JPS6370001A - Nuclear-reactor feedwater controller - Google Patents

Abstract

(57) [Abstract] 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 reactor water supply control device for controlling the reactor water level in a boiling water nuclear reactor to a constant level.

(Prior art) In general, in a boiling water reactor, the reactor water level is controlled to a constant level by changing the flow rate of feed water supplied to the reactor by a feed water pump.This feed water diversion is The control device to be adjusted is the reactor water supply control device,
By comparing and calculating the reactor water level setting signal and the water level signal, the water supply flow rate request signal is increased or decreased to keep the water level constant.

In addition, in general, in a reactor feed water control system, in order to perform more stable control against disturbances to the reactor water level, the ratio of the above water level signal, the deviation between the main steam flow rate flowing out of the reactor and the feed water flow rate supplied to the reactor are determined. Three-element control using signals is performed. On the other hand, when the reactor output is low and the main steam flow rate and feed water flow rate are low, such as during reactor startup and shutdown, errors in flow rate measurement may become large, and the system that controls the water level using only the reactor water signal may You are using element control.

Normally, these control systems are switched in consideration of the furnace output status.
Can be switched automatically or manually. Also, if the feed water flow rate signal and the main steam flow rate signal become abnormal during three-element control, switching operation to single-element control is performed.

The configuration of a conventional reactor water supply control system will be explained using FIG. 2. The reactor feed water control device 1 inputs the water level signal @S1 from the reactor 5, the feed water signal S2 from the water supply line 6, and the main steam flow rate signal S3 from the main steam line 7, and controls the pump flow rate signal @S1 from the pump flow control device 3. The main controller 2 outputs the water supply command signal S4 to the main controller 2, and the water supply command signal S4 from the main controller 2 is input, and the valve opening command signal 35.36 is input to the flow rate regulating valves 8 and 9.
The pump flow rate controller 3.4 outputs . Further, the flow rate control valves 8.9 adjust the discharge flow direction of the water supply pumps 10.11 in accordance with valve opening command signals S5 and S6 from the pump flow control devices 3 and 4, respectively.

[Problem that the invention seeks to solve]

In conventional reactor feed water control systems, three-element control using a reactor water level signal, single feed water flow signal, and main steam flow rate signal, and single-element control using only the reactor water level signal are used to control the reactor water level. This switching is done automatically or manually depending on the furnace output.

When adjusting this reactor control system, the control gain of the main controller must be set to perform stable control at each output including the rated output state, but three-element control and single-element control are required. The optimum control gain for element control is slightly different.

Conventionally, the three-element control normally used during reactor operation was used as the standard, and the control gain was adjusted within the range where optimal control could be achieved with three-element control and almost stable control could be achieved with single-element control. .

However, during reactor operation, there is a possibility that the reactor will be operated under single element control due to an abnormality in the feedwater flow single signal or the main steam flow rate, and it is desirable to be able to perform R-appropriate control even in single element control.

The purpose of the present invention is to add a function to automatically switch the control gain of the main controller in response to switching between three-element control and single-element control in each output state of the reactor.
The object of the present invention is to provide a reactor feed water control system that always has optimal controllability in both three-element % control and single-element &lIm control.

(Structure of the Invention) (Means for Solving the Problems) The reactor feed water control device of the present invention controls the reactor water level of a boiling water reactor using a reactor water level signal, a feed water flow single signal, and a main steam flow rate signal. In a control system that switches between three-element control and single-element control that uses only the reactor water level signal,
It is characterized by having a function of automatically switching the control gain of the main controller between the three-element control and the single-element control.

(Function) In the present invention, when the reactor is in normal operation and there are sufficient feed water flow rate signals and main steam flow rate signals, the main controller performs three-element control. If three-element control becomes impossible due to a malfunction in the feed water flow rate signal or main steam flow rate signal, the triple switching contact is turned OFF using the triple switching signal.
F state and single-element control using a water level signal and a water level setting signal. At this time, a triple switching signal is simultaneously received to set the proportional gain setter and the integral gain setter to R appropriate gains during three-element control.

(Example) The invention will now be described with reference to FIG.

FIG. 1 shows the configuration of a main controller 2 during operation of a nuclear reactor according to the present invention. In the drawings, 2 is the main controller of the nuclear reactor control system of the present invention. Mismatch deviation itching device 21
calculates the deviation between the feedwater flow rate signal s2 and the main steam line @S3, and outputs the result to the mismatch gain calculator 22 as a mismatch flow rate signal 311.

The mismatch gain calculator 22 receives the mismatch flow rate signal @
S11 is input, and a mismatch signal 312, which is a mismatch flow rate signal 311 multiplied by a mismatch gain, is outputted to the water level deviation calculator 24 via the triple switching contact 23. The water level deviation calculator 24 receives a water level setting signal 3 from the water level setting device 25.
13, the water level signal s1, and the mismatch signal 312, and outputs the result as a water level deviation signal 314.

The water level deviation signal 314 is input to the proportional calculator 26 and the integral calculator 27, respectively. The proportional calculator 26 inputs the water level deviation signal S14, performs a proportional calculation set by the proportional gain setter QS15 output from the proportional gain setter 28, and sends the result to the adder 30.
Output as 7. Further, the integral calculator 27 inputs the water level deviation signal 314, performs an integral calculation set by the integral gain setting signal 316 output from the integral gain setting device 29, and outputs the result to the adder 30 as an integral calculation signal 31B. .

In addition, a proportional gain setter 26 and an integral gain setter 2
7 is the triple switching signal 819 from the external interlock circuit.
It has the ability to change the setting values respectively. The triple switching contact 23 is also operated by the triple switching signal S19. The adder 30 receives the proportional calculation signal 317 and the integral calculation signal 31B.
is added and output as the water supply command signal @S4.

Next, the operation of the reactor water supply control system of the present invention will be explained. In FIG. 1, when the reactor is normally in operation and there are sufficient feedwater flow rate signals S2 and main steam flow rate signals S3, the main controller 2 performs three-element control, and the triple switching contacts 23 It is in the "ON" state by the switching signal 319. In addition, the triple switching signal 319 causes the proportional calculator 2
6 and the integral calculator 27 have optimum gains during three-element control.

In this state, the water level deviation calculator 24 receives the water level setting signal S13 from the water level setter 25 and the reactor water level signal @S1, as well as the feed water flow rate signal S2 and the main steam flow rate signal S3.
A mismatch signal 312 obtained by multiplying a mismatch flow rate signal 311 by a mismatch gain is input, and control is performed using three elements.

Here, feed water flow meter @S2 or main steam flow rate signal S33
If three-element control becomes impossible due to a malfunction,
The triple switching contact 23 is turned OFF by the triple switching signal S19.
j state and performs single-element control using the water level signal S1 and the water level setting signal 313. At the same time, the triple switching signal 31
9, the proportional calculator 26 and the integral calculator 27 output the proportional gain setting signal 315 from the proportional gain setter 28 and the integral gain setter 29 and the integral gain setter @81.
6 provides the optimum gain when controlling the three elements 1j.

In this way, we decided to change the tlJ control gain at the same time as switching the three elements. Even when switching from three-element control to single-element control due to abnormalities in the feed water flow rate signal and main steam flow rate signal, the optimum control gain will be maintained. Iil+ control becomes possible, and even in three-element 1iII control, it is not necessary to consider the case of switching to a single element, and it becomes possible to independently adjust the optimum gain.

(Effects of the Invention) As described above, in the present invention, optimal control characteristics can be obtained both during three-element water level control during normal operation and when switching to single element water level control due to an abnormality, etc., resulting in plant safety. Effects such as improved performance and reliability can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of the main controller of the reactor feed water control system of the present invention, and FIG. 2 is a system diagram showing the configuration of the feed water control system. 1...Reactor water supply control device 2...Main controller 3.4
...Pump flow rate controller 5...Reactor 6...Water supply line 7...Main steam line 8.9...Flow rate control valve to, ii...Water supply pump 21...
- Mismatch deviation calculator 22... Mismatch gain calculator 23... Triple switching contact 24... Water level deviation calculator 25... Water level setter 26... Proportional calculator 27... Integral calculator 28...Proportional gain setter 29...Integral gain setter 30...Adder agent Patent attorney Rule Noriyuki Chika Yudo Hirofumi Mitsumata I Country Figure 2

Claims (2)

[Claims] (1) Three-element control that controls the reactor water level of a boiling water reactor using a reactor water level signal, a feed water flow rate signal, and a main steam flow rate signal;
In a control system that performs control by switching between single-element control and single-element control using only reactor water level signals, the control system has a function of automatically switching the control gain of the main controller between three-element control and single-element control. Characteristic reactor water supply control system. (2) The main controller includes a three-element control system that calculates a water supply command signal based on the main steam flow rate signal, the water supply flow rate signal, and a reactor water level signal, and a single element control that calculates a water supply command signal based only on the reactor water level signal. A patent claim characterized in that the main controller has a function of automatically or arbitrarily switching between the three-element control and the single-element control, and also has a function of changing the control constant of the PID calculator inside the main controller by switching between the three-element control and the single-element control. A nuclear reactor feed water control system according to item 1.