowing into the medium-pressure turbine section 12 is below the limit value (FIG. 6B), the power generation output increases by about 7% MW (see FIG. 6C).

（実施例１の条件４の場合）
実施例１の条件４の場合では、図３に示すように、発電出力Ｌが８５％ＭＷである状態で通常運転を実行しているときに、系統周波数の減少（図１５参照）を検出し、出力増大運転を行う場合に関して示している。つまり、図２に示したように、系統周波数の減少を検出した時点で発電機１４から電力系統に出力された電力が８５％ＭＷ（第３の閾値Ｌ３）以下である場合（８５≦Ｌの場合）において、出力増大運転を行う場合に関して例示している。 (In the case of condition 4 of Example 1)
In the case of condition 4 of the first embodiment, as shown in FIG. 3, a decrease in the system frequency (see FIG. 15) is detected during normal operation in a state where the power generation output L is 85% MW. , The case where the output increase operation is performed is shown. That is, as shown in FIG. 2, when the power output from the generator 14 to the power system at the time when the decrease in the system frequency is detected is 85% MW (third threshold value L3) or less (85 ≦ L). Case) exemplifies the case where the output increasing operation is performed.

上記の場合において、実施例１の条件４の場合では、図７Ａに示すように、第１の高圧抽気絞り弁Ｖ３１、第２の高圧抽気絞り弁Ｖ３２、および、第３の高圧抽気絞り弁Ｖ３３について、「絞り動作」を実行する。すなわち、第１の高圧抽気絞り弁Ｖ３１の開度、第２の高圧抽気絞り弁Ｖ３２の開度、および、第３の高圧抽気絞り弁Ｖ３３の開度を小さくした状態で、出力増大運転を行う。ここでは、全開状態の開度（１００％）から、たとえば、５％の開度になるように、第１の高圧抽気絞り弁Ｖ３１の開度、第２の高圧抽気絞り弁Ｖ３２の開度、および、第３の高圧抽気絞り弁Ｖ３３の開度のそれぞれを同じ割合で小さくする。その後、第１の高圧抽気絞り弁Ｖ３１の開度、第２の高圧抽気絞り弁Ｖ３２の開度、および、第３の高圧抽気絞り弁Ｖ３３の開度のそれぞれを徐々に大きくする。具体的には、第１の高圧抽気絞り弁Ｖ３１の開度および第２の高圧抽気絞り弁Ｖ３２の開度の両者を同じ割合で徐々に大きくする。また、第３の高圧抽気絞り弁Ｖ３３については、第１の高圧抽気絞り弁Ｖ３１の開度および第２の高圧抽気絞り弁Ｖ３２の開度を大きくする割合よりも大きい割合で、開度を大きくする。そして、主蒸気加減弁ＶＦ４の開度は、従来技術と同様に増加され、場合によっては全開する。 In the above case, in the case of the condition 4 of the first embodiment, as shown in FIG. 7A, the first high-pressure bleed throttle valve V31, the second high-pressure bleed throttle valve V32, and the third high-pressure bleed throttle valve V33. "Aperture operation" is executed. That is, the output increasing operation is performed with the opening degree of the first high-pressure bleeding throttle valve V31, the opening degree of the second high-pressure bleeding throttle valve V32, and the opening degree of the third high-pressure bleeding throttle valve V33 reduced. .. Here, the opening degree of the first high-pressure bleeding throttle valve V31, the opening degree of the second high-pressure bleeding throttle valve V32, for example, from the opening degree (100%) in the fully open state to the opening degree of 5%. The opening degree of the third high-pressure bleeding throttle valve V33 is reduced by the same ratio. After that, the opening degree of the first high-pressure bleeding throttle valve V31, the opening degree of the second high-pressure bleeding throttle valve V32, and the opening degree of the third high-pressure bleeding throttle valve V33 are gradually increased. Specifically, both the opening degree of the first high-pressure bleeding throttle valve V31 and the opening degree of the second high-pressure bleeding throttle valve V32 are gradually increased at the same ratio. Further, regarding the third high-pressure bleeding throttle valve V33, the opening degree is increased by a ratio larger than the ratio of increasing the opening degree of the first high-pressure bleeding throttle valve V31 and the opening degree of the second high-pressure bleeding throttle valve V32. do. Then, the opening degree of the main steam control valve VF4 is increased as in the prior art, and in some cases, it is fully opened.

これにより、図７Ｂに示すように、高圧タービン部１１に流入する蒸気の流量、および、中圧タービン部１２に流入する蒸気の流量が増加する。その結果、図７Ｃに示すように、発電出力が増加する。実施例１の条件４の場合では、高圧タービン部１１に流入する蒸気の流量が制限値以下の状態であると共に、中圧タービン部１２に流入する蒸気の流量が制限値以下の状態で（図７Ｂ参照）、発電出力が約９％ＭＷ増加する（図７Ｃ参照）。 As a result, as shown in FIG. 7B, the flow rate of the steam flowing into the high-pressure turbine section 11 and the flow rate of the steam flowing into the medium-pressure turbine section 12 increase. As a result, as shown in FIG. 7C, the power generation output increases. In the case of condition 4 of the first embodiment, the flow rate of the steam flowing into the high-pressure turbine section 11 is below the limit value, and the flow rate of the steam flowing into the medium-pressure turbine section 12 is below the limit value (FIG. 7B), the power generation output increases by about 9% MW (see FIG. 7C).

（比較例の条件１の場合）
比較例の条件１の場合では、図３に示すように、実施例１の条件１の場合と同様に、発電出力Ｌが１００％ＭＷである状態で通常運転を実行しているときに、系統周波数の減少（図１５参照）を検出し、出力増大運転を行う場合に関して示している。 (In the case of condition 1 of the comparative example)
In the case of the condition 1 of the comparative example, as shown in FIG. 3, as in the case of the condition 1 of the first embodiment, when the normal operation is executed in the state where the power generation output L is 100% MW, the system The case where the frequency decrease (see FIG. 15) is detected and the output increase operation is performed is shown.

上記の場合において、比較例の条件１の場合では、図８Ａに示すように、実施例１の条件１の場合の場合と異なり、第１の高圧抽気絞り弁Ｖ３１、第２の高圧抽気絞り弁Ｖ３２、および、第３の高圧抽気絞り弁Ｖ３３について、「絞り動作」を実行する（実施例１の条件４の場合と同様）。そして、主蒸気加減弁ＶＦ４の開度は、実施例１と同様に増加され、場合によっては全開する。 In the above case, in the case of the condition 1 of the comparative example, as shown in FIG. 8A, unlike the case of the case of the condition 1 of the first embodiment, the first high-pressure bleeding throttle valve V31 and the second high-pressure bleeding throttle valve A "squeezing operation" is executed for V32 and the third high-pressure bleeding throttle valve V33 (similar to the case of condition 4 of the first embodiment). Then, the opening degree of the main steam control valve VF4 is increased in the same manner as in the first embodiment, and in some cases, it is fully opened.

これにより、図８Ｂに示すように、高圧タービン部１１に流入する蒸気の流量、および、中圧タービン部１２に流入する蒸気の流量が増加する。その結果、図８Ｃに示すように、発電出力が増加する。しかしながら、比較例の条件１の場合では、実施例１の条件１の場合と異なり、高圧タービン部１１に流入する蒸気の流量が制限値を超えた状態であると共に、中圧タービン部１２に流入する蒸気の流量が制限値を超えた状態になる（図８Ｂ参照）。 As a result, as shown in FIG. 8B, the flow rate of the steam flowing into the high-pressure turbine section 11 and the flow rate of the steam flowing into the medium-pressure turbine section 12 increase. As a result, as shown in FIG. 8C, the power generation output increases. However, in the case of the condition 1 of the comparative example, unlike the case of the condition 1 of the first embodiment, the flow rate of the steam flowing into the high-pressure turbine section 11 exceeds the limit value and flows into the medium-pressure turbine section 12. The flow rate of steam exceeds the limit value (see FIG. 8B).

（比較例の条件２の場合）
比較例の条件２の場合では、図３に示すように、実施例１の条件２の場合と同様に、発電出力Ｌが９５％ＭＷである状態で通常運転を実行しているときに、系統周波数の減少（図１５参照）を検出し、出力増大運転を行う場合に関して示している。 (In the case of condition 2 of the comparative example)
In the case of the condition 2 of the comparative example, as shown in FIG. 3, as in the case of the condition 2 of the first embodiment, when the normal operation is executed in the state where the power generation output L is 95% MW, the system The case where the frequency decrease (see FIG. 15) is detected and the output increase operation is performed is shown.

上記の場合において、比較例の条件１の場合では、図９Ａに示すように、実施例１の条件２の場合の場合と異なり、第１の高圧抽気絞り弁Ｖ３１、第２の高圧抽気絞り弁Ｖ３２、および、第３の高圧抽気絞り弁Ｖ３３について、「絞り動作」を実行する（実施例１の条件４の場合と同様）。そして、主蒸気加減弁ＶＦ４の開度は、実施例１と同様に増加され、場合によっては全開する。 In the above case, in the case of the condition 1 of the comparative example, as shown in FIG. 9A, unlike the case of the condition 2 of the first embodiment, the first high-pressure bleeding throttle valve V31 and the second high-pressure bleeding throttle valve The "squeezing operation" is executed for V32 and the third high-pressure bleeding throttle valve V33 (similar to the case of condition 4 of the first embodiment). Then, the opening degree of the main steam control valve VF4 is increased in the same manner as in the first embodiment, and in some cases, it is fully opened.

これにより、図９Ｂに示すように、高圧タービン部１１に流入する蒸気の流量、および、中圧タービン部１２に流入する蒸気の流量が増加する。その結果、図９Ｃに示すように、発電出力が増加する。しかしながら、比較例の条件２の場合では、実施例１の条件２の場合と異なり、中圧タービン部１２に流入する蒸気の流量が制限値を超えた状態になる（図９Ｂ参照）。 As a result, as shown in FIG. 9B, the flow rate of the steam flowing into the high-pressure turbine section 11 and the flow rate of the steam flowing into the medium-pressure turbine section 12 increase. As a result, as shown in FIG. 9C, the power generation output increases. However, in the case of the condition 2 of the comparative example, unlike the case of the condition 2 of the first embodiment, the flow rate of the steam flowing into the medium pressure turbine section 12 exceeds the limit value (see FIG. 9B).

（比較例の条件３の場合）
比較例の条件３の場合では、図３に示すように、実施例１の条件３の場合と同様に、発電出力Ｌが９０％ＭＷである状態で通常運転を実行しているときに、系統周波数の減少（図１５参照）を検出し、出力増大運転を行う場合に関して示している。 (In the case of condition 3 of the comparative example)
In the case of the condition 3 of the comparative example, as shown in FIG. 3, as in the case of the condition 3 of the first embodiment, when the normal operation is executed in the state where the power generation output L is 90% MW, the system The case where the frequency decrease (see FIG. 15) is detected and the output increase operation is performed is shown.

上記の場合において、比較例の条件３の場合では、図１０Ａに示すように、実施例１の条件３の場合の場合と異なり、第１の高圧抽気絞り弁Ｖ３１、第２の高圧抽気絞り弁Ｖ３２、および、第３の高圧抽気絞り弁Ｖ３３について、「絞り動作」を実行する（実施例１の条件４の場合と同様）。そして、主蒸気加減弁ＶＦ４の開度は、実施例１と同様に増加され、場合によっては全開する。 In the above case, in the case of the condition 3 of the comparative example, as shown in FIG. 10A, unlike the case of the case of the condition 3 of the first embodiment, the first high-pressure bleeding throttle valve V31 and the second high-pressure bleeding throttle valve A "squeezing operation" is executed for V32 and the third high-pressure bleeding throttle valve V33 (similar to the case of condition 4 of the first embodiment). Then, the opening degree of the main steam control valve VF4 is increased in the same manner as in the first embodiment, and in some cases, it is fully opened.

これにより、図１０Ｂに示すように、高圧タービン部１１に流入する蒸気の流量、および、中圧タービン部１２に流入する蒸気の流量が増加する。その結果、図１０Ｃに示すように、発電出力が増加する。しかしながら、比較例の条件３の場合では、実施例１の条件３の場合と異なり、中圧タービン部１２に流入する蒸気の流量が制限値を超えた状態になる（図１０Ｂ参照）。 As a result, as shown in FIG. 10B, the flow rate of the steam flowing into the high-pressure turbine section 11 and the flow rate of the steam flowing into the medium-pressure turbine section 12 increase. As a result, as shown in FIG. 10C, the power generation output increases. However, in the case of the condition 3 of the comparative example, unlike the case of the condition 3 of the first embodiment, the flow rate of the steam flowing into the medium pressure turbine section 12 exceeds the limit value (see FIG. 10B).

上記の結果からわかるように、実施例１の場合においては、蒸気タービン１（高圧タービン部１１，中圧タービン部１２）に流入する蒸気の流量が制限値以下の状態で、発電出力を増加させることができる。これに対して、比較例の場合においては、蒸気タービン１（高圧タービン部１１，中圧タービン部１２）に流入する蒸気の流量について制限値以下の状態にすることができない。 As can be seen from the above results, in the case of the first embodiment, the power generation output is increased in a state where the flow rate of the steam flowing into the steam turbine 1 (high pressure turbine section 11, medium pressure turbine section 12) is equal to or less than the limit value. be able to. On the other hand, in the case of the comparative example, the flow rate of the steam flowing into the steam turbine 1 (high pressure turbine section 11, medium pressure turbine section 12) cannot be set to a state below the limit value.

本実施例では、給水温度が高い側の抽気絞り弁について優先的に「絞り動作」を実行させ、給水温度が低い側の抽気絞り弁をできるだけ絞らない運用を実現する。これにより、より給水温度が低い給水加熱器は、通常通りの運転となる。これにより、より給水温度が高い給水加熱器から給水温度が低い給水加熱器へドレン水が送られるドレン回収時に、ドレン水を受け入れる側の給水加熱器の運転は通常運転であるため、ドレン水を受け入れる側の給水加熱器の運転がより安定して行われる副次的な効果が得られる。 In this embodiment, the "drawing operation" is preferentially executed for the bleed air throttle valve on the side where the water supply temperature is high, and the operation in which the bleed air throttle valve on the side where the water supply temperature is low is not throttled is realized. As a result, the feed water heater having a lower feed water temperature operates as usual. As a result, when drain water is sent from a feed water heater with a higher water supply temperature to a feed water heater with a lower water supply temperature, the operation of the feed water heater on the side that receives the drain water is normal operation, so drain water is used. A secondary effect is obtained that the operation of the feed water heater on the receiving side is performed more stably.

具体的には、実施例１の条件２の場合には、第１の高圧抽気絞り弁Ｖ３１について「絞り動作」を行い、第２の高圧抽気絞り弁Ｖ３２と第３の高圧抽気絞り弁Ｖ３３については「絞り動作」を行わない。第１の給水加熱器３１では、第１の高圧抽気絞り弁Ｖ３１の「絞り動作」により蒸気Ｂ１ａが減少し、その後、第１の高圧抽気絞り弁Ｖ３１の「絞り動作」の解消により蒸気Ｂ１ａが増加する。この結果、ドレン水Ｂ３１は減少した後に増加する。この間、ドレン水Ｂ３１を受け入れる第２の高圧給水加熱器３２については、第２の高圧抽気絞り弁Ｖ３２の「絞り動作」が行われずに通常通りの運転が行われるので、ドレン水Ｂ３１の減増に対しても安定な運転が実現できる。また、ドレン水Ｂ３１の減増に伴ってドレン水Ｂ３２も減増する。この間、ドレン水Ｂ３２を受け入れる第３の高圧給水加熱器３３については、第３の高圧抽気絞り弁Ｖ３３の「絞り動作」が行われずに通常通りの運転が行われるるので、ドレン水Ｂ３２の減増に対しても安定な運転が実現できる。 Specifically, in the case of the condition 2 of the first embodiment, the "squeezing operation" is performed on the first high-pressure bleeding throttle valve V31, and the second high-pressure bleeding throttle valve V32 and the third high-pressure bleeding throttle valve V33. Does not perform "aperture operation". In the first feed water heater 31, the steam B1a is reduced by the "throttle operation" of the first high-pressure bleed air throttle valve V31, and then the steam B1a is reduced by the elimination of the "squeeze operation" of the first high-pressure bleed air throttle valve V31. To increase. As a result, the drain water B31 decreases and then increases. During this period, the second high-pressure feed water heater 32 that receives the drain water B31 is operated as usual without performing the "throttle operation" of the second high-pressure bleed air throttle valve V32, so that the drain water B31 is reduced. Stable operation can be realized even for the above. Further, as the drain water B31 decreases, the drain water B32 also decreases. During this period, the third high-pressure feed water heater 33 that receives the drain water B32 is operated as usual without performing the "throttle operation" of the third high-pressure bleed air throttle valve V33, so that the drain water B32 is reduced. Stable operation can be realized even if the number increases.

更に具体的な説明を記載する。実施例１の条件３の場合には、第１の高圧抽気絞り弁Ｖ３１と第２の高圧抽気絞り弁Ｖ３２について「絞り動作」を行い、第３の高圧抽気絞り弁Ｖ３３については「絞り動作」を行わない。第１の給水加熱器３１では、第１の高圧抽気絞り弁Ｖ３１の「絞り動作」により蒸気Ｂ１ａが減少し、その後、第１の高圧抽気絞り弁Ｖ３１の「絞り動作」の解消により蒸気Ｂ１ａが増加する。この結果、ドレン水Ｂ３１は減少した後に増加する。この間、ドレン水Ｂ３１を受け入れる第２の高圧給水加熱器３２についても、第２の高圧抽気絞り弁Ｖ３２の「絞り動作」を行い、その後「絞り動作」を解消するため、蒸気Ｂ１ｂ＿２は減少した後に増加する。この時、ドレン水Ｂ３１の減増と、蒸気Ｂ１ｂ＿２の減増は、ほぼ同じタイミングで発生するため、第２の高圧給水加熱器３２の運転状態は全体がバランスした状態で推移し、安定に運転することができる。ドレン水Ｂ３１とドレン水Ｂ３２が減増する間、ドレン水Ｂ３２を受け入れる第３の高圧給水加熱器３３については、第３の高圧抽気絞り弁Ｖ３３の「絞り動作」が行われず通常通りの運転が行われるあるので、ドレン水Ｂ３２の減増に対しても安定な運転が実現できる。 A more specific explanation will be described. In the case of the condition 3 of the first embodiment, the first high-pressure bleed air throttle valve V31 and the second high-pressure bleed air throttle valve V32 are "squeezed", and the third high-pressure bleed air throttle valve V33 is "squeezed". Do not do. In the first feed water heater 31, the steam B1a is reduced by the "throttle operation" of the first high-pressure bleed air throttle valve V31, and then the steam B1a is reduced by the elimination of the "squeeze operation" of the first high-pressure bleed air throttle valve V31. To increase. As a result, the drain water B31 decreases and then increases. During this period, the second high-pressure feed water heater 32 that receives the drain water B31 also performs the "squeezing operation" of the second high-pressure bleed air throttle valve V32, and then eliminates the "squeezing operation", so that the steam B1b_2 is reduced. To increase. At this time, the decrease of the drain water B31 and the decrease of the steam B1b_2 occur at almost the same timing, so that the operating state of the second high-pressure feed water heater 32 changes in a balanced state as a whole and operates stably. can do. While the drain water B31 and the drain water B32 decrease, the third high-pressure feed water heater 33 that accepts the drain water B32 does not perform the "throttle operation" of the third high-pressure bleed air throttle valve V33 and operates normally. Since it is performed, stable operation can be realized even when the drain water B32 is reduced.

更に具体的な説明を記載する。本実施例とは逆に、実施例の条件２の場合に、第１の高圧抽気絞り弁Ｖ３１と第２の高圧抽気絞り弁Ｖ３２については「絞り動作」を実行せずに、第３の高圧抽気絞り弁Ｖ３３のみについて「絞り動作」を実行する状態を検討する。中圧タービン部１２の通過蒸気流量には十分な余裕があり、高圧タービン部１１の通過蒸気流量の余裕が小さい場合には、この方法が適している。すなわち、「出力増大運転」の時に、第１の高圧抽気絞り弁Ｖ３１が「絞り動作」を実行しないことにより、高圧タービン部１１の通過蒸気流量増加は、加減弁ＶＦ４の開度が増加し、場合によっては全開することによる蒸気流量増加にとどまるため、高圧タービン部１１の蒸気流量Ｂ１ｂは、制限値以上に増加することは無い。また、第３の高圧抽気絞り弁Ｖ３３が「絞り動作」を実行することにより、発電機１４の出力を効果的に増加させることができる。なお、第３の高圧給水加熱器３３は、第３の高圧抽気絞り弁Ｖ３３が「絞り動作」を実行することにより抽気蒸気流量が減少し、一方でドレン水Ｂ３２はほぼ一定の流量が供給されるため、抽気流量とドレン水流量のバランスが、「出力増大運転」の前と後とでは異なる状態となる。このバランスが一定範囲を逸脱しない範囲で第３の高圧抽気絞り弁Ｖ３３を「絞り動作」させることにより、給水加熱器３３を安定に運転することができる。具体的には、「絞り動作」時の第３の高圧抽気絞り弁Ｖ３３の開度変化を、実施例１の条件２における第１の高圧抽気絞り弁Ｖ３１の開度変化に対して半分程度にする方法と、第３の高圧抽気絞り弁Ｖ３３の「絞り動作」の継続時間を、実施例１の条件２における第１の高圧抽気絞り弁Ｖ３１の場合よりも半分程度に短くする方法との少なくとも一方の方法により、給水加熱器３３を安定に運転することができる。 A more specific explanation will be described. Contrary to this embodiment, under the condition 2 of the embodiment, the first high-pressure bleed throttle valve V31 and the second high-pressure bleed throttle valve V32 do not execute the "drawing operation", and the third high pressure is applied. Consider a state in which the "squeezing operation" is executed only for the bleed air throttle valve V33. This method is suitable when the passing steam flow rate of the medium-pressure turbine section 12 has a sufficient margin and the passing steam flow rate of the high-pressure turbine section 11 has a small margin. That is, since the first high-pressure bleeding throttle valve V31 does not execute the "throttle operation" during the "output increasing operation", the increase in the passing steam flow rate of the high-pressure turbine section 11 increases the opening degree of the control valve VF4. In some cases, the steam flow rate B1b of the high-pressure turbine section 11 does not increase more than the limit value because the steam flow rate increases only by fully opening. Further, the output of the generator 14 can be effectively increased by executing the "throttle operation" by the third high-pressure bleed air throttle valve V33. In the third high-pressure feed water heater 33, the bleed steam flow rate is reduced by the third high-pressure bleeding throttle valve V33 executing the "squeezing operation", while the drain water B32 is supplied with a substantially constant flow rate. Therefore, the balance between the bleed air flow rate and the drain water flow rate is different between before and after the "output increase operation". By "squeezing" the third high-pressure bleed throttle valve V33 within a range in which this balance does not deviate from a certain range, the feed water heater 33 can be operated stably. Specifically, the change in the opening degree of the third high-pressure bleeding throttle valve V33 during the "throttle operation" is reduced to about half of the change in the opening degree of the first high-pressure bleeding throttle valve V31 under the condition 2 of the first embodiment. And a method of shortening the duration of the "squeezing operation" of the third high-pressure bleeding throttle valve V33 to about half as compared with the case of the first high-pressure bleeding throttle valve V31 in the condition 2 of the first embodiment. By one method, the feed water heater 33 can be operated stably.

［変形例］
なお、給水加熱部３が備える給水加熱器の台数は、適宜、変更してもよい。また、図２および図３に示した発電出力Ｌの値は、例示であって、発電プラントおよび許容値等に応じて適宜設定される。また、高圧抽気絞り弁Ｖ３１、Ｖ３２、Ｖ３３は、出力増大運転の際に５％の開度にする場合について記載したが、全閉を含む他の開度でも良い。 [Modification example]
The number of feed water heaters included in the feed water heater 3 may be changed as appropriate. Further, the value of the power generation output L shown in FIGS. 2 and 3 is an example, and is appropriately set according to the power plant, the allowable value, and the like. Further, although the high-pressure bleeding throttle valves V31, V32, and V33 have been described in the case where the opening degree is set to 5% during the output increasing operation, other opening degrees including fully closed may be used.

＜第２実施形態＞
［動作］
本実施形態の火力発電プラントにおいて「出力増大運転」を行うときの動作の一例に関して、図１１を用いて説明する。図１１では、図２と同様に、「出力増大運転」を実行する場合に、系統周波数の減少を検出した時点で発電機１４が電力系統に出力していた値Ｌ（％）と、抽気絞り弁Ｖ３１～Ｖ３３の動作との関係を例示している。図１１においても、抽気絞り弁Ｖ３１～Ｖ３３について開度を小さくする「絞り動作」を実行する場合を「有」と示し、「絞り動作」を実行しない場合を「無」と示している。 <Second Embodiment>
[motion]
An example of the operation when performing the “output increasing operation” in the thermal power plant of the present embodiment will be described with reference to FIG. In FIG. 11, similarly to FIG. 2, when the “output increasing operation” is executed, the value L (%) output to the power system by the generator 14 at the time when the decrease in the system frequency is detected and the bleed air throttle The relationship with the operation of the valves V31 to V33 is illustrated. Also in FIG. 11, the case where the “throttle operation” for reducing the opening degree of the bleed air throttle valves V31 to V33 is executed is shown as “yes”, and the case where the “throttle operation” is not executed is shown as “no”.

図１１に示すように、本実施形態では、第１実施形態の場合と同様に、系統周波数の減少を検出した時点で発電機１４から電力系統に出力された電力（発電出力）が低くなるに伴って、「絞り動作」を実行する抽気絞り弁Ｖ３１～Ｖ３３の数が増加している。ここでは、上述したように、抽気絞り弁Ｖ３１～Ｖ３３の「絞り動作」は、系統周波数の減少を検出した時点で発電機１４から電力系統に出力された電力（発電出力）が低くなるに伴って、給水加熱器３１～３３において加熱媒体の圧力が高い側から低い側に向けて加熱媒体が供給される流量を低減させる給水加熱器３１～３３の数が増加するように制御される。 As shown in FIG. 11, in the present embodiment, as in the case of the first embodiment, the electric power (power generation output) output from the generator 14 to the power system becomes low when the decrease in the system frequency is detected. Along with this, the number of bleeding throttle valves V31 to V33 that execute the "squeezing operation" is increasing. Here, as described above, in the "throttle operation" of the bleed-out throttle valves V31 to V33, the power (power generation output) output from the generator 14 to the power system at the time when the decrease in the system frequency is detected becomes lower. Therefore, in the feed water heaters 31 to 33, the number of feed water heaters 31 to 33 that reduce the flow rate at which the heating medium is supplied is controlled to increase from the side where the pressure of the heating medium is high to the side where the pressure is low.

しかし、本実施形態では、系統周波数の減少を検出した時点で発電機１４から電力系統に出力された電力（発電出力Ｌ）が９５％ＭＷ（第１の閾値Ｌ１）を超えた値である場合（９５＜Ｌの場合）の動作に関して、第１実施形態の場合と異なる。この点、および、関連する点を除き、本実施形態は、第１実施形態の場合と同様であるため、重複する事項に関しては、適宜、説明を省略する。 However, in the present embodiment, when the power output from the generator 14 to the power system (power generation output L) at the time when the decrease in the system frequency is detected is a value exceeding 95% MW (first threshold value L1). The operation (in the case of 95 <L) is different from that in the first embodiment. Except for this point and related points, the present embodiment is the same as that of the first embodiment, and therefore, the description of overlapping matters will be omitted as appropriate.

図１１に示すように、系統周波数の減少を検出した時点で発電機１４から電力系統に出力された電力（発電出力Ｌ）が９５％ＭＷを超えた値である場合（９５＜Ｌの場合）、本実施形態では、第１実施形態の場合（図２参照）と同様に、第２の高圧抽気絞り弁Ｖ３２および第３の高圧抽気絞り弁Ｖ３３に関しては「絞り動作」を実行しない。しかしながら、本実施形態では、制御装置８００は、第１の高圧抽気絞り弁Ｖ３１については「絞り動作」を実行する。つまり、第１の高圧抽気絞り弁Ｖ３１の開度を小さくし、かつ、第２の高圧抽気絞り弁Ｖ３２の開度および第３の高圧抽気絞り弁Ｖ３３の開度を保持させた状態で、出力増大運転を行う。 As shown in FIG. 11, when the power output from the generator 14 to the power system (power generation output L) exceeds 95% MW at the time when the decrease in the system frequency is detected (when 95 <L). In the present embodiment, as in the case of the first embodiment (see FIG. 2), the "drawing operation" is not executed for the second high-pressure bleeding throttle valve V32 and the third high-pressure bleeding throttle valve V33. However, in the present embodiment, the control device 800 executes a "throttle operation" for the first high-pressure bleed air throttle valve V31. That is, the output is performed in a state where the opening degree of the first high-pressure bleeding throttle valve V31 is reduced and the opening degree of the second high-pressure bleeding throttle valve V32 and the opening degree of the third high-pressure bleeding throttle valve V33 are maintained. Perform augmented operation.

本実施形態において、上記の発電出力Ｌが９５％ＭＷを超えた値である場合（９５＜Ｌの場合）に実行する「絞り動作」の一例について、図１２を用いて説明する。 In the present embodiment, an example of the “throttle operation” to be executed when the power generation output L exceeds 95% MW (when 95 <L) will be described with reference to FIG.

既に第１実施形態の説明で述べたように、上記の発電出力Ｌが９５％ＭＷ以下の値である場合（Ｌ≦９５）に実行する「絞り動作」は、本実施形態においても、発電出力Ｌの値に関わらずに、各高圧抽気絞り弁Ｖ３１～Ｖ３３を、予め定めた一定の開度（たとえば、５％の開度）まで小さくしている。 As already described in the description of the first embodiment, the "throttle operation" executed when the above power generation output L is a value of 95% MW or less (L ≦ 95) is also the power generation output in this embodiment. Regardless of the value of L, each high-pressure bleeding throttle valve V31 to V33 is reduced to a predetermined constant opening degree (for example, an opening degree of 5%).

しかしながら、本実施形態において、上記の発電出力Ｌが９５％ＭＷを超えた値である場合（９５＜Ｌ）に実行する「絞り動作」は、図１２に示すように、発電出力Ｌが小さくなるに伴って第１の高圧抽気絞り弁Ｖ３１の開度が小さい値になるように実行される。 However, in the present embodiment, in the "throttle operation" executed when the power generation output L exceeds 95% MW (95 <L), the power generation output L becomes smaller as shown in FIG. Therefore, the opening degree of the first high-pressure bleeding throttle valve V31 is set to a small value.

具体的には、上記の発電出力Ｌが９５％ＭＷの場合には、第１の高圧抽気絞り弁Ｖ３１の開度を５％まで絞る。そして、上記の発電出力Ｌが９７％ＭＷの場合には、第１の高圧抽気絞り弁Ｖ３１の開度を２５％まで絞る。上記の発電出力Ｌが９５％ＭＷから９７％ＭＷまでの範囲である場合には、第１の高圧抽気絞り弁Ｖ３１の開度を、５％と２５％との間を線形補間した値になるように絞る。 Specifically, when the power generation output L is 95% MW, the opening degree of the first high-pressure bleed throttle valve V31 is reduced to 5%. When the power generation output L is 97% MW, the opening degree of the first high-pressure bleed throttle valve V31 is reduced to 25%. When the power generation output L is in the range of 95% MW to 97% MW, the opening degree of the first high-pressure bleed throttle valve V31 is a value linearly interpolated between 5% and 25%. Squeeze like.

そして、上記の発電出力Ｌが９８％ＭＷの場合には、第１の高圧抽気絞り弁Ｖ３１の開度を２９％まで絞る。上記の発電出力Ｌが９７％ＭＷから９８％ＭＷまでの範囲である場合には、第１の高圧抽気絞り弁Ｖ３１の開度を、２５％と２９％との間を線形補間した値になるように絞る。 When the power generation output L is 98% MW, the opening degree of the first high-pressure bleed throttle valve V31 is reduced to 29%. When the power generation output L is in the range of 97% MW to 98% MW, the opening degree of the first high-pressure bleed throttle valve V31 is linearly interpolated between 25% and 29%. Squeeze like.

そして、上記の発電出力Ｌが９９％ＭＷの場合には、第１の高圧抽気絞り弁Ｖ３１の開度を３５％まで絞る。上記の発電出力Ｌが９８％ＭＷから９９％ＭＷまでの範囲である場合には、第１の高圧抽気絞り弁Ｖ３１の開度を、２９％と３５％との間を線形補間した値になるように絞る。 When the power generation output L is 99% MW, the opening degree of the first high-pressure bleed throttle valve V31 is reduced to 35%. When the power generation output L is in the range of 98% MW to 99% MW, the opening degree of the first high-pressure bleed throttle valve V31 is linearly interpolated between 29% and 35%. Squeeze like.

そして、上記の発電出力Ｌが１００％ＭＷの場合には、第１の高圧抽気絞り弁Ｖ３１の開度を４０％まで絞る。上記の発電出力Ｌが９９％ＭＷから１００％ＭＷまでの範囲である場合には、第１の高圧抽気絞り弁Ｖ３１の開度を、３５％と４０％との間を線形補間した値になるように絞る。 When the power generation output L is 100% MW, the opening degree of the first high-pressure bleed throttle valve V31 is reduced to 40%. When the power generation output L is in the range of 99% MW to 100% MW, the opening degree of the first high-pressure bleed throttle valve V31 is linearly interpolated between 35% and 40%. Squeeze like.

図１２に示す関数テーブルは、一例であり、高圧タービン部１１および中圧タービン部１２のそれぞれにおいて通過する蒸気の流量の制限値と、それぞれの抽気カットによって生ずる蒸気の流量の増加分とに応じて、適宜、設定される。 The function table shown in FIG. 12 is an example, and corresponds to the limit value of the flow rate of steam passing through each of the high-pressure turbine section 11 and the medium-pressure turbine section 12 and the increase in the flow rate of steam caused by each bleed air cut. It is set as appropriate.

［実施例］
以下より、本実施形態の火力発電プラントで実行する出力増大運転に関する実施例について説明する。 [Example]
Hereinafter, an example relating to the output increasing operation executed in the thermal power plant of the present embodiment will be described.

図１３は、第２実施形態に係る実施例２について、条件を示す図である。 FIG. 13 is a diagram showing conditions for Example 2 according to the second embodiment.

図１４Ａから図１４Ｃは、実施例２の条件１の場合について示す図である。ここで、図１４Ａから図１４Ｃのうち、図１４Ａは、各高圧抽気絞り弁Ｖ３１～Ｖ３３の開度を示している。そして、図１４Ｂは、高圧タービン部１１（ＨＰ ＳＴ）に流入する蒸気の流量と、中圧タービン部１２（ＩＰ ＳＴ）に流入する蒸気の流量とを実線で示すと共に、高圧タービン部１１（ＨＰ ＳＴ）に流入する蒸気の制限値、および、中圧タービン部１２（ＩＰ ＳＴ）に流入する蒸気の制限値を破線で示している。図１４Ｃにおいては、発電出力を実線で示している。なお、実施例２の条件２から条件４のそれぞれは、実施例１の条件２から条件４のそれぞれと同じであるため、具体的な説明を省略する。 14A to 14C are diagrams showing the case of condition 1 of the second embodiment. Here, of FIGS. 14A to 14C, FIG. 14A shows the opening degrees of the high-pressure bleeding throttle valves V31 to V33. 14B shows the flow rate of steam flowing into the high-pressure turbine section 11 (HP ST) and the flow rate of steam flowing into the medium-pressure turbine section 12 (IP ST) with a solid line, and shows the flow rate of the steam flowing into the high-pressure turbine section 11 (HP ST) with a solid line. The limit value of the steam flowing into the ST) and the limit value of the steam flowing into the medium pressure turbine section 12 (IPST) are shown by a broken line. In FIG. 14C, the power generation output is shown by a solid line. Since each of the conditions 2 to 4 of the second embodiment is the same as each of the conditions 2 to 4 of the first embodiment, a specific description thereof will be omitted.

（実施例２の条件１の場合）
実施例２の条件１の場合では、図１３に示すように、発電出力Ｌが１００％ＭＷである状態で通常運転を実行しているときに、系統周波数の減少（図１５参照）を検出し、出力増大運転を行う場合に関して示している。つまり、図１１に示したように、系統周波数の減少を検出した時点で発電機１４から電力系統に出力された電力（発電出力Ｌ）が９５％ＭＷ（第１の閾値Ｌ１）を超えた値である場合（９５＜Ｌの場合）において、出力増大運転を行う場合に関して例示している。 (In the case of condition 1 of Example 2)
In the case of condition 1 of the second embodiment, as shown in FIG. 13, a decrease in the system frequency (see FIG. 15) is detected during normal operation in a state where the power generation output L is 100% MW. , The case where the output increase operation is performed is shown. That is, as shown in FIG. 11, the value of the power (power generation output L) output from the generator 14 to the power system when the decrease in the system frequency is detected exceeds 95% MW (first threshold value L1). In the case where (95 <L), the case where the output increasing operation is performed is illustrated.

実施例２の条件１の場合では、図１４Ａに示すように、実施例１の条件１の場合と異なり、第１の高圧抽気絞り弁Ｖ３１については、「絞り動作」を実行するのに対して、第２の高圧抽気絞り弁Ｖ３２および第３の高圧抽気絞り弁Ｖ３３については、「絞り動作」を実行しない。すなわち、第１の高圧抽気絞り弁Ｖ３１の開度を小さくし、かつ、第２の高圧抽気絞り弁Ｖ３２の開度および第３の高圧抽気絞り弁Ｖ３３の開度を保持させた状態で、出力増大運転を行う。ここでは、図１２に示したように、全開状態の開度（１００％）から、たとえば、４０％の開度になるように、第１の高圧抽気絞り弁Ｖ３１の開度を小さくする。その後、第１の高圧抽気絞り弁Ｖ３１の開度を徐々に大きくする。 In the case of the condition 1 of the second embodiment, as shown in FIG. 14A, unlike the case of the condition 1 of the first embodiment, the "throttle operation" is executed for the first high-pressure bleed air throttle valve V31. , The second high-pressure bleeding throttle valve V32 and the third high-pressure bleeding throttle valve V33 do not execute the "drawing operation". That is, the output is performed in a state where the opening degree of the first high-pressure bleeding throttle valve V31 is reduced and the opening degree of the second high-pressure bleeding throttle valve V32 and the opening degree of the third high-pressure bleeding throttle valve V33 are maintained. Perform augmented operation. Here, as shown in FIG. 12, the opening degree of the first high-pressure bleeding throttle valve V31 is reduced so that the opening degree is, for example, 40% from the opening degree (100%) in the fully open state. After that, the opening degree of the first high-pressure bleeding throttle valve V31 is gradually increased.

これにより、図１４Ｂに示すように、高圧タービン部１１に流入する蒸気の流量、および、中圧タービン部１２に流入する蒸気の流量が増加する。その結果、図１４Ｃに示すように、発電出力Ｌが増加する。実施例２の条件１の場合では、高圧タービン部１１に流入する蒸気の流量が制限値以下の状態であると共に、中圧タービン部１２に流入する蒸気の流量が制限値以下の状態で（図１４Ｂ参照）、発電出力が一時的に約２．３％ＭＷ増加する（図１４Ｃ参照）。つまり、実施例２の条件１の場合では、実施例１の条件１の場合（１．８％ＭＷ増加）よりも大きな発電出力Ｌを得ることができる。 As a result, as shown in FIG. 14B, the flow rate of the steam flowing into the high-pressure turbine section 11 and the flow rate of the steam flowing into the medium-pressure turbine section 12 increase. As a result, as shown in FIG. 14C, the power generation output L increases. In the case of condition 1 of the second embodiment, the flow rate of the steam flowing into the high-pressure turbine section 11 is below the limit value, and the flow rate of the steam flowing into the medium-pressure turbine section 12 is below the limit value (FIG. (See 14B), the power generation output temporarily increases by about 2.3% MW (see FIG. 14C). That is, in the case of the condition 1 of the second embodiment, a larger power generation output L can be obtained than in the case of the condition 1 of the first embodiment (1.8% increase in MW).

なお、上記のように、第１の高圧抽気絞り弁Ｖ３１の開度を可変的に調整する絞り動作ためには、主蒸気加減弁で用いられる制御弁のように、動作が高速であって開度調整が可能な制御弁を用いることで、実用化が可能である。 As described above, in order to variably adjust the opening degree of the first high-pressure bleeding throttle valve V31, the operation is fast and open like the control valve used in the main steam control valve. It can be put into practical use by using a control valve that can adjust the degree.

以上の結果から判るように、本実施形態では、蒸気タービンを作動媒体として通過する蒸気の流量が上限許容値以下になるように、出力増大運転を容易に実行可能である共に、出力増大運転の際に、上記した第１実施形態の場合よりも大きな発電出力Ｌを得ることが可能である。 As can be seen from the above results, in the present embodiment, the output increasing operation can be easily executed so that the flow rate of the steam passing through the steam turbine as the operating medium is equal to or less than the upper limit allowable value, and the output increasing operation is performed. At the same time, it is possible to obtain a larger power generation output L than in the case of the first embodiment described above.

［変形例］
上記した第２実施形態では、上記の発電出力Ｌが９５％ＭＷを超えた値である場合（９５＜Ｌ）に実行する「絞り動作」において、第１の高圧抽気絞り弁Ｖ３１の開度に関して、発電出力Ｌが小さくなるに伴って小さくする場合を説明したが、これに限らない。他条件の「絞り動作」においても、発電出力Ｌが小さくなるに伴って各弁の開度を小さくしてもよい。つまり、第２の高圧抽気絞り弁Ｖ３２および第３の高圧抽気絞り弁Ｖ３３に関しても、「絞り動作」において、発電出力Ｌが小さくなるに伴って開度が小さくなるように、制御を行ってもよい。 [Modification example]
In the second embodiment described above, in the "throttle operation" executed when the power generation output L exceeds 95% MW (95 <L), regarding the opening degree of the first high-pressure bleed air throttle valve V31. The case where the power generation output L is reduced as the power generation output L becomes smaller has been described, but the present invention is not limited to this. Even in the "throttle operation" under other conditions, the opening degree of each valve may be reduced as the power generation output L becomes smaller. That is, even if the second high-pressure bleed throttle valve V32 and the third high-pressure bleed throttle valve V33 are controlled so that the opening degree decreases as the power generation output L decreases in the "drawing operation". good.

＜その他＞
本発明のいくつかの実施形態を説明したが、これらの実施形態は、例として提示したものであり、発明の範囲を限定することは意図していない。これら新規な実施形態は、その他の様々な形態で実施されることが可能であり、発明の要旨を逸脱しない範囲で、種々の省略、置き換え、変更を行うことができる。これら実施形態やその変形は、発明の範囲や要旨に含まれるとともに、特許請求の範囲に記載された発明とその均等の範囲に含まれる。 <Others>
Although some embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other embodiments, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are also included in the scope of the invention described in the claims and the equivalent scope thereof.

１…蒸気タービン、２…復水器、３…給水加熱部、３Ａ…高圧給水加熱部、３Ｂ…低圧給水加熱部、４…ボイラ、１１…高圧タービン部、１２…中圧タービン部、１３…低圧タービン部、１４…発電機、３１…第１高圧給水加熱器、３２…第２高圧給水加熱器、３３…第３高圧給水加熱器、３１１…脱気器、８００…制御装置、Ａ１１…供給口、Ａ１１ａ…抽気口、Ａ１１ｂ…排気口、Ａ１２…供給口、Ａ１２ａ…抽気口、Ａ１２ｂ…排気口、Ａ１２ｃ…排気口、Ａ１３…供給口、Ａ１３ａ…抽気口、Ａ１３ｅ…排気口、Ｐ２…復水ポンプ、Ｐ３１１…給水ポンプ、Ｖ３１…第１の高圧抽気絞り弁、Ｖ３２…第２の高圧抽気絞り弁、Ｖ３３…第３の高圧抽気絞り弁、ＶＢ４…インターセプト弁、ＶＦ４…主蒸気加減弁 1 ... Steam turbine, 2 ... Feed water heater, 3 ... Feed water heater, 3A ... High pressure feed water heater, 3B ... Low pressure feed water heater, 4 ... Boiler, 11 ... High pressure turbine, 12 ... Medium pressure turbine, 13 ... Low-pressure turbine section, 14 ... generator, 31 ... first high-pressure feed water heater, 32 ... second high-pressure feed water heater, 33 ... third high-pressure feed water heater, 311 ... deaerator, 800 ... control device, A11 ... supply Port, A11a ... Boiler port, A11b ... Exhaust port, A12 ... Supply port, A12a ... Boiler port, A12b ... Exhaust port, A12c ... Exhaust port, A13 ... Supply port, A13a ... Boiler port, A13e ... Exhaust port, P2 ... Restoration Water pump, P311 ... Feed water pump, V31 ... First high-pressure bleeding throttle valve, V32 ... Second high-pressure bleeding throttle valve, V33 ... Third high-pressure bleeding throttle valve, VB4 ... Intercept valve, VF4 ... Main steam control valve

Claims (6)

蒸気タービンと、
前記蒸気タービンから排気された蒸気を冷却して凝縮させる復水器と、
前記蒸気タービンから抽気された蒸気を加熱媒体として用いて、前記復水器において凝縮された水を加熱する給水加熱部と、
前記給水加熱部において加熱された水を加熱することによって蒸気を生成するボイラと、
前記ボイラで生成された蒸気が前記蒸気タービンに供給されることによって前記蒸気タービンが回転し、その駆動力によって発電を行う発電機と
を備え、抽気絞り弁を介して前記加熱媒体が供給される給水加熱器を前記給水加熱部が複数備えている、火力発電プラントであって、
電力系統における系統周波数の減少を検出した際に前記発電機の発電出力を増加させる出力増大運転を行う場合に、前記系統周波数の減少を検出した時点における前記発電機の発電出力に基づいて、前記複数の抽気絞り弁のそれぞれに関して、開度を小さくする動作と開度を保持させる動作とのいずれか一方を行うように制御する制御装置
を有する、
火力発電プラント。 With a steam turbine,
A condenser that cools and condenses the steam exhausted from the steam turbine,
A water supply heating unit that heats the condensed water in the condenser by using the steam extracted from the steam turbine as a heating medium.
A boiler that generates steam by heating the water heated in the water supply heating unit, and
The steam generated by the boiler is supplied to the steam turbine to rotate the steam turbine, and a generator for generating electricity by the driving force thereof is provided, and the heating medium is supplied via an bleeding throttle valve. It is a thermal power generation plant equipped with a plurality of feed water heaters in the feed water heating unit.
When an output increase operation is performed to increase the power generation output of the generator when a decrease in the system frequency in the power system is detected, the power generation output of the generator at the time when the decrease in the system frequency is detected is used as described above. It has a control device for controlling each of a plurality of bleeding throttle valves to perform either an operation of reducing the opening degree or an operation of maintaining the opening degree .
Thermal power plant. 前記給水加熱部は、
前記複数の給水加熱器のそれぞれに供給される前記加熱媒体の圧力が、前記復水器で凝縮した水の流れに沿って順次高くなるように構成され、かつ、前記復水器で凝縮した水が前記複数の給水加熱器を順次流れることによって、前記復水器で凝縮した水の温度が上昇するように構成されており、
前記制御装置は、前記出力増大運転を行う際には、前記複数の給水加熱器において前記加熱媒体の圧力が高い側から低い側に向けて前記加熱媒体が供給される流量を低減させる前記給水加熱器の数が、前記系統周波数の減少を検出した時点における前記発電機の発電出力が低くなるに伴って増加するように、前記複数の抽気絞り弁の動作を制御する、
請求項１に記載の火力発電プラント。 The water supply heating unit is
The pressure of the heating medium supplied to each of the plurality of feed water heaters is configured to be sequentially increased along the flow of water condensed by the condenser, and the water condensed by the condenser. Is configured to raise the temperature of the condensed water in the condenser by sequentially flowing through the plurality of feed water heaters.
The control device reduces the flow rate at which the heating medium is supplied from the side where the pressure of the heating medium is high to the side where the pressure of the heating medium is low in the plurality of feed water heaters when the output increasing operation is performed. The operation of the plurality of bleed throttle valves is controlled so that the number of heaters increases as the power generation output of the generator decreases at the time when the decrease in the system frequency is detected.
The thermal power plant according to claim 1. 前記給水加熱部は、前記給水加熱器として、
第１給水加熱器と、
前記加熱媒体の圧力が前記第１給水加熱器よりも低い第２給水加熱器と
を少なくとも含み、前記復水器で凝縮した水が、前記第２給水加熱器と前記第１給水加熱器とを順次流れることによって温度が上昇するように構成されていると共に、
前記抽気絞り弁として、
前記第１給水加熱器に流れる前記加熱媒体の流量を調整する第１の抽気絞り弁と、
前記第２給水加熱器に流れる前記加熱媒体の流量を調整する第２の抽気絞り弁とを少なくとも含み、
前記制御装置は、
前記系統周波数の減少を検出した時点における前記発電機の発電出力が第１の閾値を超えた値である場合には、前記第１の抽気絞り弁の開度および前記第２の抽気絞り弁の開度を保持させた状態で前記出力増大運転を行い、
前記系統周波数の減少を検出した時点における前記発電機の発電出力が前記第１の閾値以下であって前記第１の閾値よりも小さい第２の閾値を超えた値である場合には、前記第１の抽気絞り弁の開度を小さくし、かつ、前記第２の抽気絞り弁の開度を保持させた状態で前記出力増大運転を行い、
前記系統周波数の減少を検出した時点における前記発電機の発電出力が前記第２の閾値以下であって前記第２の閾値よりも小さい第３の閾値を超えた値である場合には、前記第１の抽気絞り弁の開度および前記第２の抽気絞り弁の開度を小さくした状態で前記出力増大運転を行う、
請求項１に記載の火力発電プラント。 The feed water heater is used as the feed water heater.
The first feed water heater and
The pressure of the heating medium includes at least a second feed water heater whose pressure is lower than that of the first feed water heater, and the water condensed by the condenser makes the second feed water heater and the first feed water heater. It is configured so that the temperature rises as it flows in sequence, and
As the bleed air throttle valve,
A first bleed throttle valve that adjusts the flow rate of the heating medium flowing through the first feed water heater, and
It includes at least a second bleed throttle valve for adjusting the flow rate of the heating medium flowing through the second feed water heater.
The control device is
When the power generation output of the generator at the time when the decrease in the system frequency is detected is a value exceeding the first threshold value, the opening degree of the first bleed throttle valve and the second bleed throttle valve The output increasing operation is performed while the opening is maintained, and the output is increased.
When the power generation output of the generator at the time when the decrease in the system frequency is detected is a value equal to or less than the first threshold value and exceeds the second threshold value smaller than the first threshold value, the first threshold value is exceeded. The output increasing operation is performed in a state where the opening degree of the bleed air throttle valve 1 is reduced and the opening degree of the second bleed air throttle valve is maintained.
When the power generation output of the generator at the time when the decrease in the system frequency is detected is a value equal to or less than the second threshold value and exceeds the third threshold value smaller than the second threshold value, the second threshold value is exceeded. The output increasing operation is performed with the opening degree of the bleed air throttle valve 1 and the opening degree of the second bleed air throttle valve reduced.
The thermal power plant according to claim 1. 前記給水加熱部は、前記給水加熱器として、
第１給水加熱器と、
前記加熱媒体の圧力が前記第１給水加熱器よりも低い第２給水加熱器と
を少なくとも含み、前記復水器で凝縮した水が、前記第２給水加熱器と前記第１給水加熱器とを順次流れることによって温度が上昇するように構成されていると共に、
前記抽気絞り弁として、
前記第１給水加熱器に流れる前記加熱媒体の流量を調整する第１の抽気絞り弁と、
前記第２給水加熱器に流れる前記加熱媒体の流量を調整する第２の抽気絞り弁とを少なくとも含み、
前記制御装置は、
前記系統周波数の減少を検出した時点における前記発電機の発電出力が第１の閾値を超えた値である場合には、前記発電出力の値が小さくなるに伴って前記第１の抽気絞り弁の開度を小さくなるように前記第１の抽気絞り弁の開度を調整し、かつ、前記第２の抽気絞り弁の開度を保持させた状態で、前記出力増大運転を行い、
前記系統周波数の減少を検出した時点における前記発電機の発電出力が前記第１の閾値以下であって前記第１の閾値よりも小さい第２の閾値を超えた値である場合には、前記第１の抽気絞り弁の開度を小さくし、かつ、前記第２の抽気絞り弁の開度を保持させた状態で前記出力増大運転を行い、
前記系統周波数の減少を検出した時点における前記発電機の発電出力が前記第２の閾値以下であって前記第２の閾値よりも小さい第３の閾値を超えた値である場合には、前記第１の抽気絞り弁の開度および前記第２の抽気絞り弁の開度を小さくした状態で前記出力増大運転を行う、
請求項１に記載の火力発電プラント。 The feed water heater is used as the feed water heater.
The first feed water heater and
The pressure of the heating medium includes at least a second feed water heater whose pressure is lower than that of the first feed water heater, and the water condensed by the condenser makes the second feed water heater and the first feed water heater. It is configured so that the temperature rises as it flows in sequence, and
As the bleed air throttle valve,
A first bleed throttle valve that adjusts the flow rate of the heating medium flowing through the first feed water heater, and
It includes at least a second bleed throttle valve for adjusting the flow rate of the heating medium flowing through the second feed water heater.
The control device is
When the power generation output of the generator at the time when the decrease in the system frequency is detected is a value exceeding the first threshold value, the value of the power generation output becomes smaller and the bleed air throttle valve of the first is used. The output increasing operation is performed while adjusting the opening degree of the first bleeding throttle valve so as to reduce the opening degree and maintaining the opening degree of the second bleeding throttle valve.
When the power generation output of the generator at the time when the decrease in the system frequency is detected is a value equal to or less than the first threshold value and exceeds the second threshold value smaller than the first threshold value, the first threshold value is exceeded. The output increasing operation is performed in a state where the opening degree of the bleed air throttle valve 1 is reduced and the opening degree of the second bleed air throttle valve is maintained.
When the power generation output of the generator at the time when the decrease in the system frequency is detected is a value equal to or less than the second threshold value and exceeds the third threshold value smaller than the second threshold value, the second threshold value is exceeded. The output increasing operation is performed with the opening degree of the bleed air throttle valve 1 and the opening degree of the second bleed air throttle valve reduced.
The thermal power plant according to claim 1. 前記給水加熱部は、
前記加熱媒体の圧力が前記第２給水加熱器よりも低い第３給水加熱器
を前記給水加熱器として更に含み、前記復水器で凝縮した水が、前記第３給水加熱器と前記第２給水加熱器と前記第１給水加熱器とを順次流れることによって温度が上昇するように構成されていると共に、
前記抽気絞り弁として、
前記第３給水加熱器に流れる前記加熱媒体の流量を調整する第３の抽気絞り弁を更に含み、
前記制御装置は、
前記系統周波数の減少を検出した時点における前記発電機の発電出力が第１の閾値を超えた値である場合には、前記第１の抽気絞り弁の開度、前記第２の抽気絞り弁の開度、および、前記第３の抽気絞り弁の開度を保持させた状態で前記出力増大運転を行い、
前記系統周波数の減少を検出した時点における前記発電機の発電出力が前記第１の閾値以下であって前記第２の閾値を超えた値である場合には、前記第１の抽気絞り弁の開度を小さくし、かつ、前記第２の抽気絞り弁の開度および前記第３の抽気絞り弁の開度を保持させた状態で前記出力増大運転を行い、
前記系統周波数の減少を検出した時点における前記発電機の発電出力が前記第２の閾値以下であって前記第３の閾値を超えた値である場合には、前記第１の抽気絞り弁の開度および前記第２の抽気絞り弁の開度を小さくし、かつ、前記第３の抽気絞り弁の開度を保持させた状態で前記出力増大運転を行い、
前記系統周波数の減少を検出した時点における前記発電機の発電出力が前記第３の閾値以下である場合には、前記第１の抽気絞り弁の開度、前記第２の抽気絞り弁の開度、および、前記第３の抽気絞り弁の開度を小さくした状態で前記出力増大運転を行う、
請求項３または４に記載の火力発電プラント。 The water supply heating unit is
A third feed water heater whose pressure in the heating medium is lower than that of the second feed water heater is further included as the feed water heater, and the water condensed by the feed water heater is the third feed water heater and the second feed water heater. It is configured so that the temperature rises by sequentially flowing through the heater and the first feed water heater.
As the bleed air throttle valve,
A third bleed throttle valve for adjusting the flow rate of the heating medium flowing through the third feed water heater is further included.
The control device is
When the power generation output of the generator at the time when the decrease in the system frequency is detected is a value exceeding the first threshold value, the opening degree of the first bleeding throttle valve and the opening of the second bleeding throttle valve The output increasing operation is performed while maintaining the opening degree and the opening degree of the third bleed air throttle valve.
When the power generation output of the generator at the time when the decrease in the system frequency is detected is equal to or less than the first threshold value and exceeds the second threshold value, the first bleed air throttle valve is opened. The output increasing operation was performed in a state where the degree was reduced and the opening degree of the second bleeding throttle valve and the opening degree of the third bleeding throttle valve were maintained.
When the power generation output of the generator at the time when the decrease in the system frequency is detected is equal to or less than the second threshold value and exceeds the third threshold value, the first bleed air throttle valve is opened. The output increasing operation was performed with the degree and the opening degree of the second bleeding throttle valve reduced and the opening degree of the third bleeding throttle valve maintained.
When the power generation output of the generator at the time when the decrease in the system frequency is detected is equal to or less than the third threshold value, the opening degree of the first bleeding throttle valve and the opening degree of the second bleeding throttle valve. And, the output increasing operation is performed in a state where the opening degree of the third bleed air throttle valve is reduced.
The thermal power plant according to claim 3 or 4. 前記給水加熱部は、
高圧給水加熱部と、
前記加熱媒体の圧力が前記高圧給水加熱部よりも低い低圧給水加熱部と
を含み、前記復水器で凝縮した水が、前記低圧給水加熱部と前記高圧給水加熱部とを順次流れることによって温度が上昇するように構成されており、
前記第１給水加熱器、前記第２給水加熱器、および、前記第３給水加熱器は、前記高圧給水加熱部を構成する、
請求項５に記載の火力発電プラント。 The water supply heating unit is
High-pressure water supply heating unit and
The temperature of the heating medium includes the low-pressure water supply heating unit whose pressure is lower than that of the high-pressure water supply heating unit, and the water condensed by the condenser flows through the low-pressure water supply heating unit and the high-pressure water supply heating unit in sequence. Is configured to rise,
The first feed water heater, the second feed water heater, and the third feed water heater constitute the high-pressure feed water heater.
The thermal power plant according to claim 5.
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