JP5618336B2 - Combined cycle power plant and operation method - Google Patents

Combined cycle power plant and operation method Download PDF

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JP5618336B2
JP5618336B2 JP2012012235A JP2012012235A JP5618336B2 JP 5618336 B2 JP5618336 B2 JP 5618336B2 JP 2012012235 A JP2012012235 A JP 2012012235A JP 2012012235 A JP2012012235 A JP 2012012235A JP 5618336 B2 JP5618336 B2 JP 5618336B2
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pressure
high
main steam
low
turbine
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JP2013151887A (en
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岳史 長山
岳史 長山
祐介 眞鍋
祐介 眞鍋
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三菱日立パワーシステムズ株式会社
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    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02EREDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E20/00Combustion technologies with mitigation potential
    • Y02E20/10Combined combustion
    • Y02E20/16Combined cycle power plant [CCPP], or combined cycle gas turbine [CCGT]

Description

  The present invention relates to a combined cycle power plant and an operation method.

Conventionally, a combined cycle type power plant (hereinafter referred to as a C / C power plant) includes one steam turbine, one or more gas turbines, and an associated one, as described in Patent Documents 1 and 2. It includes auxiliary equipment (reheater, steam generator, etc.).
The C / C power plant is configured such that steam generated by exhaust heat generated by the operation of the gas turbine is supplied to the steam turbine.
In such a C / C power plant, when the gas turbine is operated with a single load, it is necessary to supply the return steam to the reheater in order to suppress the temperature rise of the reheater.
The multi-shaft combined cycle plant (C / C power generation plant) disclosed in Patent Document 1 performs single load operation of a gas turbine by returning steam to a reheater via a high-pressure turbine bypass pipe when the steam turbine is stopped. Configured to allow.

JP 2004-27938 A JP-A-9-68004

As in the multi-shaft combined cycle plant disclosed in Patent Document 1, in order to operate the gas turbine with a single load, a high-pressure turbine bypass pipe for returning steam to the reheater is required.
Further, as disclosed in Patent Document 2, in a combined cycle power plant in which steam generated by exhaust heat of a gas turbine flows directly into a condenser via a high-pressure turbine bypass pipe (turbine bypass circuit), the gas turbine During the single load operation, the steam generated by the exhaust heat of the gas turbine cannot be returned to the reheater as return steam. Therefore, in the combined cycle power plant configured in this way, the reheater may reach a high temperature exceeding the allowable heat resistance value, so that the single load operation of the gas turbine is not performed.

  Therefore, the present invention provides a combined cycle type power plant and an operation method capable of operating a gas turbine independently even if steam generated by exhaust heat of the gas turbine flows into the condenser without returning to the reheater. The issue is to provide.

  In order to solve the above problems, the present invention relates to a gas turbine, a high-pressure turbine driven by high-pressure main steam generated using exhaust heat contained in the exhaust gas of the gas turbine, and a medium generated using the exhaust heat. A steam turbine comprising an intermediate pressure turbine driven by pressure main steam, a low pressure turbine driven by low pressure main steam generated using the exhaust heat, and the high pressure main steam discharged from the high pressure turbine is condensed The condenser that generates condensate, the exhaust heat recovery boiler that superheats the condensate generated in the condenser with the exhaust heat, and the high pressure in the condensate that is overheated with the exhaust heat recovery boiler A high-pressure drum that generates main steam, a high-pressure turbine bypass pipe that bypasses the high-pressure turbine and introduces the high-pressure main steam generated in the high-pressure drum into the condenser, and the high-pressure turbine bypass pipe High pressure main steam pressure adjusting means for adjusting the pressure of the high pressure main steam and introducing the high pressure main steam into the condenser, and is generated in the exhaust heat recovery boiler by the high pressure drum. A high-pressure superheater that superheats the high-pressure main steam with the exhaust heat, and a reheater that superheats the high-pressure main steam exhausted from the high-pressure turbine with the exhaust heat, in this order from the upstream with respect to the flow of the exhaust gas. The combined cycle power plant to be arranged and the operation method thereof are provided. Then, when the steam turbine is stopped, the high-pressure main steam generated in the high-pressure drum is introduced into the condenser through the high-pressure turbine bypass pipe, and the high-pressure main steam pressure adjusting means depressurizes the high-pressure main steam. By increasing the evaporation amount of the high-pressure drum to increase the heat absorption amount of the exhaust heat in the high-pressure superheater, the high-pressure drum evaporation amount does not exceed the allowable maximum evaporation amount of the high-pressure drum. The pressure of the high-pressure main steam in the turbine bypass pipe is adjusted, and the reheater does not exceed a heat-resistant allowable value due to the exhaust heat contained in the exhaust gas after being absorbed by the high-pressure superheater. As described above, the gas turbine can be operated independently by adjusting the operation load of the gas turbine.

  According to the present invention, there is provided a combined cycle type power plant and an operation method capable of operating the gas turbine independently even when the steam generated by the exhaust heat of the gas turbine flows into the condenser without returning to the reheater. it can.

It is a schematic block diagram of a C / C power plant. It is a figure which shows the functional block which controls a low pressure turbine bypass valve. It is a figure which shows the functional block which controls an intermediate pressure turbine bypass valve. It is a figure which shows an example of an intermediate pressure characteristic diagram. It is a figure which shows the functional block which controls a high pressure turbine bypass valve. It is a figure which shows an example of a high voltage | pressure characteristic diagram. It is a figure which shows the functional block which controls a gas turbine. It is a figure which shows an example of a turbine load characteristic diagram. It is a figure which shows the state which a driving load switches.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings as appropriate.
As shown in FIG. 1, a combined cycle power plant (C / C power plant 1) according to the present embodiment includes a gas turbine 11 and a steam turbine 10 (a high pressure turbine 12, an intermediate pressure turbine 13, and a low pressure turbine 14). The control device 2 is a multi-shaft power plant in which a generator G is connected to each of the output shafts of the gas turbine 11 and the steam turbine 10.

  In the normal operation in which both the gas turbine 11 and the steam turbine 10 are operated, the steam generated in the high-pressure drum 22 provided in the exhaust heat recovery boiler 54 installed on the exhaust side of the gas turbine 11 is transferred to the high-pressure superheater 54j, the high-pressure main unit. It flows through the steam pipe 45 and flows into the high-pressure turbine 12. The steam (low-temperature steam) that has worked in the high-pressure turbine 12 flows through the low-temperature reheat steam pipe 46, flows into the reheater 54 i provided in the exhaust heat recovery boiler 54, and is included in the exhaust gas exhausted from the gas turbine 11. After being heated by the amount of heat generated (hereinafter referred to as turbine exhaust heat), it flows through the high-temperature reheat steam pipe 47 and the intercept valve 83 and flows into the intermediate pressure turbine 13. Then, the steam that has worked in the intermediate pressure turbine 13 flows through the crossover pipe 81 and flows into the low pressure turbine 14.

The high pressure main steam pipe 45 branches from the high pressure turbine bypass valve 23 (high pressure main steam pressure adjusting means) for adjusting the pressure of the high pressure main steam and the high pressure turbine bypass pipe 51a provided with the temperature reducer 88. 45 is connected to the condenser 15 via the high-pressure turbine bypass pipe 51a so that the high-pressure main steam generated in the high-pressure drum 22 can be introduced into the condenser 15 by bypassing the high-pressure turbine 12, and The pressure is adjustable.
The high pressure main steam pipe 45 is provided with a high pressure control valve 82 between the branch point of the high pressure main steam pipe 45 and the high pressure turbine bypass pipe 51 a and the high pressure turbine 12.
Further, the pressure of the steam (high pressure main steam pressure) flowing through the high pressure main steam pipe 45 is detected by the high pressure turbine inlet pressure detector 26 provided in the high pressure main steam pipe 45, and the high pressure flow rate detector provided in the high pressure main steam pipe 45. 401 detects the flow rate of steam flowing through the high-pressure main steam pipe 45 (high-pressure main steam flow rate).

Steam discharged from the low-pressure turbine 14 is condensed into condensate by the condenser 15, pressurized by the low-pressure feed water pump 16, circulated through the feed water pipe 50, and exhaust heat recovery boiler via the ground steam condenser 18. 54 flows into the low-pressure economizer 54 a and is heated by the turbine exhaust heat while flowing through the low-pressure economizer 54 a and flows into the low-pressure drum 20. Further, a part of the condensate flowing through the feed pipe 50 is pressurized by the high / medium pressure feed water pump 19 and flows into the medium pressure economizer 54c and the high pressure economizer 54f of the exhaust heat recovery boiler 54 and is heated by the turbine exhaust heat. And flow into the intermediate-pressure drum 21 and the high-pressure drum 22, respectively.
A part of the condensate pressurized by the high / medium-pressure feed water pump 19 is introduced into the temperature reducer 88 and used to reduce the temperature of the high-pressure main steam flowing through the high-pressure turbine bypass pipe 51a. Flows into the vessel 15. In addition, a part of the condensate pressurized by the low-pressure feed water pump 16 is introduced into the temperature reducer 89 and used to reduce the temperature of the medium-pressure main steam flowing through the medium-pressure turbine bypass pipe 52a. It flows into the water bottle 15.

The condensate flowing into the low-pressure drum 20 is heated by the low-pressure evaporator 54b to become high-temperature condensate and returns to the low-pressure drum 20, and a part thereof becomes steam (saturated steam) via the low-pressure superheater inlet connecting pipe. And flows into the low pressure superheater 54d. Then, the steam heated by the low-pressure superheater 54 d is guided to the final stage of the intermediate-pressure turbine 13 by the low-pressure main steam pipe 48, flows through the crossover pipe 81, and flows into the low-pressure turbine 14.
A low-pressure turbine bypass pipe 53 provided with a low-pressure turbine bypass valve 25 (low-pressure main steam pressure adjusting means) for adjusting the pressure of the low-pressure main steam branches from the low-pressure main steam pipe 48, and the low-pressure main steam pipe 48 is a low-pressure turbine bypass. It is connected to the condenser 15 via a pipe 53. The low-pressure main steam generated in the low-pressure drum 20 can be directly introduced into the condenser 15 and the pressure of the low-pressure main steam can be adjusted.
Further, the low pressure main steam pipe 48 is provided with a low pressure adjusting valve 84 between the branch point of the low pressure main steam pipe 48 and the low pressure turbine bypass pipe 53 and the intermediate pressure turbine 13.
Further, the pressure of the steam (low pressure main steam pressure) flowing through the low pressure main steam pipe 48 is detected by the low pressure turbine inlet pressure detector 28 provided in the low pressure main steam pipe 48, and the low pressure flow rate detector provided in the low pressure main steam pipe 48. 201 detects the flow rate of the steam flowing through the low-pressure main steam pipe 48 (low-pressure main steam flow rate).

Further, the condensate flowing into the intermediate pressure drum 21 is heated by the intermediate pressure evaporator 54e to become high-temperature condensate and returns to the intermediate pressure drum 21, and a part thereof becomes saturated steam, and the intermediate pressure superheater inlet connecting pipe. To the intermediate pressure superheater 54g. Then, the steam heated by the intermediate pressure superheater 54 g flows into the low temperature reheat steam pipe 46 through the intermediate pressure main steam pipe 39.
An intermediate pressure turbine bypass pipe 52a provided with an intermediate pressure turbine bypass valve 24 (intermediate pressure main steam pressure adjusting means) for adjusting the pressure of the intermediate pressure main steam and a temperature reducer 89 branches from the intermediate pressure main steam pipe 39. The intermediate pressure main steam pipe 39 is connected to the condenser 15 via the intermediate pressure turbine bypass pipe 52a. The intermediate pressure main steam generated by the intermediate pressure drum 21 can be directly introduced into the condenser 15 and the pressure of the intermediate pressure main steam can be adjusted.
Further, an intermediate pressure main steam cutoff valve 91 is provided in the intermediate pressure main steam pipe 39 between the branch point of the intermediate pressure main steam pipe 39 and the intermediate pressure turbine bypass pipe 52 a and the low temperature reheat steam pipe 46.
The intermediate pressure main steam cutoff valve 91 is opened during normal operation in which both the steam turbine 10 and the gas turbine 11 are operated, and the intermediate pressure main steam generated in the intermediate pressure drum 21 is intermediated via the reheater 54i. Supply to pressure turbine 13. Further, when the steam turbine 10 is stopped and the gas turbine 11 is operated with a single load, the intermediate pressure main steam cutoff valve 91 is closed.

  Further, the pressure of the steam flowing through the intermediate pressure main steam pipe 39 (intermediate pressure main steam pressure) is detected by the intermediate pressure turbine inlet pressure detector 27 provided in the intermediate pressure main steam pipe 39. An intermediate pressure flow rate detector 301 provided therein detects the flow rate of the steam flowing through the intermediate pressure main steam pipe 39 (intermediate pressure main steam flow rate).

  Further, the condensate flowing into the high-pressure drum 22 is heated by the high-pressure evaporator 54h to become high-temperature condensate and returns to the high-pressure drum 22, and a part thereof becomes saturated steam and passes through the high-pressure superheater inlet connecting pipe. It flows into the high pressure superheater 54j, flows through the high pressure main steam pipe 45 as described above, and flows into the high pressure turbine 12.

The exhaust heat recovery boiler 54 is provided with a denitration device 92 so that nitrogen oxides contained in the gas discharged from the gas turbine 11 are decomposed into nitrogen and water vapor.
Reference numeral 90 denotes a high-pressure turbine first-stage post-pressure detector that detects the first-stage post-stage pressure of the high-pressure turbine 12.

  When the C / C power plant 1 configured as described above stops the steam turbine 10 (the high-pressure turbine 12, the intermediate-pressure turbine 13, and the low-pressure turbine 14) and operates the gas turbine 11 with a single load, the high-pressure control valve 82 is provided. The intercept valve 83 and the low pressure adjusting valve 84 are closed to control the supply of steam to the steam turbine 10 (the high pressure turbine 12, the intermediate pressure turbine 13, and the low pressure turbine 14).

However, when the gas turbine 11 is operated with a single load, if the steam does not flow into the reheater 54i, the temperature of the reheater 54i rises due to the turbine exhaust heat contained in the exhaust gas exhausted from the gas turbine 11, and the design temperature Exceeding this causes problems such as breakage of the reheater 54i.
Therefore, the control device 2 of the present embodiment controls the C / C power plant 1 so as to reduce the amount of turbine exhaust heat in the reheater 54 i when the gas turbine 11 is operated with a single load.

Specifically, the control device 2 increases the exchange heat amount (absorption heat amount of the turbine exhaust heat) in the high-pressure superheater 54j disposed upstream of the reheater 54i in the exhaust gas flow of the gas turbine 11, thereby increasing the reheater 54i. Reduce the amount of turbine exhaust heat.
Therefore, the control device 2 opens the high-pressure turbine bypass valve 23, introduces the steam from the high-pressure main steam pipe 45 and the high-pressure turbine bypass pipe 51a into the vacuum condenser 15, and decompresses the high-pressure main steam. As a result, the saturated steam temperature in the high-pressure drum 22 is lowered, the amount of evaporation in the high-pressure drum 22 is increased, and the amount of steam flowing through the high-pressure superheater 54j is increased, whereby the amount of exchange heat in the high-pressure superheater 54j is increased. As a result, overheating of the reheater 54i is suppressed.

However, since the allowable maximum evaporation amount is set as a design value for the high-pressure drum 22, it is preferable to set the evaporation amount so as not to exceed the allowable maximum evaporation amount. The evaporation amount of the high pressure drum 22 is determined by the internal steam pressure, and the internal steam pressure of the high pressure drum 22 is determined by the opening degree of the high pressure turbine bypass valve 23.
That is, the opening degree of the high-pressure turbine bypass valve 23 is required to be set so that the evaporation amount of the high-pressure drum 22 does not exceed the allowable maximum evaporation amount.

  In the present embodiment, the control device 2 determines the operating load of the gas turbine 11, the opening of the high pressure turbine bypass valve 23, the opening of the intermediate pressure turbine bypass valve 24, and the opening of the low pressure turbine bypass valve 25 as follows. The gas turbine 11 is operated with a single load by setting.

<< Setting of Operation Load of Gas Turbine 11 >>
The control device 2 determines the operation load of the gas turbine 11 when the steam turbine 10 of the C / C power plant 1 is stopped and switched to the single load operation of the gas turbine 11. The maximum value of the operating load of the gas turbine 11 at which the exhaust gas temperature is equal to or lower than the heat resistance temperature of the reheater 54i in a state where the evaporation amount of 22 does not change (that is, the exchange heat amount in the high pressure superheater 54j does not change) The operating load of the gas turbine 11 is determined.

  This operating load is a value determined according to the heat resistance temperature of the reheater 54 i and the evaporation amount of the high-pressure drum 22. For example, if the map format data indicating the relationship between the evaporation amount of the high-pressure drum 22, the temperature of the exhaust gas that has passed through the high-pressure superheater 54j, and the operating load of the gas turbine 11 is set in advance, The control device 2 can determine the operation load of the gas turbine 11 at which the exhaust gas temperature is equal to or lower than the heat resistance temperature of the reheater 54 i by referring to the map format data based on the evaporation amount of the high-pressure drum 22. It should be noted that the exhaust gas temperature and the operating load are set as map format data, and are not limited to the map format as long as the control device 2 can refer to them.

<< Opening setting of low-pressure turbine bypass valve 25 >>
When the steam turbine 10 is stopped, the control device 2 controls the low-pressure main steam pressure by adjusting the opening degree of the low-pressure turbine bypass valve 25. When the low-pressure turbine bypass valve 25 is opened, the low-pressure drum 20 communicates with the condenser 15 through the low-pressure superheater 54d to reduce the pressure inside. In the low-pressure drum 20, the saturation temperature is lowered and the evaporation amount is increased as the pressure is reduced.
The control device 2 sets the initial value (low pressure initial value) of the low pressure main steam pressure so that the evaporation amount of the low pressure drum 20 becomes the maximum evaporation amount within a range not exceeding the preset allowable value (allowable maximum evaporation amount). And the opening degree of the low-pressure turbine bypass valve 25 is controlled so that the low-pressure main steam pressure of the low-pressure turbine bypass pipe 53 becomes the low-pressure pressure initial value. The low pressure initial value may be a predetermined value.

<< Opening setting of intermediate pressure turbine bypass valve 24 >>
When the steam turbine 10 is stopped, the control device 2 adjusts the opening degree of the intermediate pressure turbine bypass valve 24 and sets the evaporation amount of the intermediate pressure drum 21. Similarly to the low-pressure drum 20, when the intermediate-pressure turbine bypass valve 24 is opened, the intermediate-pressure drum 21 communicates with the condenser 15 through the intermediate-pressure superheater 54g, and the inside is depressurized. In the intermediate pressure drum 21, the saturation temperature is lowered and the evaporation amount is increased as the pressure is reduced.
The control device 2 determines the initial value (intermediate pressure pressure) of the intermediate pressure main steam pressure so that the evaporation amount of the intermediate pressure drum 21 becomes the maximum evaporation amount within a range that does not exceed a preset allowable value (allowable maximum evaporation amount). An initial value) is set, and the opening degree of the intermediate pressure turbine bypass valve 24 is controlled such that the intermediate pressure main steam pressure of the intermediate pressure turbine bypass pipe 52a becomes the intermediate pressure initial value. The intermediate pressure initial value may be a predetermined value.

<< Opening setting of high-pressure turbine bypass valve 23 >>
Further, when the steam turbine 10 is stopped, the control device 2 adjusts the opening degree of the high-pressure turbine bypass valve 23 and sets the evaporation amount of the high-pressure drum 22. As with the low pressure drum 20, when the high pressure turbine bypass valve 23 is opened, the high pressure drum 22 communicates with the condenser 15 via the high pressure superheater 54j, and the inside is depressurized. In the high-pressure drum 22, the saturation temperature decreases and the amount of evaporation increases as the pressure decreases.
The control device 2 sets the initial value (high pressure initial value) of the high-pressure main steam pressure so that the evaporation amount of the high-pressure drum 22 becomes the maximum evaporation amount within a range not exceeding a preset allowable value (allowable maximum evaporation amount). And the opening degree of the high-pressure turbine bypass valve 23 is controlled so that the high-pressure main steam pressure of the high-pressure turbine bypass pipe 51a becomes the high-pressure pressure initial value. The high pressure initial value may be a predetermined value.

  When the steam turbine 10 is stopped, the control device 2 sets the operation load, the high pressure initial value, the medium pressure initial value, and the low pressure initial value of the gas turbine 11 as described above. While the control device 2 operates the gas turbine 11 alone, the operation load of the gas turbine 11, the opening of the high-pressure turbine bypass valve 23, the opening of the intermediate-pressure turbine bypass valve 24, and the low-pressure turbine bypass valve 25 The opening degree is continuously controlled (adjusted) as follows.

<< Opening degree adjustment of low-pressure turbine bypass valve 25 >>
The control device 2 includes the functional blocks shown in FIG. 2 and controls the low pressure turbine bypass valve 25. As shown in FIG. 2, the control device 2 uses the detected value of the low-pressure turbine inlet pressure detector 28 as an actual measurement value of the pressure of the low-pressure main steam (low-pressure main steam pressure) in the low-pressure main steam pipe 48. A deviation (low pressure main steam pressure deviation ΔPL) obtained by subtracting the measured value of the low pressure main steam pressure by the subtractor 100b from the allowable maximum value (low pressure main steam allowable maximum pressure value) is calculated. Then, the control device 2 adjusts the opening degree of the low-pressure turbine bypass valve 25 so that the low-pressure main steam pressure deviation ΔPL becomes zero by, for example, the PI operation (proportional / integral operation) in the PI operating unit 100c.

When the low-pressure main steam pressure deviation ΔPL is positive, the control device 2 adjusts the low-pressure turbine bypass valve 25 to close in order to increase the measured value of the low-pressure main steam pressure, and when the low-pressure main steam pressure deviation ΔPL is negative, In order to lower the actual measurement value of the main steam pressure, the control device 2 adjusts the low-pressure turbine bypass valve 25 to open.
Note that when the steam turbine 10 is not stopped (that is, during normal operation in which both the steam turbine 10 and the gas turbine 11 are operated), the control device 2 sets in advance instead of the low-pressure main steam allowable maximum pressure value. The low pressure set value to be set is selected by the selector 100a. This low pressure set value is a fixed value set in the low pressure turbine 14 during normal operation and is determined as a characteristic value of the C / C power plant 1 (see FIG. 1).

The control device 2 is a subtractor 100b that calculates the low-pressure main steam pressure deviation ΔPL by subtracting the actual measurement value of the low-pressure main steam pressure from the selected low-pressure set value, so that the low-pressure main steam pressure deviation ΔPL is zero. The bypass valve 25 is controlled.
The control device 2 controls the low-pressure turbine bypass valve 25 to adjust the opening degree and adjust the pressure of the low-pressure main steam in the low-pressure turbine bypass pipe 53 in the above procedure.

<< Adjustment of Opening of Intermediate Pressure Turbine Bypass Valve 24 >>
The control device 2 is configured to include the functional blocks shown in FIG. 3, and the intermediate pressure turbine bypass valve 24 so that the steam flow rate of the low pressure main steam in the low pressure main steam pipe 48 (see FIG. 1) is less than the low pressure allowable maximum flow rate. To control. As shown in FIG. 3, the control device 2 uses the detected value of the low-pressure flow detector 201 provided in the low-pressure main steam pipe 48 as an actual measurement value of the low-pressure main steam flow in the low-pressure main steam pipe 48 and is allowed in the low-pressure main steam pipe 48. The subtractor 200a subtracts the actually measured value from the low pressure allowable maximum flow rate (low pressure allowable maximum flow rate−actual value) to calculate the low pressure flow rate deviation ΔFL.
Further, the control device 2 predicts the flow rate (low pressure main steam flow rate) of the low pressure main steam pipe 48 corresponding to the operation load of the gas turbine 11 and the currently set intermediate pressure main steam pressure target value by the flow rate predictor 200b. To do. In the present embodiment, the control device 2 predicts the low-pressure main steam flow rate based on the characteristic diagram (intermediate pressure characteristic diagram) shown in FIG.
Further, the control device 2 calculates the intermediate pressure main steam pressure target value necessary for changing the predicted low pressure main steam flow so that the calculated low pressure flow deviation ΔFL becomes zero.

For example, as shown in FIG. 4, when the operation load of the gas turbine 11 is “W1” and the currently set intermediate pressure main steam pressure target value is “PM1”, the control device 2 displays an intermediate pressure characteristic diagram. Based on this, the low-pressure main steam flow rate is predicted as “FL1”.
Further, when the low-pressure flow deviation ΔFL is positive (that is, when the measured value of the low-pressure main steam flow is smaller than the low-pressure allowable maximum flow), the control device 2 is more than ΔFL than “FL1” that is the predicted value of the low-pressure main steam flow. “FL3”, which is higher than that, is set as the low-pressure main steam flow rate, and the intermediate-pressure main steam pressure “PM3” corresponding to “FL3” is set as the intermediate-pressure main steam pressure target value. On the other hand, when the low-pressure flow deviation ΔFL is negative (that is, when the measured value of the low-pressure main steam flow is larger than the low-pressure allowable maximum flow), the control device 2 is more than ΔFL than “FL1” that is the predicted value of the low-pressure main steam flow. “FL2”, which is lower than this, is set as the low-pressure main steam flow rate, and the intermediate-pressure main steam pressure “PM2” corresponding to “FL2” is set as the intermediate-pressure main steam pressure target value.

  Further, the control device 2 subtracts the actual measurement value of the intermediate pressure main steam flow detected by the intermediate pressure flow detector 301 from the maximum allowable intermediate pressure flow allowed in the intermediate pressure main steam pipe 39 with the low monitor 207 shown in FIG. Monitor the value. When the value obtained by subtracting the measured value of the medium pressure main steam flow rate from the medium pressure allowable maximum flow rate is positive, that is, when the medium pressure main steam flow rate is smaller than the measured value of the medium pressure allowable maximum flow rate, the low monitor 207 The output of the selector 200c is switched so as to output the intermediate pressure main steam pressure target value predicted by the predictor 200b. On the other hand, when the value obtained by subtracting the intermediate pressure main steam flow rate from the actual measurement value of the maximum allowable intermediate pressure flow rate is negative, that is, when the intermediate pressure main steam flow rate is larger than the actual measurement value of the maximum allowable intermediate pressure flow rate, the low monitor 207 outputs To switch the output of the selector 200c.

The control device 2 subtracts the actual measured value of the intermediate pressure main steam pressure detected by the intermediate pressure turbine inlet pressure detector 27 from the intermediate pressure main steam pressure target value output from the selector 200c via the selector 200d. Is subtracted (medium pressure main steam pressure target value-actual value) to calculate medium pressure main steam pressure deviation ΔPM. And the control apparatus 2 adjusts the opening degree of the intermediate pressure turbine bypass valve 24 so that the intermediate pressure main steam pressure deviation ΔPM becomes zero, for example, by the PI operation in the PI operation unit 200f.
When the intermediate pressure main steam pressure deviation ΔPM is positive, the control device 2 adjusts the intermediate pressure turbine bypass valve 24 to close in order to increase the intermediate pressure main steam pressure, and when the intermediate pressure main steam pressure deviation ΔPM is negative, In order to lower the medium-pressure main steam pressure, the control device 2 adjusts the medium-pressure turbine bypass valve 24 in the opening direction.

When the steam turbine 10 is not stopped, the control device 2 replaces the calculated intermediate pressure main steam pressure target value with the pressure after the first stage of the high pressure turbine 12 detected by the pressure detector 90 after the first stage of the high pressure turbine. Then, the target pressure determined by the function generator 200g is selected by the selector 200d to obtain the intermediate pressure main steam pressure target value. When the steam turbine 10 is not stopped (that is, in the normal operation in which both the gas turbine 11 and the steam turbine 10 are operated), the intermediate pressure turbine bypass valve 24 is closed as the target pressure determined by the function generator 200g. To be decided.
The intermediate pressure characteristic diagram may be a map format, a table format, or a function format, and the data format is not limited as long as the control device 2 can refer to it.

The control device 2 controls the intermediate pressure turbine bypass valve 24 to adjust the opening degree by the procedure as described above, and adjusts the pressure of the intermediate pressure main steam in the intermediate pressure turbine bypass pipe 52a.
When the opening degree of the intermediate pressure turbine bypass valve 24 shown in FIG. 1 changes, the evaporation amount of the intermediate pressure drum 21 changes, and the exchange heat amount (heat absorption amount from the turbine exhaust heat) in the intermediate pressure superheater 54g changes. As a result, the amount of turbine exhaust heat contained in the exhaust gas passing through the low-pressure evaporator 54b provided downstream of the intermediate-pressure superheater 54g changes, and the condensate temperature in the low-pressure drum 20 changes, whereby the low-pressure drum 20 The amount of evaporation changes. Therefore, the low pressure main steam flow rate in the low pressure main steam pipe 48 can be adjusted by adjusting the opening degree of the intermediate pressure turbine bypass valve 24.

<< Adjustment of opening degree of high-pressure turbine bypass valve 23 >>
The control device 2 is configured to include the functional blocks shown in FIG. 5, and the high pressure turbine bypass so that the steam flow rate of the intermediate pressure main steam in the intermediate pressure main steam pipe 39 (see FIG. 1) is less than the maximum allowable intermediate pressure flow rate. The valve 23 is controlled. As shown in FIG. 5, the control device 2 uses the detected value of the intermediate pressure flow detector 301 provided in the intermediate pressure main steam pipe 39 as the actual measurement value of the intermediate pressure main steam flow in the intermediate pressure main steam pipe 39, and the intermediate pressure main steam. An intermediate pressure flow rate deviation ΔFM is calculated by subtracting an actual measured value from the maximum allowable medium pressure flow allowed in the pipe 39 by the subtractor 300a (intermediate allowable pressure maximum flow−actual measured value). Further, the control device 2 calculates the correction coefficient k by dividing the preset intermediate pressure by the divider 300b by the intermediate pressure main steam pressure target value selected by the selector 200d (see FIG. 3). Then, the control device 2 corrects the intermediate pressure flow deviation ΔFM by multiplying the calculated correction coefficient k by the multiplier 300c by the intermediate pressure flow deviation ΔFM. The intermediate pressure setting value set in advance is a fixed value that is a condition for setting a high-pressure characteristic diagram to be described later, and is a characteristic value determined by the configuration of the C / C power plant 1.

Further, the control device 2 predicts the flow rate of the intermediate pressure main steam pipe 39 corresponding to the operation load of the gas turbine 11 and the currently set high pressure main steam pressure target value (medium pressure main steam flow rate) by the pressure calculator 300d. Then, a high pressure main steam pressure target value for changing the intermediate pressure main steam flow rate is calculated so that the intermediate pressure flow rate deviation correction value kΔFM obtained by multiplying the calculated intermediate pressure flow rate deviation ΔFM by the correction coefficient k is zero.
The control device 2 calculates a high-pressure main steam pressure target value based on a characteristic diagram (high-pressure characteristic diagram) at a preset intermediate-pressure main steam pressure shown in FIG.
As described above, the correction coefficient k by which the intermediate pressure flow rate deviation ΔFM is multiplied is the ratio between the preset intermediate pressure setting value and the intermediate pressure main steam pressure target value, and the control device 2 sets the correction coefficient k to the intermediate correction coefficient k. By multiplying the pressure flow deviation ΔFM, the deviation on the high pressure characteristic diagram at the preset intermediate pressure main steam pressure is calculated.

For example, as shown in FIG. 6, when the operation load of the gas turbine 11 is “W1” and the currently set high-pressure main steam pressure target value is “PH1”, the control device 2 is based on the high-pressure characteristic diagram. The medium-pressure main steam flow rate is predicted as “FM1”.
Further, the control device 2 is the predicted value of the intermediate pressure main steam flow rate when the intermediate pressure flow rate deviation correction value kΔFM is positive (that is, when the measured value of the intermediate pressure main steam flow rate is smaller than the allowable intermediate pressure maximum flow rate). “FM3”, which is higher than “FM1” by kΔFM, is the medium-pressure main steam flow rate, and the high-pressure main steam pressure “PH3” corresponding to “FM3” is the high-pressure main steam pressure target value. On the other hand, when the intermediate pressure flow rate deviation correction value kΔFM is negative (that is, when the actual measurement value of the intermediate pressure main steam flow rate is larger than the intermediate pressure allowable maximum flow rate), the control device 2 is the predicted value of the intermediate pressure main steam flow rate. “FM2”, which is lower than “FM1” by kΔFM, is the medium-pressure main steam flow rate, and the high-pressure main steam pressure “PH2” corresponding to “FM2” is the high-pressure main steam pressure target value.
The high-voltage characteristic diagram may be a map format, a table format, or a function format, and the data format is not limited as long as the control device 2 can refer to it.

Further, as shown in FIG. 5, the control device 2 subtracts the measured value of the high-pressure main steam pressure detected by the high-pressure turbine inlet pressure detector 26 from the calculated high-pressure main steam pressure target value by the subtractor 300f (high-pressure main pressure). The high-pressure main steam pressure deviation ΔPH is calculated by (steam pressure target value−actual value). And the control apparatus 2 adjusts the opening degree of the high-pressure turbine bypass valve 23 so that the high-pressure main steam pressure deviation ΔPH becomes zero by, for example, the PI operation in the PI operating unit 300g.
When the high-pressure main steam pressure deviation ΔPH is positive, the controller 2 adjusts the high-pressure turbine bypass valve 23 in the closing direction to increase the high-pressure main steam pressure, and when the high-pressure main steam pressure deviation ΔPH is negative, In order to lower the pressure, the control device 2 adjusts the high pressure turbine bypass valve 23 in the opening direction.
When the steam turbine 10 is not stopped, the control device 2 selects a preset high-pressure main steam set pressure with the selector 300e instead of the high-pressure main steam pressure target value calculated with the pressure calculator 300d. The high pressure main steam set pressure is set as the high pressure main steam pressure target value.

The control device 2 controls the high-pressure turbine bypass valve 23 to adjust the opening degree by the procedure as described above, and adjusts the pressure of the high-pressure main steam in the high-pressure turbine bypass pipe 51a.
When the opening degree of the high-pressure turbine bypass valve 23 shown in FIG. 1 changes, the evaporation amount of the high-pressure drum 22 changes, and the exchange heat amount (heat absorption amount from the turbine exhaust heat) in the high-pressure superheater 54j changes. As a result, the amount of heat of the turbine exhaust heat contained in the exhaust gas passing through the intermediate pressure evaporator 54e provided downstream of the high pressure superheater 54j changes, and the temperature of the condensate in the intermediate pressure drum 21 changes, thereby changing the intermediate pressure. The evaporation amount of the drum 21 changes. Therefore, the intermediate-pressure main steam flow rate in the intermediate-pressure main steam pipe 39 can be adjusted by adjusting the opening degree of the high-pressure turbine bypass valve 23.

<< Adjustment of operation load of gas turbine 11 >>
The control device 2 is configured to include the functional blocks shown in FIG. 7 and controls the gas turbine 11. As shown in FIG. 7, the control device 2 uses the detected value of the high-pressure flow detector 401 provided in the high-pressure main steam pipe 45 (see FIG. 1) as an actual measurement value of the high-pressure main steam flow rate in the high-pressure main steam pipe 45. The actual value of the high-pressure main steam flow rate is subtracted by the subtractor 400a (high-pressure allowable maximum flow rate−actual value) from the high-pressure allowable maximum flow rate allowed in the pipe 45 to calculate the high-pressure flow rate deviation ΔFH.

Further, the control device 2 is a load calculator 400b, which is a characteristic line shown in FIG. 8 based on the high pressure main steam pressure target value selected by the selector 300e (see FIG. 5) and the current operation load of the gas turbine 11. With reference to the figure (turbine load characteristic diagram), the high-pressure main steam flow corresponding to the high-pressure main steam pressure and the operation load of the gas turbine 11 is predicted.
Further, the control device 2 uses the load calculator 400b to change the operation load of the gas turbine 11 on the characteristic line of the turbine load characteristic diagram so that the calculated high-pressure flow deviation ΔFH becomes zero.

For example, as shown in FIG. 8, when the high pressure main steam pressure target value is “PH1” and the operation load of the gas turbine 11 is “W1”, the high pressure main steam flow rate “FH1” is predicted based on the turbine load characteristic diagram. The In this case, when the high-pressure flow deviation ΔFH is negative (that is, when the measured value of the high-pressure main steam flow exceeds the high-pressure allowable maximum flow rate), the control device 2 indicates that the high-pressure main steam flow corresponds to the high-pressure flow deviation ΔFH. The operating load “W2” that is the intersection of “FH2” that has decreased from “FH1” by the amount and the straight line that indicates the high-pressure main steam pressure “PH1” is set as the operating load of the gas turbine 11. On the other hand, when the high-pressure flow deviation ΔFH is positive (that is, when the actual measured value of the high-pressure main steam flow is lower than the high-pressure allowable maximum flow), the controller 2 determines that the high-pressure main steam flow is equal to the high-pressure flow deviation ΔFH. The operating load “W3” that is the intersection of “FH3” increased from “FH1” and the straight line indicating the high-pressure main steam pressure “PH1” is set as the operating load of the gas turbine 11.
The control device 2 can make the calculated high-pressure flow deviation ΔFH zero by operating the gas turbine 11 with the operation load set in this way. As shown in FIG. 6, when the high-pressure main steam pressure is “PH2” or “PH3”, the control device 2 has a turbine load characteristic corresponding to “PH2” or “PH3”. Thus, the turbine load characteristic diagram is appropriately changed.

Further, the control device 2 calculates and selects a deviation (load deviation ΔW) obtained by subtracting the set operating load (set value) of the gas turbine 11 by the subtractor 400c shown in FIG. 7 from the current operating load (current value). Output from the device 400d. At this time, when the steam turbine 10 is not stopped (that is, in the normal operation in which both the gas turbine 11 and the steam turbine 10 are operated), the control device 2 replaces the load deviation ΔW calculated by the subtractor 400c with zero. Is selected by the selector 400d, and the load deviation ΔW is set to zero.
Then, the control device 2 adjusts the operation load of the gas turbine 11 using the load deviation ΔW output from the selector 400d as a load increase / decrease command for the operation load of the gas turbine 11.

  As described above, the control device 2 (see FIG. 1) according to the present embodiment performs the low-pressure turbine bypass valve 25 (see FIG. 1) and the intermediate-pressure turbine bypass when the gas turbine 11 (see FIG. 1) is operated with a single load. The C / C power plant 1 (see FIG. 1) is adjusted while adjusting the valve opening degree of the valve 24 (see FIG. 1) and the high-pressure turbine bypass valve 23 (see FIG. 1) and the operation load of the gas turbine 11. drive.

  As shown in FIG. 9, the gas turbine 11 (see FIG. 1) according to the present embodiment is operated with the first load during the normal operation in which the steam turbine 10 (see FIG. 1) is operated. When the operation of the steam turbine 10 is stopped and the gas turbine 11 is operated with a single load, the temperature of the exhaust gas exceeds the heat resistance temperature of the reheater 54i (see FIG. 1) in the first stage after the stop of the steam turbine 10. The second load is set so as not to exist. Further, as a second stage, the evaporation amounts in the low pressure drum 20 (see FIG. 1), the intermediate pressure drum 21 (see FIG. 1), and the high pressure drum 22 (see FIG. 1) do not exceed the allowable maximum evaporation amounts. The third load is adjusted as follows.

  As described above, the C / C power plant 1 (see FIG. 1) of the present embodiment switches the operation load stepwise as shown in FIG. 9 when the gas turbine 11 (see FIG. 1) is operated with a single load. Prevents the reheater 54i (see FIG. 1) in the state where steam does not flow in from exceeding the heat-resistant temperature, and the low pressure drum 20 (see FIG. 1), the intermediate pressure drum 21 (see FIG. 1), In addition, it is possible to prevent the evaporation amount of the high-pressure drum 22 (see FIG. 1) from exceeding the allowable maximum evaporation amount, and further, the gas turbine 11 can be operated in a single load with the maximum operation load as much as possible.

Further, there is no pipe for returning the steam discharged from the high-pressure superheater 54j (see FIG. 1) to the reheater 54i (see FIG. 1) as steam without passing through the steam turbine 10 (see FIG. 1). Even in the case of the / C power plant 1 (see FIG. 1), the temperature rise of the reheater 54i when the gas turbine 11 (see FIG. 1) is operated with a single load can be suppressed to the heat resistant temperature or lower. Therefore, even in the C / C power plant 1 having a structure in which the return steam does not flow into the reheater 54i, the gas turbine 11 can be operated with a single load with the maximum operating load as much as possible.
And, for example, in an emerging country such as an emerging country, when the steam turbine 10 is stopped, the gas turbine 11 can be supplied with a maximum load so that the power can be stably supplied. .
Furthermore, the configuration in which the exhaust heat recovery boiler 54 includes the denitration device 92 can reduce the environmental load and shorten the startup time of the steam turbine 10 by recovering heat in the exhaust heat recovery boiler 54.

A bypass stack (not shown) and an exhaust gas switching damper (not shown) are provided so as to bypass the exhaust heat recovery boiler 54, and the gas turbine 11 (FIG. 1) is switched by switching the exhaust gas switching damper to the bypass stack side. A configuration is also conceivable in which the gas turbine 11 is operated with a single load by discharging the exhaust gas of (see) to the atmosphere. However, in such a configuration, there is a problem that the exhaust gas of the gas turbine 11 is released to the atmosphere and affects the surrounding environment.
In the C / C power plant 1 (see FIG. 1) according to the present embodiment, the exhaust gas of the gas turbine 11 is taken into the exhaust heat recovery boiler 54 (see FIG. 1) and is not released to the atmosphere. Therefore, the gas turbine 11 can be operated with a single load without affecting the surrounding environment.

Further, as shown in FIG. 1, the C / C power plant 1 according to the present embodiment includes a “triple pressure exhaust heat recovery boiler” having three steam drums, a low pressure drum 20, an intermediate pressure drum 21, and a high pressure drum 22. However, it is not limited to this configuration. The present invention can be applied to a C / C power plant having one or two steam drums, and can also be applied to a C / C power plant having four or more steam drums. It is.
Further, the present invention is not limited to the multi-shaft type C / C power plant 1 shown in FIG. 1, and the present invention can also be applied to a power plant in which a gas turbine 11 and a steam turbine 10 are connected in series with one shaft. . In this case, the gas turbine 11 can be operated with a single load in a state where there is no malfunction in the steam turbine 10.

  Further, since the temperature of the exhaust gas of the gas turbine 11 (see FIG. 1) changes according to the change in the atmospheric temperature, for example, even if the output of the gas turbine 11 is the same, the generated steam flow rate in summer and winter There will be a difference. Therefore, each turbine bypass valve (the high pressure turbine bypass valve 23 (see FIG. 1), the intermediate pressure turbine bypass valve 24 (see FIG. 1), and the low pressure turbine bypass valve 25 (see FIG. 1)) is set to the atmospheric temperature instead of the steam flow rate. It is good also as a structure correct | amended based on.

  Moreover, it is good also as a structure which makes the fixed value the target value of the operation load of the gas turbine 11 (refer FIG. 1), and the setting value of each turbine bypass valve calculated | required by heat balance calculation based on this target value. In this case, the target value of the operation load of the gas turbine 11 is preferably set to be low.

1 C / C power plant (combined cycle power plant)
DESCRIPTION OF SYMBOLS 10 Steam turbine 11 Gas turbine 12 High pressure turbine 13 Medium pressure turbine 14 Low pressure turbine 15 Condenser 20 Low pressure drum 21 Medium pressure drum 22 High pressure drum 23 High pressure turbine bypass valve (high pressure main steam pressure adjustment means)
24 Medium pressure turbine bypass valve (Medium pressure main steam pressure adjusting means)
25 Low pressure turbine bypass valve (Low pressure main steam pressure adjusting means)
51a High-pressure turbine bypass pipe 52a Medium-pressure turbine bypass pipe 53 Low-pressure turbine bypass pipe 54 Waste heat recovery boiler 54i Reheater 54j High-pressure superheater

Claims (4)

  1. A gas turbine,
    A high-pressure turbine driven by high-pressure main steam generated using exhaust heat contained in the exhaust gas of the gas turbine, an intermediate-pressure turbine driven by medium-pressure main steam generated using the exhaust heat, and the exhaust A steam turbine comprising a low pressure turbine driven by low pressure main steam generated using heat;
    A condenser for condensing the high-pressure main steam discharged from the high-pressure turbine to generate condensate;
    An exhaust heat recovery boiler that superheats the condensate generated in the condenser with the exhaust heat;
    A high-pressure drum that generates the high-pressure main steam from the condensate superheated by the exhaust heat recovery boiler;
    The high-pressure main steam generated in the high-pressure drum bypasses the high-pressure turbine and is introduced into the condenser, and the pressure of the high-pressure main steam in the high-pressure turbine bypass pipe is adjusted to adjust the high-pressure main steam. High pressure main steam pressure adjusting means for introducing the gas into the condenser,
    In the exhaust heat recovery boiler,
    A high-pressure superheater that superheats the high-pressure main steam generated in the high-pressure drum with the exhaust heat;
    A reheater that superheats the high-pressure main steam exhausted from the high-pressure turbine with the exhaust heat, is a combined cycle type power plant arranged in this order from the upstream with respect to the flow of the exhaust gas,
    When the steam turbine stops,
    The high-pressure main steam generated in the high-pressure drum is introduced into the condenser through the high-pressure turbine bypass pipe, and the high-pressure main steam pressure is reduced by the high-pressure main steam pressure adjusting means, thereby reducing the evaporation amount of the high-pressure drum. While increasing the heat absorption amount of the exhaust heat in the high-pressure superheater,
    Adjusting the pressure of the high-pressure main steam in the high-pressure turbine bypass pipe so that the evaporation amount of the high-pressure drum does not exceed the allowable maximum evaporation amount of the high-pressure drum,
    Further, the gas turbine is adjusted by adjusting an operation load of the gas turbine so that the exhaust heat contained in the exhaust gas after being absorbed by the high-pressure superheater does not exceed a heat-resistant allowable value and does not reach a high temperature. A combined cycle power plant characterized by being capable of operating a turbine alone.
  2. An intermediate pressure drum for generating the intermediate pressure main steam;
    An intermediate pressure turbine bypass pipe for introducing the intermediate pressure main steam generated in the intermediate pressure drum into the condenser bypassing the intermediate pressure turbine, and adjusting the pressure of the intermediate pressure main steam in the intermediate pressure turbine bypass pipe Medium pressure main steam pressure adjusting means for introducing the medium pressure main steam into the condenser;
    A low-pressure drum that generates the low-pressure main steam;
    The low-pressure main steam generated in the low-pressure drum bypasses the low-pressure turbine and is introduced into the condenser, and the pressure of the low-pressure main steam in the low-pressure turbine bypass pipe is adjusted to adjust the low-pressure main steam. And a low-pressure main steam pressure adjusting means for introducing into the condenser,
    When the steam turbine stops,
    The intermediate pressure main steam generated in the intermediate pressure drum is introduced into the condenser through the intermediate pressure turbine bypass pipe, and the intermediate pressure main steam is reduced by the intermediate pressure main steam pressure adjusting means. While increasing the evaporation amount of the pressure drum, adjusting the pressure of the intermediate pressure main steam in the intermediate pressure turbine bypass pipe so that the evaporation amount of the intermediate pressure drum does not exceed the allowable maximum evaporation amount of the intermediate pressure drum,
    The low-pressure main steam generated in the low-pressure drum is introduced into the condenser through the low-pressure turbine bypass pipe, and the low-pressure main steam pressure adjusting means depressurizes the low-pressure main steam, thereby reducing the evaporation amount of the low-pressure drum. The combined pressure according to claim 1, wherein the pressure of the low-pressure main steam in the low-pressure turbine bypass pipe is adjusted so that the evaporation amount of the low-pressure drum does not exceed an allowable maximum evaporation amount of the low-pressure drum. Cycle power plant.
  3. A gas turbine,
    A high-pressure turbine driven by high-pressure main steam generated using exhaust heat contained in the exhaust gas of the gas turbine, an intermediate-pressure turbine driven by medium-pressure main steam generated using the exhaust heat, and the exhaust A steam turbine comprising a low pressure turbine driven by low pressure main steam generated using heat;
    A condenser for condensing the high-pressure main steam discharged from the high-pressure turbine to generate condensate;
    An exhaust heat recovery boiler that superheats the condensate generated in the condenser with the exhaust heat;
    A high-pressure drum that generates the high-pressure main steam from the condensate superheated by the exhaust heat recovery boiler;
    The high-pressure main steam generated in the high-pressure drum bypasses the high-pressure turbine and is introduced into the condenser, and the pressure of the high-pressure main steam in the high-pressure turbine bypass pipe is adjusted to adjust the high-pressure main steam. High pressure main steam pressure adjusting means for introducing the gas into the condenser,
    In the exhaust heat recovery boiler,
    A high-pressure superheater that superheats the high-pressure main steam generated in the high-pressure drum;
    A reheater that superheats the high-pressure main steam exhausted from the high-pressure turbine with the exhaust heat, and the gas turbine alone in a combined cycle power plant arranged in this order from the upstream with respect to the flow of the exhaust gas. A driving method for driving,
    The high pressure main steam pressure is increased so that the amount of evaporation of the high pressure drum is increased in order to increase the heat absorption amount of the exhaust heat in the high pressure superheater, and the amount of evaporation of the high pressure drum does not exceed the allowable maximum amount of evaporation of the high pressure drum. Adjusting the pressure of the high-pressure main steam in the high-pressure turbine bypass pipe via adjusting means;
    Adjusting the operating load of the gas turbine so that the reheater does not exceed a heat-resistant allowable value due to the exhaust heat contained in the exhaust gas after being absorbed by the high-pressure superheater. A driving method characterized by that.
  4. An intermediate pressure drum for generating the intermediate pressure main steam;
    An intermediate pressure turbine bypass pipe for introducing the intermediate pressure main steam generated in the intermediate pressure drum into the condenser bypassing the intermediate pressure turbine, and adjusting the pressure of the intermediate pressure main steam in the intermediate pressure turbine bypass pipe Medium pressure main steam pressure adjusting means for introducing the medium pressure main steam into the condenser;
    A low-pressure drum that generates the low-pressure main steam;
    The low-pressure main steam generated in the low-pressure drum bypasses the low-pressure turbine and is introduced into the condenser, and the pressure of the low-pressure main steam in the low-pressure turbine bypass pipe is adjusted to adjust the low-pressure main steam. In the combined cycle type power plant, comprising a low-pressure main steam pressure adjusting means for introducing the water into the condenser,
    The pressure of the intermediate pressure main steam in the intermediate pressure turbine bypass pipe is adjusted via the intermediate pressure main steam pressure adjusting means so that the evaporation amount of the intermediate pressure drum does not exceed the allowable maximum evaporation amount of the intermediate pressure drum. Procedure and
    Adjusting the pressure of the low-pressure main steam in the low-pressure turbine bypass pipe via the low-pressure main steam pressure adjusting means so that the evaporation amount of the low-pressure drum does not exceed the allowable maximum evaporation amount of the low-pressure drum;
    The operation method according to claim 3, further comprising:
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US9500103B2 (en) * 2013-08-22 2016-11-22 General Electric Company Duct fired combined cycle system
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JP6615358B2 (en) * 2015-12-22 2019-12-04 シーメンス エナジー インコーポレイテッド Chimney energy control in combined cycle power plants.
JP2017180406A (en) * 2016-03-31 2017-10-05 三菱重工業株式会社 Exhaust heat recovery system, internal combustion engine system, ship and control method for exhaust heat recovery system

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JP2826394B2 (en) * 1991-06-25 1998-11-18 株式会社東芝 Pressure control system for combined cycle power plant
JP3068972B2 (en) * 1992-12-28 2000-07-24 株式会社東芝 Combined cycle power plant
JP3641030B2 (en) * 1995-09-01 2005-04-20 株式会社東芝 Safety valve operation test method for combined cycle power plant
JPH1113488A (en) * 1997-06-27 1999-01-19 Hitachi Ltd Full fired heat recovery combined plant using steam cooling type gas turbine
DE19736889C1 (en) * 1997-08-25 1999-02-11 Siemens Ag Operating method for combined gas-and-steam turbine plant
JP4052414B2 (en) * 1999-08-23 2008-02-27 三菱重工業株式会社 Combined power generation facility
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