JPH052277B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Industrial Application Field) The present invention relates to a reactor recirculation flow rate control device for a boiling water nuclear power plant used in nuclear power generation and the like.

(Prior Art) FIG. 3 shows a block diagram of a conventional reactor recirculation flow control system in a boiling water nuclear power plant. Steam generated by the boiling water reactor 1 passes through the main steam pipe 23 and flows into the turbine 2 via the control valve 4 to drive the turbine 2. Turbine 2 drives generator 3 . Main steam pipe 2 upstream of control valve 4
3, a pressure detector 24 is installed to detect the pressure of steam generated by the boiling water reactor 1. The pressure comparator 27 compares the steam pressure signal 25, which is the output of the pressure detector 24, with a preset turbine inlet pressure setting value 26, and calculates a pressure deviation 2, which is the deviation thereof.
Outputs 8. Based on this pressure deviation 28, the pressure controller 12 controls a reactor output signal 13 representing the output of the boiling water reactor and a valve opening that instructs the valve opening of the control valve 4 so that the pressure deviation 28 becomes zero. outputs a degree instruction signal 16. The load comparator 14 compares the reactor output signal 13 and the turbine load signal 11 representing the load on the turbine, and outputs a load deviation 15 that is the deviation thereof. Based on this load deviation 15 and the output 35 of the speed detector 30 that detects the speed of the recirculation pump 5 that discharges the recirculation flow rate of the coolant that adjusts the output of the boiling water reactor 1, Furnace recirculation flow control device 40 controls the speed of recirculation pump 5 so that load deviation 15 becomes zero.

This conventional reactor recirculation flow rate control device 40 includes:
Comparing the load deviation 15 and a predetermined output change width, and outputting the predetermined output change width when the magnitude of the load deviation 15 is larger than the predetermined output change width;
A load deviation limiter 31 that outputs the load deviation 15 when it is small, and a recirculation system that outputs the speed change amount of the recirculation pump 5 such that the load deviation 15 becomes zero based on the output of the load deviation limiter 31. The flow rate main controller 21 compares the speed change amount which is the output of this recirculation flow rate main controller 21 with a predetermined speed change width of the recirculation pump 5, and the magnitude of the speed change amount is determined as the predetermined speed change. a recirculation pump speed change limiter 32 that outputs the predetermined speed change width when it is larger than the width, and outputs the speed change amount when it is smaller; The speed controller 22 controls the speed of the recirculation pump based on the current speed 35 of the recirculation pump 5 which is the output of the speed detector 30.

Therefore, the conventional reactor recirculation flow rate control device 40 uses the load deviation limiter 31 and the recirculation pump to prevent scrams due to high neutron flux even when the output is changed near the rated operating point, especially when the output is increased. The predetermined value of the speed change limiter 32 is kept low to prevent sudden or large changes in the recirculation flow rate. On the other hand, during partial output operation, etc., although these restrictions are further relaxed and high-speed response is possible, the response is suppressed because the limit values are based on the premise of operation near the rated value.

(Problems to be Solved by the Invention) The present invention makes the limit values of the load deviation limiter and the recirculation pump speed limiter variable depending on the operating point and load deviation of the boiling water reactor. It is an object of the present invention to provide a reactor recirculation flow rate control device that achieves the fastest or drastic output change of a boiling water reactor while preventing such events.

[Structure of the invention]

(Means for Solving the Problems) The present invention provides a boiling water nuclear reactor, a turbine driven by steam generated by the boiling water reactor, and a turbine connected to the boiling water reactor, A main steam pipe through which steam that drives the turbine passes; a control valve installed in the main steam pipe to adjust the amount of steam that drives the turbine; and a control valve installed in the main steam pipe upstream of the control valve. , a pressure detector for detecting the pressure of steam generated by the boiling water reactor; and a preset turbine inlet and the pressure of the steam generated by the boiling water reactor detected by the pressure detector. a pressure comparator that outputs a pressure deviation based on the pressure set value; and a reactor output signal that represents the output of the boiling water reactor based on the pressure deviation that is the output of the pressure comparator. , a pressure controller that outputs a valve opening instruction signal that instructs the valve opening of the control valve so that the pressure deviation becomes zero; and the reactor output signal output by the pressure controller; a load comparator that outputs a load deviation based on a turbine load signal representing the load of the turbine; and a recirculation unit that outputs a recirculation flow rate of coolant that adjusts the output of the boiling water reactor. a nuclear power plant comprising a pump and a speed detector for detecting the speed of the recirculation pump; An operating point of the boiling water reactor is determined based on a core flow rate signal representing a core flow rate of coolant of the boiling water reactor, and an operating point of the boiling water reactor is determined based on the operating point and a load deviation that is the output of the load comparator. , an arithmetic unit that outputs an allowable output change width and an allowable speed change range of the recirculation pump that can be allowed as the boiling water reactor without causing a high neutron flux event, and an allowable output that is the output of the arithmetic unit. The output change width is compared with the load deviation which is the output of the load comparator, and when the magnitude of this load deviation is larger than the allowable output change width, the allowable output change width is output, and when it is smaller, the load deviation is output. a recirculation flow rate main controller that outputs a speed change amount of the recirculation pump such that the load deviation becomes zero based on the output of the load deviation limiter; Compare the speed change amount that is the output of the circulation flow rate main controller with the allowable speed change width that is the output of the arithmetic unit, and if the size of the speed change amount is larger than the size of the allowable speed change width, the above-mentioned allowable speed change amount is a recirculation pump speed change limiter that outputs a speed change width and outputs the speed change amount when it is small; and an output of the recirculation pump speed change limiter and the output of the speed detector of the recirculation pump and a speed controller that controls the speed of the recirculation pump based on the current speed.

(Function) The reactor recirculation flow rate control device according to the present invention has the following features:
The current operating point of the boiling water reactor (hereinafter referred to as the reactor) is determined based on the APRM signal and the core flow rate signal, and based on this operating point and the load deviation signal, the reactor at that time is determined to be By providing an arithmetic unit that outputs the reactor output change range and the recirculation pump speed change range that are allowable without causing any problems, it becomes possible to change the output as quickly as possible.

(Embodiment) FIG. 1 is a block diagram showing an embodiment of a nuclear reactor recirculation flow rate control device according to the present invention. The control system other than the reactor recirculation flow rate control device according to the present invention is the same as that shown in FIG. 3 described in the prior art section, and is therefore omitted.

FIG. 2 is a graph showing the operating range of the reactor based on the APRM signal and core flow rate.

A nuclear reactor recirculation flow rate control device 50, which is an embodiment of the present invention shown in FIG.
Based on the core flow rate signal 52, an operating point is determined from the operating region of the reactor shown in FIG. request signal 11
an arithmetic unit 53 that outputs an allowable output change width 54 of the reactor output and an allowable speed change width 56 of the recirculation pump 5 that are allowable as a nuclear reactor without causing an event of high neutron flux, based on the deviation from The allowable output change range 54, which is the output of this calculator 53, is compared with the load deviation 15, which is the output of the load comparator 14, and if the magnitude of the load deviation 15 is larger than the allowable output change range 54, the allowable output A load deviation limiter 55 that outputs a change width 54 and outputs a load deviation 15 when it is small, and a speed change of the recirculation pump 5 such that the load deviation 15 becomes zero based on the output of the load deviation limiter 55. Recirculation flow main controller 2 that outputs the amount
1, the speed change amount which is the output of this recirculation flow rate main controller 21 and the allowable speed change width 56 which is the output of the calculator 53, and the magnitude of the speed change amount is compared with the allowable speed change width 56. a recirculation pump speed change limiter 57 that outputs the allowable speed change width 56 when the size is larger than the size, and outputs the speed change amount when it is smaller than the recirculation pump speed change limiter 57;
speed controller 2 for controlling the speed of recirculation pump 5 based on the output of
2.

The computing unit 53 determines, based on the position of the operating region which is the reactor operating point at that time and the load deviation 15, the reactor's allowable output change range 54 and the recirculation pump 5, which will not reach the neutron flux height even if the output of the nuclear power plant changes. The allowable speed change width 56 is calculated and output. In other words, when the output is low, there is a margin in the neutron flux height even if the output is rapidly increased, so these allowable widths 54 and 56 are
Increase the output response. On the other hand, in the case of high output, an excessively rapid increase in output or a large increase in output will lead to high neutron flux and impede safe operation of the reactor, so these allowable ranges 54,
56 is made small, and variations in output are allowed within a range that ensures stable nuclear reactor operation. In addition, when the output is high, if the load deviation signal 15 is large, the allowable speed change width 56 of the recirculation pump 5 is made smaller, and conversely, if the load deviation signal 15 is small, the allowable speed change width 56 of the recirculation pump is made slightly larger. Based on the reactor operating point and load deviation 15, the allowable range 5 is set according to the operating state of the nuclear power plant.
The computing unit 53 can obtain 4.56.

Although the settings of the calculation formula of the calculator 53 are determined in advance through simulation, the allowable ranges 54 and 56 can also be determined by performing a high-speed online simulation of the state of the nuclear power plant.

Therefore, according to this embodiment, it is possible to change the output with the fastest response according to the state of the nuclear power plant without reaching the operating limit value of the nuclear power plant, and to meet the demands of the power system. Nuclear power plants can be operated automatically.

〔Effect of the invention〕

The reactor recirculation flow control device according to the present invention is designed to operate as quickly as possible while preventing high neutron flux events depending on the reactor operating point and load deviation (difference between required load and reactor power). It is possible to realize a significant change in the output of a nuclear reactor.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing an embodiment of the reactor recirculation flow rate control device according to the present invention, and FIG.
FIG. 3, a graph showing the operating range of the nuclear reactor based on the APRM signal and the core flow signal, is a block diagram of a conventional reactor recirculation flow control system in a nuclear power plant. 21... Recirculation flow rate main controller, 22... Speed controller, 31, 55... Load deviation controller, 32, 57...
Recirculation pump speed change limiter, 40...Conventional reactor recirculation flow control device, 50...Reactor recirculation flow control device according to the present invention, 51...APRM signal, 5
2... Core flow rate signal, 53... Arithmetic unit, 54... Allowable output change range, 56... Allowable speed change range.

Claims (1)

[Claims] 1. A boiling water reactor, a turbine driven by steam generated by the boiling water reactor, and a main steam pipe connected to the boiling water reactor and passing the steam that drives the turbine; A control valve installed in the main steam pipe to adjust the amount of steam that drives the turbine; and a control valve installed in the main steam pipe upstream of the control valve to pressure the steam generated by the boiling water reactor. a pressure detector that detects the pressure of steam generated by the boiling water reactor detected by the pressure detector and a preset turbine inlet pressure setting value, and a pressure that is the deviation between these pressures. A pressure comparator that outputs a deviation, a reactor output signal representing the output of the boiling water reactor based on the pressure deviation output from this pressure comparator, and the adjustment so that the pressure deviation becomes zero. a pressure controller that outputs a valve opening instruction signal that instructs the valve opening of the valve;
a load comparator that outputs a load deviation that is a deviation between the reactor output signal and the turbine load signal that represents the load on the turbine, which are output by the pressure controller; and the boiling water reactor. In a nuclear power plant equipped with a recirculation pump that discharges a recirculation flow rate of coolant that adjusts the output of the reactor, and a speed detector that detects the speed of the recirculation pump, the neutrons in the core of the boiling water reactor are represents the power output of the boiling water reactor based on the
The operating point of the boiling water reactor is determined based on the APRM signal and the core flow rate signal representing the core flow rate of the coolant of the boiling water reactor, and the load deviation is the output of the operating point and the load comparator. an arithmetic unit that outputs an allowable output change range and an allowable speed change range of the recirculation pump that can be allowed as the boiling water reactor without causing a neutron flux high event, based on the above, and an output of this arithmetic unit; The allowable output change width is compared with the load deviation which is the output of the load comparator, and when the magnitude of the load deviation is larger than the allowable output change width, the allowable output change width is output, and when it is smaller, the load deviation is output. a load deviation limiter that outputs the load deviation; and a recirculation flow rate main controller that outputs a speed change amount of the recirculation pump such that the load deviation becomes zero based on the output of the load deviation limiter. , Compare the speed change amount that is the output of this recirculation flow rate main controller with the allowable speed change width that is the output of the arithmetic unit, and when the size of the speed change amount is larger than the size of the allowable speed change width. is a recirculation pump speed change limiter that outputs the permissible speed change width, and outputs the speed change amount when it is small; A nuclear reactor recirculation flow rate control device comprising: a speed controller that controls the speed of the recirculation pump based on the current speed of the circulation pump.