JP2020084947A - Steam turbine equipment, starting method of steam turbine equipment, and combined cycle plant - Google Patents

Abstract

To provide steam turbine equipment, and a combined cycle plant, suppressing increase in cooling fluid inlet/outlet temperature difference of a condenser.SOLUTION: The steam turbine equipment includes: a first steam line 72; a first steam valve 22 provided in the first steam line; a second steam line 74; a first bypass line 110 including a first branched passage 112 branched from the first steam line at a side upstream of the first steam valve, and reaching a condenser 18 from the first steam line through the first branched passage without passing through a first turbine 12, a reheater 65, and a second turbine 14; a second bypass line 120 including a second branched passage 122 branched from the first steam line at a side upstream of the first steam valve, and reaching the condenser from the first steam line through the second branched passage and the reheater without passing through the first turbine and the second turbine; a first bypass valve 114 provided in the first branched passage; and a second bypass valve 124 provided in the second branched passage.SELECTED DRAWING: Figure 2

Description

The present disclosure relates to a steam turbine facility, a method for starting a steam turbine facility, and a combined cycle plant.

In a typical steam turbine facility start-up method, when starting the steam turbine facility, the excess steam is dumped (discharged) by using a bypass line that bypasses the turbine and flows from the steam drum to the condenser before the steam is vented to the turbine. ).

In this regard, in Patent Document 1, a high-pressure turbine bypass pipe from the high-pressure drum to the condenser without passing through the high-pressure steam turbine and the reheater, and a high-pressure turbine bypass valve provided in the high-pressure turbine bypass pipe are provided. A method of operating a thermal power plant is disclosed. When the pressure of the high-pressure drum rises when the plant starts and the pre-pressure of the high-pressure turbine bypass valve reaches the set pressure, the high-pressure turbine bypass valve opens and excess steam is dumped into the condenser via the high-pressure turbine bypass pipe. It has become so.
Further, although Patent Document 1 does not aim at dumping excess steam, it does not blow the high-pressure drum to blow the reheat system (low-temperature reheat steam pipe, reheater, and high-temperature reheat steam pipe). It also describes the provision of a blow high-pressure steam supply pipe connected to the low-temperature reheat steam pipe without passing through the high-pressure steam turbine. When the blow high-pressure steam supply valve provided in the blow high-pressure steam supply pipe is opened, blow steam flows from the high-temperature reheat steam pipe to the condenser via the blow high-pressure steam supply valve and the reheater.

JP, 2000-240405, A

However, in the steam turbine facility described in Patent Document 1, the high-pressure turbine bypass valve controls the pre-pressure (that is, the pressure of the high-pressure main steam pipe). The amount of steam that is bypassed and bypassed by the high-pressure turbine must be sufficient and necessary to control the pressure of the front pressure.
Therefore, in the steam turbine facility described in Patent Document 1, when the excess steam is dumped to the condenser, it flows from the high-temperature reheat steam pipe into the condenser via the blow high-pressure steam supply valve and the reheater. If the amount of blow steam is excessive, the outlet temperature of the cooling fluid used for steam cooling in the condenser will rise excessively.

Therefore, it is an object of some embodiments of the present invention to provide a steam turbine facility, a steam turbine facility starting method, and a combined cycle plant that suppress an increase in a cooling fluid inlet/outlet temperature difference of a condenser.

(1) A method for starting a steam turbine facility according to some embodiments of the present invention is
A first steam line connected to the inlet of the first turbine;
A first steam valve provided in the first steam line;
A second steam line connected to an inlet of a second turbine having an inlet steam pressure lower than that of the first turbine;
A reheater provided in the second steam line,
The first steam line includes a first branch passage that branches from the first steam line upstream of the first steam valve, and does not pass through the first turbine, the reheater, and the second turbine. From the first bypass line to the condenser via the first branch passage,
A second branch passage that branches from the first steam line on the upstream side of the first steam valve, without passing through the first turbine and the second turbine; and the second branch from the first steam line. A second bypass line leading to the condenser via a passage and the reheater;
A first bypass valve provided in the first branch passage,
A second bypass valve provided in the second branch passage,
A method for starting a steam turbine facility including:
A step of performing pressure control of the first steam line using at least one of the first bypass valve and the second bypass valve while maintaining the first steam valve in a closed state,
In the step of performing the pressure control, before the temperature difference ΔT (hereinafter referred to as “cooling fluid temperature difference ΔT”), which is the difference between the inlet temperature and the outlet temperature of the cooling fluid of the condenser, reaches the allowable value ΔT1. In at least a part of the period, the pressure control is performed using the second bypass valve with the first bypass valve being at least partially opened.

According to the starting method of (1) above, the pressure control using the first bypass valve or the second bypass valve makes it possible to appropriately maintain the pressure of the first steam line before the ventilation to the first turbine and the second turbine. An appropriate amount of excess steam is appropriately dumped into the condenser via the first bypass valve or the second bypass valve.
On the other hand, during execution of the pressure control using the second bypass valve, and during at least a part of the period before reaching the allowable value ΔT1 of the cooling fluid temperature difference ΔT of the condenser, the first bypass valve is at least partially connected. It will be in an open state. In this state, since the second bypass valve plays a role of control (pressure control) for appropriately maintaining the pressure of the first steam line, the first bypass valve itself must execute the pressure control. The restriction is released, and the degree of freedom in setting the opening degree of the first bypass valve is improved. Therefore, by setting the opening degree of the first bypass valve to a relatively large value, it is possible to suppress an increase in the cooling fluid temperature difference ΔT of the condenser due to the dump of the excess steam from the first steam line. ..

(2) In some embodiments, in the method of (1) above,
In the step of performing the pressure control, in the step of waiting, after a lapse of a specified time from the start of the pressure control by the second bypass valve, and during the execution of the pressure control using the second bypass valve, The first bypass valve, which was maintained in the closed state, is opened.

When the pressure of the first steam line rises to some extent and the pressure control by the second bypass valve is started at the time of starting the steam turbine equipment, excess steam of the first steam line is transferred to the condenser via the second bypass line. Inflow, the cooling fluid temperature difference ΔT of the condenser begins to increase.
Therefore, if the time from the pressure control start of the second bypass valve to the opening of the first bypass valve is set appropriately, the dump of surplus steam using the first bypass line that does not pass through the reheater can be performed appropriately. Starting at the timing, it is possible to suppress an increase in the cooling fluid temperature difference ΔT of the condenser.

(3) In some embodiments, in the above method (1),
In the step of performing the pressure control, the opening degree of the second bypass valve is controlled so as to maintain the pressure of the first steam line at a target value, and based on the temperature difference ΔT, the first state of the closed state is changed to the first state. 1 Open the bypass valve.

By thus controlling the pressure of the first steam line by the second bypass valve, the first bypass valve is released from the role of pressure control, and the condenser cooling is performed regardless of the pressure of the first steam line. The opening timing of the first bypass valve can be determined based on the fluid temperature difference ΔT. Therefore, it is possible to start the dump of the excess steam using the first bypass line that does not pass through the condenser at an appropriate timing, and suppress the increase of the cooling fluid temperature difference ΔT of the condenser.

(4) In some embodiments, in the above method (3),
In the step of performing the pressure control, when the temperature difference ΔT exceeds a specified value ΔT2 lower than the allowable value ΔT1, the first bypass valve is opened from the closed state.

Thus, by setting the opening timing of the first bypass valve at the time when the condenser cooling fluid temperature difference ΔT reaches the specified value ΔT2 which is lower than the allowable value ΔT1, the condenser cooling fluid temperature difference ΔT is set. It is possible to effectively prevent the situation where the value exceeds the allowable value ΔT1 and becomes excessive.

(5) In some embodiments, in the above method (1),
The step of performing the pressure control,
The first bypass valve is used to maintain the pressure of the first steam line at a target pressure with the second bypass valve closed until the opening degree of the first bypass valve reaches a specified value A1. And a first step of performing the pressure control,
A second step of switching the valve for performing the pressure control from the first bypass valve to the second bypass valve after the opening degree of the first bypass valve reaches the specified value A1;
including.

In the above method (5), when dumping the excess steam from the first steam line, the first bypass valve is first opened to control the pressure of the first steam line (first step), and finally Causes the second bypass valve to control the pressure of the first steam line.
In this way, if the second bypass valve is finally made to control the pressure of the first steam line, the first bypass valve is released from the role of pressure control and the first bypass valve is opened during the execution of the second step. Since the degree of freedom in setting the degree is improved, an increase in the cooling fluid temperature difference ΔT of the condenser can be suppressed.
Further, by performing the pressure control by the first bypass valve first, during the execution of the first step, the excess steam is dumped to the condenser through the first bypass line that does not pass through the reheater, and the cooling fluid of the condenser is cooled. The increase in temperature difference ΔT can be further suppressed.

(6) In some embodiments, in the above method (5),
After the execution of the second step, the opening of the second bypass valve is controlled while maintaining the opening of the first bypass valve at the specified value A1, and the opening of the second bypass valve is set to the specified value A2. Is reached, the opening degree of the first bypass valve is made larger than the specified value A1.

In this way, after the execution of the second step, the opening degree of the first bypass valve is not suddenly increased, but is waited until the opening degree of the second bypass valve reaches the specified value A2 by the pressure control, and (2) Since the opening degree of the first bypass valve is increased after the allowance for adjusting the opening degree of the bypass valve is secured, it is possible to smoothly switch the valve that executes the pressure control.

(7) A method for starting a combined cycle plant according to some embodiments,
A gas turbine,
A boiler configured to generate steam using the heat of exhaust gas from the gas turbine,
Steam turbine equipment configured to be supplied with steam from the boiler,
A method for starting a combined cycle plant including:
After increasing the load on the gas turbine to a specified value and then increasing the load on the gas turbine to the specified value, the steam turbine facility is installed by the starting method according to any one of (1) to (6). To start.

In order to shorten the start-up time of the combined cycle plant, if the gas turbine is maintained under a high load (for example, near the rated load) before ventilation of the steam turbine equipment, it is necessary to dump a large amount of excess steam into the condenser. , The cooling load of the condenser may become excessive.
In this respect, the method of starting the combined cycle plant of the above (7) is, as described in the above (1), during the execution of the pressure control using the second bypass valve and at the time of the cooling fluid temperature difference ΔT of the condenser. Since the first bypass valve is opened during at least a part of the period before reaching the allowable value ΔT1, the degree of freedom in setting the opening degree of the first bypass valve is increased to increase the cooling fluid temperature difference ΔT of the condenser. Can be suppressed. Therefore, the combined cycle plant can be started at high speed while suppressing an increase in the cooling fluid temperature difference ΔT of the condenser.

(8) In some embodiments, in the method of (7) above,
The first steam valve is opened while maintaining the load of the gas turbine at a high load (for example, 90% of the rated load).

In this case, since the gas turbine has a high load at the start of starting the steam turbine facility, a large amount of exhaust heat of the gas turbine can be used to quickly establish the steam condition of each steam line of the steam turbine facility. .. Therefore, the combined cycle plant can be started at high speed.

(9) The steam turbine equipment according to some embodiments includes:
A first steam line connected to the inlet of the first turbine;
A first steam valve provided in the first steam line;
A second steam line connected to an inlet of a second turbine having an inlet steam pressure lower than that of the first turbine;
A reheater provided in the second steam line,
The first steam line includes a first branch passage that branches from the first steam line upstream of the first steam valve, and does not pass through the first turbine, the reheater, and the second turbine. From the first bypass line to the condenser via the first branch passage,
A second branch passage that branches from the first steam line on the upstream side of the first steam valve, without passing through the first turbine and the second turbine; and the second branch from the first steam line. A second bypass line leading to the condenser via a passage and the reheater;
A first bypass valve provided in the first branch passage,
A second bypass valve provided in the second branch passage,
A control device for controlling the first bypass valve and the second bypass valve;
Steam turbine equipment including:
The control device is
While maintaining the first steam valve in a closed state, it is configured to adjust the opening degree of at least one of the first bypass valve or the second bypass valve so as to control the pressure of the first steam line,
The first bypass valve is at least partially opened in at least a part of the period before the temperature difference ΔT, which is the difference between the inlet temperature and the outlet temperature of the cooling fluid of the condenser, reaches the allowable value ΔT1. , The opening degree of the second bypass valve is adjusted so as to perform the pressure control.

According to the above configuration (9), the pressure control using the first bypass valve or the second bypass valve makes it possible to maintain the pressure of the first steam line before the ventilation of the first turbine and the second turbine. A quantity of excess steam is appropriately dumped into the condenser via the first bypass valve or the second bypass valve.
On the other hand, during execution of the pressure control using the second bypass valve, and during at least a part of the period before reaching the allowable value ΔT1 of the cooling fluid temperature difference ΔT of the condenser, the first bypass valve is at least partially connected. It will be in an open state. In this state, since the second bypass valve plays a role of control (pressure control) for appropriately maintaining the pressure of the first steam line, the first bypass valve itself must execute the pressure control. The restriction is released, and the degree of freedom in setting the opening degree of the first bypass valve is improved. Therefore, by setting the opening degree of the first bypass valve to a relatively large value, it is possible to suppress an increase in the cooling fluid temperature difference ΔT of the condenser due to the dump of the excess steam from the first steam line. ..

(10) In some embodiments, in the configuration of (9) above,
The control device controls the opening degree of the second bypass valve so as to maintain the pressure of the first steam line at a target value, and based on the temperature difference ΔT, changes from the closed state to the first bypass valve. Control to open.

According to the configuration of (10) above, by performing the pressure control of the first steam line by the second bypass valve, the first bypass valve is released from the role of pressure control, and is independent of the pressure of the first steam line. The opening timing of the first bypass valve can be determined based on the cooling fluid temperature difference ΔT of the condenser. Therefore, it is possible to start dumping of the excess steam using the first bypass line that does not pass through the reheater at an appropriate timing, and suppress an increase in the cooling fluid temperature difference ΔT of the condenser.

(11) In some embodiments, in the configuration of (10) above,
The control device controls to open the first bypass valve from the closed state when the temperature difference ΔT exceeds a specified value ΔT2 lower than the allowable value ΔT1.

According to the configuration of (11) above, by setting the opening timing of the first bypass valve at the time when the cooling fluid temperature difference ΔT of the condenser reaches the specified value ΔT2 lower than the allowable value ΔT1, the condenser is set. It is possible to effectively prevent the situation in which the cooling fluid temperature difference ΔT exceeds the allowable value ΔT1 and becomes excessive.

(12) In some embodiments, in the configuration of (9) above,
The control device keeps the pressure of the first steam line at a target value with the second bypass valve closed until the opening degree of the first bypass valve reaches a specified value A1. 1 Perform the pressure control using a bypass valve,
After the opening degree of the first bypass valve reaches the specified value A1, control for switching the valve that performs the pressure control from the first bypass valve to the second bypass valve is performed.

According to the above configuration (12), when dumping the excess steam from the first steam line, the first bypass valve is first opened to control the pressure of the first steam line, and finally the first steam line. The pressure control of the steam line is performed by the second bypass valve.
In this way, if the second bypass valve is finally made to control the pressure of the first steam line, the first bypass valve is released from the role of pressure control and the first bypass valve is opened during the execution of the second step. Since the degree of freedom in setting the degree is improved, an increase in the cooling fluid temperature difference ΔT of the condenser can be suppressed.
Further, by performing the pressure control by the first bypass valve first, during execution of the pressure control using the first bypass valve, the excess steam is dumped to the condenser through the first bypass line that does not pass through the reheater, It is possible to further suppress an increase in the cooling fluid temperature difference ΔT of the condenser.

(13) In some embodiments, in the configuration of (12) above,
The control device controls the opening degree of the second bypass valve while maintaining the opening degree of the first bypass valve at the specified value A1 after the opening degree of the first bypass valve reaches the specified value A1. Then, when the opening degree of the second bypass valve reaches the specified value A2, the opening degree of the first bypass valve is configured to be larger than the specified value A1.

According to the above configuration (13), after switching the valve for performing pressure control from the first bypass valve to the second bypass valve, the opening degree of the first bypass valve is not suddenly increased, but is controlled by the pressure control. Since the opening of the second bypass valve reaches the specified value A2 and the adjustment amount of the opening of the second bypass valve is secured, the opening of the first bypass valve is increased. It is possible to smoothly switch the valve for executing.

(14) A combined cycle plant according to some embodiments,
A gas turbine,
A boiler configured to generate steam using the heat of exhaust gas from the gas turbine,
Steam turbine equipment according to any one of (9) to (13) above,
Equipped with
The steam turbine facility is configured to be supplied with steam from the boiler.

In order to shorten the start-up time of the combined cycle plant, if the gas turbine is maintained under a high load (for example, near the rated load) before ventilation of the steam turbine equipment, it is necessary to dump a large amount of excess steam into the condenser. , The cooling load of the condenser may become excessive.
In this regard, as described in (1) above, the combined cycle plant configured in (14) above is performing pressure control using the second bypass valve, and the cooling fluid temperature difference ΔT of the condenser is Since the first bypass valve is opened during at least a part of the period before reaching the allowable value ΔT1, the degree of freedom in setting the opening degree of the first bypass valve is increased to increase the cooling fluid temperature difference ΔT of the condenser. Can be suppressed. Therefore, the combined cycle plant can be started at high speed while suppressing an increase in the cooling fluid temperature difference ΔT of the condenser.

Some embodiments of the present invention provide a steam turbine facility that suppresses an increase in a cooling fluid inlet/outlet temperature difference of a condenser, a steam turbine facility starting method, and a combined cycle plant.

It is a schematic diagram of a gas turbine combined cycle plant concerning one embodiment. It is a schematic diagram of steam turbine equipment concerning one embodiment. It is a time chart which shows an example of operation of the 1st bypass valve and the 2nd bypass valve. It is a time chart which shows an example of operation of the 1st bypass valve and the 2nd bypass valve. It is a time chart which shows an example of operation of the 1st bypass valve and the 2nd bypass valve. It is a flow chart which shows an example of the starting procedure of a GTCC plant. It is a figure which shows an example of the starting pattern of a GTCC plant.

Hereinafter, some embodiments of the present invention will be described with reference to the accompanying drawings. However, the dimensions, materials, shapes, relative positions, etc. of the components described as the embodiments or shown in the drawings are not intended to limit the scope of the present invention thereto, but are merely illustrative examples. Absent.

Hereinafter, the combined cycle plant including the steam turbine facility according to the embodiment of the present invention will be described, and then the details of the steam turbine facility will be described.
The steam turbine facility according to the embodiment of the present invention is not limited to the steam turbine facility for the combined cycle plant described below, and is a boiler that burns fuel such as coal, petroleum, liquefied natural gas, and heavy oil. It may be steam turbine equipment for a steam power plant that drives a steam turbine with the generated steam.

FIG. 1 is a schematic diagram of a gas turbine combined cycle plant (hereinafter, abbreviated as GTCC plant) according to an embodiment. The GTCC plant 1 shown in FIG. 1 includes a steam turbine 10, a gas turbine 40, a generator 4, and an exhaust heat recovery boiler 50.

The steam turbine 10 includes a plurality of turbines including a first turbine 12 and a second turbine 14 having an inlet steam pressure lower than that of the first turbine 12. The turbine having the lowest inlet steam pressure among the plurality of turbines forming the steam turbine 10 is the low-pressure turbine 16 connected to the condenser 18.
In the exemplary embodiment shown in FIG. 1, the steam turbine 10 includes three types of high pressure turbines as the first turbine 12, a medium pressure turbine as the second turbine 14, and a low pressure turbine 16 having different inlet steam pressures. Including turbine. In another embodiment, the low pressure turbine 16 functions as the second turbine 14, and the steam turbine 10 includes two types of turbines, a first turbine 12 and a second turbine 14 (ie, the low pressure turbine 16 ). In still another embodiment, the steam turbine 10 has a very high inlet pressure, that is, a very high pressure turbine (VHP) having a higher inlet steam pressure than a high pressure turbine, and a high pressure turbine, an intermediate pressure turbine, and a low pressure turbine. It includes four types of turbines, and either the ultra-high pressure turbine or the high-pressure turbine functions as the first turbine 12, and the high-pressure turbine or the intermediate-pressure turbine functions as the second turbine 14.
A steam valve (first steam valve 22, second steam valve 24 and low-pressure steam valve 26) is provided at the inlet of each turbine, and the steam is supplied through each steam valve (22, 24, 26). Each turbine is driven by the generated steam. A plurality of turbines forming the steam turbine 10 are connected to the generator 4 and drive the generator 4.

The steam for driving the steam turbine 10 is generated by using the exhaust gas of the gas turbine 40 as a heat source.
The gas turbine 40 includes a compressor 42 for generating compressed air, a combustor 44 for combusting a fuel using the compressed air generated by the compressor 42 to generate combustion gas, and a combustor 44. And a turbine 46 driven by the combustion gas. The rotor of the turbine 46 is connected to the input shaft of the generator 4, and in the generator 4, mechanical energy input from the turbine 46 is converted into electric power. The rotary shaft of the compressor 42 is connected to the rotor of the turbine 46, and the turbine 42 drives the compressor 42.

In the gas turbine 40, the combustion gas that has passed through the turbine 46 is guided to the exhaust heat recovery boiler 50 as the exhaust gas 48.
The exhaust heat recovery boiler 50 includes a plurality of drums (52, 54, 56) provided corresponding to a plurality of types of turbines constituting the steam turbine 10, and an evaporator connected to each drum (52, 54, 56). It includes a heater (53, 55, 57) and a superheater (62, 64, 66) for superheating steam from each drum (52, 54, 56). In the embodiment shown in FIG. 1, three types of the first drum 52, the second drum 54, and the low-pressure drum 56 are provided corresponding to the first turbine 12, the second turbine 14, and the low-pressure turbine 16 constituting the steam turbine 10, respectively. A drum is provided, and three types of evaporators (53, 55, 57) and three types of superheaters (62, 64, 66) are provided corresponding to each drum.

Further, the exhaust heat recovery boiler 50 having the above configuration and the steam turbine 10 are connected by a plurality of steam lines. Specifically, from the first drum 52, the second drum 54, and the low-pressure drum 56 of the exhaust heat recovery boiler 50 to the first turbine 12, the second turbine 14, and the low-pressure turbine 16, respectively, a first steam line 72 and a first steam line 72. A two steam line 74 and a low pressure steam line 76 are provided. The above-described steam valves (the first steam valve 22, the second steam valve 24, and the low-pressure steam valve 26) are connected to the respective turbine inlets in the first steam line 72, the second steam line 74, and the low-pressure steam line 76. Each is provided.

Further, a first steam discharge line 73 for guiding the exhaust gas from the first turbine 12 to the reheater 65 is provided. The first steam discharge line 73 has an upstream end connected to the outlet of the first turbine 12, and a downstream end connected to a portion of the second steam line 74 between the superheater 64 and the reheater 65. Have.

Further, a second steam discharge line 75 that guides exhaust gas from the second turbine 14 to the low pressure turbine 16 is provided. The second steam discharge line 75 has an upstream end connected to the outlet of the second turbine 14, and a downstream end of the low pressure steam line 76 connected to the downstream side of the superheater 66 and the downstream side of the low pressure steam valve 26. Have.

The above-mentioned superheaters (62, 64, 66) of the exhaust heat recovery boiler 50 are arranged on the steam lines (72, 74, 76) leading to the inlets of the turbines (12, 14, 16), respectively.
Further, in addition to the superheater 64, a reheater 65 is further provided on the downstream side of the superheater 64 in the second steam line 74 communicating with the intermediate pressure turbine as the second turbine 14.

Further, in the example shown in FIG. 1, the exhaust heat recovery boiler 50 is connected with a water supply line 78 for supplying water from the condenser 18 connected to the low-pressure turbine 16 to each drum (52, 54, 56). . The steam that has passed through the low-pressure turbine 16 is condensed in the condenser 18 and returned to the drums (52, 54, 56) via the water supply line 78.

In the GTCC plant 1 having the above-described configuration, the exhaust gas of the gas turbine 40 is guided to the exhaust heat recovery boiler 50, so that the evaporator (53, 55, 57), steam is generated and stored in each drum (52, 54, 56). In addition, the steam from each drum (52, 54, 56) is heated by the superheater (62, 64, 66) and the reheater 65, and the plurality of turbines (12, 14, 16) configuring the steam turbine 10 are included. Is supplied to. The steam that has passed through the first turbine 12 is guided to the second steam line 74 via the first steam discharge line 73, merges with the steam from the superheater 64, and passes through the reheater 65 to the second turbine. You are led to 14. The steam that has passed through the second turbine 14 is guided to the low-pressure steam line 76 via the second steam discharge line 75, merges with the steam from the superheater 66, and is guided to the low-pressure turbine 16. The steam that has passed through the low-pressure turbine 16 is condensed in the condenser 18, and is returned to the drums (52, 54, 56) of the exhaust heat recovery boiler 50 via the water supply line 78 as described above.

In the case of the configuration in which the steam turbine 10 and the gas turbine 40 drive the common generator 4 as in the example described above, the shaft of the steam turbine 10 and the shafts of the gas turbine 40 and the generator 4 are connected via a clutch. You may connect by connecting. In another embodiment, a generator driven by the steam turbine 10 and a generator driven by the gas turbine 40 are provided separately.

Although not shown in FIG. 1, when the steam turbine 10 is started, the steam supplied to each turbine (12, 14, 16) via each steam line (72, 74, 76) has a predetermined value. Until the conditions are satisfied, the turbines (12, 14, 16) may be bypassed and excess steam from each drum (52, 54, 56) may be dumped to the condenser 18.

Hereinafter, with reference to FIGS. 2 to 5, the steam turbine equipment according to the embodiment of the present invention capable of dumping excess steam into the condenser 18 will be described in detail.
In the following description, the components already described with reference to FIG. 1 are designated by the same reference numerals in FIG. 2, and the description thereof will be omitted.

FIG. 2 is a schematic diagram of a steam turbine facility according to one embodiment.
The steam turbine facility 100 shown in the figure includes a plurality of turbines including a first turbine 12 and a second turbine 14. A condenser 18 is connected to the low-pressure turbine 16 having the lowest inlet steam pressure among the plurality of turbines, and exhaust gas from the low-pressure turbine 16 is guided to the condenser 18. A first steam line 72 connected to the inlet of the first turbine 12 and a second steam line 74 connected to the inlet of the second turbine 14 are provided, and the reheater 65 is provided in the second steam line 74. Are placed.

The steam turbine facility 100 includes a first bypass line 110 that bypasses the first turbine 12 and the reheater 65 and guides excess steam flowing through the first steam line 72 to the condenser 18. The first bypass line 110 includes a first branch passage 112 that branches from the first steam line 72 on the upstream side of the first steam valve 22. A first bypass valve 114 is provided in the first branch passage 112.
Although FIG. 2 shows an example in which the first branch passage 112 is directly connected to the condenser 18, in another embodiment, the first bypass line 110 includes the first branch passage 112 and the condenser 18. Other lines may be included between and. For example, the first bypass line 110 may include a first branch passage 112 and a part of the second bypass line 120 described later on the downstream side of the reheater 65 or the low-pressure bypass line 80. In this case, the downstream end of the first branch passage 112 is connected to the condenser 18 via a portion of the second bypass line 120 on the downstream side of the reheater 65 or the low pressure bypass line 80.

The steam turbine facility 100 also includes a second bypass line 120 that extends from the first steam line 72 to the condenser 18 without passing through the first turbine 12 and the second turbine 14. The second bypass line 120 includes a second branch passage 122 that branches from the first steam line 72 on the upstream side of the first steam valve 22. The second bypass line 120 reaches the condenser 18 from the first steam line 72 via the second branch passage 122 and the reheater 65. A second bypass valve 124 is provided in the second branch passage 122.
In the example shown in FIG. 2, the upstream end of the second branch passage 122 is connected to a portion of the first steam line 72 on the upstream side of the first steam valve 22, and the downstream end of the second branch passage 122 is the first steam. It is connected to the discharge line 73. The second bypass line 120 also includes a connection line 126 that connects the condenser 18 to the downstream side of the reheater 65 and the upstream side of the second steam valve 24 in the second steam line 74.

The steam turbine facility 100 includes the control device 90 for controlling the valve opening degrees of the first bypass valve 114 and the second bypass valve 124 described above.

In some embodiments, the control device 90 may be input with detection signals of sensors for detecting various states of the steam turbine equipment 100.
In the example shown in FIG. 2, the steam turbine facility 100 includes a pressure sensor 92 for detecting the pressure of the first steam line 72, and a cooling fluid used for condensing the exhaust gas of the low pressure turbine 16 in the condenser 18. Temperature sensors 94 and 96 for detecting the inlet temperature and the outlet temperature of the. For example, the detection signals of at least one of the pressure sensor 92 or the temperature sensors 94 and 96 may be input to the control device 90, and the detection signals of these sensors may be used for the control in the control device 90.

Hereinafter, specific operations of the first bypass valve 114 and the second bypass valve 124 under the control of the control device 90 will be described with reference to the time charts shown in FIGS. 3 to 5.

FIG. 3 is a time chart showing an example of operations of the first bypass valve 114 and the second bypass valve 124 under the control of the control device 90.
In the example shown in FIG. 3, after the pressure control by the second bypass valve 124 is started, the closed state is maintained after the stipulated time has elapsed and during the pressure control using the second bypass valve 124. The control for opening the 1 bypass valve 114 is performed.
The time chart shown in FIG. 3 is merely an example, and the pressure P of the first steam line 72, the inlet/outlet temperature difference (cooling fluid temperature difference) ΔT of the cooling fluid of the condenser 18, and the first bypass valve 114 and The change in the valve opening degree of the second bypass valve 124 may not be the same as the example shown in FIG. 3 depending on the specifications of the steam turbine facility 100.

When the boiler (exhaust heat recovery boiler 50) is started (time t0), various valves including the first steam valve 22, the first bypass valve 114, and the second bypass valve 124 are in a closed state, so that each steam drum is closed. The pressure of the steam generated at (52, 54, 56) gradually rises. In FIG. 3, it is shown that the pressure of the first steam line 72 connected to the first drum 52 gradually increases after time t0.

At time t1 when the pressure P of the first steam line 72 increases to some extent, the control device 90 gives the second bypass valve 124 an opening degree command capable of maintaining the pressure of the first steam line 72 at a target value. As a result, the pressure control of the second bypass valve 124 by the control device 90 is started.
For example, the control device 90 sets the second feedback command value based on the deviation between the pressure detection value of the first steam line 72 obtained from the pressure sensor 92 shown in FIG. 2 and the target pressure value of the first steam line 72. It may be given to the bypass valve 124 as an opening command.
This pressure control is shown by the wavy line at times t1 to tc in the time chart showing the second bypass valve opening degree in FIG. 3, and shows how the valve controls the pressure while opening and closing in small steps. Shows.

The target pressure value of the first steam line 72 may be determined by any method. For example, the target value of the pressure of the first steam line 72 may be determined based on the detected value of the pressure of the first steam line 72. In addition, for example, the target value of the pressure of the first steam line 72 may gradually increase toward the specified pressure Pc.
In FIG. 3, after time t1, the opening degree of the second bypass valve 124 is adjusted so that the pressure of the first steam line 72 is a target value (in the example of FIG. 3, the target value is gradually set toward the specified pressure Pc). It has been shown to be maintained.

At time t1, when the pressure control by the second bypass valve 124 is started and excess steam starts to be dumped into the condenser 18 through the second bypass line 120, cooling in the condenser 18 is performed as shown in FIG. The fluid inlet/outlet temperature difference ΔT starts to rise.

After that, at a time t2 after the lapse of the specified time Δt from the start time (time t1) of the pressure control of the second bypass valve 124, the control device 90 issues an opening command to the first bypass valve 114 which has been closed until then. give. At this time, the pressure control of the second bypass valve 124 started at time t1 is continuously executed.
In the example shown in FIG. 3, the control device 90 controls the first bypass valve 114 until the time t3 after which the pressure P of the first steam line 72 is sufficiently close to the specified pressure Pc (pressure suitable for ventilation of the turbine) after the time t2. The opening degree of is increased at a specified rate. Since the first bypass valve 114 is at least partially opened, a part of the excess steam in the first steam line 72 is transferred to the condenser 18 via the first bypass line 110 without passing through the reheater 65. Is discharged. As a result, as shown in FIG. 3, after time t2, an increase in the inlet/outlet temperature difference ΔT of the cooling fluid in the condenser 18 is suppressed.

The period (specified time) Δt from the pressure control start time (time t1) of the second bypass valve 124 to the opening time (time t2) of the first bypass valve 114 is determined by the specifications of the steam turbine facility 100 (for example, the first steam line). Depending on the excess steam amount and excess steam temperature of 72, and the flow rate of the cooling fluid of the condenser 18, the inlet/outlet temperature difference ΔT of the cooling fluid of the condenser 18 becomes the allowable value ΔT1 from the dump start point of the excess steam. It may be set to a period shorter than the estimated value of the time required to reach it. In this case, the first bypass valve 114 can be opened during the pressure control of the second bypass valve 124 before the inlet/outlet temperature difference ΔT of the cooling fluid of the condenser 18 reaches the allowable value ΔT1.
The above-mentioned estimated value may be obtained from the operation record of the steam turbine facility 100, or may be calculated from the specifications of the steam turbine facility 100.

After that, after the time tc when the steam in the first steam line 72 satisfies the conditions (pressure, temperature, etc.) suitable for the ventilation of the turbine, the first steam valve 22 is opened to start the first steam line 72 from the first steam line 72. Start steam supply (ventilation) to the turbine.

According to the embodiment shown in FIG. 3, if the time Δt from the start of pressure control of the second bypass valve 124 to the opening of the first bypass valve 114 is set appropriately, the first bypass that does not pass through the reheater 65 Dumping of the excess steam using the line 110 can be started at an appropriate timing, and the increase in the cooling fluid temperature difference ΔT of the condenser 18 can be suppressed.

In the case of the GTCC plant 1 shown in FIG. 1, for example, after a lapse of a specified time from the time of ignition of the gas turbine, or after a lapse of the specified time from the time of inclusion of a generator connected to the gas turbine, and the second bypass. The first bypass valve 114, which has been maintained in the closed state, may be opened while the pressure control using the valve 124 is being performed. That is, the starting point of the specified time Δt (the time point of starting pressure control by the second bypass valve 124 in the example of FIG. 3) that serves as the reference for the timing of opening the first bypass valve 114 is set to the ignition time point of the gas turbine or the above-mentioned generator. It may be the point of time of admission.

In a GTCC plant having a predetermined specification, under a predetermined operating condition, the time from the ignition time of the gas turbine to the pressure control start time of the second bypass valve 124 (time t1 in FIG. 3) or the above-mentioned generator The time from the insertion time to the pressure control start time by the second bypass valve 124 is substantially constant. Therefore, by setting these times as the above-mentioned specified time Δt and appropriately setting Δt, the surplus using the first bypass line 110 that does not pass through the reheater 65, as described with reference to FIG. It is possible to start the dump of steam at an appropriate timing and suppress an increase in the cooling fluid temperature difference ΔT of the condenser 18.

FIG. 4 is a time chart showing another example of the operation of the first bypass valve 114 and the second bypass valve 124 under the control of the control device 90.
In the example shown in FIG. 4, the opening degree of the second bypass valve 124 is controlled so as to maintain the pressure of the first steam line 72 at a target value, and based on the inlet/outlet temperature difference ΔT of the cooling fluid of the condenser 18. The control for opening the closed first bypass valve is performed.
The time chart shown in FIG. 4 is merely an example, and the pressure P of the first steam line 72, the inlet/outlet temperature difference ΔT of the cooling fluid of the condenser 18, and the first bypass valve 114 and the second bypass valve 124. The change in the valve opening may not be the same as the example shown in FIG. 4 depending on the specifications of the steam turbine facility 100.

4 is common to the example shown in FIG. 3 except for the opening timing of the first bypass valve 114 and the control logic, and the phenomenon during the period from time t0 to time t1 has already been described with reference to FIG. Therefore, the description is omitted here.

After time t1, the opening degree of the second bypass valve 124 is adjusted and the pressure of the first steam line 72 is maintained at the target value. This pressure control is shown by the wavy line at times t1 to tc in the time chart showing the second bypass valve opening degree in FIG. 4, and shows how the valve controls the pressure while opening and closing in small steps. Shows.
Note that in the example of FIG. 4, the target value gradually increases toward the specified pressure Pc. After the pressure control of the second bypass valve 124 is started at time t1, the surplus steam in the first steam line 72 is discharged to the condenser 18 via the second bypass line 120, so that the condenser 18 is cooled. As shown in FIG. 4, the fluid inlet/outlet temperature difference ΔT gradually increases after time t1.

Then, at time t4 when the inlet/outlet temperature difference ΔT of the cooling fluid reaches the specified value ΔT2 which is lower than the allowable value ΔT1, the controller 90 gives an opening command to the first bypass valve 114. For example, the control device 90 compares the inlet/outlet temperature difference ΔT (=Tout−Tin) of the cooling fluid obtained from the detection values Tin and Tout of the temperature sensors 94 and 96 shown in FIG. 2 with the specified value ΔT2, and ΔT> An opening command may be given to the first bypass valve 114 when the condition of ΔT2 is satisfied.
In the example shown in FIG. 4, the control device 90 controls the first bypass valve 114 until the time t5 at which the pressure P of the first steam line 72 is sufficiently close to the specified pressure Pc (pressure suitable for ventilation of the turbine) after the time t4. The opening degree of is increased at a specified rate. Since the first bypass valve 114 is at least partially opened, a part of the excess steam in the first steam line 72 is transferred to the condenser 18 via the first bypass line 110 without passing through the reheater 65. Is discharged. As a result, as shown in FIG. 4, after time t4, the rise in the inlet/outlet temperature difference ΔT of the cooling fluid in the condenser 18 is suppressed.

After that, after the time tc when the steam in the first steam line 72 satisfies the conditions (pressure, temperature, etc.) suitable for the ventilation of the turbine, the first steam valve 22 is opened to start the first steam line 72 from the first steam line 72. Start steam supply (ventilation) to the turbine.

According to the embodiment shown in FIG. 4, by controlling the pressure of the first steam line 72 by the second bypass valve 124, the first bypass valve 114 is released from the role of pressure control, and the pressure of the first steam line 72 is released. Regardless of this, the opening timing of the first bypass valve 114 can be determined based on the cooling fluid temperature difference ΔT of the condenser 18. Therefore, it is possible to start dumping of the excess steam using the first bypass line 110 that does not pass through the condenser 18 at an appropriate timing, and suppress an increase in the cooling fluid temperature difference ΔT of the condenser 18.

FIG. 5 is a time chart showing still another example of the operation of the first bypass valve 114 and the second bypass valve 124 under the control of the control device 90.
In the example shown in FIG. 5, after starting the boiler, first, pressure control is performed using the first bypass valve 114, and then, when the opening degree of the first bypass valve 114 reaches a specified value, a valve that performs pressure control Is switched from the first bypass valve 114 to the second bypass valve 124.
Note that the period from time t0 to time t1 in FIG. 5 is the same as that already described with reference to FIG. 3, so description thereof will be omitted here. The time chart shown in FIG. 5 is merely an example, and the pressure P of the first steam line 72, the inlet/outlet temperature difference ΔT of the cooling fluid of the condenser 18, and the first bypass valve 114 and the second bypass valve 124. The change in the valve opening may not be the same as the example shown in FIG. 5 depending on the specifications of the steam turbine facility 100.

At time t1, when the pressure in the first steam line 72 reaches a specified value, the control device 90 gives an opening degree command to the first bypass valve 114 capable of maintaining the pressure in the first steam line 72 at a target value. As a result, the control device 90 starts the pressure control of the first bypass valve 114. Note that, unlike the examples of FIGS. 3 and 4, in the example shown in FIG. 5, the second bypass valve 124 remains closed after time t1.
This pressure control is shown by the wavy line at times t1 to t6 in the time chart showing the first bypass valve opening degree in FIG. 5, and shows how the valve controls the pressure while opening and closing in small steps. Shows.

For example, the control device 90 sets the first feedback command value based on the deviation between the pressure detection value of the first steam line 72 obtained from the pressure sensor 92 shown in FIG. 2 and the target pressure value of the first steam line 72. It may be given to the bypass valve 114 as an opening degree command.

In FIG. 5, after the time t1, it is shown that the opening degree of the first bypass valve 114 is adjusted and the pressure of the first steam line 72 is maintained at the target value. In the example of FIG. 5, the target value gradually increases toward the specified pressure Pc.

At time t1, when the pressure control by the first bypass valve 114 is started and excess steam starts to be dumped into the condenser 18 through the first bypass line 110, the condenser 18 is returned as shown in FIG. The inlet/outlet temperature difference ΔT of the cooling fluid starts to rise. However, since the first bypass line 110 can dump the excess steam in the first steam line 72 to the condenser 18 without passing through the reheater 65, the first bypass valve after time t1 in FIG. The increasing rate of ΔT during the pressure control of 114 is slower than the increasing rate of ΔT during the pressure control of the second bypass valve 124 after time t1 in FIGS. 3 and 4.

After that, at time t6 when the opening degree of the first bypass valve 114 reaches the specified value A1, the control device 90 sets the valve that performs the pressure control for maintaining the pressure of the first steam line 72 at the target value to the first bypass valve 114. To the second bypass valve 124.
That is, at time t6, the control device 90 stops the pressure control by the first bypass valve 114 and maintains the opening degree of the first bypass valve 114 at the specified value A1. Instead, the control device 90 gives an opening command to the second bypass valve 124, and starts the pressure control by the second bypass valve 124 after time t6.
This pressure control is shown by a wavy line from time t6 to time tc in the time chart showing the second bypass valve opening degree in FIG. 5, and shows how the valve controls the pressure while opening and closing in small steps. Shows.

For example, during execution of pressure control by the second bypass valve 124, the control device 90 detects the pressure detection value of the first steam line 72 obtained from the pressure sensor 92 shown in FIG. 2 and the target pressure value of the first steam line 72. A feedback command value that is determined based on the deviation of 1 may be given to the second bypass valve 124 as an opening command.

In FIG. 5, after time t6, the opening degree of the first bypass valve 114 is maintained at the specified value A1, while the opening degree of the second bypass valve 124 is adjusted so that the pressure of the first steam line 72 reaches the target value. It has been shown to be maintained. The specified value A1 of the opening degree of the first bypass valve 114 may be, for example, 70% or more and 90% or less.
Since the second bypass valve 124 is opened after the time t6, the relatively high temperature excess steam is dumped through the second bypass line 120 passing through the reheater 65, so that the inlet/outlet of the cooling fluid in the condenser 18 is reached. The rising speed of the temperature difference ΔT becomes somewhat large.

After starting the pressure control of the second bypass valve 124, at time t7 when the opening degree of the second bypass valve 124 reaches the specified value A2, the opening degree of the first bypass valve 114 is made larger than the specified value A1. In the example illustrated in FIG. 5, at time t7, the control device 90 starts increasing the opening degree of the first bypass valve 114 toward full opening (100% opening degree) at the specified rate. In this way, the pressure control of the second bypass valve 124 by the control device 90 is continued while the opening degree of the first bypass valve 114 is increased (from time t7 to time t8). The specified value A2 of the opening degree of the second bypass valve 124 may be, for example, 20% or more and 40% or less.
Thus, finally, the pressure control of the second bypass valve 124 is performed with the first bypass valve 114 maintained at an opening larger than the specified value A1 (100% opening in the example shown in FIG. 5). Thus, while maintaining the pressure of the first steam line 72 at the target value, the surplus steam of the first steam line 72 can be dumped to the condenser 18 via the first bypass line 110 and the second bypass line 120. it can.

After that, after the time tc when the steam in the first steam line 72 satisfies the conditions (pressure, temperature, etc.) suitable for the ventilation of the turbine, the first steam valve 22 is opened to start the first steam line 72 from the first steam line 72. Start steam supply (ventilation) to the turbine.

According to the embodiment shown in FIG. 5, when dumping the excess steam from the first steam line 72, the first bypass valve 114 is first opened to control the pressure of the first steam line 72, and finally. Causes the second bypass valve 124 to control the pressure of the first steam line 72.
In this way, when the second bypass valve 124 is finally made to control the pressure of the first steam line 72, the first bypass valve 114 is released from the role of pressure control during that time, and the opening degree of the first bypass valve 114 is increased. Since the degree of freedom in the setting of is increased, the increase of the cooling fluid temperature difference ΔT of the condenser 18 can be suppressed.
In addition, by first performing pressure control by the first bypass valve 114, during that time, excess steam is dumped into the condenser 18 through the first bypass line 110 that does not pass through the reheater 65, and the cooling fluid of the condenser 18 is cooled. The increase in temperature difference ΔT can be further suppressed.

Furthermore, after the execution of the pressure control of the second bypass valve 124, the opening degree of the first bypass valve 114 does not suddenly increase, but the opening degree of the second bypass valve 124 reaches the specified value A2 by the pressure control. After that, the opening amount of the first bypass valve 114 is increased after the adjustment allowance of the opening amount of the second bypass valve 124 is secured, so that the valve for performing the pressure control can be smoothly switched. it can.

As described above with reference to FIGS. 3 to 5, in some embodiments, the control device 90 of the steam turbine facility 100 maintains the first steam valve 22 in the closed state, and after time t1, It is configured to adjust the opening degree of at least one of the first bypass valve 114 and the second bypass valve 124 so as to control the pressure of the first steam line 72. Further, in some embodiments, the control device 90 causes the first bypass valve 114 to be at least partially operated during at least a part of the period before the cooling fluid temperature difference ΔT of the condenser 18 reaches the allowable value ΔT1. In the opened state, the opening degree of the second bypass valve 124 is adjusted so as to control the pressure of the first steam line 72.

According to the steam turbine facility 100 having the above configuration, the pressure of the first steam line 72 is controlled by the pressure control using the first bypass valve 114 or the second bypass valve 124 before the ventilation of the first turbine 12 and the second turbine 14. The appropriate amount of excess steam that can maintain the temperature is appropriately dumped into the condenser 18 via the second bypass valve 124.
On the other hand, during execution of the pressure control using the second bypass valve 124, and during at least a part of the period before the cooling fluid temperature difference ΔT of the condenser 18 reaches the allowable value ΔT1, the first bypass valve 114 is , At least partially open. In this state, the second bypass valve 124 plays the role of control (pressure control) for appropriately maintaining the pressure of the first steam line 72, and therefore the first bypass valve 114 itself must execute pressure control. The constraint that it must be released is released, and the degree of freedom in setting the opening degree of the first bypass valve 114 is improved. Therefore, by setting the opening degree of the first bypass valve 114 to a relatively large value, the increase in the cooling fluid temperature difference ΔT of the condenser 18 due to the dump of the excess steam from the first steam line 72 is suppressed. be able to.

Next, a method for starting the GTCC plant 1 including the steam turbine facility 100 having the above configuration will be described with reference to FIGS. 6 and 7. The method for starting the GTCC plant 1 described below may be performed using the above-described control device or may be performed manually.

FIG. 6 is a flowchart showing an example of the starting procedure of the GTCC plant 1. FIG. 7 is a diagram showing an example of a startup pattern of the GTCC plant 1.

As shown in FIG. 6, first, the burner of the combustor 44 of the gas turbine 40 is ignited (step S10). As a result, the combustion gas from the combustor 44 is supplied to the turbine 46, and as shown in FIG. 7, the rotation speed 202 of the gas turbine 40 starts to increase.

When the rotation speed 202 of the gas turbine 40 reaches the rated rotation speed, as shown in FIG. 7, the generator 4 is inserted into the power system while the rotation speed 202 of the gas turbine 40 is maintained at the rated rotation speed. The load 204 of the gas turbine 40 starts to increase (step S12).

Then, the load 204 of the gas turbine 40 is gradually increased (step S14) until the load of the gas turbine 40 reaches a specified value B (for example, a predetermined load of 90% or more of the rated load). The ascent continues (NO determination in step S16).
The specified value B may be the rated load (100% load) of the gas turbine 40.

When the load of the gas turbine 40 reaches the specified value B (YES determination in step S16), while maintaining the load of the gas turbine 40 at the specified value B, the process waits until the steam condition of the steam turbine 10 is satisfied.

Since the steam turbine 10 is not ventilated until the steam conditions of the steam turbine 10 are satisfied, the surplus steam generated in the exhaust heat recovery boiler 50 using the exhaust gas from the gas turbine 40 as a heat source is various bypass lines ( 110, 120, 80) and must be dumped into the condenser 18. Therefore, in step S18, the load of the gas turbine 40 is maintained at the specified value B, while in step S20, excess steam in the first steam line 72 is dumped to the condenser 18.

The dumping of the excess steam in step S20 is performed using the first bypass valve 114 and the second bypass valve 124. Specifically, when the pressure in the first steam line 72 rises to some extent while maintaining the first steam valve 22 in the closed state, the first steam is generated by using at least one of the first bypass valve 114 and the second bypass valve 124. The pressure of the line 72 is controlled. At this time, for example, as shown in FIGS. 3 and 4, the pressure control of the first steam line 72 may be performed using only the second bypass valve 124, or, as shown in FIG. The pressure control of the first steam line 72 may be performed using both the bypass valve 114 and the second bypass valve 124. When performing the pressure control of the first steam line 72, the first bypass valve 114 is at least partially opened during at least a part of the period before the cooling fluid temperature difference ΔT of the condenser 18 reaches the allowable value ΔT1. In this state, the pressure control of the first steam line 72 is performed using the second bypass valve 124.
The detailed operations of the first bypass valve 114 and the second bypass valve 124 during the dump of the excess steam in step 20 are as shown in FIGS. 3 to 5.

When the steam condition of the steam turbine 10 is satisfied (YES determination in step S22), ventilation to the steam turbine 10 is started (step S24). As a result, as shown in FIG. 7, the rotation speed 212 of the steam turbine 10 increases to the rated rotation speed. When the rotation speed 212 of the steam turbine 10 reaches the rated rotation speed, the generator 4 of the steam turbine 10 is inserted into the power system, and the load 214 of the steam turbine 10 is started to increase (step S26).
When the gas turbine 40 and the steam turbine 10 are coaxially arranged and connected to the common input shaft of the generator 4, instead of step S26, the generator already included in the power system. A clutch may be fitted so that the mechanical energy from the steam turbine 10 is transmitted to the clutch 4.

After that, the fuel supply amount to the combustor 44 and the steam supply amount to the steam turbine 10 are increased, and the loads on the gas turbine 40 and the steam turbine 10 are increased (step S28). However, when the specified value B is the rated load itself of the gas turbine 40, it is not necessary to further increase the load of the gas turbine 40 because the gas turbine 40 has already reached the rated load at the start of step S28. ..
Finally, the loads of the gas turbine 40 and the steam turbine 10 reach the rated load (step S30).
With such a procedure, the GTCC plant 1 can be quickly started.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and includes modified forms of the above-described embodiments and combinations of these forms as appropriate.

In the present specification, an expression representing a relative or absolute arrangement such as "in a certain direction", "along a certain direction", "parallel", "orthogonal", "center", "concentric", or "coaxial". Not only represents such an arrangement strictly, but also represents a state of relative displacement or a relative displacement with an angle or distance such that the same function can be obtained.
For example, expressions such as "identical", "equal", and "homogeneous" that indicate that they are in the same state are not limited to a state in which they are exactly equal to each other. It also represents the existing state.
In addition, in the present specification, expressions that represent shapes such as a quadrangle and a cylinder do not only represent shapes such as a quadrangle and a cylinder in a geometrically strict sense, but also within a range in which the same effect can be obtained. A shape including an uneven portion, a chamfered portion, etc. is also shown.
In this specification, the expressions “comprising”, “including”, or “having” one element are not exclusive expressions excluding the existence of other elements.

1 GTCC plant 4 generator 10 steam turbine 12 first turbine 14 second turbine 16 low pressure turbine 18 condenser 20 step 22 first steam valve 24 second steam valve 26 low pressure steam valve 40 gas turbine 42 compressor 44 combustor 46 Turbine 48 Exhaust gas 50 Exhaust heat recovery boiler 52 First drum 54 Second drum 56 Low pressure drum 64 Superheater 65 Reheater 66 Superheater 72 First steam line 73 First steam discharge line 74 Second steam line 75 Second steam discharge Line 76 Low-pressure steam line 78 Water supply line 80 Low-pressure bypass line 90 Controller 92 Pressure sensor 94 Temperature sensor 96 Temperature sensor 100 Steam turbine equipment 110 First bypass line 112 First bypass passage 114 First bypass valve 120 Second bypass line 122 Second 2-branch passage 124 Second bypass valve 126 Connection line 202 Gas turbine speed 204 Gas turbine load 212 Steam turbine speed 214 Steam turbine load

Claims (14)

A first steam line connected to the inlet of the first turbine;
A first steam valve provided in the first steam line;
A second steam line connected to an inlet of a second turbine having an inlet steam pressure lower than that of the first turbine;
A reheater provided in the second steam line,
The first steam line includes a first branch passage that branches from the first steam line upstream of the first steam valve, and does not pass through the first turbine, the reheater, and the second turbine. From the first bypass line to the condenser via the first branch passage,
A second branch passage that branches from the first steam line on the upstream side of the first steam valve, without passing through the first turbine and the second turbine; and the second branch from the first steam line. A second bypass line leading to the condenser via a passage and the reheater;
A first bypass valve provided in the first branch passage,
A second bypass valve provided in the second branch passage,
A method for starting a steam turbine facility including:
A step of performing pressure control of the first steam line using at least one of the first bypass valve and the second bypass valve while maintaining the first steam valve in a closed state,
In the step of performing the pressure control, the first bypass valve is operated in at least a part of the period before the temperature difference ΔT, which is the difference between the inlet temperature and the outlet temperature of the cooling fluid of the condenser, reaches the allowable value ΔT1. A method for starting steam turbine equipment, comprising performing the pressure control using the second bypass valve in an at least partially opened state. In the step of performing the pressure control, the closed state is maintained after a predetermined time has elapsed since the second bypass valve started the pressure control and while the pressure control using the second bypass valve is being performed. The method for starting steam turbine equipment according to claim 1, wherein the first bypass valve that has been opened is opened. In the step of performing the pressure control, the opening degree of the second bypass valve is controlled so as to maintain the pressure of the first steam line at a target value, and based on the temperature difference ΔT, the first state of the closed state is changed to the first state. The method for starting a steam turbine facility according to claim 1, wherein the first bypass valve is opened. The steam according to claim 3, wherein, in the step of performing the pressure control, the first bypass valve is opened from the closed state when the temperature difference ΔT exceeds a specified value ΔT2 lower than the allowable value ΔT1. How to start turbine equipment. The step of performing the pressure control,
The first bypass valve is used to maintain the pressure of the first steam line at a target value with the second bypass valve closed until the opening degree of the first bypass valve reaches a specified value A1. And a first step of performing the pressure control,
A second step of switching the valve for performing the pressure control from the first bypass valve to the second bypass valve after the opening degree of the first bypass valve reaches the specified value A1;
The method for starting steam turbine equipment according to claim 1, further comprising: After the execution of the second step, the opening of the second bypass valve is controlled while maintaining the opening of the first bypass valve at the specified value A1, and the opening of the second bypass valve is set to the specified value A2. 6. The method for starting steam turbine equipment according to claim 5, wherein the opening degree of the first bypass valve is made larger than the specified value A1 when the above condition is reached. A gas turbine,
A boiler configured to generate steam using the heat of exhaust gas from the gas turbine,
Steam turbine equipment configured to be supplied with steam from the boiler,
A method for starting a combined cycle plant including:
A method for starting a combined cycle plant, comprising: starting the steam turbine facility by the starting method according to any one of claims 1 to 6 after increasing the load of the gas turbine to a specified value. The method for starting a combined cycle plant according to claim 7, wherein the first steam valve is opened while maintaining a high load on the gas turbine. A first steam line connected to the inlet of the first turbine;
A first steam valve provided in the first steam line;
A second steam line connected to an inlet of a second turbine having an inlet steam pressure lower than that of the first turbine;
A reheater provided in the second steam line,
The first steam line includes a first branch passage that branches from the first steam line upstream of the first steam valve, and does not pass through the first turbine, the reheater, and the second turbine. From the first bypass line to the condenser via the first branch passage,
A second branch passage that branches from the first steam line on the upstream side of the first steam valve, without passing through the first turbine and the second turbine; and the second branch from the first steam line. A second bypass line leading to the condenser via a passage and the reheater;
A first bypass valve provided in the first branch passage,
A second bypass valve provided in the second branch passage,
A control device for controlling the first bypass valve and the second bypass valve;
Steam turbine equipment including
The control device is
While maintaining the first steam valve in a closed state, it is configured to adjust the opening degree of at least one of the first bypass valve or the second bypass valve so as to control the pressure of the first steam line,
The first bypass valve is at least partially opened in at least a part of the period before the temperature difference ΔT, which is the difference between the inlet temperature and the outlet temperature of the cooling fluid of the condenser, reaches the allowable value ΔT1. The steam turbine facility is configured to adjust the opening degree of the second bypass valve so as to perform the pressure control. The control device controls the opening degree of the second bypass valve so as to maintain the pressure of the first steam line at a target value, and based on the temperature difference ΔT, changes from the closed state to the first bypass valve. 10. The steam turbine equipment according to claim 9, wherein the steam turbine equipment is configured to open. The control device is configured to open the first bypass valve from the closed state when the temperature difference ΔT exceeds a specified value ΔT2 lower than the allowable value ΔT1. Steam turbine equipment. The control device is
The first bypass valve is opened so that the pressure of the first steam line is maintained at a target value while the second bypass valve is closed until the opening degree of the first bypass valve reaches a specified value A1. Adjust the degree,
The valve for performing the pressure control is configured to be switched from the first bypass valve to the second bypass valve after the opening degree of the first bypass valve reaches the specified value A1. 9. The steam turbine facility according to item 9. The control device is
After the opening degree of the first bypass valve reaches the specified value A1, the opening degree of the second bypass valve is controlled while maintaining the opening degree of the first bypass valve at the specified value A1. The steam turbine facility according to claim 12, wherein when the opening degree of the bypass valve reaches a specified value A2, the opening degree of the first bypass valve is made larger than the specified value A1. A gas turbine,
A boiler configured to generate steam using the heat of exhaust gas from the gas turbine,
A steam turbine facility according to any one of claims 9 to 13,
Equipped with
The combined cycle plant, wherein the steam turbine facility is configured to be supplied with steam from the boiler.

Images