JPH0410039B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to an output control device for a nuclear power plant. [Technical Background of the Invention] In general, the output control device of a boiling water nuclear power plant includes a control rod drive system that drives control rods in the reactor core to be inserted and withdrawn, and a recirculation flow rate that controls the amount of cooling water flowing through the reactor core. There is a control system and a turbine control system (EHC) that controls the flow rate of steam flowing into the turbine. Among these, the control rod drive system and the recirculation flow control system control the reactor output, and the turbine control system controls the output of the generator by controlling the steam flow rate to the turbine. FIG. 1 shows the configuration of a conventional output control device for a boiling water nuclear power plant. There is a reactor core 2 inside the reactor pressure vessel 1.
is provided and contains a coolant (soft water). Two systems of recirculation piping 3A, 3B are provided outside the pressure vessel 1, and the jet pumps 5... The reactor core 2 is configured to supply coolant from above and recirculate the coolant to the core 2. The amount of coolant recirculated through the core 2 is controlled according to the rotational speed of the recirculation pumps 4A, 4B. Further, the rotational speed of the recirculation pumps 4A, 4B is controlled by adjusting the output frequency of the frequency power supply devices 7A, 7B that supply electric power to the electric motors 6A, 6B for driving the pumps. This frequency adjustment is then performed by the recirculation flow rate controller 8. On the other hand, in addition to fuel rods (not shown), a plurality of control rods 9 are inserted into the reactor core 2 from below, and a plurality of neutron detectors 10 for detecting the core output are provided. The control rods 9 are driven up and down by a control rod drive mechanism 11 provided below the pressure vessel 1, and are inserted into and pulled out of the reactor core 2. Main steam generated in the nuclear reactor is sent out from the main steam pipe 12. A turbine main steam stop valve 13 and a steam control valve 14 are inserted into the main steam pipe 12 . The main steam sent out from the main steam pipe 12 is then supplied to the turbine 15.
to drive. The turbine 15 also drives a generator 16, the electrical output of which is supplied to the power system through a power transmission line 17. The steam pressure at the turbine inlet is measured by a pressure detector 18 installed upstream of the turbine main steam stop valve 13.
The detected pressure is converted into an electrical signal and compared with a pressure setting value of the turbine control system (EHC) 19. When the detected pressure is higher than the pressure setting value, the opening degree of the turbine bypass valve 20 is increased to increase the bypass flow rate from the main steam pipe 12 to the condenser 21. On the other hand, the opening degree of the steam control valve 14 is determined by the load setting device 22 of the EHC 19.
It is controlled according to the deviation of a generator output detector 25 that detects power from a voltage transformer 23 and a current transformer 24 provided on the power transmission line 17. Note that the generator output detector 25 can also replace the pressure after the turbine inlet first stage blade. [Problems with background technology] Output control from reactor startup to rated power operation is performed by the control rod drive system up to approximately 65% of the rated power, and thereafter by the recirculation flow control system. . Furthermore, since the control rod drive system and the recirculation flow control system are operated by separate operators,
With the introduction of so-called PCIOMR operation, which requires a large number of operators and also prevents fuel damage due to interaction between fuel pellets and fuel cladding,
There was a problem that required a high degree of skill on the part of the operator. [Object of the Invention] The present invention was made based on the above circumstances, and its purpose is to automate output control to reduce the burden on the operator, reduce fuel consumption, and reduce fuel adjustment time. An object of the present invention is to provide an output control device for a nuclear power plant that can reduce the time required. [Summary of the invention] The output control device for a nuclear power plant according to the present invention includes:
A recirculation flow rate control system that controls the rotational speed of the recirculation pump, a reactor power calculator that calculates the reactor power by inputting information that determines the power in the reactor pressure vessel, and this reactor power calculator. an output setting calculator that calculates a fluctuation rate of the power plant output by inputting the output signal of the power generator and the setting signal from the power plant output setting device; and an operation pattern selection device that switches the operating pattern in the output setting calculator; a control rod density setting calculator that determines a control rod control procedure based on the output signal of the output setting calculator and the control rod position signal; the output signal of the control rod density setting calculator and the output of the output setting calculator; a status display device that displays the output control status of the power plant based on the signal;
a control mode selection device for switching the output control mode to a control rod operation mode or a recirculation flow rate control mode;
a recirculation flow rate setting calculator that adjusts the set value of the recirculation flow rate control system based on the output signal of the output setting calculator and the recirculation flow rate signal; and a reactor output based on the output signal of the reactor output calculator. The present invention is characterized in that it includes a turbine output setting calculator that adjusts the output setting value of the turbine in accordance with the rise. [Embodiment of the Invention] An embodiment of the present invention will be described below with reference to FIGS. 2 and 3. Figures 2 and 3 show the configuration of the output control device of a nuclear reactor power plant.The boiling water reactor plant has the same configuration as Figure 1, so the same parts are given the same reference numerals. Detailed explanation will be omitted. 30 in the figure indicates the recirculation flow rate control system, and 31 in the figure
is the main controller of this recirculation flow rate control system 30 .
The output signal of this main control system 31 passes through a speed limiter 32, and then passes through two automatic/manual switching systems 33A and 33B.
becomes the input. The speed limiter 32 is the reactor power
It allows a signal of speed equivalent to 75% or higher to pass through, and the automatic/manual switchers 33A and 33B are used to select between automatic and manual mode. When manual mode is selected, the operator can operate the adjustment dial directly, or can also operate the adjustment dial using electrical signals from the outside. Therefore, first, the operator gradually increases the speed of the recirculation pumps 4A and 4B to the limit value of the speed limiter 32 in manual mode, and then
When switches A and 33B are switched to automatic mode, automatic/manual switchers 33A and 33B are controlled by a signal from main controller 31. Each automatic/manual switch 33
The output signals of A and 33B are the speed control devices 34A and 3
4B, it becomes an input to the variable frequency power supply devices 7A, 7B, and is further output to the electric motors 6A, 6B to control the rotational speed of the recirculation pumps 4A, 4B. On the other hand, numeral 41 in the figure is a reactor output calculator, and this calculator 41 collects information that determines the output inside the reactor pressure vessel 1, such as neutron flux detectors 10 inside the reactor core 2, main steam flow rate detectors ( input signals from a thermal output detector (not shown), etc.
Outputs calculation results according to the reactor output status.
This output signal becomes an input to the output setting calculator 42, the reactor output detector 43, and the turbine output setting calculator 44. Note that 43A and 43B in the figure are output contacts of the reactor power detector 43. The output setting calculator 42 receives a request signal from the power plant output setting device 47 and the reactor output calculator 4 by the closing operation of the output control pattern switching contacts 45 and 46.
At the same time, a limit value for the load increase rate of the reactor and turbine is calculated. The calculation results are then sent to the recirculation flow rate setting calculator 48, the control rod density setting calculator 49, and the status display controller 50.
Output each. Further, the control rod density setting calculator 49 compares the position signals of the control rods 9 . . . with the output from the output setting calculator 42, and outputs the result to the status display control device 50. Therefore, this status display control device 50 inputs the signal from the output setting calculator 42 and the signal from the control rod density setting calculator 49, and displays the status of the control rods 9 in the reactor core 2, reactor output information, etc. on the display 51. to be displayed. Accordingly, the operator can operate the control rod position monitoring device (not shown), the main controller 31, the automatic/manual switchers 33A, 33B, etc. according to the information on the display 51. That is, the status display control device 50 and the display 51 constitute a status display device that displays the control details of the reactor power calculator 41. On the other hand, detection signals from the flow rate detectors 53A, 53B provided in the recirculation pipes 3A, 3B are inputted to the recirculation total flow rate calculator 54.
A recirculation total flow rate signal from the recirculation flow rate setting calculator 48 is outputted to the recirculation flow rate setting calculator 48. Therefore, this recirculation flow rate setting calculator 48 compares the reactor output request signal from the output setting calculator 42 and the recirculation total flow rate signal, and outputs the deviation amount as a pulse signal. If the reactor output is, for example, less than 75% of the target output, the relay contact 55 is closed, and the automatic/manual switch 33 is activated by the output signal of the recirculation flow rate setting calculator 48.
The output signal adjustment dials of A and 33B are now controlled, and if the reactor output is 75% or more of the target output, the relay contact 56 is closed, and the output signal of the recirculation flow rate setting calculator 48 is used to control the main controller. 31 output signal adjustment dial is controlled. When the mode switching contacts 57, 58A, and 58B of the main controller 31 and automatic/manual switchers 33A and 33B are open, the manual mode is selected and the output signal adjustment dial can be externally controlled. . In this way, the main controller 31
It is also possible to raise each output signal adjustment dial of the automatic/manual switching devices 33A and 33B by one step. The output is increased by operating the control rods until the reactor output reaches 65% of the target output, and then the output is increased by controlling the recirculation flow rate until the target output is reached. This is performed by one output control pattern switching signal contact 45 provided in the arithmetic unit 42. The other contact 46 is for PCIOMR operation, and even if the reactor output is less than 65% of the target output, the recirculation flow control system 30 is used to increase the output, and control rod operation and recirculation flow control are performed several times. By repeating the process once at a time, the output can be increased to the target output. FIG. 3 shows the configuration of the output selection device. In the figure, 59 and 60 are control mode selection switches that are alternatively closed, and 61 and 62 are operation pattern selection switches that are alternatively closed. It's a switch. When one control mode selection switch 59 is closed, the control rod operation mode is selected, and when the other control mode selection switch 60 is closed, the recirculation flow rate control mode is selected. When one driving pattern selection switch 61 is closed, the first output control mode is selected, and when the other driving pattern selection switch 62 is closed, the second output control mode is selected. In the figure, 64 and 65 are contacts that are closed when the nuclear reactor system is normal, and 66 and 67 in the figure are contacts that are closed when the turbine generator system is normal. Furthermore, 68 in the figure is a contact that is closed when the control rod manual control system is normal, and 69 in the figure is a contact that is closed when the control rod position indicating system is normal. 70 in the figure is a relay for setting the output control mode to the control rod operation mode, and the contact 70A of this relay 70 is connected to the output setting calculator 4.
2 and the control rod density setting calculator 49. In the figure, 71 and 72 are also contacts of the reactor power detector 43, and the contact 71 is connected to the target power 75 when the reactor power is the target power.
% or less, and the contact 72 closes when the reactor power is between 75% and 100% of the target power. In addition, 73 in the figure is one automatic/manual switch 33A.
is a contact that is closed when in manual mode, and 74 in the figure is a contact that is closed when the other automatic/manual switch 33B is in manual mode. And 75 in the figure
76 is a contact that is closed when one automatic/manual switch 33B is in automatic mode, and 76 is a contact that is closed when the other automatic/manual switch 33B is in automatic mode. In the figure, 77 and 78 are relays for setting the recirculation flow rate control mode. One relay 77 closes the contact 55 and switches the automatic/manual switch 33
A and 33B modes are selected, and the other relay 78 closes the contact 56 to select the mode of the main controller 31. And relays 70, 77,
78 constitutes a control mode selection device together with the control mode selection switches 59 and 60. In the figure, 79 is a relay that sets the operation pattern when the fuel rod density in the core 2 is a predetermined density, and its output contact is contact 4 in Figure 2.
It is 5. Also, 80 in the figure is a driving pattern
With the auxiliary relay set in the PCIOMR operation pattern,
Its output contact is contact 46 in FIG. In addition,
These relays 79 and 80 constitute a driving pattern selection device together with the driving pattern selection switches 61 and 62. Further, reference numeral 81 in the figure is a contact point of a blade breaker (not shown) that connects the generator 16 to the power system, and the turbine output setting calculator 44 operates the blade breaker via this contact 81. Signal and reactor power calculator 41
Input the reactor output signal from
is biased, and the result is output to the load setter 22 of the EHC 19 via the load setter drive device 82 to set the turbine output. Next, the operation of the output control device for a nuclear power plant configured as described above will be explained. When starting up a nuclear power plant, the operation pattern selection switch 61 shown in FIG.
At the same time, the control mode selection switch 59 is closed to select the control rod operation mode, and the power plant output setting device 47 sets the target output. Therefore, when the nuclear reactor system and turbine generator system are normal, the relay 70 operates and its output contact 7
0A is closed, and the output signal of the output setting calculator 42 is input to the control rod density setting calculator 49. Then, the control rod withdrawal procedure is displayed on the display 51 so that the temperature of each part in the pressure vessel 1 and the coolant is increased in a predetermined pattern. The operator can then operate a control rod position monitoring device (not shown) according to the information on the display 51 and perform a control rod withdrawal operation. And with the rise in reactor power, EHC19
gradually increases the opening degree of the turbine bypass valve 20, and when the reactor output reaches 10% of the target output, the generator 16 is connected to the power system. after that,
The load setter 22 of the EHC 19 is gradually driven in an increasing direction by the turbine output setting calculator 44, thereby gradually increasing the output of the generator 16 and completely closing the turbine bypass valve 20. During this time, the reactor power is held constant. When the turbine bypass valve 20 is fully closed, the output signal of the output setting calculator 42 and the output signal of the control rod density setting calculator 49 are input to the status display controller 50, and the withdrawal status of the control rods 9 is displayed on the display 51.
will be displayed. The operator can then pull out the control rods 9 according to this display. Until the reactor output reaches 65% of the target output due to the withdrawal of the control rods 9, the recirculation pump 4
The rotational speeds of A and 4B will increase by approximately 20%, and the core flow rate will increase slightly above the natural circulation rate. During this period, the reactor output changes from point A to point B on the output curve shown in Figure 4.
transition to a point. When the reactor output reaches point B, the signal from the output setting calculator 42 is output to the status display control device 50, and the display 51 displays an instruction to close the control mode selection switch 60. Therefore, when the operator closes the selection switch 60 and selects the recirculation flow rate control mode, if the reactor system and turbine generator system are normal, the relay 77
operates, the contact 55 closes, and the output setting calculator 4
2 stops the control rod withdrawal operation, and the output signal of the recirculation flow rate setting calculator 48 changes to the automatic/manual switch 33A,
33B. The speeds of the recirculation pumps 4A and 4B are then controlled so that the reactor output reaches the target output at a predetermined rate of increase. Next, when the reactor output becomes 75% or more of the target output, the relay 78 is activated, the contact 57 is closed, and the main controller 31 controls the recirculation flow rate. In addition, when 100% output is set by the power plant output setting device 47, the reactor output is B of the output curve.
From point to point C. On the other hand, if PCIOMR operation is required, the operation pattern selection switch 62 is closed. Then, the auxiliary relay 80 operates, its contact 46 closes, and an input is made to the output setting calculator 42. Furthermore, the control rod operation mode is selected by closing the control mode selection switch 59, and the output setting device 4
7, point D on the output curve in FIG. 4 is set as the output rising point. The output curve is
This is for PCIOMR operation. and display 5
1, the control rod withdrawal procedure up to the output increase point D is displayed in response to a signal from the status display control device 50, so the operator can perform the control rod withdrawal operation in accordance with this display. In this manner, when the reactor output reaches point D on the output curve, the display 51 displays a message indicating that control rod withdrawal has been stopped and a message indicating that the control mode has been changed. Therefore, the operator closes the control mode selection switch 60 to select the recirculation flow rate control mode, and also uses the output setting device 47 to select the recirculation flow rate control mode.
Set the point as the next output rising point. As a result, the output signal of the output setting calculator 42 is input to the recirculation flow rate setting calculator 48, the recirculation flow rate increases at a predetermined rate of increase, and the reactor output reaches point E on the output power curve. When it rises to 51, display 51
The control mode change is displayed. When the operator closes the control mode selection switch 59 again to select the control rod operation mode and sets the next output increase point to point F on the output curve using the power plant output setting device 47, the display 51 A control rod withdrawal indication will be displayed. The operator then performs the control rod withdrawal operation again in accordance with this display. When the reactor output reaches point F on the output curve, the display 51 displays a message indicating that control rod withdrawal is to be stopped and a message indicating that the control mode should be changed. Therefore, the operator closes the control mode selection switch 60 to select the recirculation flow rate control mode, and sets the final target output point, point C, using the power plant output setting device 47. As a result, the output signal of the output setting calculator 42 is input to the recirculation flow rate setting calculator 48, and the recirculation flow rate is increased at a predetermined rate of increase. When the reactor output reaches point C, the display 51 indicates that the target output has been reached. In the above explanation, the control mode is changed by performing control rod operation and recirculation flow rate control twice, but depending on the burnup of the fuel rods, the control mode may be changed more often. Good too. In addition, not only the output increase but also the output decrease can be automatically controlled by the output setting in the power plant output setting device 47. Further, in the above embodiments, an analog control circuit is used in the control system, but a digital control circuit may also be used. Additionally, when digital hardware is employed, a programmed digital computer can be incorporated into the control circuit by known means. [Effects of the Invention] As detailed above, according to the output control device for a nuclear power plant according to the present invention, the nuclear reactor system and the turbine generator system are coordinated to automatically control the output until the target output is reached. This makes it possible to improve fuel economy and shorten fuel adjustment time. In addition, the operation pattern can be changed according to the combustion density of the fuel rods, making it easier to operate the PCIOMR, making it possible to quickly change the load after the PCIOMR operation is completed, and automating output control to reduce the burden on operators. It can be reduced.

[Brief explanation of drawings]

Fig. 1 is a system diagram showing an output control device of a boiling water nuclear power plant, Figs. 2 and 3 show an embodiment of the present invention, and Fig. 2 shows an output control device of a boiling water nuclear power plant. FIG. 3 is a system diagram of the control device, FIG. 3 is a system diagram showing an output selection device of the power control device, and FIG. 4 is an output characteristic diagram in the relationship between core flow rate and reactor output. 1...Reactor pressure vessel, 2...Reactor core, 4A, 4
B... Recirculation pump, 9... Control rod, 10... Neutron detector, 15... Turbine, 16... Generator, 30 ... Recirculation flow control system, 41... Reactor power calculator, 42 ...Output setting calculator, 44...
Turbine output setting calculator, 47... Power plant output setting device, 48... Recirculation flow rate setting calculator, 49...
Control rod density setting calculator, 50...Status display control device, 51...Display, 53A, 53B...
Flow rate detector, 59, 60...control mode selection switch, 61, 62...operation mode selection switch,
70, 77, 78, 79, 80...Relay.

Claims (1)

[Scope of Claims] 1. A recirculation flow rate control system that controls the rotational speed of a recirculation pump, and a reactor power calculator that calculates the reactor power by inputting signals that are power determining factors in the reactor pressure vessel. and an output setting calculator that calculates the rate of increase in power plant output by inputting the output signal of the reactor output calculator and the setting signal from the power plant output setting device, and an output control mode that is set to control rod operation mode or a control mode selection device for switching to recirculation flow rate control mode, and an operation pattern in the output setting calculator that switches between the control rod operation mode and the recirculation flow rate control mode once before the reactor output reaches the target output. an operation pattern selection device that switches between a first operation pattern that is performed only once and a second operation pattern that is performed multiple times; and an output signal of the output setting calculator when the control rod operation mode is selected by the control mode selection device. and a control rod density setting calculator that determines a control rod control procedure based on the control rod position signal; and an output signal of the power plant based on the output signal of the control rod density setting calculator and the output signal of the output setting calculator. a status display device for displaying a control state; and a status display device for setting the recirculation flow rate control system based on the output signal of the output setting calculator and the recirculation flow rate signal when the recirculation flow rate mode is selected by the control mode selection device. A recirculation flow rate setting calculator that adjusts the value; and a turbine output setting calculator that adjusts the turbine output setting value in accordance with an increase in reactor output based on the output signal of the reactor output calculator. An output control device for a nuclear power plant characterized by: