JPH04179803A - Turbine controller - Google Patents

Abstract

PURPOSE:To prevent any increase in turbine inlet steam pressure or nuclear reactor dome pressure for stable control by providing a signal switching portion for outputting a turbine bypass valve forcibly opening degree set value and an adder for adding the turbine bypass valve forcibly opening degree set value to a turbine bypass valve opening command value. CONSTITUTION:A signal switching portion 25 is constituted of a turbine bypass valve forcibly opening degree setter 26 and a relay contact 27. The relay contact 27 is closed on the basis of a CV closure failure signal upsilon19. Upon closure of the relax contact 27, a turbine bypass valve forcibly opening degree set value is added to a TBV opening deviation upsilon11 which is obtained by subtraction of a CV opening command value upsilon8 from a pressure control command value upsilon7 by an adder 28a, thus obtaining a final TBV opening command value upsilon13. In the case where a CV closure failure occurs during a pressure control operation, the CV closure failure detector 24 detects a CV closure failure, to forcibly open a TBV 6. Therefore, it is possible to prevent any increase in turbine inlet steam pressure or nuclear reactor dome pressure. Furthermore, a CV 6 stably controls the turbine inlet pressure or nuclear reactor dome pressure.

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a turbine control device for an atomic couplant.

(Prior Art) FIG. 3 shows an example of a turbine system in an atomic coupler.

In Figure 3, the steam generated in reactor 1 is:

It flows into the turbine 4 through a main steam stop valve (hereinafter referred to as MSV) 2 and a steam control valve (hereinafter referred to as Cv) 3, drives the turbine, and is condensed in a condenser 5.

Further, some of the steam passes through a turbine bypass valve (hereinafter referred to as TBV) 6 from before the MSV 2, bypasses the turbine 4, and flows into the condenser 5.

Normally, MSV2 is kept fully open, and the valve openings of CV3 and TBV6 are adjusted to control the turbine speed and turbine inlet steam pressure.

In this case, the turbine inlet steam pressure and turbine speed are detected by a pressure detector 7 provided before the main steam stop valve 2 and a speed detector 8 attached to the turbine shaft, respectively.

In the new type of reactor, the turbine speed and the reactor dome pressure are controlled by detecting the reactor dome pressure instead of the turbine inlet steam pressure and adjusting the valve openings of Cv3 and TBV6.

FIG. 4 shows a functional block diagram of a conventional turbine control device.

In FIG. 4, the set speed set by the speed setting device 9?
, and the actual speed S2 detected by the speed detector 8 are the adder 1.
The value is subtracted by 0, and the speed deviation y, (=y, -ya) is output as the speed control command value. On the other hand, the pressure setting device 11
The set pressure V set in and the actual pressure ys detected by the pressure detector 7 are subtracted by an adder 12, and the pressure deviation Z's (
=9s? J is taken out as a pressure command value v7 via a maximum flow rate limiter 13 that limits the reactor maximum steam flow rate.

Above speed? 3 and the pressure control command value V7 are input to the low value selector 14, and the lower command value is selected and output as the C■ opening command value V8, and the actual opening of Cv3 detected by the valve position converter 15 is The opening degree deviation V1° ("z' s v s ) is compared with the opening degree ys by an adder 16, and the opening degree deviation V1° ("z' s v s ) is used to control the valve opening degree of Cv3 through the valve drive unit 17 in accordance with the opening command value I. .

In addition, multiple Cv3s are usually installed, and all Cv3s are
The same Cv opening command value V is applied to all Cv openings, and all Cvs are controlled to the same opening degree.

On the other hand, the pressure control signal V and the Cv opening command value v0 are subtracted by an adder 18, and the difference y, -vs is output as the TBV opening deviation 'Vxx. TB■Setting opening degree V1□ set with the bypass valve opening jack setting device 19
are input to the high value selector 20, the higher value is selected and output as the TBV opening command value u13, and the actual opening υ0. of the TBV6 detected by the valve position converter 21. and adder 22
The opening deviation is compared with 1. (=su, 3-sa, 4)
controls the valve opening of the TBV 6 via the valve driver 23 in accordance with the opening command value U□.

Using the above control device, the following pressure control operation is normally performed.

In pressure control operation, the set speed is set to the maximum flow limiter 13.
The speed control command value v1 is set to be lower than the limit value of the pressure control command value 1P, and the speed control command value v1 is set to be slightly higher than the pressure control command value 1P. , I'm trying to yell.

Therefore, the pressure control command value y, = CV opening command value V, and the TBV relation deviation ui1 becomes zero, and since the bypass valve opening jack setting device 19 is normally set to zero, The high value selector 20 selects zero as the high value, and the TBV opening command value 1. Therefore, TBV6 is fully closed and pressure control is performed only by Cv3.

When the actual speed u2 increases during pressure control operation, the speed control command value S decreases, and the speed control command value U becomes lower than the pressure control command value -v7, so the cV opening command value S, becomes the speed control command The value becomes V, and the CV opening degree is controlled in the closing direction.

At this time, the pressure control command value try>cv opening command value S, so the TBV opening deviation υ, 1>o, and the TBV is controlled in the opening direction.

That is, by closing Cv3, the amount of steam flowing into the turbine 4 decreases, excess steam flows into the TBV6, the steam flow rate seen from the reactor 1 becomes constant, and the inlet steam pressure of the turbine 4 also remains constant.

As described above, during normal pressure control operation, even if the actual speed and actual pressure vary, the turbine inlet pressure is controlled to be constant by controlling the opening degrees of Cv3 and TBV6.

(Problem to be solved by the invention) As mentioned above, during normal pressure control operation, the opening degrees of Cv3 and TBV6 are controlled even if the actual speed and actual pressure change,
Since the turbine inlet steam pressure is controlled to be constant, no problem occurs, but if the actual pressure U increases due to a Cv closing failure, the following problem occurs.

Assume that one valve among multiple installed Cv3s has a closing failure.

Due to the CVI valve closing failure, the amount of steam flowing into the turbine 4 decreases and the actual pressure -v5 increases, so the CV opening command value -v8 increases and the CV opening is controlled in the opening direction.

When the actual pressure -zrS increases further, the pressure control command value?
? ＞Speed control command value υ, and CV opening command value υ
. = Speed control command value 13 = constant V, is V.

The Cv opening degree is controlled to be constant. At this time, T.B.
V opening deviation S, 1 = pressure control command value v7 - speed control command value υ, >0, and the TBV opening is controlled in the opening direction.

Even if the Cv opening degree and the TBV opening degree are controlled in the opening direction, if the actual pressure υ further increases, the pressure control command value becomes = maximum flow rate limit value, and the TBV opening degree deviation □ = maximum flow rate limit value - Speed control command value9. : - constant, and the TBV opening degree is controlled constant.

Therefore, the maximum opening degree of CV3 is suppressed by the speed control command value S8, that is, the set speed V1, and the maximum opening degree of TBV6 is suppressed by the maximum flow rate limit value - the speed control command value V3°, that is, the maximum flow rate limit value - the set speed fyu. The supply steam flow rate flowing through Cv3 and TBV6 is suppressed to the steam flow rate at the maximum opening of CV3+the steam flow rate at the maximum opening of TBV6 at the time of CV closing failure.

If all of the multiple CV3 units are normal, the amount of steam generated in reactor 1 is equal to the steam flow rate at maximum opening of CV3 during normal operation + TBV6
There is no problem because the steam flow rate at the maximum opening is established, but C
In the case of a Vl valve closing failure, the air flow rate at the maximum opening of CV3 becomes smaller than normal, and the amount of steam generated in the reactor 1 > the steam flow rate at the maximum opening of CV3 at the time of the C closing failure + the steam flow rate at the maximum opening of TBV6, resulting in a surplus. There is a risk that the steam will increase the reactor pressure and activate the reactor protection interlock, leading to a reactor scram.

The present invention detects a Cv closing failure based on the deviation between the actual opening degrees of a plurality of Cvs, forcibly closes the TBV using a Cv closing failure signal, and thereby prevents an increase in turbine inlet steam pressure or reactor dome pressure. It is an object of the present invention to provide a turbine control device that stably controls turbine inlet steam pressure or reactor dome pressure.

[Structure of the invention]

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a plurality of steam control valves that adjust the flow rate of steam generated in a nuclear reactor and guided to a turbine, and a flow rate of steam that bypasses the turbine. In a turbine control device that controls the turbine speed and turbine inlet steam pressure or reactor dome pressure by controlling the opening of the turbine bypass valve that adjusts the A steam moderation valve closing failure detection section detects a moderation valve closing failure and outputs a steam moderation valve closing failure signal, and a steam moderation valve closing failure signal output from the steam moderation valve closing failure detection section opens the turbine bypass valve. The present invention is characterized by being provided with a signal switching unit that outputs a turbine bypass valve forced opening setting to be operated, and an addition unit that adds the turbine bypass valve forced opening setting to a turbine bypass valve opening command value. .

(Function) As a result, even when Cv3 has a closing failure, TBV6 is forcibly closed, thereby preventing an increase in turbine inlet steam pressure or reactor dome pressure, and stable pressure control is performed by Cv3.

(Example) An embodiment of the present invention is shown in FIG.

FIG. 1 is the same as FIG. 4 except for the addition of a portion indicated by a two-dot chain line to the conventional FIG. 4.

In FIG. 1, the number of installed Cv3s is n.

Is the CV opening/closing failure detection 24 the first CV actual opening? ,.

2nd CV actual opening degree V□1. The n-th CV actual opening degree V1° is input, and the Cv closed failure signal V1.
Output.

The signal switching unit 25 is a turbine bypass valve forced opening setting 2
6 and a relay contact 27, and the relay contact 27 is closed by the Cv closing fault signal υ,9. When this relay contact 27 is closed, the turbine bypass valve forced opening setting is added by the adder 28a to the TBV opening deviation v11 obtained by subtracting the Cv opening command value V from the pressure control command value S, and the final value is This becomes the TBV opening command value vig.

FIG. 2 shows an embodiment of the Cv closing failure detection unit 24 when Cv3 has four valves.

The first CV actual opening degree yis and the second CV actual opening degree yit are subtracted by an adder 28, and the deviation y, -y1. is comparator 2
9, and when the deviation is equal to or greater than the specified value, the comparator 29 outputs the first/second CV abnormal signal V2°.

Similarly, the first CV actual opening degree f□ and the third CV actual opening degree yzx
is subtracted by the adder 30, the deviation V2□-pis is input to the comparator 31, and when the deviation is greater than or equal to the specified value, the comparator 31 outputs the first/third CV abnormal signal v2□.

Similarly, the first CV actual opening degree is 1. and 4th CV actual opening degree 2.
is subtracted by the adder 32, and the deviation is subtracted by the adder 32. -vl is input to the comparator 1133, and when the deviation is greater than or equal to the specified value, the comparator 33 outputs the first/fourth CV abnormal signal S.

is output.

Each abnormal signal # , , ? ,, , ? 2. is input to a 27 out of 30 pick 34 for detecting a false detection ratio due to an erroneous signal, and a 2 out of 30 pick 34 receives each abnormal signal v2°, v2□, 2. If two or more of the following are true, is the 1st CV closed failure? Outputs a 2s logic signal.

2nd CV closed failure made in the same way 35. 3rd Cv closed failure v27. 4th CV closing failure2. The logic signal is input to the OR logic 35, and the OR logic 35 outputs a Cv closed fault signal yxs.

As described above, during normal pressure control operation, TBv6 is fully closed and pressure control is performed only by Cv3.

If a Cv closing failure occurs during pressure control operation, the Cv closing failure is detected by the Cv opening/closing failure detection 24 almost at the same time as the actual pressure υ5 starts to rise, and the relay contact 27 of the signal switching unit 25 is closed. Therefore, the turbine bypass valve forced opening setting is added to the TBV opening deviation V11, resulting in the final TBV opening command value 1r1. is output and TBV6 is forcibly interrupted.

Turbine bypass valve forced opening setting 26 is set as follows: Nuclear reactor 1 generated steam amount < CV3 maximum steam flow rate at CV closing failure 10T
By setting the steam flow rate at the forced opening of BV6, all reactor generated steam can flow at Cv3 and TBV6, thereby preventing an increase in turbine inlet steam pressure or reactor dome pressure.

In addition, the amount of steam generated in the reactor 1 is the steam flow rate at the maximum opening of Cv3 at the time of a Cv closing failure, and the steam flow rate at the forced opening of TBV6, and the amount of steam generated in the reactor 1 is BV6. Since the steam flow rate is the same at forced opening, CV3 steam flow rate when Cv closed pupil is low, and dv3 maximum maximum opening low steam flow rate when Cv closed failure occurs.Cv6 follows the pressure control command value V7, that is, the actual pressure vs. to perform stable pressure control.

'If a Cv closing failure occurs during pressure control operation in this way, the Cv closing failure is detected by the Cv opening/closing failure detection 24, and the TBV 6 is forcibly closed, thereby preventing an increase in the turbine inlet steam pressure or the reactor dome pressure. Prevented.

Further, control of the turbine inlet pressure or the reactor dome pressure after the TBV is forced open is stably performed by Cv6.

【Effect of the invention〕

As explained above, according to the present invention, even if a Cv closing failure occurs, an increase in turbine inlet steam pressure or reactor dome pressure is prevented, and Cv stabilizes the turbine inlet steam pressure or reactor dome pressure. Control takes place.

[Brief explanation of the drawing]

FIG. 1 is a functional block diagram showing an embodiment of a turbine control device according to the present invention, FIG. 2 is a functional block diagram showing an embodiment of a steam control valve closing failure detection section of the present invention, and FIG. 3 is a functional block diagram showing an embodiment of a turbine control device according to the present invention. Block diagram showing the general configuration of a turbine plant, No. 4
The figure is a functional block diagram showing an example of a conventional turbine control device. 3...Steam control valve 6...Turbine bypass valve 20...High value selector 24...CV opening/closing failure detection 25...Signal switching section 28a = Adder agent Patent attorney Noriyuki Chika Figure 3 Figure 4

Claims (1)

[Claims] A turbine is manufactured by controlling the opening degrees of a plurality of steam control valves that adjust the flow rate of steam generated in the nuclear reactor and guided to the turbine, and a turbine bypass valve that adjusts the flow rate of steam that bypasses the turbine. In a turbine control device that controls speed, turbine inlet steam pressure, or reactor dome pressure, a steam regulator valve closing failure is detected based on the deviation between the actual opening degrees of the multiple steam regulator valves, and a steam regulator valve closing failure is detected. A steam moderation valve closing failure detection unit outputs a signal, and a turbine bypass valve forced opening degree setting for opening the turbine bypass valve is output based on the steam moderation valve closing failure signal output from the steam moderation valve closure failure detection unit. A turbine control device comprising: a signal switching unit for adding a turbine bypass valve forced opening setting to a turbine bypass valve opening command value;