JP4503995B2 - Reheat steam turbine plant and operation method thereof - Google Patents

Description

  The present invention relates to a reheat steam turbine plant and a method for operating the reheat steam turbine plant, and in particular, a reheat steam turbine capable of reducing start-up time by flowing steam to both a high-pressure turbine and an intermediate-pressure turbine at start-up. The present invention relates to a plant and an operation method thereof.

  Recent power plants have come to adopt an operation pattern in which a nuclear power plant is operated for base load and a thermal power plant is operated for peak load.

  For this reason, in a thermal power plant, as a measure for improving the operation pattern, DSS operation (Daily Start Start: once a day start / stop operation) is performed using a turbine bypass device. “Thermal Nuclear Power Generation” “Improvement and Operational Performance of Turbine Bypass Startup Method” (Thermal and Nuclear Power Engineering Association, June 1991, pages 68 to 83) (Non-Patent Document 1).

  Conventionally, a reheat steam turbine plant that performs DSS operation includes, for example, a heater 2 and a reheater 3 incorporated in a steam generator 1 such as a boiler, a high pressure turbine 4, and an intermediate pressure turbine, as shown in FIG. 5, a low pressure turbine 6, a condenser 7, a feed water pump 8, and a part of the steam generated by the heater 2 of the steam generator 1 is a main steam provided with a main steam stop valve 9 and a steam control valve 10. After being supplied to the high-pressure turbine 4 through the system 11 and generating power by performing expansion work here, a part of the high-pressure turbine exhaust is passed through a low-temperature reheat steam system 13 having a check valve 12. To supply to the reheater 3.

  The remaining steam branched from the main steam system 11 is part of the high-pressure turbine exhaust discharged from the high-pressure turbine 3 in the low-temperature reheat steam system 13 via the high-pressure turbine bypass system 15 including the high-pressure bypass valve 14. To join.

  The remainder of the high-pressure turbine exhaust discharged from the high-pressure turbine 3 is supplied to the condenser 7 via a ventilator system 17 having a ventilator valve 16.

  The ventilator valve 16 and the ventilator system 17 have a small amount of steam. For example, the ventilator valve 16 and the ventilator system 17 suppress an abnormally high temperature in the high-pressure turbine exhaust chamber due to windage loss that occurs during rotation of the high-pressure turbine. When closed.

  Further, the reheat steam that has exited the reheater 3 is supplied to the intermediate pressure turbine 23 via a reheat steam system 22 having a reheat steam stop valve 20 and an intercept valve 21, where expansion work is performed. After power is generated and the low-pressure turbine 6 performs expansion work again to generate power, it is supplied to the condenser 7 as low-pressure turbine exhaust and condensed with cooling water such as seawater to become condensate.

  On the other hand, a part of the reheated steam exiting the reheater 3 is supplied to the condenser 7 via a low pressure turbine bypass system 19 having a low pressure bypass valve 18.

  Condensate obtained by condensing the steam supplied to the condenser 7 from each of the low-pressure turbine 5, the low-pressure turbine bypass valve 18, and the ventilator system 17 is boosted by the feed water pump 8 and returned to the steam generator 1 again.

In the reheat steam turbine plant having such a configuration, the steam pressure generated from each of the heater 2 and the reheater 3 in the steam generator 1 during start-up is as shown in Table 1 during rated load operation. It is lower than that.

  Here, at the time of start-up, the pressure of the reheat steam generated from the reheater 3 is controlled by the low pressure bypass valve 18, and the pressure of about 0.7 MPa corresponds to a midway load zone of about 5% to 50% of the turbine load. Thus, the pressure is set to the pressure when the low pressure bypass valve 18 is fully closed under the pressure control operation.

  In the reheat steam turbine plant, at the time of start-up, the turbine bypass operation (upstream pressure control) is performed by the high pressure bypass valve 14 and the low pressure bypass valve 18, and the intercept valve 21 is opened with the steam control valve 10 fully closed. The valve is controlled to control the flow rate, and the rotation of the turbine is increased to start the load operation.

  At this time, the high-pressure turbine 4 rotates without being supplied with steam from the heater 2 of the steam generator 1, so that the room temperature rises from the final stage of the turbine to the turbine exhaust chamber due to windage caused by the rotation, and overheating occurs. It becomes a state.

  For this reason, the reheat steam turbine plant opens the ventilator valve 16 of the ventilator system 17 and communicates with the condenser 7, maintains the high-pressure turbine 4 in a vacuum, and suppresses temperature rise in the high-pressure turbine. .

  When the high-pressure turbine 4 is instructed to start expansion work, the reheat steam turbine plant opens the steam control valve 10, and steam from the heater 2 of the steam generator 1 to the high-pressure turbine 4 via the main steam system 11. Until the check valve 12 of the low-temperature reheat steam system 13 is fully opened, the high-pressure turbine exhaust is discharged to the condenser 6 via the ventilator valve 16 of the ventilator system 17, and the high-pressure turbine final stage and high-pressure turbine are discharged. The turbine is cooled. When the predetermined load is reached, the reheat steam turbine plant closes the ventilator valve 16 to bring the high-pressure turbine 4, the intermediate-pressure turbine 5, and the low-pressure turbine 6 to rated loads.

As described above, the conventional reheat steam turbine plant effectively utilizes the turbine bypass system to improve the start-up characteristics and adjust the absorption between the steam generator load and the turbine load.
Literature “Thermal Power Generation” “Turbine Bypass Startup Method Improvement and Operational Results” (Thermal Power Generation Technology Association, June 1991, pages 68-83)

Reheat steam turbine plant shown in FIG. 4, a high pressure turbine bypass system, but those with an improved starting characteristics or the like by effectively using a low-pressure turbine bypass system, but still the improvements such as to shorten the still start time There is room for it.

Further, for example, during a rated load operation, there is a command such as a trip for some reason, and after restarting the turbine after stopping the operation of the turbine, as shown in Table 1, the steam of the high-pressure turbine bypass system 15 If the pressure does not reach about 8.0 MPa, the high pressure bypass valve 14 does not open, and if the steam pressure of the low pressure turbine bypass system 19 does not reach about 0.7 MPa, the low pressure bypass valve 18 does not open. It has become.

  On the other hand, in a recent thermal power plant, an operation record of a combined cycle power plant that uses a waste heat recovery boiler instead of a boiler or the like and generates steam using the exhaust heat gas of a gas turbine is increasing.

  The steam generated from this waste heat recovery boiler may be used not only for power generation, but also for process steam at paper mills, Atsunobu mill, aluminum smelting mill, etc., and for district heating / cooling steam for cogeneration. .

  However, considering that the reheat steam turbine plant cannot be started unless the restart operation is reduced to the steam pressure shown in Table 1, during this time, process steam and district heating / cooling steam cannot be used at all. It was coming.

The present invention has been made based on such circumstances, and in addition to providing a reheat steam turbine plant that can further shorten the startup time, in a reheat steam turbine plant that supplies steam to other systems, , even if a stop command, such as trips and load shedding in the steam turbine, while high to maintain the pressure of the steam generated from the steam generator, the reheat steam turbine plant to perform a stable supply of steam to the other strains The purpose is to provide a driving method.

  In order to achieve the above object, a reheat steam turbine plant according to the present invention includes a ventilator system that connects a high-pressure turbine and an intermediate-pressure turbine to each other, and a main steam system of a steam generator. A first steam supply system that branches from between the branch point of the high-pressure turbine bypass system and the main steam stop valve, and the branch point and reheat steam stop of the low-pressure turbine bypass system in the high-temperature reheat steam system of the steam generator And a second steam supply system that branches from the valve.

  In order to achieve the above-mentioned object, the reheat steam turbine plant according to the present invention includes a ventilator valve and a ventilator valve provided in the main steam system as described in claim 2. The valve opening degree of the steam control valve and the valve opening degree operation of the intercept valve provided in the high-temperature reheat steam system are respectively reversed.

  Moreover, in order to achieve the above-mentioned object, the operation method of the reheat steam turbine plant according to the present invention supplies the first steam supply system as process steam as described in claim 3. is there.

  Moreover, in order to achieve the above-described object, the reheat steam turbine plant operating method according to the present invention is such that the second steam supply system supplies heat supply steam as described in claim 4. It is.

  Moreover, in order to achieve the above-mentioned object, the operation method of the reheat steam turbine plant according to the present invention provides a part of the steam generated from the heater of the steam generator at start-up as described in claim 5. Is supplied to the high-pressure turbine via the main steam system, the rest is supplied to the high-pressure turbine bypass system, and a part of the high-pressure turbine exhaust exiting the high-pressure turbine is supplied to the intermediate-pressure turbine via the ventilator valve of the ventilator system. The remaining steam is combined with the steam from the high-pressure turbine bypass system in the low-temperature reheat steam system, and the combined steam is supplied to the reheater of the steam generator to generate reheat steam, and the generated reheat is generated. In the operation method of the reheat steam turbine plant in which a part of the steam is supplied to the high-temperature reheat steam system and the rest is supplied to the low-pressure turbine bypass system, the main steam is used until a predetermined turbine load is reached. When the turbine speed is controlled by a steam control valve provided in the engine and a predetermined turbine load is exceeded, the turbine speed is controlled by the steam control valve provided in the main steam system and the intercept valve provided in the high-temperature reheat steam system. This is a method of performing number control.

  Moreover, in order to achieve the above-mentioned object, the reheat steam turbine plant operating method according to the present invention provides a part of the steam generated from the heater of the steam generator at start-up as described in claim 6. Is supplied to the high-pressure turbine via the main steam system, the rest is supplied to the high-pressure turbine bypass system, and a part of the high-pressure turbine exhaust exiting the high-pressure turbine is supplied to the intermediate-pressure turbine via the ventilator valve of the ventilator system. The remaining steam is combined with the steam from the high-pressure turbine bypass system in the low-temperature reheat steam system, and the combined steam is supplied to the reheater of the steam generator to generate reheat steam, and the generated reheat is generated. In the operation method of the reheat steam turbine plant in which a part of the steam is supplied to the high-temperature reheat steam system and the rest is supplied to the low-pressure turbine bypass system, the main steam is used until a predetermined turbine load is reached. When the turbine speed is controlled by a steam control valve provided in the engine, and a predetermined turbine load is exceeded, the ventilator valve and the intercept valve provided in the high-temperature reheat steam system have an interlocking relationship between the valve openings. This is a method for carrying out cooperative control.

Reheat steam turbine plant according to the present invention, only setting the ventilator system connecting the intermediate pressure turbine and the high pressure turbine directly, during the starting operation, supply direct steam supplied to the high pressure turbine to the medium-pressure turbine via a ventilator system While the high-pressure turbine is being cooled, the intercept valve is opened by increasing the pressure and temperature of the reheat steam, so that stable reheat steam can be supplied to the intermediate pressure turbine and the startup time is shortened. Can be made . In addition, a first steam supply system is provided by branching between the branch point of the high-pressure turbine bypass system of the main steam system and the main steam stop valve, and the branch point and reheat of the low-pressure turbine bypass system of the high-temperature reheat steam system are provided. In a reheat steam turbine plant that branches from the steam stop valve to provide a second steam supply system and supplies steam to other systems, each of the high pressure steam and reheat steam is supplied to the steam supply system. Since each of the components can be supplied as it is, stable high-pressure steam and reheated steam can be stably supplied to each of the steam supply systems even during a load operation even if there is a turbine trip command.

  Hereinafter, a reheat steam turbine plant and an operation method thereof according to the present invention will be described with reference to the drawings and reference numerals attached to the drawings.

  FIG. 1 is a schematic system diagram showing a first embodiment of a reheat steam turbine plant according to the present invention.

  The reheat steam turbine plant according to this embodiment includes a heater 23 and a reheater 24 incorporated in a steam generator 22, a high pressure turbine 25, a medium pressure turbine 26, a low pressure turbine 27, a condenser 28, and a feed water pump. 29, a part of the steam generated by the heater 23 of the steam generator 22 is supplied to the high-pressure turbine 25 through a main steam system 32 having a main steam stop valve 30 and a steam control valve 31, After the expansion work is performed to generate power, a part of the high-pressure turbine exhaust is supplied to the reheater 24 through the low-temperature reheat steam system 34 including the check valve 33.

  The remaining steam branched from the main steam system 33 is part of the high-pressure turbine exhaust discharged from the high-pressure turbine 25 by the low-temperature reheat steam system 34 via the high-pressure turbine bypass system 36 having the high-pressure bypass valve 35. To join.

  The high-pressure turbine exhaust combined with the steam from the high-pressure turbine bypass system 36 in the low-temperature reheat steam system 34 is reheated in the reheater 24 and partly provided with a low-pressure bypass valve 37 as the reheat steam. 38 is supplied to the condenser 28, and the remainder is supplied to the intermediate pressure turbine 26 via a high-temperature reheat steam system 41 including a reheat steam stop valve 39 and an intercept valve 40.

  In the reheat steam turbine plant having such a configuration and starting to start, the intermediate pressure turbine 26 causes the reheat steam from the high temperature reheat steam system 41 to perform expansion work to generate power. The expansion work is performed to generate power, and the low-pressure turbine exhaust that has finished the expansion work is condensed by the condenser 28 to condensate, and the condensate is boosted by the feed water pump 29 to form feed water, and the feed water is again steamed. It is returned to the generator 22.

  In order to ensure good start-up operation, in the reheat steam turbine plant, the high-pressure turbine exhaust chamber of the high-pressure turbine 25 or the extraction port of the high-pressure turbine intermediate stage to the inlet of the intermediate-pressure turbine 26, for example, the nozzle box or the middle A ventilator system 43 is provided which is connected to the steam chamber in the intermediate stage of the pressure turbine and has a ventilator valve 42 interposed in the middle thereof.

  The ventilator system 43 cools the high-pressure turbine 25 during startup, and the pressure of the steam supplied from the main steam system 32 is higher than the pressure of the reheated steam flowing through the low-pressure turbine bypass system 38 from the reheater 24. When the check valve 33 of the low-temperature reheat steam system 34 is closed, the ventilator valve 42 is opened to flow the steam to the intermediate pressure turbine 26, and the wind loss generated during the rotation of the high pressure turbine 25 is reduced. The overheating of the accompanying high pressure turbine final stage and the high pressure turbine exhaust chamber is suppressed.

  Next, an operation method of the reheat steam turbine plant according to the present embodiment will be described.

  FIG. 2 is a time for explaining the operation method of the reheat steam turbine plant according to the present embodiment, in which the vertical axis indicates the turbine rotation speed, the turbine load, and various valve openings, and the horizontal axis indicates the dimensionless time. It is a chart.

First, at T ₁ at the start of start-up operation, the ventilator valve 42 is fully open, the steam control valve 31 is fully closed, the intercept valve 40 is fully closed, and the reverse side provided in the low-temperature reheat steam system 34 on the outlet side of the high-pressure turbine 25. The stop valve 33 is fully closed, and the high pressure bypass valve 35 of the high pressure turbine bypass system 36 and the low pressure bypass valve 37 of the low pressure turbine bypass system 38 are both controlled to open and close so that the pressure can be controlled in accordance with the flow rate of the steam amount and the reheat steam amount. Is done.

  Here, the main steam stop valve 30 and the reheat steam stop valve 39 are only rapidly closed only in an emergency, and are fully opened from the start.

When the time enters the turbine speed increasing process of T ₂ from T _1, the reheat steam turbine plant, under towards the target speed (rated speed) the valve opening and closing control of the steam regulating valve 31, while the rotational speed control Increase turbine speed.

On the other hand, the high pressure bypass valve 35 and the low pressure bypass valve 37 gradually reduce the valve opening. At this time, more steam generated from the heater 23 of the steam generator 22 is supplied to the high-pressure turbine 25 via the steam control valve 31 of the main steam system 32. Thereafter, at a time T _2, the turbine speed reaches the rated, thereafter, it enters the constant speed control.

From time T ₂ to T ₃ , the reheat steam turbine plant starts turbine load operation and gradually opens the steam control valve 31 until the turbine load reaches a predetermined load. It is performed speed control according to the steam control valve 31, allowed to reach a predetermined turbine load by the time T ₃ (target load).

When the time becomes T _3, the reheat steam turbine plant, while the turbine load operation, the reheat steam generated from the reheater 24 the steam generator 22 to the intermediate pressure turbine 26 via a hot reheat steam system 41 Start preparing to supply.

Furthermore, ventilator valve 42 is closed in accordance with the valve closing speed rate predetermined from the fully open position at time T ₃ to the fully closed position at time T _6.

Since the reheat steam operation using the reheat steam is started between the times T _{3 and} T ₄ , the ventilator valve 42 is throttled according to the above-described valve closing speed rate. As the valve opening of the ventilator valve 42 is reduced, the reheat steam supplied to the intermediate pressure turbine 26 decreases in flow rate and falls in the turbine load. At this time, the reheat steam turbine plant operates an automatic load regulator (ALR) (not shown) to increase the valve opening degree of the steam control valve 31, increase the inflow steam amount, and reduce the above-described turbine load drop. It is made to urge and it changes from turbine load fixed control by ALR to load increase control.

Reaches the time T _4, the reheat steam turbine plant, with to open the intercept valve 40, to terminate the pressure control by the low-pressure turbine bypass bypassing system 38, to close the low pressure bypass valve 37.

Between times T _{4 and} T ₅ , the reheat steam turbine plant opens the intercept valve 40 according to a turbine load request signal from a turbine controller (not shown), and the reheat generated from the reheater 24 of the steam generator 22. Hot steam is supplied to the intermediate pressure turbine 26.

  Here, the flow rate of the reheat steam supplied to the intermediate pressure turbine 26 is the same as the flow rate that decreases when the ventilator valve 42 is closed and the flow rate that increases when the intercept valve 40 opens, or the turbine load I try to get more than that on demand. That is, the valve opening degree of the ventilator valve 42 and the intercept valve 40 has an interlocking relationship and performs cooperative control so that the turbine load does not drop.

  While the valve openings of the ventilator valve 42 and the intercept valve 40 are interlocked, the reheat steam turbine plant causes the steam control valve 31 and the intercept valve 40 to perform rotational speed control, thereby increasing the turbine load.

  At this time, the low-pressure bypass valve 37 has already been fully closed, and the pressure control of the reheat steam coming out of the reheater 24 is released.

  In such an operating situation, when the reheat steam turbine plant opens the intercept valve 40, the amount of reheat steam supplied to the intermediate pressure turbine 26 increases, but the reheat from the reheater 24 increases. Steam pressure drops rapidly, causing operational problems.

  That is, the pressure drop of the reheat steam changes the phase of the reheat steam, that is, changes from dry steam to wet steam, so that the low pressure turbine 27 and the condenser 28 of the intermediate pressure turbine 26 and later including the intermediate pressure turbine 26 It becomes a factor of performance degradation.

  Therefore, the intercept valve 40 is provided with an inlet steam pressure control device (IPC), and the operation of the inlet steam pressure control device (IPC) prevents unstable operation such as a sudden change in the turbine speed and a change in turbine load. Thus, the pressure of the reheated steam supplied to the intermediate pressure turbine 26 is immediately recovered to enable stable supply.

Between times T _{5 and} T ₆ , the reheat steam turbine plant supplies all the reheat steam from the reheater 24 to the intermediate pressure turbine 26, and the steam is increased or decreased in response to the increase / decrease request of the turbine load. It is made to respond by opening / closing control of the valve 31.

  On the other hand, the ventilator valve 42 of the ventilator system 43 continues the valve closing operation, and gradually reduces the supply of steam to the intermediate pressure turbine 26 during this time. Immediately before the ventilator valve 42 is fully closed, in the reheat steam turbine plant, the pressure before and after the check valve 33 provided in the low temperature reheat steam system 34 is balanced, and the pre-valve pressure eventually increases. Then, the check valve 33 is suddenly opened.

Thereafter, it closed ventilator valve 42 is full, at the time T ₆ after, the reheat steam turbine plant, causes loaded raised to the intermediate pressure turbine 26 to the high pressure bypass valve 35 of the high pressure turbine bypass system 36 fully closed.

  As described above, the reheat steam turbine plant and the operation method thereof according to the present embodiment branch from the upstream side of the check valve 33 provided in the low-temperature reheat steam system 34 on the outlet side of the high-pressure turbine 25 and in the middle. A ventilator system 43 having a ventilator valve 42 is connected to the intermediate pressure turbine 26, and at the time of start-up operation, the high pressure turbine exhaust from the high pressure turbine 25 is directly supplied to the intermediate pressure turbine 26 via the ventilator system 43. Since the intercept valve 40 is opened by increasing the pressure and temperature of the reheat steam while the inside of the turbine 25 is being cooled, it is possible to supply stable reheat steam to the intermediate pressure turbine and start up. Time can be shortened.

  FIG. 3 is a schematic system diagram showing a second embodiment of the reheat steam turbine plant according to the present invention.

  The reheat steam turbine plant according to the present embodiment branches from between a branch point of the high-pressure turbine bypass system 35 of the main steam system 32 and the main steam stop valve 30, for example, a process steam supply system 44 (hereinafter referred to as a factory steam supply system 44). , A first process steam supply system) and a branch from between the branch point of the low-pressure turbine bypass system 38 of the high-temperature reheat steam system 41 and the reheat steam stop valve 39, for example, heat supply for cogeneration A system 45 (hereinafter referred to as a second process steam supply system) is provided. Since the other constituent elements are the same as the constituent elements of the first embodiment, the same reference numerals as those used in the first embodiment are used, and redundant description is omitted here.

As shown in Table 2, the reheat steam turbine plant having such a configuration has a high pressure bypass valve 35 for restarting operation from the turbine stop state such as the steam pressure generated from the heater 23 and the turbine trip during rated operation. The set pressure is maintained at the same pressure, and the reheat steam pressure generated from the reheater 24 during rated load operation and the restart operation from a turbine stop state such as a turbine trip, The set pressure is maintained at the same pressure.

  Therefore, in the second embodiment, both the set pressure of the high-pressure bypass valve 35 and the set pressure of the low-pressure bypass valve 37 are set to be high, and during the load operation, for example, even if there is a turbine trip command, the heater 23 and the reheater Since the pressures of the steam and reheat steam from 24 are high, the steam can be supplied to at least one of the first process steam supply system 44 and the second process steam supply system 45 as it is. Each of the main steam and reheated steam can be supplied.

  In addition, what is necessary is just to start restart according to the time chart shown in FIG. 2, when restarting again from the steam conditions shown in Table 2. In this case, although the high-pressure bypass valve 35 and the low-pressure bypass valve 37 are already under pressure control, they are in the closed state. Therefore, only the steam control valve 31, the ventilator valve 42, and the intercept valve 40 are included in the time chart shown in FIG. The valve opening / closing operation may be noted. As a result, the steam turbine side can be started from the rated steam condition.

1 is a schematic system diagram showing a first embodiment of a reheat steam turbine plant according to the present invention. The time chart for demonstrating the operating method of the reheat steam turbine plant which concerns on this invention. The schematic system diagram which shows 2nd Embodiment of the reheat steam turbine plant which concerns on this invention. The schematic system diagram which shows the conventional reheat steam turbine plant.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Steam generator 2 Heater 3 Reheater 4 High pressure turbine 5 Medium pressure turbine 6 Low pressure turbine 7 Condenser 8 Water supply pump 9 Main steam stop valve 10 Steam control valve 11 Main steam system 12 Check valve 13 Low-temperature reheat steam System 14 High pressure bypass valve 15 High pressure turbine bypass system 16 Ventilator valve 17 Ventilator system 18 Low pressure bypass valve 19 Low pressure turbine bypass 20 Reheat steam stop valve 21 Intercept valve 22 Steam generator 23 Heater 24 Reheater 25 High pressure turbine 26 Medium pressure Turbine 27 Low pressure turbine 28 Condenser 29 Feed water pump 30 Main steam stop valve 31 Steam control valve 32 Main steam system 33 Check valve 34 Low temperature reheat steam system 35 High pressure bypass valve 36 High pressure turbine bypass system 37 Low pressure bypass valve 38 Low pressure turbine Bypass system 39 Reheat steam stop valve 40 Intercept valve 41 High temperature reheat steam system 2 Ventilator valve 43 ventilator system 44 first process steam supply system 45 a second process steam supply system

Claims (6)

A ventilator system for connecting the high-pressure turbine and the intermediate-pressure turbine to each other; a first steam supply system that branches from between a branch point of the high-pressure turbine bypass system and the main steam stop valve in the main steam system of the steam generator; A reheat steam turbine plant comprising a second steam supply system that branches from between a branch point of a low-pressure turbine bypass system and a reheat steam stop valve in a high-temperature reheat steam system of a generator. The ventilator system is provided with a ventilator valve, and the ventilator valve is configured to reverse the valve opening operation of the steam control valve provided in the main steam system and the valve opening operation of the intercept valve provided in the high-temperature reheat steam system. The reheat steam turbine plant according to claim 1. The reheat steam turbine plant according to claim 1, wherein the first steam supply system is supplied as process steam. The reheat steam turbine plant according to claim 1, wherein the second steam supply system supplies steam as heat supply steam. At startup, a part of the steam generated from the heater of the steam generator is supplied to the high-pressure turbine through the main steam system, the rest is supplied to the high-pressure turbine bypass system, and one of the high-pressure turbine exhausts exiting the high-pressure turbine is supplied. Is supplied to the intermediate pressure turbine via the ventilator valve of the ventilator system, and the remainder is combined with the steam from the high pressure turbine bypass system in the low temperature reheat steam system, and the combined steam is reheated in the steam generator. In the operation method of the reheat steam turbine plant, a part of the generated reheat steam is supplied to the high temperature reheat steam system and the rest is supplied to the low pressure turbine bypass system. Turbine rotation speed control is performed by a steam control valve provided in the main steam system until a predetermined turbine load is reached, and when a predetermined turbine load is exceeded, the main steam system is provided. The method of operating reheat steam turbine plant and performing turbine speed control by the intercept valve provided in said the gas control valve hot reheat steam system. At startup, a part of the steam generated from the heater of the steam generator is supplied to the high-pressure turbine through the main steam system, the rest is supplied to the high-pressure turbine bypass system, and one of the high-pressure turbine exhausts exiting the high-pressure turbine is supplied. Is supplied to the intermediate pressure turbine via the ventilator valve of the ventilator system, and the remainder is combined with the steam from the high pressure turbine bypass system in the low temperature reheat steam system, and the combined steam is reheated in the steam generator. In the operation method of the reheat steam turbine plant, a part of the generated reheat steam is supplied to the high temperature reheat steam system and the rest is supplied to the low pressure turbine bypass system. Turbine rotational speed control is performed by a steam control valve provided in the main steam system until a predetermined turbine load is reached, and when a predetermined turbine load is exceeded, the ventilator valve The method of operating reheat steam turbine plant which comprises bringing serial perform each valve opening cooperative control by providing the interlocking relationship between intercept valve provided on the hot reheat steam system.

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