JPS63204003A - Steam generation plant output controller - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a steam generation plant output control device, and particularly to a steam generation plant output control device suitable for controlling the output of a generator.

[Conventional technology]

As the proportion of power generated by nuclear power plants in the electric power system increases, demands for load following operation are also increasing for nuclear power plants, which have traditionally been responsible for base load operation. Load following operation of a nuclear power plant is basically performed by changing the reactor output through recirculation flow rate control. At this time, it is necessary to control the core flow rate so that the transient and steep fluctuations in neutron flux are within an allowable range.

On the other hand, there is a method of load following operation in which the flow rate of turbine extraction air sent from the turbine to the feedwater heater is controlled, and the turbine steam flow rate is changed to control the generator output. This load following operation using turbine bleed air flow rate control is characterized in that the response of one generator output is improved because the turbine steam flow rate changes quickly compared to load following operation using recirculation flow rate control.

An example of a load following operation using a turbine bleed M control device that utilizes such characteristics is ``Load Immediate Control System for Boiling Water Nuclear Power Plant'' published in Japanese Patent Publication No. 13437/1983. In this example, turbine speed fluctuations are converted into load fluctuations of the nuclear power plant, and the turbine bleed air flow rate is controlled based on the load fluctuations to change the turbine steam flow rate to follow one generator output with good responsiveness.

[Problem that the invention seeks to solve]

The above conventional technology is an effective means for improving the responsiveness of one generator output compared to load following operation using recirculation flow rate control. However, for example, automatic frequency control signals from a central dispatch center
When load fluctuations continue for a certain period of time (as in the case of AFC signal), there is a problem in that the reactor output fluctuates greatly as the feed water temperature changes due to control of the turbine bleed air flow rate.

Also, when load following operation is performed by combining turbine bleed air flow control and conventional recirculation flow control.

In addition to changes in the turbine steam flow rate due to changes in the turbine bleed air flow rate, there is a problem in that the settling time of the generator output is delayed due to changes in the reactor steam flow rate due to changes in the reactor output.

An object of the present invention is to provide a nuclear reactor power control device that improves load following performance by suppressing unnecessary fluctuations in the output of a steam generator and shortening the settling time of the generator output in response to load fluctuations. [Means for solving the problem] In order to achieve the above object, for example, in response to an automatic frequency control signal, a steam generator output control device (for example, a recirculation flow control device system) is used to control steam generation. At the same time, the turbine extraction flow rate is controlled based on the deviation signal between the load setting signal, which is a sum signal of the base load signal and the automatic frequency control signal, and the generator output signal. The configuration includes a bleed valve controller.

[Effect]

Conventional recirculation flow control devices change reactor power and respond to reactor steam flow by controlling recirculation flow to automatic frequency control signals. At this time, the short-term portion of the automatic frequency control signal cannot be adequately tracked due to the response delay of the recirculation flow control system or the thermal response delay within the reactor, so the recirculation flow control is unable to follow the load for the long-term portion. Uke has.

On the other hand, since the response of the turbine steam flow rate by the turbine bleed air flow rate control is excellent in immediate response, the receiver can follow the load for the short-term portion of the automatic frequency control signal.

That is, the excess or deficiency in the response of the reactor steam flow rate due to the recirculation flow rate control with respect to the target automatic frequency control signal is compensated for by the turbine bleed air flow rate control.

As a result, the settling time of the generator output can be shortened without reducing the initial response of the generator output, and since the change in the turbine bleed air flow rate is reduced, fluctuations in the feed water temperature are suppressed, and the resulting fluctuations in the neutron flux are reduced. Necessary fluctuations can be suppressed.

〔Example〕

Hereinafter, one embodiment of the present invention will be described in detail using the drawings.

FIG. 1 shows an embodiment in which the steam generation plant output control device of the present invention is applied to a boiling water nuclear power plant. Steam generated in a reactor core 1 loaded with fuel assemblies is guided from a reactor pressure vessel (a type of steam generator) 2 to an eight turbine 5 via a main steam pipe 3 provided with a steam control valve 4 .

This steam rotates the turbine 5 and the power generation 13 connected to the turbine 5. Steam exhausted from the turbine 5 is condensed into water in a condenser 6.

This condensed water is pressurized as feed water by a condensate pump 7 and then sent to a low pressure feed water heater 8, where it is heated.The feed water heated by the low pressure feed water heater 8 is further pressurized by a water feed pump 9. After being heated to a predetermined temperature in the high-pressure feedwater heater 10, it is supplied to the reactor pressure vessel 2. The turbine bypass valve 12 is provided in a bypass pipe 12A that connects the main steam pipe 3 and the condenser 6, and is used to prevent the turbine 5 from overspeeding when the load on the turbine 5 suddenly decreases. When the reactor suddenly closes, the steam is directly bypassed to the condenser 6 in order to avoid a sudden increase in reactor pressure due to excess steam and a scram. The reactor output can be changed by controlling the recirculation flow rate with the recirculation pump 14.
This is done by adjusting the core flow rate supplied to the core. Moreover, the position of the control rods 16 in the reactor core 1 can be changed by the control rod control device 15 as needed, and the neutron flux contributing to the nuclear reaction can be controlled to change the reactor output.

The heat source of the low-pressure feedwater heater 8 and the high-pressure feedwater heater 10 uses steam extracted from the turbine 5. That is,
Although not shown, the turbine 5 is composed of a high pressure turbine and a low pressure turbine.

The steam extracted from the high-pressure turbine is sent to the high-pressure feedwater heater 10 through the high-pressure turbine oil air pipe 23, and heats the feedwater passing through the high-pressure feedwater heater 10. Although not shown, the steam extracted from the low pressure turbine is similarly sent to the low pressure feed water heater 8.

The turbine output control device 18 adds the turbine inlet pressure signal SL, turbine speed signal S2, and base load signal S6 detected by the pressure gauge 17 to the automatic frequency control signal (AFC signal) S5 from the central power dispatch center. The load setting signal S7, which is a signal, is used as an input signal, and the turbine adjustment valve opening request signal S3 is sent to the adjustment valve drive bag [20, and the load following error signal S
4 are output to the recirculation flow rate control system 19, respectively. The regulator valve drive device 2o controls the opening degree of the steam regulator valve 4 according to the steam regulator opening request signal S3, and changes the regulator valve steam flow rate (the flow rate of steam passing through the steam regulator valve 4), thereby driving the generator. Change the output. Further, the recirculation flow rate control system 19 controls the reactor output by changing the rotation speed of the recirculation pump 14 and changing the recirculation flow rate in response to the recirculation pump speed request signal S12.

In addition to the above conventional technology, the turbine bleed air control device 31 of this embodiment has the following structure. The electrical output signal S8 (measured by an electrical output detector) of the power generation 13 is converted into a generator output signal S9 as a percentage by a converter 21 whose coefficient is Ka.
is converted to Load setting signal S7 to bias signal S1
The oil valve opening request signal Sll, which is a deviation signal between the signal obtained by removing 0 and the generator output signal S9, is sent to the bleed valve controller 22. The bleed valve controller 22 controls the high pressure turbine bleed pipe 23 according to the input oil valve opening request signal Sll.
The opening degree of the turbine bleed valve 11 attached to the turbine is changed.

By controlling the turbine bleed air flow rate in this manner, the turbine steam flow rate is changed.

FIG. 2 shows the turbine output control device 18 and turbine bleed air control device 31 shown in FIG. 1 in more detail. In FIG. 2, the reactor power is controlled by the turbine power control device 18 as follows. The turbine speed deviation signal S22, which is the difference between the turbine speed signal S2 and the speed setting signal S13, is multiplied by the reciprocal of the speed regulation rate in the speed controller 25, and becomes the speed controller output signal S14.

This speed controller output signal S14 is added to the load setting signal S7 to form a load request signal S15. Further, the pressure deviation signal S17, which is the deviation between the turbine inlet pressure signal S1 and the pressure setting signal S16, is obtained by the pressure controller 24 after performing lead/lag compensation calculation and multiplication by the reciprocal of the pressure adjustment rate. This becomes a request signal 318. This load request No. 43 5
15 and the total steam flow rate request signal S18 are sent to the low value selection circuit 2.
6 input signals. However, normally, the load request signal S15 has a high value by the amount of the bias signal when setting the base load, so the total steam flow rate request signal 818 is higher than the low value selection circuit 2.
6 and becomes the turbine control valve opening request signal S3. This turbine control valve opening request signal S3, total steam flow rate request signal S18, and chattering prevention bias signal S
The deviation signal of 20 is the turbine bypass valve opening request signal S
It will be 21. Load request signal S15, total steam flow rate request signal 818, and bias signal S19 when setting base load
The deviation signal between the two is sent to the recirculation flow rate control system 19 as a load following error signal S4.

The turbine bleed air control device 31 outputs an automatic frequency control signal S5.
The load following operation is performed in combination with reactor output change using conventional recirculation flow rate control and turbine steam flow rate control using turbine bleed air flow rate control based on the deviation between load setting signal S7, generator output signal S9, and bias signal S10. This will be done.

Here, the oil/air valve controller 22 includes a function generator, a gain/phase compensator, and an oil/air valve drive device that corrects the nonlinear relationship between the opening degree of the air bleed valve 11 and the turbine bleed air flow rate passing through the air bleed valve 11. It includes.

With the above configuration, the reactor output is changed by the load setting signal S7 including the automatic frequency control signal S5, and turbine bleed air is It is possible to compensate for excess or deficiency in the turbine steam flow rate by controlling the flow rate.

FIG. 3 shows the response of the turbine bleed air control device 31 used in this embodiment to the automatic frequency control signal S5. That is, the load request signal 51 including the automatic frequency control signal S5
By controlling the recirculation flow rate by 5, the reactor power is increased and the reactor steam flow rate is increased. however,
Due to the response delay of the recirculation flow rate control device 19 and the thermal response delay within the reactor, its initial response is not sufficient, but at this time, the load setting signal S7 and the generator output signal S9
The increase in turbine steam flow rate resulting from reducing the turbine bleed air flow rate based on the deviation is added to the reactor steam flow rate. Therefore, the response to the change in generator output is not a first-order delayed response to the reactor steam flow rate, but rather a response with a shortened initial response time.

If the reactor output sufficiently responds to the automatic frequency control signal and the reactor steam flow rate increases sufficiently by recirculation flow rate control, the deviation between the automatic frequency signal S5 and the generator output signal S9 disappears, so the turbine The bleed air flow returns to steady state. For this reason, it is possible to reduce the change in the turbine bleed air flow rate, thereby suppressing the fluctuation in the feed water temperature and the accompanying fluctuation in the neutron flux. and the response of the turbine steam flow rate due to the turbine bleed air flow rate control are added, and although the initial response of the generator output signal is improved, the settling time of one generator output is delayed. In addition, the neutron flux increases due to a decrease in the feed water temperature associated with the turbine bleed air flow rate control, and when combined with the increase in neutron flux due to the recirculation flow rate control, the amount of fluctuation cannot be ignored.

As described above, according to the turbine bleed air control device 31 used in this embodiment, the recirculation flow rate is controlled in response to the automatic frequency control signal, the reactor output is changed, and the reactor steam flow rate is made to respond. The excess or deficiency in the response of the reactor steam flow rate is compensated for by turbine bleed air flow control to ensure the overall turbine steam flow rate. Therefore, the initial response time and settling time of the generator output can be shortened. In addition, since the turbine bleed air flow rate control is used as a supplementary role to the reactor output change by recirculation flow rate control, there is little effect on feed water temperature fluctuations. Therefore, unnecessary fluctuations in neutron flux can be suppressed.

FIG. 4, FIG. 5, and FIG. 6 show the turbine extraction control device 3.
1 shows another embodiment of No. 1.

The difference in Fig. 4 from Fig. 2 is that the automatic frequency signal S
5 is input to the oil valve opening degree regulator 27, and a signal obtained by performing predetermined arithmetic processing is set as the oil valve opening request signal Sll. The calculation in the oil valve opening degree regulator 27 is performed, for example, by performing an incomplete differential calculation on the automatic frequency control signal S5, and the bleed valve opening degree request signal Sll is set such that the change in the bleed air flow rate shown in FIG. 3 is obtained.

5 differs from FIG. 2 in that the speed controller output signal S14 is input to the high frequency filter 28, and the sum signal of the high frequency filter output signal 5141 and the load setting signal S7 is used as the modified load setting signal S71. Further, the deviation signal from the generator output signal S9 is used as the oil valve opening request signal Sll, and the deviation between the high frequency filter output signal 5141 and the load request signal S15 is used as the modified load request signal 5151. As a result, the turbine bleed air flow rate is controlled by the high frequency filter output signal 5141 and the load setting signal S7, and the recirculation flow rate is controlled by the low frequency component of the load setting signal S7 and the speed controller output signal SL4. Try to follow up. Note that the modified load request signal 5151 can also be obtained by applying a low frequency filter to the load request signal S15.

Furthermore, the difference between FIG. 6 and FIG. 2 is that the total steam flow rate request signal S18, which is the output of the pressure controller 24, is input to the steam flow rate regulator 29, and the corrected total steam flow rate request signal 518
1 and set the bleed valve opening request signal Sll based on the deviation from the load setting signal S7. The steam flow rate regulator 29 simulates the response of the one-generator output signal S9 by performing, for example, a -order lag calculation on the total steam flow rate request signal S18. In this case, a signal 1 obtained by performing appropriate gain/phase compensation on the load following error signal S4, for example, a signal obtained by performing a -th lag calculation, is used as the bleed valve opening request signal Sl.
It is also possible to use it as l.

In the turbine bleed air control device 31 as described above, the feed water temperature changes due to a change in the turbine bleed air flow rate. Therefore, by predicting the change in the feed water temperature from the change in the turbine bleed air flow rate and sending a compensation signal to the recirculation flow rate control, it is also possible to suppress the change in the feed water temperature or the accompanying neutron flux fluctuation. An example at this time is shown in FIG. The difference between FIG. 7 and FIG. 2 is that the recirculation flow rate compensator 30 performs gain/phase compensation on the oil valve opening request signal Sll to obtain a recirculation flow rate compensation signal 5111, and also performs load tracking. It is added to the error signal S4 to obtain a modified load following error signal 841. The recirculation flow compensator 30 is 1
For example, by performing an integral calculation on the bleed valve opening request signal Sll, an integral value of a change in the turbine bleed air flow rate can be obtained. The integral value of the change in the turbine bleed air flow rate corresponds to the change in the feed water temperature. therefore,
A recirculation flow rate compensator number 5111 is sent to the recirculation flow rate control system 19 to control the reactor output so as to suppress fluctuations in the feed water temperature.

The turbine bleed air control device 31 can also be realized by combining various embodiments in addition to the circuit for changing the set pressure of the reactor pressure. In addition, in explaining the turbine bleed air control device 31, the relationship between the turbine and the turbine bleed air flow rate was not described in detail, but considering the capacity of the turbine bleed pipe, the efficiency of the turbine, and the influence on the feed water temperature, For example, a high pressure turbine bleed pipe will be selected. Furthermore, as a basic method of changing the reactor output, control of the recirculation flow rate using the recirculation flow rate control system has been explained as an example, but there is also a method of changing the reactor output by driving control rods. Furthermore, although the nuclear reactor power control device of the present invention has been described using an example of application to a boiling water nuclear power plant,
It is clear that the invention can be applied to steam generation plants that utilize turbine oil, such as pressurized water nuclear power plants and thermal power plants.

As a method of controlling the recirculation flow rate to change the reactor output, there is a method based on the load setting signal S7 and the generator output signal S9. FIG. 8 shows an embodiment in which the recirculation flow rate control and the turbine bleed air control device 31 are used together to make the generator signal S8 follow the automatic frequency control signal S5. The feature of this embodiment is that the oil valve opening request signal Sll
The deviation between the generator compensator output signal S92 and the generator output signal S9 for which the generator output compensator 32 has performed gain/phase compensation calculation is defined as a modified generator output signal S91, and this modified generator output signal S91 and The point is that the recirculation flow rate is controlled based on the load following error signal S4, which is the deviation from the load setting signal S7.

That is, the oil valve opening request signal Sll can be considered to be a change in the turbine steam flow rate accompanied by the opening control of the turbine bleed valve 11, but the turbine bleed flow rate control is caused by, for example, a second lag in this turbine steam flow rate change. It is possible to estimate the amount of change in generator output due to Therefore, the generator output compensator signal S92, which is an estimated value of the amount of change in the generator output due to the turbine bleed air flow rate control, is obtained by using the generator output compensator 32 as a -order lag element, and the A corrected generator output signal S91, which is a change component of the generator output due to the recirculation flow rate control, can be obtained from the deviation.

As a result, single generator output control can basically be performed by changing reactor output through recirculation flow rate control, and turbine extraction flow rate control can compensate for excess or deficiency in reactor steam flow rate due to recirculation flow rate control. As a result, the load followability of the generator output can be improved.

Note that the above-mentioned turbine bleed air control device uses recirculation flow rate control and turbine bleed air flow rate control in combination in order to improve load following performance such as initial response and stabilization of the generator output to automatic frequency control signals. However, its effectiveness increases by combining it with a load fluctuation prediction device that predicts fluctuations in the automatic frequency control signal. In other words, by controlling the recirculation flow rate in response to the load fluctuation prediction signal and responding to the reactor output, the excess or deficiency in the reactor steam at that time is compensated for by increasing or decreasing the turbine steam flow rate by controlling the turbine bleed air flow rate. Load following performance is further improved. Also,
Since the reactor output is changed by recirculation flow rate control in advance of the automatic frequency control signal, changes in the turbine bleed air flow rate are reduced, which suppresses fluctuations in feed water temperature, thereby eliminating unnecessary fluctuations in neutron flux. can be suppressed.

〔Effect of the invention〕

As described above, according to the steam generation plant output control device of the present invention, for the target automatic frequency control signal,
In order to compensate for the excess or deficiency in the response of the generated steam due to steam generator output control by increasing or decreasing the turbine steam flow rate through turbine oil/air control, the stability of the generator output is improved without reducing the initial response of the generator output. can be done. Also,
Since changes in the turbine bleed air flow rate at this time can be reduced, fluctuations in the feed water temperature can be suppressed, and unnecessary fluctuations in the steam generator output accompanying this can be suppressed.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a reactor power control device which is a preferred embodiment of the present invention applied to a boiling water reactor plant;
The figure is a detailed configuration diagram of the turbine output control device and turbine extraction control device in FIG. 1, and FIG. 3 is a response characteristic diagram of each process signal in FIG. 1. 8 and 8 are configuration diagrams showing other embodiments of the turbine bleed air control device. DESCRIPTION OF SYMBOLS 10... High pressure feed water heater, 11... Turbine extraction valve, 15... Control rod control device, 18... Turbine output control device, 19... Recirculation flow rate control device, 21...
Converter, 22... Oil valve controller, 23... High pressure turbine bleed pipe. 24...Pressure controller, 25... Speed controller, 26.
...Low value selection circuit, 27...Oil valve opening regulator, 28
...High frequency filter, 29...Steam flow rate regulator, 3
0... Recirculation flow rate compensator, 31... Turbine extraction control device, hour 1% 1 (Izu?) No. 40 Fig. 6 Fig. 9 Fig. 9

Claims (1)

[Claims] 1. A turbine output control device that controls turbine output;
In a steam generation plant output control device having a steam generator output control device and a turbine bleed air control device that controls a turbine bleed air flow rate supplied to a feedwater heater, the turbine bleed air control device is configured to control a load setting signal and a generator output signal. A steam generation plant control device comprising means for controlling the turbine bleed air flow rate in order to control the generator output based on a deviation signal of the generator output. 2. The steam generation plant output control device according to claim 1, wherein the load setting signal is a sum signal of a base load signal and an automatic frequency control signal from a central power dispatch center. 3. The steam generation plant control device according to claim 1, further comprising means for controlling the turbine bleed air flow rate based on the output signal of the bleed valve opening regulator that performs incomplete differential calculation on the automatic frequency control signal. . 4. The generator output signal is a signal obtained by performing gain/phase compensation calculation on the total steam flow rate request signal which is the pressure controller output signal in the turbine output control device. Steam generation plant output control device. 5. The steam according to claim 1, further comprising means for transmitting a signal obtained by performing gain/phase compensation calculation on a deviation signal between the load setting signal and the generator output signal to a steam generator output control device. Generating plant output control device.