JP2714207B2 - Monitor system - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] [Industrial Application Field] The present invention processes a detection signal of a large number of detectors such as a radiation detector or a neutron detector in a nuclear power plant or the like. The present invention relates to a monitor system that can be used for a nuclear instrumentation monitor or the like that monitors safety by using the monitor.

[Conventional technology]

As this type of monitor system, a radiation monitor system and a reactor power system monitor system are known. For example, in a conventional radiation monitoring system, an analog arithmetic processing device is connected to each of a plurality of radiation detectors installed at a plurality of locations, and each arithmetic processing device is configured by an analog signal processing circuit using an operational amplifier. .

On the other hand, in recent years, digital technology has been developed and applied in many fields, and a digital signal processing circuit has been used in this type of monitor system instead of a conventional analog signal processing circuit. Was.

In a digital signal processing circuit, since the number of input signals can be easily increased without additional hardware, an n-to-one configuration in which a plurality of detectors are connected to one arithmetic processing device is often adopted. Was.

By the way, in the analog signal processing circuit, since each operational amplifier is always in an operating state, each detection signal of a plurality of detectors is processed continuously in real time. on the other hand,
For example, the arithmetic processing performed by a digital signal processing circuit to which a microprocessor is applied is such that the microprocessor calls out instructions stored in a memory one by one and sequentially processes them. Is not performed, the input signal is discretely processed, and the result is also discretely output. Further, the processing cycle of signal processing becomes longer in proportion to the number of input signals.

Therefore, when processing a large number of signals at the same time, and when comparing a digital signal processing circuit with an analog signal processing circuit, the digital signal processing circuit has a slower response speed to a change in the input signal. Further, the digital signal processing circuit has a limit in the frequency at which the change of the input signal can be reproduced, and it is necessary to provide a filter in the input stage in advance to remove a frequency component that cannot be reproduced. However, when such a filter is provided, the response speed is further reduced.

[Problems to be solved by the invention]

Therefore, in the conventional digitized monitor system, the response speed is lower than that of the analog signal processing circuit, and it is difficult to realize a response speed that can cope with signal processing that requires a high response speed.

The present invention has been made in view of the above circumstances,
An object of the present invention is to provide a monitor system which can sufficiently cope with a change in an input signal and can realize a sufficient response speed for safety.

[Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention provides a plurality of primary detectors in which a predetermined number of detectors among the plurality of detectors perform a primary operation of a detection signal thereof. In a monitor system having a hierarchical structure such that each of the primary monitors is connected to a monitor of the next stage, and the monitor of the next stage is finally connected to a general monitor for integrally monitoring all monitors, When the number of layers from the primary monitor to the central monitor is n stages, and the next monitor is the same monitor as the central monitor, n = 2 stages is the minimum number of layers that can be taken by the primary monitor and the central monitor. The number of signals to be input to all the monitors including is set to be the optimal number based on the integer closest to the nth root of the total number of detectors.

[Action]

Since the present invention takes the above measures, the number of signals processed by all monitors including the primary monitor and the general monitor becomes a number corresponding to the nth root of the total number of detectors. Is evenly distributed over the number of signals processed by
As a result, the response time required for a signal change at the detector to be reflected on the output of the general monitor, which is the highest layer of the system, is minimized.

〔Example〕

 Hereinafter, examples of the present invention will be described.

An example in which the monitor system of the present invention is applied to a radiation monitor system as a first embodiment will be described with reference to FIG.

The radiation monitoring system according to the present embodiment includes a plurality of radiation detectors 1-1 to 1-n and a plurality of radiation detectors 1 to 1-n.
A plurality of multiplex processing devices 2 for directly processing an appropriate number of detection signals 1 to 1-n;
And a second general monitor 4 to which the outputs of all the multiplex processing devices 2 are input. (In this embodiment, since the number of layers is two, The number of outputs of the multiplex processing device 2 input to the first general monitor 3 and the second general monitor 4 is the same), the first and second general monitors
It comprises an optical transmission means 5 for performing signal transmission between 3, 4 and the multiplex processing device 2 by optical transmission, and has a two-stage hierarchical structure.

The multiplex processing device 2 is connected to an optimum number of radiation detectors 1 and sequentially selects and inputs the detection signals thereof.
1 and an analog converter for converting an analog signal of the radiation detector 1 selected by the input means 2-1 into a digital value.
Digital conversion means 2-2, digital signal processing circuit 2-3 for arithmetically processing the detection signal converted into a digital value by analog-digital conversion means 2-2, and arithmetic processing of digital signal processing circuit 2-3 Optical signal output means 2-4 for converting the result into an optical signal and outputting the result. The optimum number of radiation detectors connected to the input means 2-1 is determined by the nth root of the total number of detection signals of the radiation detectors 1-1 to 1-n input to the system body (in this embodiment, the system Is determined in consideration of the balance of the entire system when the system is partitioned based on the integer closest to the square root.

The first general monitor 3 is provided with optical signal input means 3 to which optical signals from the multiplexing processing devices equal in number to the “optimal number” are inputted.
-1 and a digital signal processing circuit 3-2 for performing arithmetic processing on the signal input by the optical signal input means 3-1.
And an output circuit 3-3 for outputting the operation result of the digital signal processing circuit 3-2.

The second general monitor 4 includes an optical signal input means 4-1 for receiving output signals from all the multiplex processing devices 2, and the "optimum number" from among the signals input to the optical signal input means 4-1. And a digital signal processing circuit 4-2 for performing arithmetic processing for selecting and processing a number of signals corresponding to the above, and an output circuit 4-3 for outputting the arithmetic result of the digital signal processing circuit 4-2.

Next, the operation of the radiation monitor system configured as described above will be described.

The multiplexing device 2 receives the detection signals of the radiation detectors 1 which are sequentially selected by the input means 2-1 and have the same number as the "optimal number", and multiplexes the plurality of detection signals. After being converted into a digital value by the analog-to-digital converter 2-2. Then, the digital value is subjected to a primary arithmetic processing in the digital signal processing circuit 2-3, and the arithmetic processing result is output from the optical signal output means 2-4 as a digital multiplexed signal converted into an optical signal. . The digital multiplexed signal output from the optical signal output unit 2-4 is transmitted to the first general monitor 3 or the second general monitor 4 via the optical transmission unit 5.

In the first general monitor 3, a predetermined number of multiplexing processing devices 2 (in this embodiment, all the multiplexing processing devices 2) Device). The input signal is subjected to secondary arithmetic processing in the digital signal processing circuit 3-2.
Comprehensive monitoring processing is performed on the detection signals of the radiation detectors 1-1 to 1-n connected via the multiplex processing devices 2 that transmit the signals.

In the second general monitor 4, the signals from all the multiplex processing devices 2 are input to the input means 4-1 and correspond to the "optimum number" from the signals input by the digital signal processing circuit 4-2. Are selected, and secondary arithmetic processing is performed. The first general monitor 3 and the second general monitor 4 are used by simultaneously operating two or one of them selectively according to the purpose.

In this way, the multiplex processing device 2 performs a primary operation on the detection signals of the plurality of radiation detectors 1, and the first or second general monitoring device performs a secondary operation on the detection signals of the plurality of radiation detectors 1. Multiplex processing unit 2 and the first or second general monitor
In sections 3 and 4, when the system is partitioned based on the integer closest to the nth root of the total number of detection signals input to the entire system (n is the number of system layers), the balance is determined in consideration of the entire system. Signal processing corresponding to the optimal number is performed.

As a result, the response time required for the signal changes in the radiation detectors 1-1 to 1-n to be reflected on the outputs of the integrated monitors 3 and 4 belonging to the uppermost layer of the system is the shortest.

For example, a case in which 100 input signals are monitored by a plurality of multiplexing processing devices and one integrated monitoring device will be described as an example.

Since the contents of signal processing in the central monitor device and the multiplex processing device are both averaging processes, it can be considered that the processing time per signal is equivalent. Therefore, assuming that the processing time per signal is t, when the number of signals input to one multiplex processing device is changed to 10, 20, and 25, the processing in the general monitor device and the multiplex processing device is performed. When the input to the multiplex processing device is 10 and the input to the general monitoring device is 10, the response time is 20t, the input to the multiplex processing device is 20, and the input to the general monitoring device is When the value is 5, the response time is 25t. When the input to the multiplex processing device is 25 and the input to the general monitor device is 4, the response time is 29t. That is, when the square root of the total number of input signals 100 (when the number of layers is 2 as in the above example) is 10, the number of signal inputs per unit is the shortest in response speed. When the number of input signals is 1000 and the system has a three-layer structure, and the number of signals to be processed in each device is 10, which is the cube root of 1000, the processing time can be minimized.

Next, an example in which the monitor system of the present invention is applied to a reactor power system monitor system will be described as a second embodiment.

FIG. 2 is a diagram showing the configuration of the second embodiment. This reactor power system monitoring system is divided into four sections, and each section divides the output signals of 208 neutron detectors 10-1 to 10-208 installed in the reactor into four equal parts. The configuration is such that the output signals of 52 neutron detectors are input. Each section is divided into four local output system monitors (hereinafter, "LPRM") that divide and process the output signals of 52 neutron detectors 10.
) 20 and an average output system monitor (hereinafter, referred to as “APRM”) 30 that receives and processes a total of eight digital multiplexed signals from the four LPRMs 20. Further, the monitor system of this embodiment has
Two control rod pullout monitoring devices (hereinafter referred to as "RBMs") 40 are provided, which receive the output signals of the LPRM 20 and select and process the output signals of the eight neutron detectors 10 from among them. .

Each LPRM 20 is connected to thirteen neutron detectors, and internally selects seven input signals 21a and six input circuits 21a and six input signals sequentially from among seven and six output signals. An input circuit 21b for selecting and inputting, and each input circuit 21
analog-to-digital converters 22a, 22 for converting each of the output signals of the neutron detector selected by a, 21b into a digital signal
b, digital signal processing circuits 23a and 23b each equipped with a microprocessor for arithmetically processing a digital signal output from each of the two digital signal processing circuits.
Optical signal output circuits 24a and 24b for converting the calculation results of 3a and 23b into optical signals and outputting the optical signals.

The APRM 30 receives and records eight optical signals output from the four LPRMs 20, and reads and processes the arithmetic processing result stored from the optical signal receiving circuit 31. It comprises a digital signal processing circuit 32 having a microprocessor mounted thereon, and an output circuit 33 for outputting the result of arithmetic processing of the digital signal processing circuit 32.

The RBM 40 includes an optical signal receiving circuit 41 that receives and records 32 optical signals output from all LPRMs 20, and a microprocessor that reads and processes the arithmetic processing result stored from the optical signal receiving circuit 41. And a output circuit 43 that outputs the result of the arithmetic processing of the digital signal processing circuit.

Note that the LPRM 20, the APRM 30, and the RBM 40 are connected by optical transmission means 50, respectively.

Next, the operation of the second embodiment configured as described above will be described.

In the present embodiment, the output signals of the 13 neutron detectors 10 are divided into 7 and 6 which are “optimal numbers” and input to each LPRM 20. The input signals are sequentially selected and output to the corresponding next-stage analog-digital converters 22a and 22b. In each of the analog-to-digital converters 22a and 22b, seven or six signals are sequentially converted to digital signals and then output to digital signal processing circuits 23a and 23b. In each of the digital signal processing circuits 23a and 23b, the input digital signal value is multiplied by a coefficient peculiar to the neutron detector that has detected the signal to convert the reactor percent output value. And
The average calculation of the reactor power percentage values of the seven and six signals is performed, and the average calculation result (partial average value) and the reactor percentage power values of the seven and six neutron detectors are output as optical signal outputs. The signals are converted into optical signals from the circuits 24a and 24b and output to the APRM 30 and the RBM 40.

In the APRM 30, eight optical signals output from the four LPRMs 20 are received and recorded by the optical signal receiving circuit 31. The microprocessor of the digital signal processing circuit 32 is a signal receiving circuit.
A total of eight partial average values calculated by each LPRM 20 are read from 31 and average calculation is performed to obtain an average value of the reactor percent output values of 52 neutron detectors 10 corresponding to one section, and this is obtained. The average power of the reactor is compared with a reference value set separately. Then, when the reactor average output value exceeds the reference value, a reactor scram signal is output from the output circuit 33.

On the other hand, in the RBM 40, 32 optical signals output from all LPRMs 20 are received and recorded by the optical signal receiving circuit 41, and the RBM 40
The "optimal number" of eight neutron detectors determined by the selection signal input separately from the 208 output signals converted into the reactor percentage output value in each LPRM20 by the microprocessor provided in the LPRM20 Are selected and read out. Then, these eight reactor percent output values are averaged to obtain a local average output around the control rod when the control rod is pulled out. Further, the local average output is used as a rod block value, and a reference value separately set is compared with the rod block value. If the rod block value exceeds the reference value, a control rod withdrawal prevention signal is output from the output circuit 43.

As described above, according to the second embodiment, the number of signal processes in each of the microprocessors mounted on each of the LPRM20, APRM30, and ABM40 constituting the monitor system is determined by the square root of the number of signals 52 input to each section, ie, 7.2111. Since the number of signal processing is made substantially equal among the microprocessors by setting the number to 7, 8, or 6 based on the integer 7 closest to..., The signal processing speed of the entire system can be minimized. .

The output of the LPRM 20 that performs primary signal processing on the output signal of the neutron detector 10 is converted to the APRM 30 that performs secondary signal processing.
And RBM40, respectively.
The signal change in the neutron detector 10 is APRM30 and RBM4
It is possible to shorten the response time until the result is reflected in each processing result of 0, and it is possible to realize a response speed sufficient for safety.

In addition, when there are a plurality of general monitoring devices with different functions such as APRM30 and RBM40 in the monitor system, LP
The configuration is such that the calculation results are transmitted directly from the RM20 to each of the general monitors 30, 40.
In this case, the response time can be further shortened, and the influence on the system due to the failure of one general monitor can be reduced to provide a highly reliable system.

The present invention is not limited to the first and second embodiments. For example, in the second embodiment, the case where the number of signal inputs to the system of one section is 52 and the number of layers of the system is 2 is shown, but the number of signal inputs and the number of layers can be arbitrarily set by the system. In particular, the number of layers can be set in consideration of the ratio between the time required for individual signal processing and the time required for signal transmission.

In the above-described embodiment, two devices are shown as devices that perform secondary processing on an input signal to the system, but the number can be changed according to the function of the system.

[Effects of the Invention] As described in detail above, according to the present invention, the response time until a signal change in the detector is reflected on the output of the general monitor can be minimized, and thereby the digitalization can be realized. It is possible to realize a sufficiently fast response speed to a change in the input signal while taking advantage of the advantage.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a radiation monitoring system according to a first embodiment, and FIG. 2 is a configuration diagram of a reactor power system monitoring system according to a second embodiment. DESCRIPTION OF SYMBOLS 1 ... Radiation detector, 2 ... Multiplex processing apparatus, 3 ... 1st general monitor, 4 ... 2nd general monitor, 10 ... Neutron detector, 20 ... LPRM, 30 ... APRM, 40 …… RBM.

Claims (1)

(57) [Claims] A predetermined number of detectors among a plurality of detectors are respectively connected to a plurality of primary monitors for performing a primary operation of a detection signal, and these primary monitors are connected to a next-stage monitor. In a monitor system having a hierarchical structure in which a monitor at a stage is finally connected to a central monitor for integrally monitoring all monitors, the number of layers from the primary monitor to the central monitor is n, and the next stage In the case where n = 2 stages where the monitor is the same monitor as the general monitor is the lowest possible number of layers, the number of signals to be input to all monitors including the primary monitor and the general monitor is calculated by A monitor system wherein an optimum number is set based on an integer closest to the nth root of the total number of detectors.