JP2013079580A - Method of operating combined power generating facility and combined power generating facility - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of operating a combined power generating facility diverting an existing steam turbine having higher thermal efficiency by minimum modification without changing the structure of a speed governing stage nozzle, and a combined power generating facility.SOLUTION: The method of operating the combined power generating facility includes a step of controlling the valve openings of the first and the second main steam regulating valves without opening the third main steam regulating valve and the fourth main steam regulating valves among four main steam regulating valves according to the flow rate of steam exhausted from an exhaust heat recovery boiler which generates steam by the use of the combustion exhaust gas of a gas turbine; a step of controlling the flow rate of main steam flowing into the speed governing stage nozzle by controlling the valve openings of the first and second steam regulating valves of the main steam regulating valves; a step of making the steam turbine work according to the flow rate of main steam to the speed governing stage nozzle; and a step of driving the generator by the work performed by the steam turbine.

Description

Embodiments described herein relate generally to a method for operating a combined power generation facility and a combined power generation facility.

While global warming is screaming worldwide, reducing the amount of carbon dioxide emissions in a thermal power generation facility that uses a large amount of fossil fuel and emits a large amount of carbon dioxide, which is one of the causes of global warming. There is an urgent need. As one of the countermeasures, it is conceivable to upgrade an existing steam turbine power generation facility to a combined power generation facility (hereinafter referred to as a combined power generation facility) combined with a gas turbine having higher thermal efficiency.

However, this requires enormous costs, and this is one of the major problems when converting a conventional steam turbine power generation facility into a combined power generation facility. As a countermeasure, there is a method in which existing steam turbine equipment is diverted as much as possible to reduce the construction period and construction cost.

On the other hand, the rated output of the steam turbine required for the combined power generation facility is determined depending on the rated output of the gas turbine, and when the existing steam turbine facility is upgraded to the combined power generation facility, the existing steam turbine has the optimum rated output. Often larger. Therefore, if the existing steam turbine is used as it is, the main steam flow rate to the steam turbine is less than the optimum flow rate, so that the steam turbine inlet pressure is lowered and the performance is significantly lowered.

Here, as a method of increasing the steam turbine inlet pressure, there is a method of physically closing a part of the steam passage portion of the nozzles in some or all of the paragraphs (hereinafter referred to as partial insertion). However, in this method, when the flow rate of steam flowing into the steam turbine changes, the nozzle partial insertion rate for achieving the optimum steam turbine inlet pressure changes, and when this is optimally changed, the structure of the nozzle is changed. However, the structural change of the governing stage nozzle is more expensive than the nozzles of the other paragraphs.

There is also a solution to install multiple gas turbines and exhaust heat recovery boilers to generate the optimal main steam flow rate of the steam turbine, but there are often site restrictions and even if it can be installed, There was a problem that the increase in construction costs was inevitable.

Japanese Patent Laid-Open No. 3-115707

The problem to be solved by the present invention is to provide a method for operating a combined power generation facility and a combined power generation facility that uses an existing steam turbine having high thermal efficiency by minimal modification without changing the structure of the governing stage nozzle. That is.

The operation method of the combined power generation facility according to the embodiment includes a third main steam control valve among the four main steam control valves according to the steam flow rate exhausted from the exhaust heat recovery boiler that generates steam using the combustion exhaust gas of the gas turbine. And a step of controlling the valve opening degree of the first main steam control valve and the second main steam control valve without opening the valves of the steam control valve and the fourth main steam control valve. And a step of controlling the flow rate of the main steam flowing into the governing stage nozzle by controlling the valve opening degree of the first steam control valve and the second steam control valve of the main steam control valve. And a step of causing the steam turbine to work according to the flow rate of the main steam of the governing stage nozzle. And a step of driving the generator by work performed by the steam turbine.

Moreover, the combined equipment of embodiment is 3rd among four steam control valves according to the steam flow rate exhausted from the exhaust heat recovery boiler which generates steam using the combustion exhaust gas of a gas turbine.
Means for controlling the valve opening degree of the first steam control valve and the second steam control valve without opening the valves of the steam control valve and the fourth steam control valve. And control means for controlling the flow rate of the main steam flowing into the governing stage nozzle by controlling the valve openings of the first steam control valve and the second steam control valve of the main steam control valve. Part. And a means for causing the steam turbine to work in accordance with the flow rate of the main steam of the governing stage nozzle. And a means for driving the generator by work performed by the steam turbine.

The schematic diagram of the combined power generation equipment of a 1st embodiment. Schematic which shows the nozzle governing speed control system of the high pressure steam turbine of the combined power generation equipment of 1st Embodiment. The graph which shows the valve opening degree of the main steam control valve of the operating method of the combined power generation equipment of 1st Embodiment. The flowchart figure which shows control of the main steam control valve of the operating method of the combined power generation equipment of 1st Embodiment. Schematic of the combined power generation facility of 2nd Embodiment. The graph which shows the valve opening degree of the main steam control valve of the operating method of the combined power generation equipment of 2nd Embodiment. The flowchart figure which shows control of the main steam control valve of the operating method of the combined power generation equipment of 2nd Embodiment.

  Hereinafter, embodiments will be described with reference to the drawings.

(First embodiment)
Hereinafter, an operation method of the combined power generation facility using the existing steam turbine of the first embodiment will be described with reference to the drawings. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals.

First, an outline of a combined power generation facility using the existing steam turbine of the first embodiment will be described. FIG. 1 is a schematic diagram of an operation method of the combined power generation facility according to the first embodiment.

FIG. 1 shows an example in which the main steam flow rate to the existing steam turbine is less than the optimum flow rate, and one exhaust heat generating steam for driving the steam turbine using one gas turbine and its exhaust heat. A combined power generation facility composed of a recovery boiler and an existing steam turbine is shown.

As shown in FIG. 1, the combined power generation facility of the first embodiment includes an exhaust heat recovery boiler 9 having a reheater that generates steam for driving a steam turbine from combustion exhaust gas of a gas turbine 10.
A high pressure steam turbine 1 driven by the steam of the exhaust heat recovery boiler 9, an intermediate pressure steam turbine 2 driven by the exhaust steam of the high pressure steam turbine 1 reheated by the reheater, and the exhaust of the intermediate pressure steam turbine 2 A low-pressure steam turbine 3 driven by the low-pressure mixed steam of the steam and the exhaust heat recovery boiler 9.

Here, the gas turbine 10 takes in fuel supplied from the outside and air supplied from the air compressor 11 and burns them to drive a generator 12 that is the same shaft as the shaft of the gas turbine 10 to generate power. To do. Further, the gas turbine 10 exhausts exhaust heat generated after combustion to the exhaust heat recovery boiler 9.

The exhaust heat recovery boiler 9 exchanges heat between the exhaust heat from the gas turbine 10 and the feed water or steam to the high pressure steam turbine 1, the intermediate pressure steam turbine 2, and the low pressure steam turbine 3.
Steam for driving the intermediate pressure steam turbine 2 and the low pressure steam turbine 3 is generated.

The high-pressure steam turbine 1 works first by the main steam supplied from the exhaust heat recovery boiler 9 to drive the generator 5.

The intermediate pressure steam turbine 2 is located between the high pressure steam turbine 1 and the low pressure steam turbine 2 in the steam flow, and reheats the extracted steam of the high pressure steam turbine 1 reheated by the exhaust heat boiler 9. The generator 5 is driven by working with steam.

Furthermore, the low-pressure steam turbine 3 finally works in the steam flow, and drives the generator 5 to generate electricity. The exhaust gas is introduced into a condenser 4 that condenses the exhaust gas. In addition, condenser 4
The exhaust gas from the low-pressure turbine 3 condensed in step S3 is supplied to the exhaust heat recovery boiler 9 through the condenser 4, the condensate pump 6, the ground steam condenser 7, and the feed water pump 8.

In the first embodiment, the existing steam turbine refers to a steam turbine that has already been constructed as a steam turbine power generation facility and has been operated, suspended, or abolished.

Here, the control unit 22 always measures the main steam amounts of the high-pressure steam turbine 1, the intermediate-pressure steam turbine 2, and the low-pressure steam turbine 3 as indicated by dotted arrows in FIG. 1. Furthermore, the control unit 22 is configured as a first steam control valve 20 of the high-pressure steam turbine 1 to be described later, as indicated by a dotted arrow in FIG.
The valve opening degree of the valve to the fourth valve is measured, and a control signal controlled by the first valve to the fourth valve of the main steam control valve 20 is transmitted to the high-pressure steam turbine 1.

Here, when the existing steam turbine power generation facility is used as the combined power generation facility as in the first embodiment, the exhaust heat recovery boiler 9 supplies the high pressure steam turbine 1 to drive the steam turbine. The main steam flow is less than the optimum flow. In the first embodiment, for example, it is assumed that the flow rate is ½ of the optimum flow rate. With such a main steam flow to the high-pressure steam turbine 1, the inlet pressure of the governing nozzle 21 to be described later of the high-pressure steam turbine 1 is greatly reduced, and the high-pressure steam turbine 1 and the medium-pressure steam turbine 2 that are steam turbines. The work volume of the low-pressure steam turbine 3 is reduced.

Next, a method for operating the combined power generation facility according to the first embodiment will be described. FIG. 2 is a schematic diagram illustrating a nozzle governing speed control method for the high-pressure steam turbine of the combined power generation facility according to the first embodiment, and FIG. 3 is a main steam of the operation method of the combined power generation facility according to the first embodiment. It is a graph which shows the valve opening degree of an adjustment valve.

First, the operation method of the combined power generation facility according to the first embodiment is intended for an existing steam turbine power generation facility having a nozzle governing speed control system that modifies the combined power generation facility.

Here, as shown in FIG. 2, the nozzle governing speed control system is the main steam control valve 20 of the high-pressure steam turbine 1 and the main steam first upstream of the main steam flow of the steam turbine. This is a system in which the governing stage nozzle 21 is used to adjust the main steam flow rate according to the number of opened main steam control valves 20 and the valve opening degree of each valve.

Specifically, as shown in FIG. 2, the main steam control valve 20 of the high-pressure steam turbine 1 has two valves. For example, the main steam control valve 20 includes a first valve, a second valve, a third valve, and a fourth valve from the right to the left in the drawing. The main steam flowing through the main steam control valve 20 flows into the governing stage nozzle 21 of the high-pressure steam turbine 1.

Here, the inlet of the governing stage nozzle 21 of the high-pressure steam turbine 1 is divided into four inlets so as to correspond to the number of the main steam control valves 20. The number of the inlet of the governing stage nozzle 21 of the high-pressure steam turbine 1 corresponds to the number from the first valve to the fourth valve of the main steam control valve 20 of the high-pressure steam turbine 1, and the main steam is counterclockwise. The flow of the main steam which flows into the 4th valve from the 1st valve of the control valve 20 is received.

Furthermore, depending on the flow direction of the main steam, the governing stage nozzle 21 of the high-pressure steam turbine 1 has
At the entrance GV # 1 corresponding to the first valve of the main steam control valve 20 of the high-pressure steam turbine 1, a force due to steam is generated in the arrow direction at the lower left of the drawing, and the second valve of the main steam control valve 20 of the high-pressure steam turbine 1 is generated. At the entrance GV # 2, a force due to steam is generated in the direction of the arrow at the lower right of the drawing. Similarly, at the entrance GV # 3 corresponding to the third valve of the main steam control valve 20 of the high-pressure steam turbine 1, a force due to steam is generated in the arrow direction at the upper right of the drawing, and the main steam control valve 2 of the high-pressure steam turbine 1 is generated.
At the entrance GV # 4 with respect to the fourth valve of 0, a force by steam is generated in the arrow direction at the upper left of the drawing.

Here, in the operation method of the combined power generation facility of the first embodiment, as the method for increasing the pressure at the inlet of the high-pressure steam turbine 1, the governing stage nozzle 21 is partially inserted. Here, the partial insertion is to close a part of the portion through which the steam of the governing stage nozzle 21 constituting the steam passage portion of the high-pressure steam turbine 1 flows.

Moreover, the operating method of the combined power generation equipment of 1st Embodiment is the main steam control valve 20 and the 2nd main steam control valve 21 which consist of all four valves as a method of inserting the speed control stage nozzle 21 partially.
It was decided to insert part by admission. Here, the admission means a valve opening pattern of the main steam control valve 20.

Here, with reference to FIG. 3 and FIG. 4, control of the valve opening degree of the main steam control valve of the operation method of the combined power generation facility of the first embodiment is shown. FIG. 3 is a graph showing the valve opening of the main steam control valve of the combined power generation facility operating method of the first embodiment, and FIG. 4 is the main steam control valve of the combined power generation facility operating method of the first embodiment. It is a flowchart figure which shows this control.

As shown in FIG. 3, the vertical axis in FIG. 3 represents the valve opening of the main steam control valve that is the main steam control valve 20, and the horizontal axis is the high-pressure steam turbine 1 that is an existing steam turbine after combined modification. , The loads of the intermediate pressure steam turbine 2 and the low pressure steam turbine 3 are shown.

Here, in FIG. 3, the valve opening degree of the main steam control valve 20 is controlled in accordance with the steam flow rate from the exhaust heat recovery boiler 9 that generates steam for driving the steam turbine using the gas turbine 10 and its combustion exhaust gas. By selecting and fixing an optimal valve opening pattern by the unit 22, the high pressure steam turbine 1, the intermediate pressure steam turbine 2, and the low pressure steam turbine 3, which are steam turbines, are controlled to perform efficient operation. Here, in FIG. 3, for example, since the optimal number of valve openings is two, the control method for controlling the valve openings of four of all four valves is used to open two of the four valves. The case where the operation is modified to the control method for controlling the degree simultaneously will be described below.

As shown in FIG. 3 and FIG. 4, among the main steam control valves 20, the control unit 22 uses the existing steam turbine after the combined retrofit for the first and second valve openings of the main steam control valve 20. As the main steam flow to the high-pressure steam turbine 1, medium-pressure steam turbine 2, and low-pressure steam turbine 3 increases (Yes in step 1 in FIG. 4), the valve opening is gradually increased, and the existing steam turbine When the main steam flow rate to the high-pressure steam turbine 1, the intermediate-pressure steam turbine 2, and the low-pressure steam turbine 3 is maximum (Yes in step 2 in FIG. 4), the third valve and the fourth valve of the main steam control valve 20 Is not opened, and the opening degree of the first valve and the second valve of the main steam control valve 20 is controlled to be 100% (step S3 in FIG. 4). That is, the first and second valves of the steam control valve 20 shown in FIG.
The main steam flows into the inlets GV # 1 and GV # 2 corresponding to the valves, and the steam control valve 20
The main steam does not flow into the inlets GV # 3 and GV # 4 corresponding to the third and fourth valves.

Here, the reason why the first valve and the second valve of the main steam control valve 20 are simultaneously controlled is to prevent the high-pressure steam turbine 1 from vibrating due to the force generated by the flow of the main steam.

In addition, by performing control that does not open the third valve and the fourth valve of the main steam control valve 20, a control method for controlling the valve openings of all four valves according to the main steam flow has been used so far. However, the third and fourth valves of the main steam control valve 20 are controlled not to open, and the control system controls the valve openings of only the first and second valves of the main steam control valve 20. It becomes.

In addition, as a control when the rotation speeds of the high pressure steam turbine 1, the intermediate pressure steam turbine 2, and the low pressure steam turbine 3, which are steam turbines, are varied, the control unit 21 is mainly used in the partial insertion of the governing stage nozzle 21. The valve opening degree of the first to fourth valves of the steam control valve 20 is appropriately controlled.

From the above, in the operation method of the combined power generation facility of the first embodiment, the control method for controlling the valve opening degree of all four valves of the main steam control valve 20 in the related art is the first of the main steam control valves 20. The main valves flow into the inlets GV # 3 and GV # 4 corresponding to the third and fourth valves of the steam control valve 20 shown in FIG. 2 and controlling the valve opening degree of only the first valve and the second valve of the main steam control valve 20, the steam control valve 20 shown in FIG.
It is possible to increase the inlet pressure of the high-pressure steam turbine 1 by operating the inlet GV # 1 and GV # 2 corresponding to the first valve and the second valve in a control system in which the main steam flows. . Therefore, the performance of the high-pressure steam turbine 1, the intermediate-pressure steam turbine 2, and the low-pressure steam turbine 3 that are existing steam turbines can be improved.

The number of gas turbines 10 and exhaust heat recovery boilers 9 listed in the first embodiment is only the main steam flowing into the high-pressure steam turbine 1, the intermediate-pressure steam turbine 2, and the low-pressure steam turbine 3, which are existing steam turbines. This is an example where the flow rate is less than the optimum flow rate, and the number of devices is not limited to this.

(Second Embodiment)
Hereinafter, the operation method of the combined power generation facility of 2nd Embodiment is demonstrated using drawing. In the following description of the drawings, the same or similar parts are denoted by the same or similar reference numerals.

The second embodiment differs from the first embodiment in that the gas turbine 15, the air compressor 16,
The generator 17, the exhaust heat recovery boiler 14, and the feed water pump 13 are further provided. The gas turbine 15, the air compressor 16, the generator 17, the exhaust heat recovery boiler 14, and the feed water pump 13 are not described. Since it is the same as that of 1 embodiment, the same code | symbol is attached | subjected to the same part and detailed description is abbreviate | omitted.

FIG. 5 is a schematic diagram of the combined power generation facility of the second embodiment. FIG. 5 shows an example in which the flow rate of the main steam flowing into the existing steam turbine is optimal. Two gas turbines 10 and 15 and two units that generate steam for driving the steam turbine using the exhaust heat thereof are shown. Waste heat recovery boiler 9
, 14 and a combined power generation facility composed of existing steam turbines.

Here, as shown in FIG. 5, the combined power generation facility of the second embodiment includes an exhaust heat recovery boiler 9 having a reheater that generates steam for driving the steam turbine from the combustion exhaust gas of the gas turbines 10 and 15. 14, a high pressure steam turbine 1 driven by main steam of the exhaust heat recovery boilers 9, 14, an intermediate pressure steam turbine 2 driven by exhaust of the high pressure steam turbine 1 reheated by a reheater, and an intermediate pressure steam turbine And the low-pressure steam turbine 3 driven by the low-pressure mixed steam of the exhaust heat recovery boilers 9 and 14.

Here, the gas turbines 10 and 15 include fuel and air compressors 11 and 16 supplied from the outside.
The air supplied from the engine is taken in and burned, and the generators 12 and 17 having the same shafts as the shafts of the gas turbines 10 and 15 are driven to generate power. The gas turbines 10 and 15 exhaust the exhaust heat generated after combustion to the exhaust heat recovery boilers 9 and 14.

The exhaust heat recovery boilers 9 and 14 are connected to the exhaust heat from the gas turbines 10 and 15 and the high pressure steam turbine 1.
The intermediate water steam turbine 2 and the low pressure steam turbine 3 are heat-exchanged with water or steam to generate steam for driving the high pressure steam turbine 1, the intermediate pressure steam turbine 2 and the low pressure steam turbine 3.

Further, the high-pressure steam turbine 1 drives the generator 5 by first performing work with the main steam supplied from the exhaust heat recovery boilers 9 and 14.

The intermediate pressure steam turbine 2 is located between the high pressure steam turbine 1 and the low pressure steam turbine 2 in the steam flow, and reheats the extracted steam of the high pressure steam turbine 1 reheated by the exhaust heat boiler 9. The generator 5 is driven by working with steam.

Furthermore, the low-pressure steam turbine 3 finally works in the steam flow, and drives the generator 5 to generate electricity. The exhaust gas is introduced into a condenser 4 that condenses the exhaust gas. In addition, condenser 4
The exhaust gas from the low-pressure steam turbine 3 condensed in the above is discharged into the exhaust heat recovery boilers 9 and 14 via the condenser 4 and the condensate pump 6, the ground steam condenser 7, the feed water pump 8, and the feed water pump 13.
To be supplied.

Further, the control unit 22 constantly measures the main steam amounts of the high-pressure steam turbine 1, the intermediate-pressure steam turbine 2, and the low-pressure steam turbine 3 as indicated by the dotted arrows in FIG. 5. Furthermore, the control unit 22
As shown by the dotted line arrows in FIG. 5, the valve openings of the first to fourth valves of the main steam control valve 20, which will be described later, of the high-pressure steam turbine 1 are measured, and the first valve to the main steam control valve 20 of the main steam control valve 20 are measured. A control signal for controlling the valve opening degree of the fourth valve is transmitted to the high-pressure steam turbine 1. Moreover, the control part 22 is always measuring the steam flow rate from the exhaust heat recovery boilers 9 and 14, as shown by the dotted line arrow of FIG.

Here, in the combined power generation facility using the existing steam turbine power generation facility of the second embodiment, the main steam flow rate to the high-pressure steam turbine 1 is set to an optimal flow rate. Under such main steam conditions, in the combined power generation facility operation method using the existing steam turbine of the first embodiment,
In particular, the inlet pressure of the high-pressure steam turbine 1 becomes excessively high, and may exceed the allowable pressure, resulting in equipment damage.

Next, a method for operating the combined power generation facility according to the second embodiment will be described. FIG. 6 is a graph showing the valve opening of the main steam control valve in the operation method of the combined power generation facility using the existing steam turbine of the second embodiment, and FIG. 7 is the operation of the combined power generation facility of the second embodiment. It is a flowchart figure which shows control of the main steam control valve of a method.

With reference to FIG. 6, FIG. 7, control of the valve opening degree of the main steam control valve of the operation method of the combined power generation equipment of 2nd Embodiment is shown. The vertical axis of FIG. 6 represents the valve opening degree of the main steam control valve, which is the main steam control valve 20, and the horizontal axis represents the high-pressure steam turbine 1 that is an existing steam turbine after combined modification.
, The loads of the intermediate pressure steam turbine 2 and the low pressure steam turbine 3 are shown.

Here, in FIG. 6, the valve opening degree of the main steam control valve 20 is the steam flow rate from the exhaust heat recovery boilers 9 and 14 that generate steam turbine driving steam using the gas turbines 10 and 15 and the combustion exhaust gas thereof. At the same time, the control unit 22 selects and fixes the optimum valve opening pattern so that the high-pressure steam turbine 1, the intermediate-pressure steam turbine 2, and the low-pressure steam turbine 3 that are the steam turbines are operated efficiently. Is done. Here, in FIG. 6, for example, a case where the control system is modified to control the valve opening degrees of four of all four valves will be described below.

As shown in FIGS. 6 and 7, the control unit 22 includes the main steam control valve 20 among the main steam control valves 20.
As for the valve opening degree of the first valve and the second valve, as the main steam flow rate to the high-pressure steam turbine 1, the intermediate-pressure steam turbine 2, and the low-pressure steam turbine 3 which are the existing steam turbines after the combined retrofit increases (FIG. 7 (Yes in step S11), the valve opening is gradually increased, and when the amount of steam supplied from one of the exhaust heat recovery boilers 9 and 14 reaches the rated flow rate (in step S12 in FIG. 7). Yes), control is performed so that the valve openings of the first and second valves of the main steam control valve 20 become 100% (step S13 in FIG. 7). That is, the main steam flows into the inlets GV # 1 and GV # 2 corresponding to the first valve and the second valve of the steam control valve 20 shown in FIG. Here, the reason why the first valve and the second valve of the main steam control valve 20 are simultaneously controlled is to prevent the high-pressure steam turbine 1 from vibrating due to the force generated by the flow of the main steam.

Furthermore, regarding the valve opening degrees of the third valve and the fourth valve of the main steam control valve 20, the control unit 22 has the valve openings of the first valve and the second valve of the main steam control valve 20 close to full open. After that, gradually increase the valve opening, when the amount of steam supplied from the two exhaust heat recovery boilers 9 and 14 reaches the rated flow rate.
(Yes in step S14 in FIG. 7), the third valve and the fourth valve of the main steam control valve 20 are controlled to be close to 100% (step S15 in FIG. 7). That is, the main steam flows into the inlets GV # 3 and GV # 4 corresponding to the third and fourth valves of the steam control valve 20 shown in FIG.

From the above, in the operation method of the combined power generation facility of the second embodiment, as compared with the first embodiment, the gas turbine 15 and the exhaust heat recovery boiler 14 are further provided, so that all four main steam control valves 20 can be provided. By operating at the rated output by using a control system that controls the valve opening, the inlet pressure of the high-pressure steam turbine 1 can be increased, and the inlet pressure of the high-pressure steam turbine 1 is excessive. It becomes high and it can prevent that it exceeds an allowable pressure and causes the damage of an apparatus. By such a valve opening control method, the main steam amount to the governing nozzle 21 of the high-pressure steam turbine 1 becomes an optimum flow rate, and the high-pressure steam turbine 1, the intermediate-pressure steam turbine 2, and the low-pressure steam turbine that are existing steam turbines. 3 performance can be improved.

The numbers of the gas turbines 10 and 15 and the exhaust heat recovery boilers 9 and 14 listed in the second embodiment are only the high-pressure steam turbine 1, the intermediate-pressure steam turbine 2, which are existing steam turbines,
This is an example in which the main steam flow rate flowing into the low-pressure steam turbine 3 is less than the optimum flow rate, and the number of devices is not limited to this.

According to the operation method and the combined power generation facility of the combined power generation facility of at least one embodiment described above, by adjusting the valve opening of the main steam control valve 20, the speed control stage nozzle 21 is partially inserted, thereby adjusting the speed. The structural change of the high speed nozzle 21 is not required, and the conditions for the flow rate of the steam flowing into the existing steam turbine, the high pressure steam turbine 1, the intermediate pressure steam turbine 2, and the low pressure steam turbine 3, are less than the optimum flow rate, and the optimum condition , The amount of main steam in the governing stage nozzle 22 of the high-pressure steam turbine 1 can be optimized.

Furthermore, according to the operation method and combined power generation facility of the combined power generation facility of at least one embodiment described above, the high-pressure steam turbine 1, which is an existing steam turbine having high thermal efficiency, with a minimum modification with reduced repair cost, A combined power generation facility using the intermediate-pressure steam turbine 2 and the low-pressure steam turbine 3 can be provided.

Needless to say, the present invention is not limited to the above-described embodiments and can be implemented with various modifications.

In short, the present invention is not limited to the above-described embodiments as they are, and can be embodied by modifying the components without departing from the scope of the invention in the implementation stage. Moreover, various forms can be formed by appropriately combining a plurality of constituent elements disclosed in the above embodiments. For example, some components may be omitted from all the components shown in the embodiment. Furthermore, constituent elements over different embodiments may be appropriately combined.

DESCRIPTION OF SYMBOLS 1 ... High pressure steam turbine 2 ... Medium pressure steam turbine 3 ... Low pressure steam turbine 4 ... Condenser 5 ... Generator 6 ... Condensate pump 7 ... Ground steam condenser 8 ... Feed water pump 9 ... Waste heat recovery boiler 10 ... Gas turbine 11 DESCRIPTION OF SYMBOLS ... Air compressor 12 ... Generator 13 ... Feed water pump 14 ... Exhaust heat recovery boiler 15 ... Gas turbine 16 ... Air compressor 17 ... Generator 20 ... Main steam control valve 21 ... Regulating stage nozzle 22 ... Control part

Claims (8)

Of the four steam control valves, the third steam control valve and the fourth steam control valve are selected according to the flow rate of steam exhausted from the exhaust heat recovery boiler that generates steam using the combustion exhaust gas of the gas turbine. Not opening and controlling the valve opening of the first steam control valve and the second steam control valve;
Controlling the flow rate of the main steam flowing into the governing stage nozzle by controlling the valve opening of the first steam control valve and the second steam control valve of the main steam control valve;
Working the steam turbine according to the flow rate of the main steam of the governing stage nozzle;
Driving the generator by work performed by the steam turbine;
A method for operating a combined power generation facility comprising: Of the four main steam control valves, the first steam control valve to the fourth steam control valve are used in accordance with the flow rate of steam exhausted from the plurality of exhaust heat recovery boilers that generate steam using the combustion exhaust gas of the plurality of gas turbines. Controlling the valve opening of the steam control valve of
Controlling the flow rate of the main steam flowing into the governing stage nozzle by controlling the valve opening of the first steam control valve to the fourth steam control valve of the main steam control valve;
Working the steam turbine according to the flow rate of the main steam of the governing stage nozzle;
Driving the generator by work performed by the steam turbine;
A method for operating a combined power generation facility comprising: The operation method of the combined power generation facility according to claim 1, wherein the main steam control valve is provided in a high-pressure steam turbine among the steam turbines. The method of operating a combined power generation facility according to claim 1 or 2, wherein the first steam control valve and the second steam control valve of the main steam control valve are simultaneously controlled. The operating method of the combined power generation facility according to any one of claims 1 to 4, wherein when the flow rate of steam generated from the gas turbine and the exhaust heat recovery boiler changes, the valve opening degree of the main steam control valve is changed. . 6. The inlet corresponding to the valve of the main steam control valve of the governing stage nozzle is divided counterclockwise from the first steam control valve to the fourth steam control valve. The operation method of the combined power generation facility of any one of these. Of the four steam control valves, the third steam control valve and the fourth steam control valve are selected according to the flow rate of steam exhausted from the exhaust heat recovery boiler that generates steam using the combustion exhaust gas of the gas turbine. Means for controlling the valve openings of the first steam control valve and the second steam control valve;
Means for controlling the flow rate of the main steam flowing into the governing stage nozzle by controlling the valve openings of the first steam control valve and the second steam control valve of the main steam control valve; ,
Means for causing the steam turbine to work according to the flow rate of the main steam of the governing stage nozzle;
Means for driving a generator by work performed by the steam turbine;
Combined power generation facility equipped with. Of the four main steam control valves, the first steam control valve to the fourth steam control valve are used in accordance with the flow rate of steam exhausted from the plurality of exhaust heat recovery boilers that generate steam using the combustion exhaust gas of the plurality of gas turbines. Means for controlling the valve opening of the steam control valve of
Means for controlling the flow rate of the main steam flowing into the governing stage nozzle by controlling the valve opening of the first steam control valve to the fourth steam control valve of the main steam control valve; ,
Means for causing the steam turbine to work according to the flow rate of the main steam of the governing stage nozzle;
Means for driving a generator by work performed by the steam turbine;
Combined power generation facility equipped with.

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