JPH09256815A - Steam cooling gas turbine, steam cooling combined cycle plant using the gas turbine, and its operating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a steam cooling gas turbine in which the cooling efficiency is improved by using the steam as the cooling medium of a gas turbine, and the inside is efficiently shaft-sealed from the atmospheric pressure in the surrounding environment by a gland seal part of a gas turbine gland, a steam cooling combined cycle plant using the gas turbine, and its operating method. SOLUTION: A steam cooling combined cycle plant 20 comprises a gas turbine plant 21, an exhaust heat recovery boiler 22, and a steam turbine plant 23, and in the plant 20, a hot part of a gas turbine 27 is cooled with steam. The gas turbine 27 is provided with a turbine cooling part 47 to cool turbine parts of the hot part of the turbine with steam, a cooling steam feeding part 44 to feed the cooling steam to the turbine cooling part 47, and a gland seal part 43 to seal the cooling steam feeding part 44 from the atmospheric pressure in the surrounding environment.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steam cooling gas turbine for cooling a turbine high temperature part of a gas turbine with steam, a steam cooling combined cycle plant using the gas turbine, and an operating method thereof.

[0002]

2. Description of the Related Art In recent large-scale thermal power plants, many combined cycle plants have been constructed in which a gas turbine plant and a steam turbine plant are combined in order to improve plant efficiency. In this combined cycle plant, it is well known that the higher the inlet temperature of the gas turbine, the better the thermal efficiency and the improvement of energy efficiency. Recently, due to the development of high-temperature resistant materials and advances in turbine cooling technology, the inlet temperature of gas turbines has been further increased (1300 ° C to 15 ° C).
00 ° C or 1500 ° C or higher), which is in the direction of improving plant efficiency.

However, even though high-temperature resistant materials have been developed, an increase in the gas turbine inlet temperature or an extremely high temperature causes an increase in temperature in the turbine component parts of the gas turbine, and the turbine component parts, particularly the turbine high temperature. There is a risk that functional deterioration of the turbine parts of the parts may be caused and life may be significantly shortened.
For this reason, the development of high-temperature resistant materials that do not cause functional deterioration of turbine components even if the inlet temperature of the gas turbine rises, and the development of cooling technology that effectively and effectively prevents the temperature rise of turbine components. Strongly desired.

Conventionally, in this type of gas turbine, air compressed by a compressor is used as a cooling medium for a turbine high temperature portion, and the compressed air is bypassed to a combustor and directly supplied to the turbine high temperature portion for cooling. ing. In this gas turbine cooling method, the proportion of air required for cooling the gas turbine increases as the temperature rises, and therefore improvement in turbine efficiency due to the temperature rise cannot be expected.

On the other hand, in a gas turbine, it has been conventionally proposed to use steam, which has a much higher cooling performance than air, as a cooling medium in a high temperature part of the turbine. However, until now, the consideration of steam cooling has not been particularly sufficient, considering that cooling of the gas turbine is sufficient with air cooling.

Further, by incorporating the steam cooling gas turbine in the combined cycle plant, the cooling efficiency of the high temperature part of the turbine of the gas turbine can be greatly improved, and further, the steam after cooling the high temperature part of the turbine is fed to the steam turbine plant. If the heat is recovered, it can contribute to the improvement of the plant output of the steam turbine plant, and the effect of two birds with one stone can be expected. Therefore, development and practical application of a steam cooling gas turbine and a steam cooling combined cycle plant equipped with this gas turbine are expected.

From such a technical background, recently, steam cooling technology using heating steam from an exhaust heat recovery boiler or extraction steam from a high-pressure steam turbine as a cooling medium of a gas turbine has been attracting attention.

The steam used as the cooling medium in the high temperature part of the turbine of the gas turbine cools the turbine parts in the high temperature part of the turbine and rises in temperature. If the cooling steam whose temperature has risen is collected in the steam turbine plant to generate an output, the heat energy obtained by cooling the high temperature part of the turbine can be recovered very effectively, and the plant efficiency can be further improved. . A combined cycle plant that uses steam as a cooling medium for cooling the high temperature part of the gas turbine is defined as a steam cooling combined cycle plant. Steam-cooled combined cycle plants include combined cycle power plants and cogeneration plants.

An example of using steam as a cooling medium for a turbine component of a gas turbine is disclosed in Japanese Patent Laid-Open No. 5-24006.
No. 4, JP-A-6-257403, JP-A-7-4210, and the like.

Among these, Japanese Patent Laid-Open No. 5-240064 discloses a steam cooling technique provided with a route for guiding cooling steam to a high temperature part of a turbine inside a gas turbine.
Japanese Patent Publication No. 257403 discloses a steam cooling technique in which cooling steam is supplied to a turbine rotor blade of a gas turbine for cooling. Further, in Japanese Patent Laid-Open No. 7-4210, the steam is extracted from the middle stage of the high-pressure steam turbine or the middle of the exhaust heat recovery boiler, and this steam is used as a cooling medium for the gas turbine to discharge the steam after cooling the gas turbine. A steam cooling technique for recovering in a reheater of a heat recovery boiler is disclosed.

[0011]

In the steam-cooled combined cycle plant, when the high temperature part of the turbine of the gas turbine is cooled with steam, it is necessary to supply the cooling steam to the inside of the gas turbine. When the cooling steam used is higher than the atmospheric pressure (ambient environment), it is necessary to seal the cooling steam from the atmospheric pressure and supply it inside the gas turbine. In particular, when supplying cooling steam to the rotating part of a gas turbine, the shaft sealing technology of the gas turbine is important. However, the steam cooling technology of the gas turbine disclosed in the conventional patent publication is a turbine rotor blade or a turbine. This is for cooling the high temperature part, and neither discloses at all, nor suggests any shaft sealing technology for the part that supplies the cooling steam to the gas turbine.

On the other hand, in the start-up operation of the steam cooling combined cycle plant, steam is generated in the exhaust heat recovery boiler and the generated boiler steam (main steam) is sent to the steam turbine for a while after the start of the gas turbine. It will be after the elapse. Therefore, in the initial stage of the start-up operation of the steam cooling combined cycle plant, the steam required for cooling the turbine parts of the gas turbine cannot be extracted from the high-pressure steam turbine or the exhaust heat recovery boiler. In the plant start-up operation, as described in Japanese Patent Laid-Open No. 7-4210, the cooling steam of the turbine component is kept until the cooling steam of the turbine high temperature part of the gas turbine can be taken out from the high pressure steam turbine or the exhaust heat recovery boiler. It must be supplied from another cooling steam supply system. However, Japanese Patent Application Laid-Open No. 7-4210 does not disclose an operating method at the time of startup operation of the steam cooling combined cycle plant, nor does it disclose or suggest a shaft sealing technique for a gas turbine.

By the way, in a conventional combined cycle plant in which a gas turbine is cooled by air, a shaft sealing technique for a steam turbine is known as shown in FIG.

The combined cycle plant is constructed by assembling a gas turbine plant 1, an exhaust heat recovery boiler, a steam turbine plant 2 and the like. The steam turbine plant 2 includes a high-pressure steam turbine 3, an intermediate-pressure steam turbine 4 and a low-pressure steam turbine 5. The turbine exhaust pressure of the high-pressure steam turbine 3 is higher than atmospheric pressure, and the turbine exhaust pressure of the low-pressure steam turbine 5 is atmospheric pressure. It is kept below. In the steam turbine plant 2, a high pressure steam turbine gland 6 and a low pressure steam turbine gland 7 are provided to seal the shaft of the steam turbine. A gland seal portion is formed in the steam turbine glands 6 and 7.

During the rated operation of the steam turbine plant 2, the leaked steam from the turbine gland of the high-pressure steam turbine 3 is leaked from the high-pressure steam turbine gland 8
Is recovered at the inlet of the low-pressure steam turbine 5 and the steam pressure is slightly reduced. Further, a part of the leaked steam in the turbine gland 6 of the high-pressure steam turbine 3 leaks from the leaked steam part 6c to the seal steam part 6b, passes through the high-pressure steam gland seal steam pipe 9, and passes through the seal steam header 1
0 is supplied.

The seal steam supplied to the seal steam header 10 is supplied to the seal steam section 7b through the low pressure steam turbine gland seal steam pipe 11 connected to the low pressure steam turbine gland 7, and the seal steam of the low pressure steam turbine 5 is supplied. Shared as. Since the turbine exhaust side of the low-pressure steam turbine 5 is connected to the condenser 12, the turbine exhaust part is kept at the atmospheric pressure or less, and the seal steam of the low-pressure steam turbine gland 7 is inside the low-pressure steam turbine 5. Inflow.

The seal steam header 10 has a condenser 1
2 is installed, and when the sealing steam leaking from the high-pressure steam turbine gland seal steam piping 9 is larger than the sealing steam supplied to the low-pressure steam turbine gland 7, the surplus steam is released into the sealing steam relief valve. 1
It is collected in the condenser 12 via This seal steam is always kept at a pressure slightly higher than the atmospheric pressure by the seal steam relief valve 14.

On the other hand, the seal glands 6a and 7a are formed on the atmosphere side in the turbine glands 6 and 7 of the high-pressure steam turbine 3 and the low-pressure steam turbine 5, respectively, and the seal steam discharge parts 6a and 7a are provided with a labyrinth packing or the like. It is separated from the surrounding environment via the sealing means 15 of FIG. A high-pressure steam turbine gland seal steam discharge pipe 16a and a low-pressure steam turbine gland seal steam discharge pipe 16b are installed in each seal steam discharge part 6a, 7a, and each discharge pipe is connected to a gland steam condenser 17.

In the gland steam condenser 17, heat is exchanged with the condensate of the steam turbine sent from the condenser 12, while the inside of the condenser is sucked by the gland steam exhauster 18 and kept at a pressure lower than atmospheric pressure at all times. Be done. For this reason, the turbine glands 6 of the high-pressure steam turbine 3 and the low-pressure steam turbine 5, which communicate with the gland steam condenser 17 via the gland seal steam discharge pipes 16a and 16b.
The seal steam discharge parts 6a and 7a of No. 7 are kept below atmospheric pressure, and the seal steam part 6a is attached to each seal steam discharge part 6a and 7a.
Both the leak seal steam from b and 7b and the atmosphere from the ambient environment are sucked in to seal the shaft of the steam turbine.

In a conventional air-cooled combined cycle plant, a steam turbine provided in the steam turbine plant 2 is equipped with a gland seal portion provided with the above-mentioned shaft sealing means to separate the inside of the steam turbine from the atmospheric pressure of the surrounding environment. There is. However, cooling steam is not supplied to the gas turbine plant 1, and it is difficult to directly apply this shaft sealing technique. Further, in the conventional gas turbine plant 1, there is no disclosure or suggestion of the shaft sealing technique of the steam cooling gas turbine.

When the cooling steam is supplied to the inside of the gas turbine provided in the steam cooling combined cycle plant, the cooling steam passage structure inside the turbine becomes complicated, and the cooling steam guided in the cooling passage has a large pressure. Receive a loss. Therefore, a technique for avoiding the pressure loss of the cooling steam is also important, but this pressure loss avoiding technique has not been given special consideration in the conventional steam cooling gas turbine.

The present invention has been made in consideration of the above-mentioned circumstances, and improves the cooling efficiency by using steam as the cooling medium of the gas turbine to improve the thermal efficiency, and at the same time, the gland seal portion of the gas turbine gland. An object of the present invention is to provide a steam-cooled gas turbine capable of efficiently and effectively axially sealing the inside from the atmospheric pressure of the surrounding environment, a steam-cooled combined cycle plant using this gas turbine, and an operating method thereof.

Another object of the present invention is to provide a steam-cooled gas turbine in which the cooling efficiency is improved by smoothly and smoothly supplying steam as a cooling medium for the gas turbine not only during rated operation but also during start-up operation. A steam-cooled combined cycle plant using a turbine and an operating method thereof are provided.

Another object of the present invention is to efficiently seal the cooling steam from the atmospheric pressure of the surrounding environment by means of the gland seal portion of the gas turbine gland, while at the same time providing the sealing steam for the shaft seal between the gas turbine plant and the steam. The present invention provides a steam-cooled combined cycle plant and a method of operating the same, which is shared by a turbine plant and is effectively shared not only during rated operation but also during start-up operation.

Still another object of the present invention is to improve the turbine cooling efficiency by reducing or avoiding the pressure loss of the cooling steam guided in the gas turbine, and to improve the steam cooling combined cycle plant and its operating method. To provide.

Another object of the present invention is to effectively secure the cooling steam of the gas turbine even during the plant start-up operation in which cooling steam is not generated from the steam turbine or the exhaust heat recovery boiler and to supply it smoothly and smoothly. The present invention provides a steam cooling combined cycle plant and an operating method capable of effectively cooling a gas turbine.

Still another object of the present invention is to effectively cool the gas turbine while axially sealing the gas turbine and simultaneously to axially seal the steam turbine to increase the vacuum even when the steam turbine plant is not ready to start up. (EN) Provided is a steam cooling combined cycle plant which can be carried out and an operating method thereof.

Still another object of the present invention is to, when the steam turbine plant is ready to be started, effectively seal the gas turbine to cool it and to smoothly increase the starting load of the steam turbine plant. (EN) A steam-cooled combined cycle plant that can be efficiently operated and an operating method thereof.

[0029]

In order to solve the above-mentioned problems, the steam-cooled gas turbine according to the present invention is, as described in claim 1, steam-cooled for cooling the high temperature part of the turbine of the gas turbine with steam. In a gas turbine, a turbine cooling unit that steam-cools turbine components in the high-temperature part of the turbine, a cooling steam supply unit that supplies cooling steam to the turbine cooling unit, and a shaft seal that seals the cooling steam supply unit from atmospheric pressure of the surrounding environment. And a gland seal part which is provided, and the gland seal part is provided on at least one side of the turbine rotor.

Further, in order to solve the above-mentioned problems, the steam-cooled gas turbine according to the present invention has the following features.
As described above, the gas turbine is provided with a gland seal housing on at least one side of the turbine rotor, and the gland seal housing partially covers the turbine rotor in the axial direction, and a cooling steam supply part is provided in the gland seal housing. And a cooling steam recovery section are formed separately, and the cooling steam supply section and the cooling steam recovery section are axially sealed from the atmospheric pressure by a gland seal section.

Further, in order to solve the above-mentioned problems,
In the steam-cooled gas turbine according to the present invention, as described in claim 3, at least the gland seal portion,
A cooling steam guide pipe is axially inserted inside the turbine rotor to form a double pipe structure, and the cooling steam guide pipe separates a cooling steam supply unit and a cooling steam recovery unit from each other in the gland seal unit. Is.

In order to solve the above-mentioned problems, the steam-cooled combined cycle plant according to the present invention comprises a gas turbine plant, an exhaust heat recovery boiler, and a steam turbine plant in combination, as set forth in claim 4. In a steam cooling combined cycle plant in which the turbine high temperature part of the turbine is cooled with steam, a turbine cooling part for cooling the turbine part of the turbine high temperature part to the gas turbine by steam, and a cooling steam for supplying the cooling steam to the turbine cooling part The supply unit and the gland seal unit that seals the cooling steam supply unit from the atmospheric pressure of the surrounding environment are provided.

In order to solve the above-mentioned problems, in the steam-cooled combined cycle plant according to the present invention, as described in claim 5, the gas turbine is
A gland seal housing is provided on at least one side of the turbine rotor, the gland seal housing partially covers the turbine rotor in the axial direction, and divides the cooling steam supply unit and the cooling steam recovery unit in the gland seal housing. The cooling steam supply part and the cooling steam recovery part are sealed by the gland seal part from the atmospheric pressure of the surrounding environment.

Further, in order to solve the above-mentioned problems,
In the steam-cooled combined cycle plant according to the present invention, as described in claim 6, the gas turbine has a double-pipe structure in which a cooling steam guide pipe is axially inserted at least inside the turbine rotor of the gland seal portion. The cooling steam supply section and the cooling steam recovery section are separated by a cooling steam guide pipe.

Further, in order to solve the above-mentioned problems, in the steam-cooled combined cycle plant according to the present invention, as described in claim 7, the cooling steam supply part is provided in the central part and the cooling steam supply part is provided. 9. A cooling vapor recovery part is formed in a substantially concentric shape on the outer peripheral side of the.
As described above, the cooling steam supply part is formed in a torus shape or a sleeve shape, and the cooling steam recovery part is formed in the central part.

Further, in order to solve the above-mentioned problems,
In the steam cooling combined cycle plant according to the present invention, as described in claim 9, a cooling steam pushing fan is provided in the cooling steam supply unit, and the cooling steam pushing fan is attached to the rotation side of the cooling steam supply unit. Moreover, as described in claim 10, a cooling steam suction fan is provided in the cooling steam recovery unit, and this cooling steam suction fan is attached to the rotation side of the cooling steam recovery unit, while the above-mentioned problems are solved. In order to solve the problems, in a steam cooling combined cycle plant according to the present invention, as described in claim 11, a high pressure steam turbine for supplying cooling steam to a cooling steam supply unit, an exhaust heat recovery boiler,
A gas turbine cooling steam supply system is configured by connecting a cooling steam supply source such as a main steam system or an auxiliary steam supply system, and a steam turbine for collecting cooling steam in a cooling steam recovery unit, a seal steam header or a condenser. The cooling steam recovery source is connected to form a gas turbine cooling steam recovery system.

In order to solve the above-mentioned problems, in the steam-cooled combined cycle plant according to the present invention, as described in claim 12, the cooling steam supply system includes the main steam, steam from the high-pressure steam turbine or A cooling steam supply pipe for supplying the auxiliary steam as cooling steam to the cooling steam supply unit, and the supply pipe is provided with a shutoff valve and a pressure control valve; and, as described in claim 13, a cooling steam recovery system. Has a cooling steam recovery pipe for recovering the recovered steam after cooling the high temperature part of the gas turbine from the cooling steam recovery part to the condenser, and equipped with a pressure adjusting valve, a shutoff valve and a desuperheater in this recovery pipe. It is a thing.

Further, in order to solve the above-mentioned problems,
In the steam cooling combined cycle plant according to the present invention, as described in claim 14, the gland seal part formed in the gas turbine gland leaks from the cooling steam supply part or the cooling steam recovery part through the steam sealing means. A leak steam recovery unit for recovering leak steam, a seal steam unit adjacent to the leak steam recovery unit via an intermediate sealing unit, and a seal steam discharge unit adjacent to the seal steam unit via a seal steam sealing unit are provided. The turbine steam generator is arranged in parallel in the axial direction of the turbine rotor, and the seal steam discharge portion is separated from the surrounding environment by the atmosphere side seal means.

Further, in order to solve the above-mentioned problems, in the steam-cooled combined cycle plant according to the present invention, as described in claim 15, the leaked steam recovery part formed in the gland seal part of the gas turbine. Is connected to a steam turbine or a condenser to form a gas turbine leakage steam recovery system, while this gas turbine leakage steam recovery system recovers leakage steam from the steam turbine gland seal section. And a seal steam portion formed in the gland seal portion of the gas turbine is connected to a seal steam source such as a seal steam header or a condenser. While the gas turbine seal steam system is configured to be a gas turbine seal steam system, the gas turbine seal steam system is And a seal turbine steam recovery system for recovering seal steam from the seal section; and further, the seal steam discharge section formed in the gland seal section is a seal discharge steam as described in claim 17. The gas turbine seal steam exhaust system is connected to a gland steam condenser that collects the steam turbine seal steam exhaust system, while the gas turbine seal steam exhaust system is a steam turbine seal steam exhaust system that recovers the seal exhaust steam from the gland seal part of the steam turbine. It is configured to be collaborative.

In order to solve the above-mentioned problems, the method for operating a steam-cooled combined cycle plant according to the present invention, as set forth in claim 18, operates a steam-cooled combined cycle plant in which the gas turbine is cooled by steam. In the method, in the initial stage of starting the gas turbine, auxiliary steam is supplied from the auxiliary steam supply system to the cooling steam supply unit via the cooling steam supply system, and after cooling the turbine high temperature part of the gas turbine with the auxiliary steam, this cooling steam is supplied. While cooling the gas turbine from the cooling steam recovery unit to the condenser while cooling the gas turbine with the above-mentioned auxiliary steam, the seal steam is supplied to the steam turbine and the gland seal part of the gas turbine, and The shaft is sealed from atmospheric pressure and the steam turbine vacuum is raised to combine steam cooling. It is an operating method for starting the cycle plant.

Further, in order to solve the above-mentioned problems, the method for operating a steam-cooled combined cycle plant according to the present invention, as set forth in claim 19, is a steam-cooled combined cycle plant for cooling a gas turbine with steam. In this operating method, when steam is generated from the exhaust heat recovery boiler by starting operation of the gas turbine, the cooling steam of the gas turbine is switched from auxiliary steam to boiler steam and this steam is supplied to the cooling steam supply unit. Supplied through the system and after cooling the turbine high temperature part of the gas turbine with the boiler steam, this cooling steam is recovered from the cooling steam recovery part to the condenser, while the auxiliary steam is used when cooling the gas turbine with the boiler steam. Auxiliary steam from the supply system is used as seal steam from the seal steam header and through the seal steam system as steam. It is supplied to the turbine and the gland seal part of the gas turbine, the gland seal part of the gas turbine is axially sealed from the atmospheric pressure of the surrounding environment, the vacuum of the steam turbine is raised, and the startup operation of the steam cooling combined cycle plant is continued. is there.

Further, in order to solve the above-mentioned problems, the method for operating a steam-cooled combined cycle plant according to the present invention, as set forth in claim 20, is a steam-cooled combined cycle plant for cooling a gas turbine with steam. In the operating method of (1), when the start-up operation of the gas turbine plant is started and the vacuum rise of the steam turbine is completed, the steam from the cooling steam recovery part that has cooled the turbine high temperature part of the gas turbine is switched from the condenser. This is an operation method in which heat is recovered in the medium-pressure steam turbine and the startup operation of the steam cooling combined cycle plant is continued while increasing the rotation and load of the steam turbine.

Furthermore, in order to solve the above-mentioned problems, the method for operating a steam-cooled combined cycle plant according to the present invention, as set forth in claim 21, is a steam-cooled combined cycle in which the gas turbine is cooled by steam. In the operating method of the plant, when the load on the gas turbine and the steam turbine increases, while leaking steam from the gland seal part of the gas turbine is recovered with heat to the steam turbine together with leaking steam from the gland seal part of the high pressure steam turbine, Supply the seal steam from the gland seal part of the gas turbine and the high pressure steam turbine as the seal steam of the gland seal part of the low pressure steam turbine,
The excess steam of this seal steam is recovered from the seal steam relief valve to the condenser, and the gland seal exhaust steam from the gland seal part of the gas turbine and the high-pressure and low-pressure steam turbine is combined with the air flowing in from the atmosphere. This is an operation method in which the steam condenser is sucked and the gland seal portions of the gas turbine and the steam turbine are sealed from the atmospheric pressure of the surrounding environment to continue the turbine load operation.

[0044]

An embodiment of the present invention will be described below with reference to the accompanying drawings.

FIG. 1 is a system diagram showing an embodiment in which the present invention is applied to a steam cooling combined cycle plant. This steam cooling combined cycle plant 20 shows an example of a combined cycle power generation plant in which a gas turbine plant 21, an exhaust heat recovery boiler 22, a steam turbine plant 23 and a generator (not shown) are combined. It may be a cogeneration plant that enables hot water supply and district heating. Each component of the steam turbine plant 22 is the same as that shown in FIG.

The steam-cooled combined cycle plant 20 shown in FIG. 1 shows an application example when the combined cycle is almost in rated operation. The pipes used in this rated operation are indicated by solid lines and used. Piping not performed is indicated by a broken line. Of the valves used for these pipes,
Valves that are open during rated operation are shown in white and valves that are closed are shown in black. The same applies to FIGS. 4 and 5.

The gas turbine plant 21 includes a compressor 25 for compressing air, a plurality of combustors 26 for combusting the compressed high-temperature and high-pressure compressed air discharged from the compressor 25 with a fuel, and a combustor 26. Steam cooling gas turbine 2 driven by the combustion gas burned in
7 and a generator (not shown) driven by the gas turbine 27.

The combustion gas supplied from the combustor 26 expands and works in the steam cooling gas turbine 27 to drive the generator, and then becomes turbine exhaust gas which is guided to the exhaust heat recovery boiler 22. The exhaust heat of the turbine exhaust gas is recovered by the exhaust heat recovery boiler 22. Exhaust heat recovery boiler 22
The exhaust heat of the turbine exhaust gas is recovered at, and the combustion gas whose temperature has dropped is subsequently released into the atmosphere from a stack (not shown).

On the other hand, in the exhaust heat recovery boiler 22, the condenser 12
The feed water supplied through the condensate water supply system 29 is heated by exchanging heat with the turbine exhaust, and the generated steam becomes main steam and is supplied to the high-pressure steam turbine 3 of the steam turbine plant 23. The steam turbine plant 23 is a Rankine cycle system in which a main steam system 30, a high-pressure steam turbine 3, a reheat steam system 31, an intermediate-pressure steam turbine 4, a low-pressure steam turbine 5, a condenser 12 and a condensate water supply system 29 are sequentially connected. To form a closed steam turbine cycle.

Main steam system 30 of steam turbine plant 23
Is connected to the high-pressure steam turbine 3 via a main steam stop valve 34 and a main steam control valve 35, and supplies main steam to the steam turbine 3 to perform work.
Drive in rotation. The turbine exhaust that has worked in the high-pressure steam turbine 3 is guided to the low-temperature reheat pipe 36 of the reheat steam system 31, and passes through the low-temperature reheat pipe 36 to exhaust heat recovery boiler 2
It is guided to 2 again and reheated.

A gas turbine 27 is installed in the exhaust heat recovery boiler 22.
The steam whose temperature has risen by exchanging heat with the turbine exhaust from the engine becomes reheated steam, and the high temperature reheated steam piping 3 of the reheated steam system 31
7, the high temperature reheat steam shutoff valve 38 and the reheat valve 39 are supplied to the intermediate pressure steam turbine 4 to drive the steam turbine 4. High-temperature reheat steam pipe 3 of reheat steam system 31
No. 8 has a pressure loss because the reheated steam that has passed through the exhaust heat recovery boiler 22 has a pressure loss, and the pressure drops from the low temperature reheat pipe 36.

On the other hand, the steam that has worked by driving the intermediate pressure steam turbine 4 is further guided to the low pressure steam turbine 5,
The low-pressure steam turbine 5 works and expands. The steam that has worked and expanded in the low-pressure steam turbine 5 is then guided to the condenser 12, and condensed in the condenser 12 to become condensed water. This condensate is returned to the exhaust heat recovery boiler 22 as feed water through the condensate water supply system 29, is heated again in this boiler 22 to become main steam, and is prepared for the next steam turbine cycle.

Further, in the gas turbine 27 for supplying the turbine exhaust for heating the feed water to the exhaust heat recovery boiler 22, the high temperature part of the turbine is cooled by steam.

The steam-cooled gas turbine 27 has a gas turbine gland 4 on at least one side of the turbine rotor 40.
1 is provided. In the gas turbine gland 41, a gland seal portion 43 that axially seals the inside from the atmospheric pressure of the surrounding environment is formed, while a cooling steam supply portion 44 is provided inside.
The cooling vapor recovery unit 45 is formed separately.
The gas turbine cooling steam supply system 46 is connected to the cooling steam supply unit 44.
Are connected, and the cooling steam is supplied from the cooling steam supply source by the cooling steam supply system 46.

The cooling steam guided to the cooling steam supply part 44 of the gas turbine 27 is supplied to the turbine cooling part 47 formed in the high temperature part of the turbine to cool turbine components in the high temperature part of the turbine. The steam that has cooled the turbine components is recovered by the cooling steam recovery unit 45. The cooling steam recovery unit 45 is connected to a cooling steam recovery source via a gas turbine cooling steam recovery system 48, and the cooling steam is finally recovered by the cooling steam recovery source.

The gas turbine cooling steam supply system 46 connects the cooling steam supply source and the cooling steam supply unit 44 of the gas turbine 27 through the cooling steam supply pipes 49 of a plurality of systems. The cooling steam supply source includes a high-pressure steam turbine 3, an exhaust heat recovery boiler 22, a main steam system 30, and an auxiliary steam supply system 50.
Etc. independently exist, and the cooling steam is selectively supplied from each cooling steam supply source to the cooling steam supply unit 44 of the gas turbine 27.

Specifically, as cooling steam for the steam cooling gas turbine 27, turbine exhaust from the high-pressure steam turbine 3 (may be turbine extraction air), boiler heating steam (may be main steam) and auxiliary steam from an exhaust heat recovery boiler. Supply system 5
Auxiliary steam from 0 is used.

In the turbine cooling steam supply pipe 49 for supplying the turbine exhaust of the high-pressure steam turbine 3 to the cooling steam supply section 44 of the gas turbine 27, a turbine cooling steam stop valve 51 is installed.
Is installed, and a boiler cooling steam supply pipe 52 and an auxiliary cooling steam supply pipe 53 are connected to the downstream side of the cooling steam stop valve 51, respectively. The boiler cooling steam supply pipe 52 is branched from the middle or downstream of the exhaust heat recovery boiler 22, and a boiler cooling steam stop valve 54, a boiler cooling steam control valve 55, and a cooling steam stop valve 56 are sequentially installed on the way.

The auxiliary steam supply system 50 is equipped with an auxiliary boiler (not shown) for supplying the cooling steam for the gas turbine 27 and an auxiliary steam header 58 connected to another plant which is already in rated operation. An auxiliary cooling steam supply pipe 53 and a seal steam supply pipe 59 for supplying auxiliary steam as cooling steam are connected to the steam header 58. The seal steam supply pipe 59 is connected to the seal steam header 62 via a seal steam shutoff valve 60 and a seal steam control valve 61. An auxiliary cooling steam stop valve 63 is installed in the auxiliary cooling steam supply pipe 53. Instead of connecting the auxiliary cooling steam supply pipe 53 directly to the auxiliary steam header 58, a seal steam supply pipe 59 is used.
It may be connected to the downstream side of the seal steam shutoff valve 60 and the supply pipe may be used together to improve the economical efficiency.

On the other hand, the cooling steam recovery unit 45 of the steam cooling gas turbine 27 is connected to a cooling steam recovery source via a gas turbine cooling steam recovery system 48. The cooling vapor recovery source includes
Medium-pressure steam turbine 4 as a steam turbine and condenser 12
The gas turbine cooling steam recovery system 48 is connected to the intermediate pressure steam turbine 4 and the condenser 12 via cooling steam recovery pipes of a plurality of systems.

The gas turbine cooling steam recovery pipe 65 for recovering the cooling steam recovery section 44 of the steam cooling gas turbine 27 to the intermediate pressure steam turbine 4 as a steam turbine is provided with a cooling steam recovery stop valve 66, and the gas turbine cooling steam is cooled. Instead of connecting the recovery pipe 65 directly to the steam turbine, the recovery pipe 65 shown in FIG.
As shown in, the high temperature reheat steam pipe 38 of the reheat steam system 31 may be connected in the middle thereof.

Further, the gas turbine cooling steam recovery system 48 is provided with a cooling steam relief pipe 68 branched from the middle of the gas turbine cooling steam recovery pipe 65, and the cooling vapor relief pipe 68 is provided with a cooling vapor relief stop valve 69, The condenser 12 is provided with the cooling steam relief valve 70 and the desuperheater 71 in sequence.
The cooling steam recovered by the cooling steam recovery unit 45 of the gas turbine 27 can be released to the condenser 12 through the cooling steam escape pipe 68.

The seal steam header 62 connected to the auxiliary steam header 58 via the seal steam supply pipe 59 is connected to the gland seal portions 75 and 76 of the turbine glands 73 and 74 of the high pressure steam turbine 3 and the low pressure steam turbine 5, respectively. To be done. Specifically, the high-pressure steam turbine gland seal steam pipe 80 and the low-pressure steam turbine gland seal steam pipe 81 are connected to the seal steam parts 77, 78 formed in the gland seal parts 75, 76, respectively. The seal steam portions 77 and 78 are configured to be able to supply seal steam for shaft sealing of the turbine rotor 82.

The seal steam header 62 is connected to the gland seal part 43 of the turbine gland 41 of the steam cooling gas turbine 27 via the gas turbine gland seal steam pipe 91 to supply the seal steam to the gland seal part 43. Leakage steam in the gland seal portion 43 can be collected in the condenser 12 via the seal steam header 62. In order to recover the leaked steam to the condenser 12, the seal steam header 62 is provided with a seal steam release pipe 85.
Is connected to the condenser 12 via. A seal steam escape valve 86 is installed in the middle of the seal steam escape pipe 85.

On the other hand, the turbine gland 41 of the steam cooling gas turbine 27 is provided with a gland seal part 43 for axially sealing the inside from the atmospheric pressure of the surrounding environment, and this gland seal part 43 is arranged in the axial direction of the turbine rotor 40. A leak vapor recovery section 87, a seal vapor section 88, and a seal vapor discharge section 89 are sequentially formed along it.

The turbine gland 41 of the steam cooling gas turbine 27 is constructed as shown in FIG. 2, and at least one side of the turbine rotor 40 is connected to, for example, the turbine rotor 40.
Has a gland seal housing or casing (case) 90 that axially covers the end of the. The gland seal housing 90 includes a sleeve-shaped tubular portion, and the gland seal portion 43 that seals the inside from the atmospheric pressure of the surrounding environment is formed in the tubular portion, while the gland seal housing 90 is cooled with the cooling steam supply portion 44. The vapor recovery unit 45 is formed so as to be concentrically separated. A connection flange 91 is provided at the shaft end of the gland seal housing 90, and the cooling steam supply pipe 49 of the gas turbine cooling steam supply system 46 is liquid-tightly or airtightly flange-connected to the connection flange 91.

A steam guide pipe 92 is rotatably and integrally inserted into the turbine rotor 40 of the steam cooling gas turbine 27 so as to penetrate at least the gland seal portion 43. The steam guide pipe 92 is inserted into the shaft hole 93 of the turbine rotor 40 to have a double pipe structure, and the steam guide pipe 92 is held in the double pipe structure by spacers 84 that are spaced in the axial direction.
By the steam guide pipe 92, a cooling steam supply portion (or passage) 44 is formed in the center of the turbine rotor 40, and a sleeve-shaped cooling steam recovery portion (passage) 45 is separately formed around it.

The cooling steam supply unit 44 is connected to a turbine cooling unit 47 formed at a high temperature part of the turbine of the gas turbine 27, and the cooling steam is supplied to the turbine cooling unit 47 to cool the turbine parts, while The cooled cooling steam is recovered by the cooling steam recovery unit 45.

The shaft end of the steam guide pipe 92 inserted into the turbine rotor 40 of the steam cooling gas turbine 27 projects outward from the shaft end of the turbine rotor 40.
It terminates near the connection flange 91 of the gland seal housing 90. A steam seal means 95 such as a labyrinth packing is provided in the gland seal housing 90 so as to face the protruding portion of the steam guide pipe 92, and the steam seal means 95 separates the cooling steam supply section 44 and the cooling steam recovery section 45. I am letting you.

As shown in FIG. 2, the cooling steam supply section 44 and the cooling steam recovery section 45 formed in the gland seal section 43 of the steam cooling gas turbine 27 have an axial cooling steam pushing fan 97 and a cooling steam suction unit. Each fan 98 is provided. Of these, the cooling steam pushing fan 97
Is installed on the rotation side of the cooling steam supply unit 44, specifically, on the inner peripheral side of the cooling steam guide pipe 92, and
It rotates together with zero. The cooling steam pushing fan 97 pushes the cooling steam into the cooling passage (cooling supply passage) by the cooling steam guide pipe 92, and reduces the pressure loss of the cooling medium flowing through the cooling passage.

The cooling steam suction fan 98 is provided on the rotation side of the cooling steam recovery unit 45, specifically, the turbine rotor 40.
Is provided at the shaft end of the. It may be provided on the inner peripheral side of the shaft hole of the turbine rotor 40. By providing the cooling steam suction fan 98 in the turbine rotor 40, the steam that has cooled the turbine components in the high temperature part of the turbine is positively sucked through the cooling passage (cooling recovery passage) to reduce the pressure loss of the steam flowing in the cooling passage. ing.

In the steam cooling gas turbine 27, in order to cool turbine components in the high temperature part of the turbine with steam, it is necessary to form a complicated cooling passage inside the turbine. Receives resistance and pressure loss. If this pressure loss is excessive, the amount of cooling steam may decrease. However, in this steam cooling gas turbine 27, a cooling steam pushing fan 97 and a cooling steam suction fan 98 are provided on the rotation sides of the cooling steam supply unit 44 and the cooling steam recovery unit 45, and the fans 97 and 9 are provided.
By rotating the pump 8, the cooling steam is positively pushed into the cooling passage or sucked out from the cooling passage to reduce the pressure loss, and effectively and surely prevent the decrease of the cooling steam amount due to the pressure loss. ing. Therefore,
By installing the cooling steam pushing fan 97 and the cooling steam suction fan 98 of axial flow on the rotating side of the steam cooling gas turbine 27, it is possible to significantly reduce the pressure loss and recover the steam pressure.

Further, the sleeve-shaped or cylindrical gland seal portion 43 for sealing the cooling steam recovery portion 44 formed in the turbine gland 41 of the steam cooling gas turbine 27 from the atmospheric pressure of the surrounding environment has a ring shape or a torus shape. The leaked steam recovery unit 87, the seal steam unit 88, and the seal steam discharge unit 89 are sequentially provided in the axial direction of the turbine rotor 40. Then, the cooling steam recovery unit 45, the leaked steam recovery unit 87, the seal steam unit 88, and the seal steam discharge unit 89.
A steam sealing means 100 such as a labyrinth packing (a labyrinth type rotor packing), an intermediate sealing means 101 and a seal steam sealing means (exhaust side sealing means) 102 are interposed between and. The seal vapor discharge portion 89 is adjacent to the ambient vapor pressure of the ambient environment via the atmospheric side sealing means 103 such as a labyrinth packing.

The respective sealing means 100, 101, 102 and 103 are mounted on the inner peripheral wall of the gland seal housing 90, and the leakage steam or the atmosphere flowing along the rotor shaft of the turbine rotor 40 is suppressed to a minimum by the continuous throttling effect. And seal it. Gas turbine ground 41
Leakage vapor recovery section 8 formed in the gland seal section 43 of
Reference numeral 7 is connected to the inlet of a steam turbine, for example, the low-pressure steam turbine 5 via a pipe 106 of a gas-turbine ground leakage steam recovery system 105, so that the low-pressure steam turbine 5 can recover the leaked steam and can effectively recover heat. It has become. A steam shutoff valve 107 is provided in the gas turbine ground leakage steam pipe 106 midway.

The gas turbine gland leakage steam recovery system 105 is made to cooperate with the high pressure steam turbine leakage steam recovery system 108, and the gas turbine gland leakage steam piping 106 is provided in the middle of the high pressure steam turbine leakage steam piping 109 of the leakage steam recovery system 108. May be connected and the steam pipes 106 and 109 may be shared for effective use. The high-pressure steam turbine leakage steam pipe 109 is also connected to the inlet of the low-pressure steam turbine 5 via the steam stop valve 110.

The seal steam portion 88 formed on the gland seal portion 43 of the gas turbine gland 41 is connected to the seal steam source via the gas turbine seal steam system 111. The seal steam source has the seal steam header 62 or the auxiliary steam supply system 50, and the seal steam section 88 is connected to, for example, the seal steam header 62 via the gas turbine gland seal steam pipe 84, and the seal steam in the seal steam section 88. Of the seal steam to the seal steam header 62, or the seal steam from the seal steam header 62 to the seal steam section 8
8, and the gland seal portion 43 of the gas turbine 27
The shaft is designed to be sealed.

Further, in the seal steam header 62, a seal steam section 77 of the high pressure steam turbine 3 and a seal steam section 78 of the low pressure steam turbine 5 are provided.
3 are connected via the gland seal steam pipes 80 and 81, and the steam turbine seal steam system 113 and the gas turbine seal steam system 111 are configured to be able to cooperate with each other.

Further, the seal steam discharge part 89 formed in the gland seal part 43 of the gas turbine gland 41 is connected to the gland steam condenser 117 via the seal steam discharge pipe 116 of the gas turbine seal steam discharge system 115, and this gland The steam condenser 117 exchanges heat with the steam turbine condensate from the condenser 12.

This gas turbine seal steam exhaust system 115
Is configured to cooperate with a steam turbine seal steam exhaust system 118. The steam turbine seal steam discharge system 118 is a high pressure steam turbine gland seal steam discharge pipe 120 derived from the seal steam discharge unit 119 of the high pressure steam turbine 3.
And the low-pressure steam turbine ground seal steam discharge pipe 122 from the seal steam discharge portion 121 of the low-pressure steam turbine 5 join together on the way and are connected to the ground steam condenser 117, while the ground seal steam discharge pipe 120,
The seal steam discharge pipe 116 of the gas turbine seal steam discharge system 115 may be connected to the downstream side of the confluence portion 122 and the discharge pipe may be shared to simplify the piping arrangement.

A ground steam exhauster 123 is connected to the ground steam condenser 117, and the inside of the ground steam condenser 117 is always kept at a pressure lower than atmospheric pressure by the operation of the air exhauster 123. Therefore, the seal steam discharge part 89 of the gas turbine 27 connected to the gland steam condenser 117 is always kept lower than the atmospheric pressure as shown in FIG. 3, and this seal steam discharge part 89 is provided in the gland seal part 43. By the gas turbine 2
The cooling steam of 7 is completely shaft sealed. The same applies to the seal steam discharge units 119 and 121 of the steam turbine. Leakage steam discharged from the seal steam discharge portion 89 of the gas turbine 27 and the seal steam discharge portions 119 and 121 of the steam turbine together with the atmosphere is subjected to heat exchange with the condensate of the steam turbine in the gland steam condenser 117. The leaked steam is returned to the condenser 12 by heat exchange, and the air is returned to the atmosphere again from the gland steam exhauster 123.

Next, a method of operating the steam cooling combined cycle plant 20 will be described.

Steam cooling combined cycle plant 2
Since steam is not generated in the steam turbine plant 23 at the start-up operation in which 0 is started, particularly in the initial stage of start-up, as shown in FIG. 4, the auxiliary steam from the auxiliary steam supply system 50 is used as the cooling steam for the gas turbine. To use as. FIG. 4 shows a state in which the steam cooling combined cycle plant 20 is being started using auxiliary steam. In this start-up operation state, the pipes used are shown by solid lines, and the pipes not used are shown by broken lines. The open valve is shown in white and the closed valve is shown in black. It is similar to FIG.

Steam cooling combined cycle plant 2
Since the steam turbine is not yet started during the start-up operation of 0, cooling steam for the gas turbine 27 is not generated from the steam turbine and is not supplied unlike the case during the rated operation. Further, since the sealing steam of the steam turbine or the gas turbine 27 is not generated, it is necessary to supply the steam from outside the system of the steam cooling combined cycle plant 20. In this case, generally, the sealing steam in the vacuum rising and starting processes of the gas turbine 27 and the steam turbines 3, 4, 5 is supplied from the auxiliary steam supply system 50. Specifically, steam from an auxiliary boiler or another plant already in rated operation is supplied as auxiliary steam, and with this auxiliary steam,
Sealing steam for the gas turbine 27 and the steam turbines 3, 4, 5 is secured.

Steam cooling combined cycle plant 2
In the 0 start-up operation, first, the gas turbine 27 is rotated and increased, and then the combustor 26 is ignited, and then the gas turbine 27 is rotated and increased to the rated rotation speed.

Next, after the rotational speed of the gas turbine 27 reaches the rated rotational speed, a generator (not shown) coupled to the gas turbine 27 is connected to the system, and the gas turbine 2
7 load (system load) operation is started, and this load is gradually increased.

On the other hand, since the exhaust heat recovery boiler 22 in which the turbine exhaust of the gas turbine 27 is guided has a very large heat capacity, the steam to be supplied to the steam turbines 3, 4, and 5 is supplied during the load increasing process of the gas turbine 27. Cannot be generated. Further, in the steam turbines 3, 4 and 5, it is necessary to evacuate the inside of the steam turbines 3, 4 and 5 by using a vacuum pump or an ejector (not shown) to keep the atmospheric pressure or lower, that is, so-called vacuum rise.

Further, the load of the gas turbine 27 has already been increased at this point, and the temperature inside the turbine is high. Therefore, it is necessary to cool the high temperature part of the turbine. Therefore, the gas turbine 27 is cooled by using the auxiliary steam from the auxiliary steam supply system 50, and this steam is secured from the auxiliary steam header 58 connected to the auxiliary boiler or another plant which is already in rated operation.

In this case, the auxiliary steam is guided from the auxiliary steam header 58 of the auxiliary steam supply system 50 to the cooling auxiliary steam supply pipe 53 which is the gas turbine cooling steam supply system 46, and passed through the seal steam stop valve 60 in the open state to seal the auxiliary steam. The steam whose pressure is adjusted by the steam control valve 61 is guided to the cooling steam supply unit 44 of the turbine gland 41 of the gas turbine 27. The guided auxiliary steam is supplied from the cooling steam supply part 44 to the high temperature part of the turbine of the gas turbine 27, and the turbine cooling part 47 provided in the high temperature part of the turbine cools the turbine components.

The steam, which has cooled the turbine parts in the high temperature part of the turbine, exchanges heat with the turbine parts and becomes high temperature and returns to the cooling steam recovery part 45. The steam recovered in the cooling steam recovery unit 45 is recovered in the condenser 12 through the cooling steam relief pipe 68 that constitutes the cooling steam recovery system 48. The steam that has cooled the steam cooling gas turbine 27 is guided to the condenser 12 through the temperature reducer 71 while being pressure-adjusted by the cooling steam relief valve 70, and is released to the condenser 12. This is because the vacuum rise of the steam turbines 3, 4, 5 has not been completed at this stage, and the steam turbines 3, 4, 5 are not yet ready to start.

On the other hand, in the cooling steam combined cycle plant 20, the auxiliary steam is used as the cooling medium even in the starting process thereof, the gas turbine 27 is effectively cooled by the auxiliary steam, and the auxiliary steam is also used as the seal steam. Gas turbine 27 and steam turbine 3, 4, 5
The turbine glands 73 and 74 are shaft-sealed. As a result, the gas turbine 27 seals the cooling steam. FIG. 6 shows the pressure distribution in the gas turbine gland 41 during the startup process of the cooling steam combined cycle plant 20.

The cooling steam of the steam cooling gas turbine 27 is
The cooling steam is supplied from the cooling steam supply pipe 49 of the cooling steam supply system 46 to the cooling steam supply section 44. The pressure distribution of the gas turbine gland 41 is as shown in FIG. It becomes the highest in the ground 41. The cooling steam cools the high temperature part of the turbine of the gas turbine 27 and returns to the cooling steam recovery part 45. Since this cooling steam recovery part is connected to the condenser 12 by the cooling steam escape pipe 68, the gas turbine ground. It is the lowest pressure area of 41.

In the starting process of the cooling steam combined cycle plant 20, the auxiliary steam from the auxiliary steam supply system 50 passes through the seal steam header 62 and the seal steam parts 88 of the gas turbine gland 41 and the steam turbine glands 73, 74. Seal steam is supplied to 77 and 78.

Of these, the seal steam portion 88 of the gas turbine gland 41 is supplied with seal steam from the seal steam header 62 via the gas turbine gland seal steam pipe 84. The seal steam header 62 includes seal steam parts 77, 7 of the high pressure steam turbine 3 and the low pressure steam turbine 5.
8 also has steam turbine gland seal steam pipes 80, 81
The seal steam is supplied to the steam turbines 3 and 5 via the shafts to seal the shafts of the steam turbines 3 and 5 so that the vacuum can be increased at the same time.

Further, by supplying the seal steam to the seal steam section 88 of the gas turbine gland 41, the seal steam leaks to the leak steam recovery section 87. In this case, the steam of the gas turbine ground leak steam recovery system 105 is used. By closing the stop valve 107, the leaked steam recovery pipe 1
06 is not used. In this case, the seal steam that has leaked to the leaked steam recovery unit 87 is recovered by the cooling steam recovery unit 45.

The seal steam supplied to the seal steam section 88 of the gas turbine gland 41 also partially flows out to the seal steam discharge section 89. A gas turbine gland seal steam discharge pipe 116 is connected to the seal steam discharge part 89, and the leaked steam joins the leaked steam from the high pressure steam turbine gland seal steam discharge pipe 120 and the low pressure steam turbine gland seal steam discharge pipe 122. Then, it is led to the ground vapor condenser 117.

The leaked steam sent to the ground steam condenser 117 undergoes heat exchange with condensed water from the steam turbines 3, 4, and 5. Also, the ground vapor condenser 11
A gland steam exhauster 123 is installed at 7, and the inside of the condenser is always kept at a pressure lower than atmospheric pressure. Leaked steam and air from the atmosphere are mixed and sucked into the ground steam condenser 117, of which steam is returned to the condensate by heat exchange, and the air is discharged into the ground steam exhauster 12
It is returned to the atmosphere again from 3. Due to this effect, the seal steam discharge portion 89 of the gas turbine gland 41 is kept lower than the atmospheric pressure as shown in FIG. The cooling steam of the gas turbine 27 is completely sealed by the gas turbine gland 41, and at the same time, the vacuum rise, which is a preparation for starting the steam turbines 3, 4, and 5, can be performed.

When the steam cooling combined cycle plant 20 is started for a while, heat exchange between the gas turbine exhaust and the feed water is performed in the exhaust heat recovery boiler 22, and when this heat exchange proceeds, the boiler steam becomes the main steam. Occurs as. FIG. 5 shows the start-up operation of the steam cooling combined cycle plant using this main steam.

When the main steam is generated in the exhaust heat recovery boiler 22, the gas turbine cooling steam supply system 46 closes the auxiliary cooling steam supply pipe 53 and opens the boiler cooling steam supply pipe 52 as shown in FIG. The boiler steam (main steam) generated in the exhaust heat recovery boiler 22 is guided to the cooling steam supply unit 44 of the gas turbine 27 as cooling steam. The boiler steam is sent to the gas turbine 27 from the boiler cooling steam supply pipe 52 through the cooling steam stop valve 54, the pressure thereof is adjusted by the cooling steam control valve 55, and the boiler steam is supplied from the cooling steam supply unit 44 of the gas turbine 27 to the turbine cooling unit 47. Where the turbine parts in the high temperature part of the turbine are cooled.

The cooling steam, which has risen in temperature by cooling the turbine parts in the high temperature part of the turbine, passes through the cooling steam escape pipe 68 from the cooling steam recovery part 45 when the vacuum rise of the steam turbines 3, 4, 5 is not completed. Collected in the condenser 12.

Further, when the vacuum rise of the steam turbines 3, 4, 5 is completed and the steam turbine plant 23 is ready for starting, the reheat valve 66 is connected from the cooling steam recovery pipe 65 of the gas turbine cooling steam recovery system 48. Through the medium pressure steam turbine 4
The intermediate pressure steam turbine 4 increases the rotation and the load.

The steam pressure before being supplied as cooling steam to the steam cooling gas turbine 27 is adjusted by the cooling steam control valve 55 of the gas turbine cooling steam supply system 46, and the pressure after cooling is adjusted by the cooling steam relief valve 70. It When the steam turbines 3, 4, 5 are ready to start, the cooling steam relief valve 70 is gradually closed to gradually increase the flow rate of steam flowing to the intermediate pressure steam turbine. In this case, the pressure distribution in the gas turbine gland 41 gradually shifts from the state shown in FIG. 6 to the state shown in FIG. 3, and eventually reaches the rated operation.

Steam cooling combined cycle plant 2
When 0 enters the rated operation, the gas turbine cooling steam supply system 4
6 and the cooling vapor recovery system 48 are set as shown in FIG.

Cooling steam as a cooling medium for the steam cooling gas turbine 27 is supplied from the turbine cooling steam supply pipe 49 of the gas turbine cooling steam supply system 46 to the cooling steam supply section 44. At this time, the pressure distribution of the gas turbine gland 41 is represented as shown in FIG.
The pressure of 4 is the highest. The cooling steam is the gas turbine 27
After cooling the high temperature part of the turbine through the inside of the pipe, it returns to the cooling steam recovery part 45.
Is switched from the cooling steam escape pipe 48 to the cooling steam recovery pipe 65 and is connected to the high temperature reheated steam pipe 38 of the reheated steam system 31, so that the pressure rises. However, the steam pressure of the adjacent cooling steam supply unit 44 is increased. Slightly lower.

A part of the steam recovered in the cooling steam recovery unit 45 for cooling the high temperature part of the steam cooling gas turbine 27 and passing through the steam sealing means 100 leaks the steam recovery unit 8.
You will be guided to 7. The leaked steam recovered by the leaked steam recovery unit 87 is sent to the low-pressure steam turbine 4 through the leaked steam pipe 106 of the gas turbine ground leaked steam system 105. This leaked steam may be joined to the leaked steam passing through the leaked steam pipe 109 of the high pressure steam turbine land leaked steam system 108 and sent to the low pressure steam turbine 5. In the low-pressure steam turbine 5, the energy of the leaked steam is recovered and used. Since the leaked steam recovery unit 87 is connected to the low-pressure steam turbine 5 in this way, the steam pressure here is lower than that in the cooling steam recovery unit 45.

The steam leaking from the leaked steam recovery section 87 of the gas turbine gland 41 is recovered by the seal steam section 88. The seal steam section 88 is connected to the seal steam header 62 via the seal steam pipe 84 of the gas turbine ground seal steam system 111, and leak steam is sent to the seal steam header 62. The seal steam header 62 is also connected to the seal steam pipe 80 of the high pressure steam turbine gland seal steam system 113, and joins with the leaked steam from the high pressure steam turbine gland 73. Seal steam (leak steam) recovered from these seal steam units 88 and 77
Is sent to the seal steam section 78 of the low pressure steam turbine gland 74 via the low pressure steam turbine gland seal steam pipe 81, and is used as the seal steam of the low pressure steam turbine 5.

Further, the seal steam header 62 is connected to the condenser 12 via the seal steam escape pipe 85, and the seal steam escape valve 86 as a pressure adjusting valve provided in the seal steam escape pipe 85 The pressure is always set slightly higher than atmospheric pressure. On the other hand, since the low-pressure steam turbine 5 is maintained at the atmospheric pressure or lower, the seal steam supplied from the low-pressure steam turbine gland seal steam pipe 81 to the low-pressure steam turbine gland 74 flows into the low-pressure steam turbine 5.

The seal steam supplied from the steam cooling gas turbine 27 and the high pressure steam turbine 3 is the low pressure steam turbine 5.
If the amount of the sealing steam is larger than the required amount, the sealing steam relief valve 86 adjusts the pressure to allow the surplus steam to escape to the condenser 12, and always keep the pressure of the sealing steam header 62 slightly higher than the atmospheric pressure. Keep it at. Therefore, the pressure of the seal steam portion 88 of the gas turbine gland 41 again decreases as shown in FIG.

Finally, the steam leaked further from the seal steam section 88 of the gas turbine gland 41 is discharged to the seal steam discharge section 8
Flow into 9 A gas turbine gland seal steam discharge pipe 115 is connected to the seal steam discharge portion 89, and the leak seal steam is leaked from the high pressure steam turbine gland seal steam discharge pipe 120 and the low pressure steam turbine gland seal steam discharge pipe 122. And is led to the ground vapor condenser 117. In this gland steam condenser 117, the leaked steam is steam turbines 3, 4, 5
Condensate and heat exchange.

Further, a grand steam exhauster 123 is installed in the gland steam condenser 117, and the condenser 11
The inside of 7 is always kept at a pressure lower than the atmospheric pressure, so that the seal vapor discharge portion 89 is also kept at the atmospheric pressure or lower. Therefore, both the leaked seal steam and the air from the atmosphere are sucked into the seal steam discharge portion 89. The sucked mixture of leak seal steam and the atmosphere is guided to the gland steam condenser 117, where the steam is returned to the condensate by heat exchange, and the air is returned from the gland steam exhauster 123 to the atmosphere again. Due to this returning effect, the seal steam discharge portion 89 is always kept lower than the atmospheric pressure as shown in FIG. 3, and as a result, the gas turbine gland 41 is completely sealed by the Graton seal portion 43 so that the cooling steam of the gas turbine 27 is completely sealed. Will be done. Steam turbine 3,5
Similarly, the shaft is sealed.

In this steam cooling combined cycle plant 20, the steam cooling gas turbine 27 and the steam turbines 3, 4, 5 are turbine rotors 40, 82 by the gland seal portions 43, 75, 76 provided on the turbine glands 41, 73, 74. The shaft seal is securely and completely performed. As a result, the cooling steam of the gas turbine 27 is completely sealed. On the other hand, the steam cooling gas turbine 27
After starting up at the beginning of start-up operation (middle start-up),
By the auxiliary steam, the steam generated from the exhaust heat recovery boiler 22 from the middle stage to the latter stage of the start-up operation,
Since the turbine exhaust of the high-pressure steam turbine 3 (which may be turbine extraction air) is used as the cooling steam during the steady operation, the gas turbine 27 is effectively and efficiently cooled as a steam cooling medium. Because of this steam cooling, the gas turbine 27
The inlet combustion gas temperature of the
(00 ° C.) or an ultrahigh temperature (1500 ° C. or higher) can be performed, and thermal efficiency can be improved, and plant efficiency can be improved.

In one embodiment of the present invention,
An example in which a cooling steam supply unit 44 is formed in the center of the turbine gland 41 of the steam cooling gas turbine 27, a cooling steam recovery unit 45 is formed around it, and the cooling steam supply unit 44 and the cooling steam recovery unit 45 are formed concentrically. However, various modified examples of the structure for supplying and recovering the cooling steam to the gas turbine gland 41 can be considered.

For example, the gas turbine gland 41A may be constructed as shown in FIG. 7, and the cooling steam supply section 44A and the cooling steam recovery section 45A may be reversed from the gas turbine gland structure shown in FIG. Cooling steam supply section 44A and cooling steam recovery section 45 formed by inserting cooling steam guide pipe 92 into the axial hole of turbine rotor 40 of gas turbine 27.
In A, the cooling steam supply unit 44A is formed in a torus shape or a sleeve shape, and the cooling steam recovery unit 4 is provided in the center thereof.
5A may be formed.

In this embodiment, the cooling steam is supplied from between the gas turbine rotor 40 and the cooling steam guide pipe 92 through the sleeve-shaped flow path, and is recovered from the inside of the cooling steam guide pipe 92. A bearing (not shown) is installed in the gas turbine rotor 40, and the turbine rotor temperature of the gas turbine gland 41 is preferably not so high. In the embodiment of FIG. 7, since the cooling steam having a relatively low temperature before cooling the gas turbine is supplied to the inside of the turbine rotor 40, the temperature of the bearing portion 130 can be kept low.

2 and 7, the principle structure of the gland seal housing 90 provided in the turbine glands 41 and 41A of the steam cooling gas turbine 27 is shown, but in the actual gland seal housing 90, the workability is improved. Considering the above, various modified examples are possible. The gland seal housing 90 has a structure shown in FIG.
It is not always necessary to process one case into a complicated shape, and a plurality of case parts may be combined together. The gland seal housing 90 forms a gland seal part 43 between the gland seal housing 90 and the turbine rotor 40.
3, a leakage steam recovery part 87, a seal steam part 88, and a seal steam discharge part 89 are formed, and a cooling steam supply part 44; 44A and a cooling steam recovery part 45; 45A are formed inside. .

Further, the turbine glands 41 and 41A of the steam cooling gas turbine 27 are connected to the gas turbine rotor 40.
Although the example in which the shaft end portion is covered in the axial direction is shown, the invention is not necessarily limited to this, and the gas turbine rotor 40 may be locally covered in the axial direction. Turbine rotor 4
In the case where the turbine gland is formed by partially covering the middle of 0, the gland seal portions 43 are formed on both sides in the axial direction of the turbine gland.

[0116]

In the steam-cooled gas turbine according to the present invention and the steam-cooled combined cycle plant equipped with this gas turbine, a cooling steam supply section for supplying cooling steam to the high temperature part of the turbine of the gas turbine is provided. Since the gland seal part that seals the supply part from the atmospheric pressure of the surrounding environment is provided, the inside can be efficiently and effectively sealed from the atmospheric pressure of the surrounding environment, and steam is used as the cooling medium of the gas turbine. It is possible to improve cooling efficiency and thermal efficiency.

In the steam-cooled combined cycle plant according to the present invention, a cooling steam guide pipe is axially inserted into at least the inside of the turbine rotor of the gland seal portion of the gas turbine to form a double pipe structure. The cooling steam supply part and the cooling steam recovery part can be separated, and the steam that has cooled the turbine high temperature part can be effectively recovered by the separated cooling steam recovery part, and the temperature-raised steam can be efficiently recovered by heat. Is possible. At this time, the cooling steam supply unit is formed in a sleeve shape or a torus shape in the turbine rotor and the cooling steam is supplied from around the shaft hole of the turbine rotor, whereby the temperature rise of the gas turbine rotor can be efficiently prevented.

Further, at least one of the cooling steam supply portion and the cooling steam recovery portion formed in the gland seal portion of the steam cooling gas turbine is provided with a cooling steam pushing fan or a cooling steam suction fan, and the fan is used to rotate the gas turbine. By installing on the side, the pressure loss of the cooling steam flowing through the gas turbine through a complicated flow path can be reduced or reduced, and a sufficient amount of cooling steam can be secured. By securing the amount of cooling steam, the cooling efficiency of the gas turbine can be improved, and the combustion gas temperature at the gas turbine inlet can be raised to a high temperature or an extremely high temperature.

Furthermore, in the steam cooling combined cycle plant according to the present invention, cooling steam is supplied to the gas turbine from a cooling steam supply source such as a high pressure steam turbine, an exhaust heat recovery boiler, a main steam system or an auxiliary steam supply system. A gas turbine cooling steam supply system and a gas turbine cooling steam recovery system for recovering the steam that has cooled the high temperature part of the gas turbine to a cooling steam recovery source such as a steam turbine, a seal steam header or a condenser are provided. The gas turbine can be smoothly and smoothly supplied by using the steam as the cooling medium not only during the rated operation but also during the startup operation, and the cooling efficiency of the gas turbine can be improved. The gas turbine can be cooled even during the start-up operation when the cooling steam for the gas turbine cannot be obtained from the exhaust heat recovery boiler or the steam turbine.

Further, in the steam-cooled combined cycle plant according to the present invention, boiler steam and main steam can be used as cooling steam for the gas turbine, and during the plant start-up operation, the boiler heating steam (main steam) ) Is generated, the generated steam can be used as a cooling medium for the gas turbine by bypassing the steam turbine, and the gas turbine can be efficiently and effectively cooled.

Further, in the steam cooling combined cycle plant according to the present invention, a pipe for guiding the steam after cooling the gas turbine to the condenser is provided in the gas turbine cooling steam recovery system, and the pressure adjusting valve and the steam shutoff valve are provided in the pipe. By installing a desuperheater and a desuperheater, the steam after cooling the gas turbine can bypass the steam turbine and flow to the condenser during the startup operation of the combined cycle plant, which enables effective heat recovery. On the other hand, in the steam-cooled combined cycle plant according to the present invention, a leak steam recovery section, a seal steam section and a seal steam discharge section are respectively formed in the gland seal section formed in the gas turbine gland through the sealing means, This gland seal part separated the cooling steam supply part or cooling steam recovery part from the surrounding environment. In can be carried out effectively and complete the shaft seal of a gas turbine.

A gas turbine leakage steam recovery system is connected to the leakage steam recovery unit and connected to a steam turbine or a condenser, and this leakage steam recovery system is constructed to be able to cooperate with the steam turbine leakage steam recovery system. Therefore, the leaked steam recovery system can be shared and the piping can be simplified.

Further, the seal steam section is connected to a seal steam source such as a seal steam header and a condenser by a gas turbine seal steam system to supply and recover the seal steam, while the gas turbine seal steam system is operated by the steam system. Since it is configured to be able to cooperate with the turbine seal steam system, the seal steam system can be shared and the piping can be simplified.

Furthermore, the seal steam discharge part is connected to the gland steam condenser by the gas turbine seal steam discharge system, and the steam turbine seal steam discharge system is also connected to this condenser, so that the condenser can be made common while Since the seal vapor discharge system is configured to be collaborative,
The piping can be shared and simplified.

A gas turbine leak steam recovery system, a seal steam system, and a seal steam exhaust system are installed in the turbine gland of the steam cooling gas turbine, and these gas turbine leak steam recovery system, seal steam system, and seal steam exhaust system are installed. By sharing the steam with each system from the steam turbine, the leaked steam is recovered by the condenser or steam turbine, and the seal steam is recovered by the seal steam header and merges with the seal steam of the high pressure steam turbine to generate low pressure steam. The shaft seal of the gas turbine can be perfected by being used as the seal steam of the turbine and sucking the leak steam of the seal steam and the air from the atmosphere from the seal steam discharge system and sending it to the gland steam condenser.

On the other hand, in the method of operating a steam-cooled combined cycle plant according to the present invention, the gas turbine is steam-cooled by using the auxiliary steam in the initial stage of starting the gas turbine, and the steam that has become high in temperature after cooling is condensed in the condenser. By recovering it through a desuperheater, the gas turbine can be cooled with steam even during plant start-up operation when cooling steam cannot be obtained from the exhaust heat recovery boiler or steam turbine, and the remaining auxiliary steam is used as steam turbine. It can be used as the seal steam of the steam turbine to simultaneously raise the vacuum of the steam turbine.

Further, in the method for operating a steam cooling combined cycle plant according to the present invention, at the time of starting operation of the combined cycle plant, when steam is generated in the exhaust heat recovery boiler, the cooling steam for the gas turbine is changed to boiler steam or When switching to main steam and simultaneously raising the vacuum of the steam turbine, and when the vacuum rise ends, the steam after cooling the gas turbine is injected into the medium-pressure steam turbine through the reheat valve, and is rotated by the medium-pressure steam turbine. It is possible to increase the load and increase the load, and heat can be effectively recovered.

Furthermore, in the method for operating a steam cooling combined cycle plant according to the present invention, the leaked steam from the cooling steam recovery section of the gas turbine is first recovered by the steam turbine, and the seal steam is leaked by the high pressure steam turbine. Combined with steam, it is used as sealing steam for low-pressure turbines. Further, the steam discharged from the gland seal of the gas turbine merges with the mixed air from the atmosphere and is guided to the gland seal condenser, so that the gas turbine can be completely sealed.

[Brief description of drawings]

FIG. 1 is a system diagram showing an embodiment of a steam cooling combined cycle plant according to the present invention, and is a diagram showing a sealed state by cooling steam for a gas turbine during a rated operation.

FIG. 2 is a sectional view showing a seal structure of a steam-cooled turbine gland according to the present invention.

FIG. 3 is an explanatory view showing a pressure distribution of the gas turbine gland when the steam cooling combined cycle plant according to the present invention is in a rated operation.

FIG. 4 is a diagram showing a plant start-up operation in which auxiliary steam is used as a cooling medium for a gas turbine in a steam-cooled combined cycle plant according to the present invention.

FIG. 5 is a schematic diagram showing a gas turbine combined cycle plant according to the present invention, in which the main steam is used as cooling steam at the time of starting operation and load increasing operation of the gas turbine, and the steam turbine is started and load increasing operation at the same time. The figure explaining the starting method of a cooling steam seal and a steam turbine.

FIG. 6 is an explanatory view showing the pressure distribution in the gas turbine during start-up operation of the steam cooling combined cycle plant according to the present invention.

FIG. 7 is a cross-sectional view showing a seal structure of a turbine gland that supplies cooling steam from the outer peripheral side of a turbine gland of a steam cooling gas turbine and recovers it from the inner peripheral side.

FIG. 8 is a system diagram showing a conventional combined cycle plant that employs air cooling for cooling a gas turbine.

[Explanation of symbols]

 3 High-pressure steam turbine 4 Medium-pressure steam turbine 5 Low-pressure steam turbine 6 High-pressure steam turbine gland 6a, 7a Seal steam discharge part 6b, 7b Seal steam part 6c Leakage steam part 7 Low-pressure steam turbine gland 10 Seal steam header 12 Condenser 17 Gland Steam condenser 20 Steam cooling combined cycle plant 21 Gas turbine plant 22 Exhaust heat recovery boiler 23 Steam turbine plant 25 Compressor 26 Combustor 27 Steam cooling gas turbine 29 Condensate water supply system 30 Main steam system 31 Reheat steam system 33 Main steam pipe 34 Main Steam Shutoff Valve 35 Main Steam Control Valve 36 Low Temperature Reheat Pipe 37 High Temperature Reheat Steam Pipe 38 High Temperature Reheat Steam Stop Valve 39 Reheat Valve 40 Turbine Rotor 41, 41A Gas Turbine Gland 43 Gland Seal Part 44, 44A Cooling Steam Supply Department 45, 45A Cooling steam recovery unit 46 Gas turbine cooling steam supply system 47 Turbine cooling unit 48 Gas turbine cooling steam recovery system 49 Turbine cooling steam supply pipe 50 Auxiliary steam supply system 51 Turbine cooling steam closed 52 Boiler cooling steam supply pipe 53 Auxiliary Cooling steam supply pipe 54 Boiler cooling steam stop valve 55 Boiler cooling steam control valve 56 Cooling steam stop valve 58 Auxiliary steam header 59 Seal steam supply pipe 60 Seal steam stop valve 61 Seal steam control valve 62 Seal steam header 63 Auxiliary cooling steam stop valve 65 Gas Turbine Cooling Steam Recovery Pipe 66 Cooling Steam Recovery Valve 68 Cooling Steam Relief Pipe 69 Cooling Steam Relief Stop Valve 70 Cooling Steam Relief Valve (Regulator Valve) 71 Desuperheater 73 High Pressure Steam Turbine Ground 74 Low Pressure Steam Turbine Ground 75,76 Ground sticker 77,78 Seal steam part 80 High-pressure steam turbine gland seal steam pipe 81 Low-pressure steam turbine gland seal steam pipe 82 Turbine rotor 84 Gas turbine gland seal steam pipe 85 Seal steam escape pipe 86 Seal steam relief valve 87 Leak steam recovery part 88 Seal steam Part 89 Seal steam discharge part 90 Gland seal housing 91 Connection flange 92 Steam guide pipe 93 Shaft hole 94 Spacer 95 Steam sealing means (labyrinth packing) 97 Cooling steam pushing fan 98 Cooling steam suction fan 100 Steam sealing means 101 Intermediate sealing means 102 Exhaust Side seal means (seal steam seal means) 103 Atmosphere side seal means 105 Gas turbine ground Leakage steam recovery system 106 Leaked steam recovery pipe 107 Steam stop valve 108 Steam turbine Leakage steam recovery system 109 High-pressure steam turbine leak steam piping 111 Gas turbine seal steam system 113 Steam turbine seal steam system 115 Gas turbine steam discharge system 116 Seal steam discharge pipe 117 Grand steam condenser 118 Steam turbine seal steam discharge system 119,121 Seal steam Exhaust part 123 Grand steam blower

Claims (21)

[Claims] 1. A steam cooling gas turbine for cooling a turbine high temperature part of a gas turbine with steam, and a turbine cooling part for cooling turbine parts of the turbine high temperature part with steam, and cooling steam for supplying cooling steam to the turbine cooling part. A steam cooling gas turbine, characterized in that a supply part and a gland seal part for axially sealing the cooling steam supply part from the atmospheric pressure of the surrounding environment are provided, and the gland seal part is provided on at least one side of the turbine rotor. 2. A gas turbine is provided with a gland seal housing on at least one side of a turbine rotor, the gland seal housing partially covering the turbine rotor in an axial direction, and a cooling steam supply part is provided in the gland seal housing. 2. The steam-cooled gas turbine according to claim 1, wherein the steam-cooled gas recovery unit is partitioned and formed, and the cooling steam supply unit and the cooling steam recovery unit are axially sealed from atmospheric pressure by a gland seal unit. 3. At least the gland seal part has a double pipe structure in which a cooling steam guide pipe is axially inserted inside the turbine rotor, and the cooling steam supply part and the cooling steam supply part are cooled in the gland seal part by the cooling steam guide pipe. The steam cooling gas turbine according to claim 1 or 2, which is formed separately from the steam recovery unit. 4. A steam-cooled combined cycle plant in which a gas turbine plant, an exhaust heat recovery boiler, and a steam turbine plant are combined to cool a turbine high temperature part of a gas turbine with steam. A turbine cooling unit that cools turbine components with steam, a cooling steam supply unit that supplies cooling steam to the turbine cooling unit, and a gland seal unit that seals the cooling steam supply unit from atmospheric pressure of the surrounding environment are provided. A characteristic steam-cooled combined cycle plant. 5. A gas turbine is provided with a gland seal housing on at least one side of a turbine rotor, the gland seal housing partially covering the turbine rotor in an axial direction, and a cooling steam supply part is provided in the gland seal housing. 5. The cooling steam recovery unit is formed by partitioning the cooling steam supply unit and the cooling steam recovery unit, and the cooling steam supply unit and the cooling steam recovery unit are sealed from the atmospheric pressure of the surrounding environment by a gland seal unit.
Steam-cooled combined cycle plant as described. 6. A gas turbine has a double pipe structure in which a cooling steam guide pipe is axially inserted at least inside a turbine rotor of a gland seal part, and a cooling steam supply part and a cooling steam recovery part are provided by the cooling steam guide pipe. The steam-cooled combined cycle plant according to claim 4, wherein 7. The steam-cooled combined cycle plant according to claim 5, wherein the cooling steam supply section is formed in the central portion, and the cooling steam recovery section is formed substantially concentrically on the outer peripheral side of the cooling steam supply section. 8. The steam-cooled combined cycle plant according to claim 5, wherein the cooling steam supply section is formed in a torus shape or a sleeve shape, and the cooling steam recovery section is formed in the central portion. 9. The steam cooling combined cycle plant according to claim 4, wherein a cooling steam pushing fan is provided in the cooling steam supply unit, and the cooling steam pushing fan is attached to a rotating side of the cooling steam supply unit. . 10. The steam cooling combined cycle plant according to claim 5, wherein a cooling steam suction fan is provided in the cooling steam recovery unit, and the cooling steam suction fan is attached to the rotation side of the cooling steam recovery unit. 11. A gas turbine cooling steam supply system is constructed by connecting a cooling steam supply source such as a high pressure steam turbine for supplying cooling steam to a cooling steam supply unit, an exhaust heat recovery boiler, a main steam system or an auxiliary steam supply system. The steam according to claim 5 or 6, wherein the cooling steam recovery unit is connected to a cooling steam recovery source such as a steam turbine for recovering the cooling steam, a seal steam header, or a condenser. Cooling combined cycle plant. 12. The cooling steam supply system has a cooling steam supply pipe for supplying the main steam, steam from the high-pressure steam turbine or auxiliary steam as cooling steam to the cooling steam supply unit, and the supply pipe has a stop valve and a pressure control. The steam-cooled combined cycle plant according to claim 11, further comprising a valve. 13. The cooling steam recovery system has a cooling steam recovery pipe for recovering recovered steam after cooling the turbine high temperature part of the gas turbine from the cooling steam recovery unit to a condenser, and a pressure control valve and a pressure adjusting valve in the recovery pipe. The steam-cooled combined cycle plant according to claim 11, comprising a shutoff valve and a desuperheater. 14. A gland seal part formed in a gas turbine gland is a leaked steam recovery part for recovering leaked steam leaking from a cooling steam supply part or a cooling steam recovery part via a steam sealing means, and this leaked steam recovery part. And a seal steam portion adjacent to the seal steam portion via the intermediate seal means and a seal steam discharge portion adjacent to the seal steam portion via the seal steam seal means are arranged in parallel in the axial direction of the turbine rotor. The steam-cooled combined cycle plant according to claim 4, wherein the part is separated from the ambient environment by an atmosphere-side sealing means. 15. The leaked steam recovery section formed in the gland seal section of the gas turbine is connected to a steam turbine or a condenser to form a gas turbine leaked steam recovery system, while the gas turbine leaked steam recovery system is 15. The steam turbine leakage steam recovery system for recovering the leakage steam from the gland seal portion of the steam turbine, wherein the steam turbine leakage steam recovery system is operable.
Steam-cooled combined cycle plant as described. 16. A seal steam portion formed in a gland seal portion of a gas turbine is connected to a seal steam source such as a seal steam header or a condenser to form a gas turbine seal steam system, and the gas turbine seal is also provided. The steam cooling combined cycle plant according to claim 14, wherein the steam system is configured to cooperate with a steam turbine seal steam system that recovers seal steam from a gland seal portion of the steam turbine. 17. A seal steam discharge part formed in a gland seal part of a gas turbine is connected to a gland steam condenser for collecting the seal discharge steam to form a gas turbine seal steam discharge system, and the gas turbine seal steam is also provided. 15. The steam cooling combined cycle plant according to claim 14, wherein the discharge system is configured to cooperate with a steam turbine seal steam discharge system that recovers seal discharge steam from the gland seal portion of the steam turbine. 18. A method of operating a steam cooling combined cycle plant, which cools a gas turbine with steam, wherein auxiliary steam is supplied from a auxiliary steam supply system to a cooling steam supply unit via the cooling steam supply system at the initial stage of starting the gas turbine. , After cooling the turbine high temperature part of the gas turbine with the auxiliary steam, while recovering this cooling steam from the cooling steam recovery part to the condenser, when cooling the gas turbine with the auxiliary steam, the steam turbine and the gas turbine Steam cooling characterized by supplying seal steam to the gland seal part, axially sealing the gland seal part of the gas turbine from the atmospheric pressure of the surrounding environment, and raising the vacuum of the steam turbine to start the steam cooling combined cycle plant How to operate a combined cycle plant. 19. In a method for operating a steam cooling combined cycle plant, which cools a gas turbine with steam, at the time when boiler steam is generated from an exhaust heat recovery boiler by starting operation of the gas turbine, cooling steam for the gas turbine is supplemented with steam. To boiler steam and supply this boiler steam to the cooling steam supply unit via the cooling steam supply system, cool the turbine high temperature part of the gas turbine with the boiler steam, and then condense this cooling steam from the cooling steam recovery unit. While cooling the gas turbine with the boiler steam, when cooling the gas turbine with the boiler steam, the auxiliary steam from the auxiliary steam supply system is supplied from the seal steam header as seal steam to the gland seal part of the steam turbine and the gas turbine through the seal steam system, It is necessary to seal the gland seal part of the gas turbine from the atmospheric pressure of the surrounding environment. A method for operating a steam-cooled combined cycle plant, characterized in that the vacuum of the steam turbine is raised to the start of the steam-cooled combined cycle plant. 20. In a method for operating a steam cooling combined cycle plant for cooling a gas turbine with steam, a turbine high temperature part of the gas turbine is started at the time when the start-up operation of the gas turbine plant is started and the vacuum rise of the steam turbine is completed. The steam from the cooling steam recovery unit that has cooled the steam is switched from the condenser to heat recovery to the intermediate pressure steam turbine, and the startup operation of the steam cooling combined cycle plant is continued while increasing the rotation and load of the steam turbine. A method for operating a steam-cooled combined cycle plant, characterized by: 21. In a method of operating a steam cooling combined cycle plant for cooling a gas turbine with steam, when a load on the gas turbine and the steam turbine increases, leakage steam from a gland seal portion of the gas turbine is removed by a high pressure steam turbine. While recovering heat to the steam turbine together with the leaked steam from the gland seal part of the gas turbine, the seal steam from the gland seal part of the gas turbine and the high pressure steam turbine is supplied as the seal steam of the gland seal part of the low pressure steam turbine. Of excess steam from the seal steam escape valve to the condenser, and the steam discharged from the gland seal from the gland seal part of the gas turbine and the high-pressure and low-pressure steam turbine is combined with the air flowing from the atmosphere to the gland steam condenser. Let it suck,
A method for operating a steam-cooled combined cycle plant, characterized in that the gland seal portion of a gas turbine and a steam turbine is sealed from the atmospheric pressure of the surrounding environment and the turbine load operation is continued.