JPS60154196A - Automatic output regulator for nuclear power plant - 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 [Technical Field of the Invention] The present invention relates to an automatic output adjustment device for a nuclear power plant.

[Technical Background of the Invention] In recent years, with the increase in the density of nuclear power plants in the power system, nuclear power plants are no longer kept in base load operation, but are now undergoing load following operation and output adjustment such as automatic frequency control (AFC>operation). The need to drive is increasing.

On the other hand, for example, in a boiling water reactor (BWR), as a core thermal output control method to adjust the output, the density is changed by changing the flow rate of the core, which has a neutron moderating function. There is a recirculation flow rate control method that changes the core thermal output, and a control rod operation method that changes the core thermal output by inserting and removing a neutron absorbing rod into the core.

Furthermore, as a result of nuclear fission in the reactor core, iodine-135 and its daughter nucleus, xenone-135, are produced, but since xenone-135 is a neutron-absorbing material, the xenone concentration also changes over time when the core thermal output is changed. , spatially variable. Therefore, when transitioning from high-output operation in the daytime to low-output operation at night in load following operation, or vice versa, be sure to take into account the fluctuations in the pinone concentration distribution and the accompanying fluctuations in the output distribution. It is necessary to adjust the core flow rate and operate the control rods.

For example, when a load following operation is performed only by adjusting the core flow rate, the core thermal output, core diversion, iodine i1i & degree, and xenone concentration change as shown in FIG. 1.

In the figure, the horizontal axis shows time, and the vertical axis shows core thermal output, core diversion, xenone concentration, and iodine concentration, respectively, where curve a is core thermal output, curve 2 is core flow rate, and curve C is The curve d and the curve d show the temporal fluctuations of the iodine concentration, respectively.

As is clear from the figure, if the core diversion is avoided, the core thermal output decreases, and if the core flow rate is increased, the core thermal output increases. Also, in order to maintain a constant output j,
The core flow rate must also be increased or decreased in accordance with the 11 degree increase or decrease in λ1. Note that at this time, the power distribution also changes temporally and spatially due to changes in the Zenone concentration distribution and changes in the core flow rate.

Therefore, manually controlling the recirculation flow rate during load following operation places a heavy burden on the operator. To alleviate this burden, BWR power plants currently automatically control the recirculation flow rate to faithfully achieve a target load curve. This output adjustment device measures the deviation between the actual output of the generator and the target output value, and controls the recirculation flow rate so that this deviation becomes O.

On the other hand, in BWR, the relationship between core thermal output and core flow rate is regulated in order to maintain the integrity of the nuclear fuel and various equipment, and the reactor must be operated within the restricted range ( ) must be. FIG. 2 shows such a restricted range, with the horizontal axis representing the core flow rate and the vertical axis representing the core thermal output, with the shaded area being the operating range of the reactor.

Furthermore, in order to maintain the integrity of the nuclear fuel, the output distribution when the nuclear fuel is run-in in advance is hereinafter referred to as a PC envelope. Changes in the output distribution are permitted only within the range (not shown).

Furthermore, if the power changes are made very quickly, the A-Basute at the neutron level, or the reactor.

Phenomena such as temporarily large fluctuations in water level may occur. Limit values are also determined for the above-mentioned neutron level A-Bashu 1~ and reactor water level fluctuation 11, and the speed of output change is also limited by these.

Therefore, C1 the above-mentioned output adjustment device must not perform load following operation while observing the various restrictions described above as operation limit values.

[Problems with blue-eye technology] At the time the output adjustment device is installed, the current output is generally not on the load curve. "The difference between the target output and the actual output is greater than a certain value." - One Moe said that currently it is possible to turn on an output adjustment device, but before turning on the output adjustment device, the generator output must be adjusted manually to match the target output. I need to keep it. In this case as well, it is necessary to comply with each of the operating limit values described above, which places a heavy burden on the operator.

[Objective of the Invention] The present invention has been made based on the above-mentioned circumstances, and provides an automatic output of an atomic horn power generation plant that can input 1q without manually changing the output even if the output of the generator deviates from the target value. The goal is to increase the number of adjustment devices to 1q.

[Summary of the Invention] The automatic power adjustment device for a nuclear power plant of the present invention inputs plant quantities such as core flow rate, core pressure, and neutron flux from various 31 measuring instruments placed inside the reactor, and calculates the core heat output and output component. A process calculation device that calculates and outputs Ii, etc.; a plant state change prediction unit that predicts changes in plant state quantities and calculates the output change rate based on the output signals of this process subtraction device; and a plant state change prediction unit that predicts changes in core state. a core change prediction unit that determines the output change rate, a target load pattern setting unit that sets the target load pattern, and a load curve that synthesizes the initial adjustment load pattern determined from the determined output change rate and the target load pattern. The present invention is characterized in that it has a load pattern modifying device that includes a combining section, and a generator output adjusting device that adjusts the generator output according to the load pattern given from the load pattern modifying device.

[Embodiment 1 of the invention The details of the present invention will be explained below with reference to the drawings.

FIG. 3 is a block diagram showing an embodiment of an automatic output adjustment device for nuclear power generation plan 1 of the present invention. In the figure, reference numeral 1 indicates a reactor C of a BWR plant, for example, and inside this reactor 1, various measuring instruments (not shown) are arranged to measure plant quantities such as core flow rate, core pressure, and neutron flux. The output of this so-called measuring instrument is connected to a process calculation device 2.

The process calculation device 2 calculates the J1 output distribution of the core heat amount, the iodine J3 concentration, the non-concentration portion A5, etc. based on the signals indicating various plans l-ffi input from the cutting instruments of the reactor 1. The system is configured to output a data signal corresponding to it. This process is carried out at a cycle of about 1 hour when the output is held constant, such as during base load operation. It is configured to calculate at even finer intervals during load following operation.

Output of process 4 calculation device 2) In other words, output data such as core thermal output, core thermal output power distribution, reactor, core flow rate, etc. 18
Various plant quantities such as the water level taken in by the pro-wrestling 81 calculation system 2 are input to the load pattern correction device 3. In the load pattern correction device 3, first, the plant change state prediction unit 4 determines the maximum value of the output change speed such that the plan 1 to amount of water level etc. does not exceed the operation limit value due to the output change.

Next, the core change prediction unit 5 uses the output change rate input from the plant state change prediction unit 4 based on the core thermal output, power distribution, iodine and U non-concentration distribution, etc. input from the process calculation device 2. , predict the changes in core state when the generator output is changed until the target load curve is reached.

As a result, if the operating limit value is exceeded, the power change rate is corrected and the core state change is predicted again. Repeat this procedure to find an output change speed that satisfies all of the operating restriction conditions. Based on the output change speed obtained in this manner, a load curve for changing the generator output from the current value to a target load curve is created. The load curve synthesis section 7 synthesizes the created load curve and the target load curve set in the target load pattern setting section 6, changes the generator output from the current value onto the target load curve, and sets the target load. After reaching the curve, create a load curve to follow it.

The load curve calculated by the load pattern correction device 3 is given to the pattern generator 9 of the generator output adjustment device 8. The generator output adjustment device 8 is connected to a recirculation flow rate control system 10 that controls the core thermal output of the nuclear reactor 1, and adjusts the output signal from the actual generator and the generator output target from the pattern generator 9. A control signal is output to the recirculation flow rate control system 10 to match the two signals.

As is clear from the above, the device of the present invention can be put into use without any preliminary manual operations.

Furthermore, the apparatus of the present invention is particularly effective in wide load following operation involving control rod operation than in load following operation solely by adjusting the recirculation flow rate as described above. In other words, in order to maintain the integrity of the current fuel oil '≧1, it is common practice not to control the recirculation flow rate when operating the control rods. Therefore, during control rod operation, the generator output does not follow the target load pattern.

Therefore, in order to perform recirculation flow rate control again after the control rod operation is completed, it is necessary to move the generator output onto the target curve without exceeding the operating limit value, but after the control rod operation, it is necessary to move the generator output onto the target curve. Since the conditions change greatly, doing this manually places a heavy burden on the operator. In such a case,
By using the device of the present invention, the burden on the operator can be reduced.

In the above-mentioned embodiment, the core state change prediction is performed after the plant state change prediction, but the prediction may be performed in the reverse order. Also, plan 1 ~ state change only becomes a problem when the output change speed is particularly fast, so
If the maximum value of the j change speed is set small in advance, the plant state prediction section can be omitted.

[Effects of the Invention] As is clear from the foregoing, the automatic power adjustment device of the present invention can start up and over from any core state, quickly enter load following operation, and improve the operating performance of the power plant. Furthermore, the rate of change in power for moving from the current core state to the negative curve is determined so as to satisfy each scale operation limit value, so that the health of the plant and fuel can be sufficiently maintained. The burden on the C1 operator is significantly reduced.

[Brief explanation of drawings]

Figure 1 is a graph of changes in the core thermal output, recirculation flow rate, moisture content, iodine degree, etc. during load following operation, and Figure 2 is a graph of changes in the reactor's operational readiness 1 (L range). FIG. 3 is a block diagram of an embodiment of the present invention.
. 1... Nuclear reactor 2... Wrestling calculation device 3... Load pattern correction device 4... Plant state change prediction unit 5... Core change prediction unit 6... Target load pattern setting unit 7...・Load curve synthesis unit 8... Generator output adjustment device 9... Pattern generator 10... Recirculation flow rate control system Application agent: Patent attorney Kikuchi Go Part 1: Figure 2

Claims (1)

[Claims] A pro-res calculation device that inputs blunt ffi such as core flow rate, core pressure) and neutron flux from various IT instruments placed in the reactor and outputs core heat output, output horn distribution, etc.; Based on the output signal of this process gI calculation device, a plan mill state change prediction unit predicts changes in the plant state fill m and calculates the output change rate, and a core change prediction unit predicts core state changes and calculates the output change rate. A load pattern correction device comprising: a 4HQ load pattern setting unit for setting a target load pattern; and a load curve synthesis unit for synthesizing the initial adjustment load pattern determined from the determined output change rate and the target load pattern. An automatic output adjustment device for a nuclear power plant, comprising: and a generator output adjustment device that adjusts the generator output according to a load pattern given from a load pattern correction device.