JPH0458003A - Turbine control device - Google Patents

Abstract

PURPOSE:To prevent fluctuation of load on a turbine during the test of opening and closing a valve by providing a load setting bias generation unit for adding a deviation signal from a computing element to a load set value at the time of testing of opening and closing the valve. CONSTITUTION:A load setting bias generation unit 31 calculates deviation of a load set value of a point where a governor valve schedule-controlled next to a governor valve to which the test of opening and closing a valve is to be conducted begins to open, from a load set value of load on a turbine. The deviation is given to an adder 13 as a bias signal GBA. When the test of valve opening and closing of a first governor valve 11a is conducted in 40% loaded state, deviation output from the load setting bias generation unit 31 becomes zero-output, and a second governor valve 11b is schedule-controlled in response to the opening and closing operations of the first governor valve 11a by a correction signal CS of a load fluctuation correcting device 18. Fluctuation of the load on the turbine during the test of valve opening and closing can thus be prevented.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention relates to a turbine control device, and more particularly, to a turbine control device that performs a valve opening/closing test of a regulating valve during operation of a turbine. Regarding.

(Prior Art) Generally, a turbine load is controlled by a plurality of control valves 11a by a turbine control device 10 as shown in FIG.

11b... is controlled by schedule control. In this schedule control, the load setting signal GB sent from the load setting device 12 is sent to an adder 13, a plurality of function generators 14a, 14b, . . . , a plurality of low value selection circuits 15a,
15b...etc., the control valve opening control signal O8], O
32..., and these control signals O8I, O82...
- controls the first regulator valve 11a from the plurality of regulator valves 11a, llb, etc., and when the first regulator valve 11a is fully open, controls the second regulator valve 11b; The third control valve 11C and the like are sequentially controlled according to a schedule.

In such a turbine, a valve opening/closing test is performed to confirm whether or not the plurality of regulating valves 11a, 11b, . . . are normally controlled to open and close during operation of the turbine. This valve opening/closing test is performed on a plurality of control valves 11a during operation of the turbine.
.

Therefore, the plurality of low value selection circuits 1.5a, 15b, . . . of this turbine control device 10 include selection switches 16a,
A test signal generator 17 is connected through the terminals 16b, . . ., and the valve opening/closing test is performed on the control valve selected by the selection switches 16a, 16b, .

By the way, since this valve opening/closing test is performed while the turbine is in operation, the turbine load may fluctuate during the valve opening/closing test. In order to prevent this fluctuation, the turbine control device 10 is provided with a negative six-wheel fluctuation correction device 18.

The second load fluctuation correction device 18 includes a turbine first stage pressure F
A pressure detector 19 for detecting SP is also provided. The first stage pressure FSP detected by this pressure detector]9 is stored in the memory section 2.
0 and is sent to the adder 21.

The storage unit 20 stores the first stage pressure FSP detected by the pressure detector 19 during the valve opening/closing test, and stores the first stage pressure FSP.
P is the reference pressure M of the turbine load during the valve opening/closing test
The signal is sent to the adder 21 as FsP. Further, the adder 2] is a reference pressure M stored in the storage section 20.
F SP and the detected pressure FSP of the pressure detector 19 detected during operation of the turbine are compared and calculated, and a deviation signal DFSP of the measured pressure is calculated. This deviation signal DFSP is sent to the adder 13 via the switch 22, and is added to the load setting signal GB as a turbine load correction signal C8, and is used as a correction control signal GD for the control valves 11a, 11b, . . .

This correction control signal GD is outputted as the regulating valve control signal ODI by the first function generator 14a when the load is 0 to 25%, and outputted by the second function generator 14b when the load is 25 to 50%. The regulating valve control signal OD2 is output, and in the same manner, when the load is 50 to 75% and 75 to 100%, the regulating valve control signals OD3 and OD4 are sequentially output by the box 3 and the fourth function generators 14c and 14d. be done.

These regulating valve control signals ODI, OD2, . . . are sent to a plurality of low value selection circuits 15a, 15b, . . . as described above. Each low value selection circuit 15a, 15b... and the regulating valve control signal O sent from each function generator 14a, 14b...
DI, OD2... and the test signal T selectively sent from the test signal generator 17 or the full-open signal generator 23.
S or the full open signal AS is selectively received, the low value signal is selected from these signals, and the low value signal is converted into the adjustment valve opening control signals O81, O82, . . .

These regulating valve opening control signals O3I, O82... are sent to the regulating valves 11a, llb..., and the regulating valves 11a, llb...
, llb, . . . are controlled in a scheduled manner as described above.

When controlling the turbine load at 40%, the load setting of 4090 loads (No. 5 GB is sent from the load setter 12 to the function generators 14a, 14b, . . . via the adder 13. This setting signal The CB sends a 250° portion of the turbine load, that is, a first regulating valve fully open signal, from the first function generator 14a to the first low value selection circuit 15a as a regulating valve control signal ODI, and the first regulating valve 11a is fully opened. On the other hand, the second function generator 14b sends a regulating valve control signal OD2 corresponding to 1596 minutes of the turbine load to the second low value selection circuit 15b.This regulating valve control signal OD
2 or the second control valve 11b, and the second control valve 11b
is controlled to an opening corresponding to 1590 minutes of turbine load.

Further, the control valve control commands OD3, OD sent from the other function generators 14c, 14d to the low value selection circuits 15c, 15d
4 is a zero output, the control valves 11c and 11d are kept fully closed. In this way, the turbine is controlled with a load of 409o by controlling the opening and closing of the two control valves 11a and llb (see FIG. 7).

Next, a case will be described in which a valve opening/closing test of the control valve 1b is performed while the turbine is in operation. First, the selection switch 16b is operated (FIG. 8(a)), the test signal generator 17 is connected to the low value selection circuit 15b, and the test signal TS having the characteristics as shown in FIG. 8(C) is set to a low value. Selection circuit 15b
sent to. Also, the switch 22 is closed (Fig. 8 (
b)) A load fluctuation correction device 18 is connected to the adder 13.

When the load fluctuation correction device 18 is connected to the adder 13, the first stage pressure FSP of the turbine is detected by the pressure detector 19, and the detected pressure FSP is stored in the storage unit 20, and is used as a reference for the turbine load 409o. Pressure MFSP is set. After this reference pressure MFSP is set, it is sent to the energizer 21 together with the first stage pressure FSP of the turbine or the reference pressure MFSP. In this adder 21, the variation in the turbine load, that is, the first stage pressure FSP of the turbine, is compared with the reference pressure MFSP, and the difference No. 15 is calculated in the adder 13.
sent to.

At the beginning of the operation of the selection switch 16b, the test signal TS is larger than the regulator control signal OD2, so the turbine load is controlled by the regulator control signal OD2, and the second regulator]]b
is maintained at the same opening as before the test started. Therefore, the first stage pressure FSP of the turbine does not change and is the same as the reference pressure MFSP, so the deviation signal DFSP is not generated.

After a short time, when the test signal TS becomes smaller than the control valve control signal OD2, the low value selection circuit 15b selects the test signal TS (FIG. 8(e)). With this selection, the control valve 11
b begins to close upon receiving the test signal TS. Control valve 11
When the pressure sensor b begins to close, the turbine load is reduced, and this reduction in the turbine load is detected by the pressure detector 19 and sent to the adder 21. The adder 21 calculates this detected pressure F.
A comparison calculation is made between SP and the reference pressure MFSP, and a deviation signal DFSP is taken out and sent to the adder 13 as a correction signal C8. This correction signal C8 is added to the load setting signal GB by an adder 13, and this added signal is used as a control correction signal GD for control valves]]b, etc. This control correction signal GD is sent to the function generators 14a, 14b, etc. (FIG. 8(d)), and is sent to the third adjustment signal GD via the third function generator 14c and the third low value selection circuit 15c. The valve 11c is controlled in the opening direction to compensate for the decrease in the turbine load (FIG. 8(f)).

In this way, the control valve 11b is fully opened, and after a predetermined period of time has elapsed, the test signal TS gradually changes to a fully open signal.
The opening degree of control valve] 1b gradually returned to the opening degree before the valve test,
Valve opening/closing test ends.

(Problems to be Solved by the Invention) As described above, in the conventional turbine control device, a valve opening/closing test of the control valve is performed while the turbine is in operation.

However, in this valve opening/closing test, since the turbine first stage pressure FSP is proportionally controlled by feedback, there may be an error between the load setting signal GB and the turbine load (Load) by the amount of the steady position deviation.

Additionally, this valve opening/closing test may cause fluctuations in the turbine load. For example, when a valve opening/closing test of the regulator valve 11b is performed at an intermediate turbine load of 40%, the regulator valve 1b is closed halfway by the test signal TS. The turbine load is reduced by this closing operation, and a correction signal C8 or a load setting signal GB is generated from the load fluctuation correction device]8.
is added to increase the correction control signal GD. but,
Even if this correction control signal CD increases, since the correction signal C8 is small, the control valve control signal OD3 has a value that opens the control valve 11c.
It does not reach.

When the control valve 11b is closed for a while and the turbine load is further reduced, the correction signal C8 from the load fluctuation correction device 18 further increases.

When this correction signal C8 exceeds a value corresponding to 1096 minutes of turbine load, the third function generator 1
The regulator valve control signal OD3 is output from 4c, and the regulator valve 11
c is now scheduled to be controlled for the first time by this control valve control signal OD3 (section d in FIG. 8(f)), and the decrease in turbine load is corrected.

Therefore, when the turbine load is 40%, the adjustment valve 1 is operated until the correction command C8 reaches 109 degrees of the turbine load.
1c is not opened and there is a problem when the turbine load is temporarily reduced. This phenomenon also causes a similar problem when testing other control valves in the middle.

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention provides a turbine load control device that does not reduce the turbine load during a valve opening/closing test of a regulating valve.

[Structure of the invention]

(Means for Solving the Problems) The present invention performs a valve opening/closing test on any one of a plurality of regulating valves that are schedule-controlled by a load setting signal during turbine operation, and also performs a valve opening/closing test on a turbine load during the valve opening/closing test. In a turbine control device designed to compensate for fluctuations, the load setting value at the point at which the regulating valve that is scheduled to be controlled next to the regulating valve that performs the valve opening/closing test starts to open is compared with the load setting value at the start of the valve opening/closing test. A load setting bias generating section is provided, which has a calculation unit that calculates a deviation, and adds the deviation signal to the load setting value when the deviation signal from the calculation unit is positive during the valve opening/closing test.

(Function) In response to the load setting signal from the load setting device, multiple control valves are scheduled and controlled to control the turbine load. During operation of the turbine, an arbitrary control valve is selected from the plurality of control valves, and a valve opening/closing test of the control valve is performed.

During a valve opening/closing test, the deviation between the load setting value immediately before the test and the load setting value at the point at which the regulating valve that is scheduled to be controlled next to the regulating valve that performs this valve opening/closing test starts to open is calculated. This deviation output is added to the load setting signal and the correction signal, and the added signal controls the regulating valve to be controlled in the next schedule in the opening direction, thereby preventing fluctuations in the turbine load during the valve opening/closing test.

(Example) An example of the turbine control device of the present invention is shown in Figs. 1 and 2 below.
The figure and FIG. 3 will be explained. The basic configuration of the turbine load control device 30 shown in FIG. 1 is almost the same as that of the conventional turbine control device 10 explained in FIG.

The turbine control device 30 of the present invention is provided with a load setting bias generating section 31. As shown in FIG. 2, this load setting bias generating section 31 generates a difference between the load setting value at the point where the regulating valve, which is scheduled to be controlled next to the regulating valve on which the valve opening/closing test is performed, starts to open and the load setting value of the turbine load. is calculated, and the deviation thereof is given to the adder 13 as a bias signal GBA.

This load setting bias generating section 31 includes a plurality of control valves 11a.
, llb, . . .
, 31b... are provided. Since these are the same, the bias generating section 31b will be explained.

The bias generating section 31b includes an adder 32b1, a positive direction limiter 33b, and a control switch 34b. The adder 32b receives the load setting signal GB and also receives the load setting signal OP3 which is the maximum control output of the regulating valve 11b, that is, the load setting value GB at the point at which the regulating valve 11c to be subjected to the next schedule control starts to open. The difference 3vas between the load setting value CB and the load setting signal OP3 is calculated. This deviation DGS is sent to the forward limiter 33b. This positive direction limiter 33b outputs the deviation output DOS when the deviation DO8, that is, the load setting signal OP3 is a positive value larger than the load setting value GB, and the deviation DGS
In other words, if the load setting command OP3 is a smaller negative value than the load setting signal GB or the same value, the deviation output DG
S or output as zero output. This forward limiter-3
The output of 3b is sent to control switch 34b.

The control switch 34b is closed when the low value selection circuit 15b selects the test signal TS and the regulating valve 11b is tested for opening and closing. Due to this closed circuit, the forward limiter 33
The deviation output DOS of b is sent to the adder 13 as a deviation correction command BAG.

In the turbine load control device 30 configured in this manner, a case will be described in which an opening/closing test is performed on the regulator valve 11b when the turbine load is controlled in step 4026 as described above.

First, operate the selection switch 16b to generate the test signal W.
17 to the low value selection circuit 15b (Fig. 4(a)).
, the switch 22 is closed and the load fluctuation correction device 18 is connected to the adder 1.
3 (Fig. 4(b)).

As a result, the test signal TS from the test signal generator 17
or is sent to the low value selection circuit 15b (FIG. 4(C)).

At this time, the pressure detector 19 or the first stage pressure FS of the turbine
P is detected, this detected pressure FSP is stored in the storage unit 17, and the reference pressure when the turbine output is 40% ~ fF
Set as sP. After that, the first stage pressure FSP detected by the pressure detector 19 and the reference pressure MFSP are added to the adder 2.
A comparison operation is performed using 1. This is similar to the conventional one.

In addition, the load setting bias generator 3] also has a load setting value GB.
and the load setting signal OP3 at the point where the control valve 11c starts to open are sent to the adder 32b, and the load setting value GB, the load setting signal OP3 and the deviation output DSG, that is, 10 of the turbine load are sent to the adder 32b.
A load of 96 minutes is calculated. This deviation output DSG is sent to the forward limiter 33b, and this deviation output DSG is sent to the control switch 34b.

The low value selection circuit 15b receives the test signal TS, and when the test signal TS becomes lower than the load setting value GB (see FIG.
e)), the regulating valve 11b begins to close. At this time, the control switch 34b is closed, and the forward limiter 33b
The deviation output DSG is added to the adder 13 (FIG. 4(d)). When this deviation output DSG is added to the load setting value GB, this addition signal becomes equal to the regulating valve control signal that just starts opening the next regulating valve 11c, and this regulating valve control signal is applied to the third function generator 15c1. 3 low value selection circuit 1
6c, and is sent to the control valve 11c of i3.

When the second control valve 11b is gradually closed in this state,
The correction signal C8 from the load fluctuation correction device 18 is added to the control valve control signal, and the third control valve 11c is gradually controlled in the direction of release (FIG. 4(f)), thereby correcting the reduction in the turbine load. . Therefore, the valve opening/closing test is performed under conditions where the turbine load does not fluctuate.

In addition, in this way, the second regulating valve 11b is fully opened, and after a predetermined period of time, the eggplant No. 1 TS gradually becomes fully open, and the opening degree of the second regulating valve 11b gradually changes from the opening before the valve test. Return to degree. Therefore, when the selection switch 16b is switched, the full open signal AS from the full open signal generator 23 is sent to the second low value selection circuit 16b, and the state before the valve test is restored.

In this way, the valve opening/closing test of the control valve 11b can be performed in a state where the turbine load does not fluctuate.

In addition, as mentioned above, in the 40% negative 4I state, the first regulating valve 1
When performing the valve opening/closing test 1a, the negative (deviation output from the Sj stage setting bias generation 31 becomes zero output, and the correction signal C8 of the load fluctuation correction device 18 causes the first control valve 1
The second control valve 11b is scheduled to be controlled in response to the opening/closing operation of the valve 1a, and a valve opening/closing test is performed while fluctuations in the turbine load are corrected by the correction signal C8.

FIG. 5 shows another modified embodiment of the turbine control device 30 shown in FIG. In this modified embodiment, instead of giving the deviation output of the load setting bias generation section 31 to the adder 13 as one signal, each bias generation section 31a
, 31b.

31 c = - deviation output DSGI, DSC2, DSC
.

3... to each function generator 14a, 14b, 14c,
Adders 35a, 35b, 35c, and
・In addition to each function generator 1.4 a, ]-4b, 14c
are controlled by the respective deviation outputs DSG1, DSC2, and DSC3. In this way, the deviation outputs DSGI, DSC2, DSC3... are sent to the function generators 14a, 14b... that should perform function conversion, and the deviation outputs DSGI, DSC2, DSG3-... are sent to the function generators 14a, 14b... Each control valve 11a, via value selection circuits 15a, 15b, .
Since it is given to llb..., the function generators 14a and 14b
. . . The control burden can be differentiated. With this control as well, the valve opening/closing test is performed without fluctuations in the turbine load, as in the previous embodiment.

〔Effect of the invention〕

The turbine control device of the present invention performs a valve opening/closing test during operation of a turbine, and provides a load setting signal at the point when the regulating valve that performs the next schedule control of the regulating valve that performs this test starts to open, and a load setting signal at the start of the test. During the valve opening/closing test, the deviation signal when this deviation signal is positive is used as the load setting value for the control valve that performs the next scheduled control.
Since the correction signal is added together with the correction signal, the correction signal accompanying the fluctuation of the turbine load is immediately applied to the control valve that performs the next schedule control, and the control valve is corrected. Therefore, fluctuations in the turbine load during the valve opening/closing test can be prevented.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the main parts of the turbine control device of the present invention, FIG. 2 is a block diagram showing the load setting bias generating section of FIG. 1, and FIGS. 3 and 4 are the device shown in FIG. 1. 5 is a block diagram showing another embodiment of the device shown in FIG. 1, FIG. 6 is a block diagram showing the main parts of a conventional turbine control device, and FIGS. FIG. 8 is an explanatory diagram illustrating the operation of the device shown in FIG. 5. 10.30.40... Turbine control device, 11a, 1
1b,] I C, 1, 1d=, control valve, 1.2,,
, load setter, 13.21.32b, 35a, 35b. 35 c-=adder, 14a, 14b, 14c. 14 d =-function generator, 15g, 15b, 15c. 15 d =-・Low value selection circuit, 16a, 16b, 16
c, 16d...Selection switch, 17...Test signal generator, 18...Load fluctuation prevention device, 19...Pressure detector, 20...Storage unit, 22...Switch, 23
...Full-open signal generator, 31...Load setting bias generation section, 31a131b, 31C...Bias generation section,
33b... Positive direction limiter - 134b... Control switch.

Claims (1)

[Claims] In a turbine control device that performs a valve opening/closing test of a plurality of regulating valves that are schedule-controlled by a load setting signal during turbine operation, and also corrects fluctuations in turbine load during the valve opening/closing test. It has a computing unit that calculates the deviation between the load setting value at the point where the regulating valve, which is scheduled to be controlled next to the regulating valve that performs the opening/closing test, starts to open and the load setting value at the time when the valve opening/closing test starts,
A turbine control device comprising: a load setting bias generating section that adds a deviation signal from the arithmetic unit to the load setting value when the deviation signal from the arithmetic unit is positive during the valve opening/closing test.