JPH0510105A - Steam turbine controller - Google Patents

Abstract

(57) [Summary] [Purpose] In a steam turbine where the steam source is independent due to the steam pressure installed in the power plant, an appropriate amount of steam is supplied to the medium- and low-pressure turbines based on the amount of steam flowing into the high-pressure turbine. Provided is a steam turbine control device capable of supplying. [Composition] Based on the amount of steam flowing into the high-pressure turbine 7 in order to supply an appropriate amount of steam to the intermediate-pressure turbine 10 after starting the start-up of the turbine, the load of the high-pressure turbine 7 reaches a predetermined value, and entering the system Based on the amount of steam flowing into the high-pressure turbine 7 in order to supply the appropriate amount of steam to the low-pressure turbine 13, and the low-pressure steam control valve 8 for controlling the valve opening of the intermediate-pressure steam control valve 9. A steam turbine control device including a low-pressure control valve controller 11 that controls a valve opening degree of a valve 12.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a steam turbine control device installed in a power plant.

[0002]

2. Description of the Related Art Generally, a steam turbine in a thermal power plant or a nuclear power plant converts thermal energy of high temperature / high pressure steam generated in a drum into mechanical energy and transmits the power to a generator.

Further, a high pressure turbine, a medium pressure turbine and a low pressure turbine are divided according to the steam pressure of steam supplied from a common steam source, and they are connected on a single shaft. That is, the steam dewatered in the drum is further heated in the superheater, is guided by the main steam pipe, and is supplied to the high-pressure turbine through the high-pressure steam control valve.

Then, the steam discharged from the high-pressure turbine, the temperature and pressure of which have been lowered, is heated through a reheater in the boiler and is again converted into high-temperature and high-pressure steam and supplied to the intermediate-pressure turbine through the intermediate-pressure steam control valve.

Then, the steam discharged from the intermediate-pressure turbine is supplied to the low-pressure turbine through the low-pressure steam control valve, and the steam that has finished its work in each turbine enters the condenser to be cooled and condensed into a condensate pump. To return to the boiler again.

In the steam turbine power generation plant having the above-described structure, the steam control valve controllers inevitably supply the steam in a well-balanced manner. On the other hand, in a combined cycle plant in which a gas turbine and a steam turbine are connected on one axis, the steam source supplied to each turbine is independent from the steam conditions. Hereinafter, an example of the steam system of the steam turbine in the combined cycle plant is shown in FIG.

The boiler 1 is provided with a high-pressure drum 2, a medium-pressure drum 3 and a low-pressure drum 4 by the pressure of steam generated by utilizing exhaust heat of a gas turbine (not shown). The high-pressure control valve controller 5 controls the high-pressure steam control valve 6 to control the valve opening of the steam produced by the high-pressure drum 2, and supplies the high-pressure turbine 7 with the amount of steam according to the load of the high-pressure turbine 7. To do.

The medium pressure control valve controller 8 includes a medium pressure steam control valve 9
The steam discharged after driving the high-pressure turbine 7 is added to the steam generated by the medium-pressure drum 3 to control the valve opening degree, thereby controlling the amount of steam according to the load of the medium-pressure turbine 10. Then, it is supplied to the intermediate pressure turbine 10.

The low-pressure control valve controller 11 controls the low-pressure steam control valve 12 to control the valve opening of the steam produced by the low-pressure drum 4, thereby controlling the amount of steam according to the load of the low-pressure turbine 13 to control the low-pressure turbine. Supply to 13. The condenser 14 cools and condenses the steam discharged after driving the intermediate pressure turbine 10 and the low pressure turbine 13. The condensate pump 15 and the water supply pump 16 feed the water produced by the condenser 14 back to the boiler 1 again. Next, each control block diagram of each control valve controller for controlling each steam control valve to control the amount of steam supplied to each turbine is shown in FIG. FIG. 6A shows a control block diagram of the high pressure regulator valve controller 5.

The high pressure control valve controller 5 comprises a high pressure turbine steam pressure controller 17a, a high pressure turbine speed controller 18a, a high pressure turbine load controller 19a, a high pressure turbine load limiter 20a and a high pressure turbine low value selector 21a. Has been done.

The high-pressure turbine steam pressure controller 17a supplies the high-pressure turbine 7 with an amount of steam required to maintain the minimum steam pressure in the high-pressure turbine 7 when the steam pressure in the high-pressure turbine 7 becomes equal to or lower than the minimum steam pressure. Therefore, a signal for controlling the valve opening of the high pressure steam control valve 6 is output.

The high-pressure turbine speed controller 18a controls the valve opening of the high-pressure steam control valve 6 from the start of starting the turbine to reaching the rated rotational speed of the turbine to control the amount of steam supplied to the high-pressure turbine 7 to control the high-pressure turbine 7. It outputs a signal to control the rotation speed of.

The high-pressure turbine load controller 19a adjusts the valve opening of the high-pressure steam control valve 6 in order to supply the high-pressure turbine 7 with an amount of steam corresponding to the load of the high-pressure turbine 7 (for example, steam pressure, steam metal temperature, etc.). It outputs a signal that is controlled and supplied to the high-pressure turbine 7. High pressure turbine load limiter 20a
Outputs a signal having a value slightly above the actual load output from the high-pressure turbine load controller 19a.

The high-pressure turbine low value selector 21a adds a signal output from the high-pressure turbine load controller 19a and a signal output from the high-pressure turbine speed controller 18a to the high-pressure turbine steam pressure controller 17a. And the three signals output from the high-pressure turbine load limiter 20a are input, and the lowest value signal to be selected is output as the high-pressure steam control valve opening setting signal Hs. FIG. 6B shows a control block diagram of the intermediate pressure control valve controller 8.

The intermediate pressure control valve controller 8 includes an intermediate pressure turbine steam pressure controller 17b, an intermediate pressure turbine speed controller 18b, an intermediate pressure turbine load controller 19b, an intermediate pressure turbine load limiter 20b, and an intermediate pressure turbine low value. And a selector 21b.

The intermediate pressure turbine steam pressure controller 17b controls the amount of steam required to maintain the minimum steam pressure in the intermediate pressure turbine 10 when the steam pressure in the intermediate pressure turbine 10 becomes equal to or lower than the minimum steam pressure. A signal for controlling the valve opening degree of the intermediate pressure steam control valve 9 for supplying to the turbine 10 is output.

The intermediate-pressure turbine speed controller 18b controls the valve opening of the intermediate-pressure steam control valve 9 from the start of turbine startup until the turbine reaches the rated rotational speed, and controls the amount of steam supplied to the intermediate-pressure turbine 10. A signal for controlling the rotation speed of the intermediate pressure turbine 10 is output.

The intermediate pressure turbine load controller 19b supplies the amount of steam corresponding to the load of the intermediate pressure turbine 10 (eg, steam pressure, steam metal temperature, etc.) to the intermediate pressure turbine 10 so that the intermediate pressure steam control valve 9 operates. Medium pressure turbine 10 by controlling the valve opening
The signal to be supplied to is output. Medium pressure turbine load limiter 2
0b outputs a signal having a value slightly above the actual load output from the intermediate pressure turbine load controller 19b.

The intermediate pressure turbine low value selector 21b is a signal obtained by adding the signal output from the intermediate pressure turbine load controller 19b and the signal output from the intermediate pressure turbine speed controller 18b and the intermediate pressure turbine steam. The three signals output from the pressure controller 17b and the intermediate pressure turbine load limiter 20b are input, and the lowest value signal to be selected is output as the intermediate pressure steam control valve opening setting signal Ms. FIG. 6 (C) shows a control block diagram of the low pressure regulator valve controller 11.

The low pressure control valve controller 11 comprises a low pressure turbine steam pressure controller 17c, a low pressure turbine speed controller 18c, a low pressure turbine load controller 19c, a low pressure turbine load limiter 20c and a low pressure turbine low value selector 21c. Has been done.

The low-pressure turbine steam pressure controller 17c supplies the low-pressure turbine 13 with the amount of steam required to maintain the minimum steam pressure in the low-pressure turbine 13 when the steam pressure in the low-pressure turbine 13 drops to the minimum steam pressure. Therefore, a signal for controlling the valve opening of the low pressure steam control valve 12 is output.

The low-pressure turbine speed controller 18c controls the valve opening of the low-pressure steam control valve 12 from the start of starting the turbine to reaching the rated rotational speed of the turbine to control the amount of steam supplied to the low-pressure turbine 13 to control the low-pressure turbine 13. It outputs a signal to control the rotation speed of.

The low-pressure turbine load controller 19c controls the opening degree of the low-pressure steam control valve 12 in order to supply the low-pressure turbine 13 with an amount of steam corresponding to the load of the low-pressure turbine 13 (for example, steam pressure, steam metal temperature, etc.). Control the low-pressure turbine 1
The signal to be supplied to 3 is output. The low-pressure turbine load limiter 20c outputs a signal having a value slightly above the actual load output from the low-pressure turbine load controller 19c.

The low pressure turbine low value selector 21c adds a signal output from the low pressure turbine load controller 19c and a signal output from the low pressure turbine speed controller 18c to the low pressure turbine steam pressure controller 17c. And the three signals output from the low-pressure turbine load limiter 20c are input, and the lowest value signal to be selected is output as the low-pressure steam control valve opening setting signal Ls. The operation of the conventional steam turbine control device having the above configuration will be described.

First, the low-pressure steam control valve 12 and an unillustrated medium-pressure drum outlet valve are fully closed, and the medium-pressure steam control valve 9 is fully opened by the medium-pressure turbine load controller 19b. The high-pressure turbine speed controller 18a gradually opens the high-pressure steam control valve 6 to supply the high-temperature / high-pressure steam generated in the high-pressure drum 2 to the high-pressure turbine 7, whereby the high-pressure turbine 7, the intermediate-pressure turbine 10, the high-pressure turbine 10 The turbine 13 starts rotation start.

At this time, the steam discharged from the high-pressure turbine 7 is heated by a reheater (not shown) in the boiler 1 to become high-temperature and high-pressure steam again and passes through the intermediate-pressure steam control valve 9 and the intermediate-pressure turbine 10. Enter the condenser 14.

Further, in order to prevent the temperature in the low pressure turbine 13 from becoming high due to the rotation in the low pressure turbine 13 in a vacuum state, the low pressure turbine 13 is cooled in order to cool the low pressure steam control valve 12 to the minimum opening degree. Secure steam for use. After the start of the turbine, the high-pressure turbine speed controller 18a controls the valve opening of the high-pressure steam control valve 6 until the rated rotation speed is reached, that is, the rotation speed of the turbine is controlled by controlling the amount of steam flowing into the turbine. To do.

When the turbine reaches the rated rotation speed, it joins the system. During this period, the steam generated in the intermediate pressure drum 3 has only the intermediate pressure drum outlet valve (not shown) fully closed, so only the steam discharged from the high pressure turbine 7 flows into the intermediate pressure turbine 10. After the system is connected, the high-pressure turbine load controller 18a gradually opens the valve opening of the high-pressure steam control valve 6 to increase the amount of steam flowing into the high-pressure turbine 7 and increase the load on the turbine, depending on the load.

Similarly, the medium pressure steam control valve 9 and the low pressure steam control valve 12 are controlled by the medium pressure turbine load controller 19b and the low pressure turbine load controller 19c when the respective steam pressure conditions and the respective steam turbine metal temperature conditions are satisfied. The valve opening is gradually opened to allow steam to flow into the intermediate-pressure turbine 10 and the low-pressure turbine 13 to gradually apply a load to the turbine. With the above configuration, each turbine operates normally by controlling each turbine individually under each steam pressure condition.

[0030]

As described above, in the conventional steam turbine control device for controlling the steam flow rate to the steam turbine in which the steam source is independent, each steam flow rate controlling the steam flow rate to each turbine is controlled. Since the controller of the steam control valve is independent, when the conditions of the steam pressure flowing into the medium pressure and low pressure turbines are satisfied, if the timing of steam flow into the medium pressure and low pressure turbines deviates, the steam flow balance of each turbine will be disrupted. Sometimes.

In addition, during control of the high-pressure steam control valve, a control system other than the pressure control system (for example, when an abnormality occurs in the main steam pipe and the steam pressure suddenly drops, an attempt is made to restore the steam pressure before the occurrence of the abnormality). Control system, etc.), the low-pressure steam control valve or the medium-pressure steam control valve may open first and the steam flow balance of each turbine may be lost. As described above, when the steam flow balance is broken, the torque balance of each turbine is also broken, and an extra force is applied to each turbine.
The shaft was twisted.

[0032]

In order to achieve the above object, the steam turbine control device of the present invention increases the high pressure turbine to a predetermined load again after the high pressure turbine reaches the rated load and the system is connected to the medium pressure and low pressure. When the steam condition of the turbine is satisfied, the medium pressure and low pressure steam flow controller appropriately controls the amount of steam flowing into the medium pressure and low pressure turbine based on the amount of high pressure steam flowing into the high pressure turbine.

[0033]

With the above configuration, after the system is connected, the amount of steam flowing into the medium-pressure and low-pressure turbines is controlled based on the amount of steam flowing into the high-pressure turbine after the medium-pressure and low-pressure steam conditions are satisfied. By balancing the amount of steam to be generated, twisting of each shaft can be prevented.

[0034]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 5 is an example of a steam system of a steam turbine in a combined cycle plant. Boiler 1 has
A high-pressure drum 2, a medium-pressure drum 3, and a low-pressure drum 4 are installed by the pressure of steam generated by using exhaust heat of a gas turbine (not shown).

The high pressure control valve controller 5 includes a high pressure steam control valve 6
By controlling the valve opening of the steam produced by the high-pressure drum 2, the steam amount is controlled according to the load of the high-pressure turbine 7 and supplied to the high-pressure turbine 7.

The medium pressure control valve controller 8 includes a medium pressure steam control valve 9
By adding the steam discharged after driving the high-pressure turbine 7 to the steam generated in the medium-pressure drum 3 to control the opening degree of the valve, the amount of steam according to the load of the medium-pressure turbine 10 can be adjusted. It is controlled and supplied to the intermediate pressure turbine 10.

The low-pressure control valve controller 11 controls the low-pressure steam control valve 12 to control the valve opening of the steam produced in the low-pressure drum 4, thereby controlling the amount of steam according to the load of the low-pressure turbine 13 to control the low-pressure. It is supplied to the turbine 13. The condenser 14 cools and condenses the steam discharged after driving the intermediate pressure turbine 10 and the low pressure turbine 13. Condensate pump 15
The water supply pump 16 feeds back the water produced by the condenser 14 to the boiler 1 again.

Next, the medium pressure control valve controller 8 and the low pressure control valve controller 11 which control the valve openings of the medium pressure steam control valve 9 and the low pressure steam control valve 12 based on the amount of steam supplied to the high pressure turbine 7. A control block diagram of the above is shown in FIG. However, the control block diagram of the high-pressure control valve controller 5 of the present embodiment is the same as that shown in FIG. 6, and therefore its explanation is omitted here.

In the figure, the same reference numerals as those in FIG. 6 indicate the same or corresponding portions, and the different portions are the intermediate pressure control valve controller 8
And a point where a vapor flow rate controller is added to the low pressure control valve controller 11. FIG. 1A shows a control block diagram of the intermediate pressure control valve controller 8.

The intermediate pressure control valve controller 8 includes an intermediate pressure turbine steam pressure controller 17b, an intermediate pressure turbine speed limiter 18b, an intermediate pressure turbine load controller 19b, an intermediate pressure turbine load limiter 20b, and an intermediate pressure steam flow rate control. 22b and a medium pressure turbine low value selector 21b.

The intermediate-pressure turbine steam pressure controller 17b controls the amount of steam required to maintain the minimum steam pressure in the intermediate-pressure turbine 10 when the steam pressure of the intermediate-pressure turbine 10 becomes lower than the minimum steam pressure. A signal for controlling the valve opening degree of the intermediate pressure steam control valve 9 for supplying to the turbine 10 is output.

The medium-pressure turbine speed controller 18b is provided with the medium-pressure steam control valve 9 from the start of turbine startup until the rated rotation speed is reached.
A signal for controlling the rotation speed of the intermediate pressure turbine 10 is output by controlling the valve opening degree of the above to control the amount of steam supplied to the intermediate pressure turbine 10.

The intermediate-pressure turbine load controller 19b supplies the intermediate-pressure turbine 10 with an amount of steam corresponding to the load of the intermediate-pressure turbine 10 (for example, steam pressure, steam metal temperature, etc.). It outputs a signal that controls the valve opening.
The intermediate pressure turbine load limiter 20b outputs a signal having a value slightly above the actual load output from the intermediate pressure turbine load controller 19b.

After the start of the turbine, the medium pressure steam flow controller 22b determines that the load on the medium pressure turbine 10, that is, the high pressure steam flow becomes a predetermined load value {(a, 0) on the X axis in FIG. 2 (A). Corresponding to the intermediate pressure steam function generator 23b for converting the high pressure steam flow rate Hf supplied to the high pressure turbine 7 into the intermediate pressure steam flow rate value according to the set proportional function. The medium pressure steam flow rate Mf supplied from the medium pressure steam control valve 9 is subtracted from the converted steam amount to obtain the PID.
The first controller 24b outputs a signal for controlling the valve opening degree of the intermediate pressure steam control valve 9 according to the control.

The intermediate pressure turbine low value selector 21b is a medium pressure turbine low value selector 21b, which is a signal obtained by adding the output signal of the intermediate pressure turbine load controller 19b and the output signal of the intermediate pressure turbine speed controller 18b which are normally input, The lowest value signal was selected from the output signal of the turbine load limiter 20b and the output signal of the intermediate pressure turbine steam pressure controller 17b, and the steam injection timing to the intermediate pressure turbine 10 was shifted after the system was connected. In the case of entering the control system other than the steam pressure control system during the control of the high pressure steam control valve 6, the output signal of the intermediate pressure steam flow controller 22b is selected when the intermediate pressure steam control valve 9 is opened first. As the medium pressure steam control valve opening degree setting signal Ms.
Output to. FIG. 1B shows a control block diagram of the low pressure regulator valve controller 11.

The low pressure control valve controller 11 includes a low pressure turbine steam pressure controller 17c, a low pressure turbine speed limiter 18c, a low pressure turbine load controller 19c, a low pressure turbine load limiter 20c, a low pressure steam flow controller 22c and a low pressure turbine low pressure controller. It is composed of a value selector 21c.

The low-pressure turbine steam pressure controller 17c supplies the low-pressure turbine 13 with the amount of steam required to maintain the minimum steam pressure in the low-pressure turbine 13 when the steam pressure in the low-pressure turbine 13 becomes lower than the minimum steam pressure. Therefore, a signal for controlling the valve opening of the low pressure steam control valve 12 is output.

The low-pressure turbine speed controller 18c controls the low-pressure steam control valve 1 from the start of the turbine until the rated rotation speed is reached.
A signal for controlling the rotation speed of the low-pressure turbine 13 is output by controlling the valve opening degree of No. 2 to control the amount of steam supplied to the low-pressure turbine 13.

The low-pressure turbine load controller 19c adjusts the valve opening degree of the low-pressure steam control valve 12 in order to supply the low-pressure turbine 13 with an amount of steam corresponding to the load of the low-pressure turbine 13 (for example, steam pressure, steam metal temperature, etc.). Control the low-pressure turbine 1
The signal to be supplied to 3 is output. The low-pressure turbine load limiter 20c outputs a signal having a value slightly above the actual load output from the low-pressure turbine load controller 19c.

The low-pressure steam flow controller 22c controls the load on the high-pressure turbine 7 after starting the turbine, that is, the high-pressure steam flow is a predetermined load value {corresponding to (b, 0) on the X-axis in FIG. 2B}. Low pressure steam function generator 23c for converting the high pressure steam flow rate Hf supplied to the high pressure turbine 7 into a low pressure steam flow rate value according to the set proportional function after reaching PID by subtracting the low-pressure steam flow rate Lf supplied from the low-pressure steam control valve 12 from the amount
A second controller 24c that outputs a signal that controls the valve opening degree of the low-pressure steam control valve 12 according to the control.

The low pressure turbine low value selector 21c is a signal obtained by adding the output signal of the low pressure turbine load controller 19c and the output signal of the low pressure turbine speed controller 18c which are normally input, and the low pressure turbine load limiter. The lowest value signal is selected from the output signal of 20c and the output signal of the low pressure turbine steam pressure controller 17c, and when the timing of steam injection to the low pressure turbine 13 is shifted after the system is connected, or the high pressure steam control valve When the control system other than the steam pressure control system is entered during the control of 6, when the low pressure steam control valve 12 opens first, the output signal of the low pressure steam flow controller 22c is selected to set the low pressure steam control valve opening degree. The signal Ls is output to the low pressure steam control valve 12. Next, the output condition processing of the high-pressure turbine load controller 19a of the high-pressure control valve controller 5 will be described with reference to the output condition logic circuit diagram of FIG.

The first AND circuit 25 receives the system merge signal S1,
Medium pressure steam condition satisfaction signal S2, low pressure steam condition satisfaction signal S3
Is input to output the first establishment signal, and the second AND circuit 26 inputs the system merge signal S1 and the high-pressure turbine load increase permission signal S4, and outputs the second establishment signal when established. When the two signals of the first establishment signal and the second establishment signal are input to the logical sum circuit 27, the high-pressure turbine load increase permission signal S4 is output, and otherwise, the logical inversion circuit 2
8 outputs a high pressure turbine predetermined load upper limit signal S5 to the high pressure turbine load controller 19a.

With the above configuration, the high-pressure turbine load controller 19a of the high-pressure steam control valve 6 outputs the system-integrated signal S1,
Medium pressure steam condition satisfaction signal S2, low pressure steam condition satisfaction signal S3
Is not established in the first AND circuit 25, a high-pressure turbine predetermined load upper limit signal S5 for limiting the load with a predetermined load is output, and after the above condition is satisfied, a high-pressure turbine load increase permission that permits a load increase beyond the predetermined load is permitted. The signal S4 is output. The operation of the steam turbine control device of the present embodiment having the above configuration will be described.

First, the low-pressure steam control valve 12 and a medium-pressure drum outlet valve (not shown) are fully closed, and the medium-pressure steam control valve 9 is fully opened by the medium-pressure turbine load controller 19b. The high-pressure turbine speed controller 18a gradually opens the high-pressure steam control valve 6 to supply the high-temperature / high-pressure steam generated in the high-pressure drum 2 to the high-pressure turbine 7, thereby forming the high-pressure turbine 7, the intermediate-pressure turbine 10, and the low-pressure turbine. The rotation start of the turbine 13 is started. At that time, the steam discharged from the high-pressure turbine 7 is reheated by a reheater (not shown) in the boiler 1 to become high-temperature / high-pressure steam, passes through the intermediate-pressure steam control valve 9, passes through the intermediate-pressure turbine 10, and becomes a condenser. Enter 14.

Further, in order to prevent the temperature inside the low pressure turbine 13 from becoming high due to the rotation inside the low pressure turbine 13 in a vacuum state, the low pressure turbine 13 is cooled so that the low pressure steam control valve 12 is cooled to the minimum opening degree. Secure steam for use. Then, after starting the turbine, the rotation speed of the turbine is controlled by the high-pressure steam control valve 6 until the rated rotation speed is reached,
When it reaches the rated speed, it will be included in the system. During this period, the steam generated in the intermediate pressure drum 3 is only closed to the intermediate pressure drum outlet valve (not shown), so that only the steam discharged from the high pressure turbine 7 flows into the intermediate pressure turbine 10.

After the system is connected, the high-pressure turbine load controller 19a gradually opens the valve opening of the high-pressure steam control valve 6 to increase the amount of steam flowing into the high-pressure turbine 7 and increase the turbine load to a predetermined load. Let

When the load of the high-pressure turbine 7 reaches a predetermined load, the high-pressure turbine load controller 19a controls the opening degree of the high-pressure steam control valve 6 by the high-pressure turbine predetermined load upper limit signal S5 output from the logic circuit of FIG. It controls and maintains a predetermined load value.

When the medium pressure steam and low pressure steam conditions are satisfied in this state, the high pressure turbine load increase permission signal S4 is output to the high pressure turbine load controller 19a as shown in the logic circuit diagram of FIG. At the same time as the valve opening of the high-pressure steam control valve 6 is gradually opened and the amount of steam flowing into the high-pressure steam control valve 6 increases, the load on the high-pressure turbine 7 increases, and at the same time, the intermediate pressure turbine 10
Also, the amount of each steam flowing into the low-pressure turbine 13 is controlled by each control valve controller.

However, when the timing of steam injection to the medium-pressure turbine 10 and the low-pressure turbine 13 is deviated, or when the steam pressure control system is not included and the amount of steam flowing into the high-pressure turbine 7 and the medium-pressure turbine 10 and the low-pressure turbine 13 is increased. When a difference in the amount of steam occurs in the intermediate pressure steam control valve controller 8, the medium pressure steam flow controller 22b outputs the medium pressure steam control valve 9 based on the amount of steam flowing into the high pressure turbine 7. The valve of the pressure steam control valve 9 is gradually opened to supply an appropriate amount of steam to the intermediate pressure turbine 10. Similarly, the low pressure steam flow controller 22c of the low pressure control valve controller 11 adjusts the amount of steam flowing into the high pressure turbine 7. Based on the opening degree setting signal of the low pressure steam control valve 12 output based on
The valve is gradually opened to supply an appropriate amount of steam to the low pressure turbine 13.

From the above, when the steam injection timing to the intermediate pressure and low pressure turbine is shifted when the intermediate pressure and low pressure steam conditions are satisfied, or when the control system other than the steam pressure control system is entered during the control of the high pressure steam control valve. However, the signal output from the medium pressure and low pressure steam flow controller is selected by the medium pressure and low pressure turbine low value selector, and output to each steam control valve to control to output the appropriate amount of steam to the medium pressure and low pressure turbine. Continue the stable operation of the steam turbine.

As described above, since the present embodiment is constructed, the amount of steam flowing into the intermediate pressure and low pressure turbines is appropriately controlled by the signal based on the amount of steam flowing into the high pressure turbine even from the start of the turbine to the normal operation. By doing so, the steam amount of each turbine can be balanced, and the shaft twist of each turbine can be prevented.

High-pressure turbine load controller 19a of this embodiment
In the above, the condition for increasing the predetermined load value of the high-pressure turbine 7 is that the high-pressure turbine 7 is connected to the system and the three conditions of the medium-pressure steam condition and the low-pressure steam condition are satisfied. If not satisfied, it may be switched so that the low value control side limits and the high value control side controls when either steam condition is satisfied.

Further, in the present embodiment, the control of the medium pressure and low pressure steam control valves is performed based on the amount of steam supplied to the high pressure turbine, whereas as shown in FIG. Even if the steam control valve is controlled based on the pressure of the generated steam, the same effect as that of the present embodiment can be obtained. Further, even if the opening degree of the high-pressure steam control valve is used instead of the high-pressure steam flow rate, the same effect as this embodiment can be obtained.

[0064]

As described above, according to the configuration of the present invention, even when the timing at which steam flows into the medium pressure and low pressure turbines when the medium pressure and low pressure steam conditions are satisfied is supplied to the high pressure turbine. By controlling the medium and low pressure steam control valves based on the amount of steam that is supplied, an appropriate amount of steam is supplied to each turbine, the balance of each turbine is stabilized, and a highly reliable steam turbine control device that prevents shaft torsion is provided. Can be provided.

[Brief description of drawings]

FIG. 1 is a control block diagram of a medium pressure and low pressure regulator valve controller that is an embodiment of the present invention.

FIG. 2 is a set function diagram of medium-pressure and low-pressure steam function generators in the medium-pressure and low-pressure steam flow rate controllers according to an embodiment of the present invention.

FIG. 3 is an output condition block circuit diagram of a high-pressure turbine load controller of a high-pressure steam control valve that is an embodiment of the present invention.

FIG. 4 is a control block diagram of a medium pressure and low pressure regulator valve controller according to another embodiment of the present invention.

FIG. 5 is a steam system diagram of a general steam turbine power plant.

FIG. 6 is a control block diagram of a conventional high-pressure / medium-pressure / low-pressure steam flow controller.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Boiler, 2 ... High pressure drum, 3 ... Medium pressure drum, 4 ... Low pressure drum, 5 ... High pressure regulator valve controller, 6 ... High pressure steam regulator valve, 7 ... High pressure turbine, 8 ... Medium pressure regulator valve controller, 9 ... Medium pressure steam control valve, 10 ... Medium pressure turbine, 11 ... Low pressure control valve controller, 12 ... Low pressure steam control valve, 13 ... Low pressure turbine,
14 ... Condenser, 15 ... Condensate pump, 16 ... Water supply pump,
17a ... High pressure turbine steam pressure controller, 17b ... Medium pressure turbine steam pressure controller, 17c ... Low pressure turbine steam pressure controller, 18a ... High pressure turbine speed controller, 18b ... Medium pressure turbine speed controller, 18c ... Low pressure turbine speed Controller, 19a ... High-pressure turbine load controller, 19b ... Medium-pressure turbine load controller, 19c ... Low-pressure turbine load controller,
20a ... High-pressure turbine load limiter, 20b ... Medium-pressure turbine load limiter, 20c ... Low-pressure turbine load limiter, 21
a ... high pressure turbine low value selector, 21b ... medium pressure turbine low value selector, 21c ... low pressure turbine low value selector, 22b ...
Medium pressure steam flow controller, 22c ... Low pressure steam flow controller, 2
3b ... Medium pressure steam function generator, 23c ... Low pressure steam function generator, 24b ... First controller, 24c ... Second controller, 25 ...
1st logical product circuit, 26 ... 2nd logical product circuit, 27 ... Logical sum circuit, 28 ... Logical inversion circuit, Hs ... High pressure steam control valve opening setting signal, Ms ... Medium pressure steam control valve opening setting signal, Ls …
Low-pressure steam control valve opening setting signal, S1 ... System input signal, S
2 ... Medium pressure steam condition satisfaction signal, S3 ... Low pressure steam condition satisfaction signal, S4 ... High pressure turbine load increase permission signal, S5 ... High pressure turbine predetermined load upper limit signal, Hf ... High pressure steam flow rate, Mf
... Medium pressure steam flow rate, Lf ... Low pressure steam flow rate, Hp ... High pressure steam pressure, Mp ... Medium pressure steam pressure, Lp ... Low pressure steam pressure.

Claims (1)

Claim: What is claimed is: 1. A steam turbine control device for a steam turbine comprising a high-pressure turbine, a medium-pressure turbine, and a low-pressure turbine, which are divided by the steam pressures supplied from independent steam sources, respectively. A medium-pressure steam control valve for adjusting the amount of medium-pressure steam flowing into the medium-pressure turbine by following the amount of high-pressure steam flowing into the high-pressure turbine when the high-pressure turbine reaches a predetermined load and each steam condition of the medium-pressure and low-pressure turbine is satisfied. And a medium-pressure steam flow controller that outputs a signal that controls the valve opening of the low-pressure steam control valve that adjusts the amount of low-pressure steam that flows into the low-pressure turbine by following the high-pressure steam flow that flows into the high-pressure turbine. And a low pressure steam flow controller that outputs a signal for controlling the steam turbine.