Redundant diversity boron concentration on-line monitoring device

Abstract

The utility model discloses a redundant diversified boron concentration on-line monitoring device. A redundant diversity boron concentration on-line monitoring device comprises an input pipeline which is in butt joint with an external nuclear sampling loop and used for being connected with a boron solution; the metal containing cavity is in butt joint with the input pipeline and is used for containing the boron solution for monitoring; the output pipeline is respectively butted with the metal accommodating cavity and the external nuclear sampling loop and is used for sending out the measured boron solution; the shell wraps the outer side of the metal containing cavity and is used for shielding neutrons; the neutron source is located in the metal containing cavity and used for emitting neutrons; the neutron source assembly is installed in the shell and used for shielding neutron rays and gamma rays; the neutron detector group is inserted into the metal accommodating cavity and is used for detecting the neutron condition of the boron solution; and the temperature detector is arranged on the output pipeline and is used for detecting the temperature of the measured boron solution. According to the utility model, the problems of complex structure, complex detection, large measurement error, high failure rate, radiation risk and the like of the existing monitoring equipment are solved.

Description

Technical Field

[0001] The utility model relates to the technical field of nuclear power, in particular to a redundant and diverse boron concentration online monitoring device. Background Art

[0002] Pressurized water reactor (PWR) nuclear power plants control reactivity and flatten core power by adjusting control rods and the boron concentration in the primary circuit. As the reactor burns up, diluting the boron solution becomes a long-term and frequent operation to release reactivity and maintain reactor power. Excessive or accidental dilution of the boron solution can pose a risk of supercriticality to the reactor. Therefore, to control the dilution rate of the boron solution and monitor its concentration in real time, PWR nuclear power plants are equipped with online boron concentration monitoring systems. Monitoring methods generally include online chemical titration and neutron absorption measurement. Online chemical titration is less commonly used due to its slow response, complex structure, and the generation of radioactive chemical wastewater. Currently, the vast majority of domestic PWR nuclear power plants are equipped with online boron concentration monitoring systems that use the neutron absorption measurement mechanism, inferring the corresponding boron concentration by measuring the neutron count rate.

[0003] Online boron concentration monitoring devices using the neutron absorption method also have different detection methods and measurement means. For example, in patent application number 201410698904.6, entitled "An Online Boron Concentration Monitoring Device," the detection device is mounted on a primary-loop pipe covered with thermal insulation material near the chemical volume system. The detection device is divided into three layers: upper, middle, and lower. The neutron source is located at the bottom of the upper layer, the primary-loop pipe is located in the middle layer, and the neutron detector is located in the lower layer. Each layer is wrapped in a metal shell to form an independent entity. The three-layer structure of the detection device is fixed by bolts running through the three layers on both sides. This monitoring device has two calibration methods. One is to set a calibration hole with the same diameter as the neutron detector tube above the neutron source. During calibration, the neutron detector is moved to the calibration hole and the current measurement value of the detector is compared with the initial measurement value. If the measurement value changes, it is corrected by comparing the current and initial measurement values. Another method is to use a pipe filled with standard boron solution for calibration. The pipe has the same structure, material and other parameters as the first-loop pipe inside the detection device. Loosen the fixing bolts on one side of the detection device, push the detection device horizontally into the pipe filled with standard boron solution, and then calibrate.The shortcomings of the patent application with application number 201410698904.6 are: First, its detection device is installed on a primary-loop pipeline near the chemical volume system. The primary-loop water has the characteristics of high temperature, high pressure and high radioactivity. Strict and reliable heat insulation measures must be adopted to ensure the normal performance of the detection device. Such a structure increases the complexity of the detection device, and the high-radioactive space environment also brings inestimable radiation exposure to the maintenance personnel of the detection device; Second, the detection device adopts an upper, middle and lower block assembly structure. Each block is covered with a metal cladding and fixed by bolts running through three layers. This block structure design makes it difficult to ensure the consistency of the overall structure of the detection device. After disassembly, it is difficult to completely assemble it to the initial state, which changes the initial structural parameters of the detection device and inevitably brings measurement errors; Third, the neutron source is at the bottom of the upper structure, and neutron rays will also escape from the gap between the upper metal cladding and the middle metal cladding, causing neutron dose hotspots and reducing the shielding performance of the detection device; Fourth 1. The calibration test of the detection device using a push-and-disassemble method in which one side is loosened and the other side is fixed is also difficult to perform, because a calibration pipe with completely identical parameters to the primary-loop pipe needs to be manufactured to perform the calibration test. Even if the pipes can be made completely identical, the structural layout of the detection device on the calibration pipe is difficult to be completely consistent with the structural layout on the primary-loop pipe. In addition, the simulation of the primary-loop high-temperature boron solution will increase the complexity of the calibration pipe process, and the precise calibration test of the detection device is difficult to implement; fifth, the signal detection and signal processing of the boron concentration monitoring device are of single-channel design. Any abnormality in any component in the channel will make the boron concentration online monitoring device unusable. At this time, it is necessary to switch to the manual frequent sampling chemical titration mode, which lags information and is not conducive to monitoring the safe operation of the reactor; sixth, in different stages such as reactor power operation, power change and shutdown and refueling, the temperature of the primary-loop boron solution changes greatly, and the measurement accuracy of the boron concentration monitoring device will be seriously affected.

[0004] For example, the patent application number is 89106482.6, and the name is "Device for measuring boron concentration in water by dual-channel neutron leakage compensation absorption". It focuses on introducing a constant temperature light water bucket detection unit and two identical automatic measurement data processing circuit systems. There is a neutron source in the center of the light water bucket, and there is an online scale ring around the neutron source that can be remotely controlled to rise and fall. Two online sampling boron water rings are symmetrically installed on both sides of the scale ring. Two thermal neutron detectors are located in the center of the boron water rings and are respectively connected to two identical automatic measurement data processing circuit systems. The patent application number 89106482.6 has the following shortcomings: First, its two-channel circuits use exactly the same and well-known instruments and equipment, so the probability of failure is greatly increased, which can easily lead to simultaneous failure of both channels; Second, the temperature probe in the constant temperature water bucket is inserted into the constant temperature water to measure the temperature of the constant temperature water. When the flow rate of the sampled boron water in the serpentine heat exchanger is fast and the sampled boron water reaches the boron water ring, the actual temperature of the boron water in the boron water ring is difficult to be equal to the constant temperature water temperature, and there is an uncertain fluctuation range, which brings uncertain measurement errors to the boron concentration measurement results; Third, the boron water sample is not directly measured. After passing through a serpentine heat exchanger, the radioactive boron water sample reaches the boron water ring. The boron water ring is made of organic glass and cannot directly withstand the pressure of the boron water in the nuclear sampling system. A special pressure reducing valve or pressure reducing device needs to be installed on the nuclear sampling system pipeline, which increases the complexity of the process pipeline and the risk of radioactive liquid leakage. If a pressure reducing valve is not installed and only organic glass is used, the radioactive boron water in the boron water ring may leak out, causing radioactive contamination of the constant temperature water in the bucket and an increase in space radioactivity. In summary, there is an urgent need to provide a boron concentration measurement device with a simple structure, high safety, small measurement error, and convenient measurement. Utility Model Content

[0005] The technical problem to be solved by the present invention is that the devices for measuring boron concentration in the prior art have problems such as complex structure, complex detection, large measurement error, high failure rate, and radiation exposure risk. The purpose is to provide a redundant and diverse boron concentration online monitoring device to solve the above problems.

[0006] The utility model is achieved through the following technical solutions:

[0007] A redundant and diverse boron concentration online monitoring device, comprising

[0008] Input pipeline, connected to the external nuclear sampling circuit, used to access the boron solution;

[0009] A metal container, connected to the input pipeline and used to contain the boron solution for monitoring;

[0010] The output pipeline is connected to the metal cavity and the external nuclear sampling circuit respectively, and is used to send out the measured boron solution;

[0011] The outer shell is wrapped around the outside of the metal cavity and is used to shield neutrons;

[0012] A neutron source, located in a metal chamber, is used to emit neutrons;

[0013] A neutron source assembly is installed in the housing and is used to shield neutron rays and gamma rays;

[0014] A neutron detector assembly is inserted into the metal cavity to detect neutrons absorbed by the boron solution;

[0015] The temperature detector is installed on the output pipeline and is used to detect the temperature of the measured boron solution.

[0016] As a possible design, the neutron detector group includes multiple neutron detectors of different types.

[0017] As a possible design, the neutron detector group includes a first neutron detector and a second neutron detector.

[0018] As a possible design, the above device further includes a shielding body, which is filled between the metal cavity and the shell.

[0019] As a possible design, the above also includes a display transmission unit, which is connected to the first neutron detector, the second neutron detector and the temperature detector, and is used to output the neutron detector pulse signal and the temperature resistance signal.

[0020] As a possible design, the display transmission unit includes a first preamplifier box, a second preamplifier box, a temperature transmitter box and a display box.

[0021] The input end of the first preamplifier box is connected to the output end of the first neutron detector through a cable, and is used to receive and amplify the neutron detector pulse signal;

[0022] The input end of the second preamplifier box is connected to the output end of the second neutron detector by a cable, and is used to receive and amplify the neutron detector pulse signal;

[0023] The input end of the temperature transmitter box is connected to the output end of the temperature detector by a cable, and is used to receive the temperature resistance signal and convert the temperature resistance signal into a current signal;

[0024] The display box is used to display boron concentration, temperature and monitoring status information.

[0025] As a possible design, the above device further includes a signal processing unit,

[0026] The input end of the signal processing unit is connected to the output end of the display transmission unit, and is used to collect and count pulse signals and receive temperature and current signals;

[0027] The output end of the signal processing unit is connected to the input end of the display transmission unit to transmit the boron concentration, boron solution temperature and monitoring status information to the display transmission unit for display.

[0028] As a possible design, the signal processing unit includes a first NIM device, a second NIM device, a first computer device, a second computer device, a first signal switching device, and a second signal switching device.

[0029] The first NIM device input terminal and the second NIM device input terminal are respectively connected to the display transmission unit, the first NIM device is used to transmit the pulse signal output from the first neutron detector, and the second NIM device is used to transmit the pulse signal output from the second neutron detector;

[0030] The first computer device input terminal is connected to the output terminal of the first NIM device, and the output terminal is connected to the input terminal of the second signal switching device, and is used to collect and count the pulse signal output by the first NIM device, and is used to convert the temperature current signal input from the first signal switching device into a temperature voltage signal, and is further used to obtain the boron concentration and alarm logic based on the pulse count and the temperature voltage signal;

[0031] The second computer device has an input terminal connected to an output terminal of the second NIM device and an output terminal connected to an input terminal of the second signal switching device, and is used to read the neutron count rate output by the second NIM device, and is used to convert the temperature current signal input from the first signal switching device into a temperature voltage signal, and is further used to obtain a boron concentration and an alarm logic based on the neutron count rate and the temperature voltage signal;

[0032] The input end of the first signal switching device is connected to the display transmission unit, and is used to receive the temperature current signal output from the temperature detector. The output end of the first signal switching device is connected to the input end of the first NIM device and the second NIM device, respectively, and is used to transmit the temperature current signal to the first NIM device or the second NIM device for processing.

[0033] The input end of the second signal switching device is connected to the output end of the first computer device and the output end of the second computer device respectively, and is used to transmit the boron concentration and alarm logic output by the first computer device or the boron concentration and alarm logic output by the second computer device to the external main control device, and is also used to transmit the boron concentration and alarm logic output by the first computer device or the boron concentration, temperature and monitoring status information output by the second computer device to the display transmission unit.

[0034] As a possible design, the first NIM device includes a main amplifier identification module, a first low-voltage power supply module, a first high-voltage power supply module and a first analog pre-processing module.

[0035] The main amplification and discrimination module is connected to the display transmission unit, and is used to receive the pulse signal output from the first neutron detector and transmit the pulse signal to the first computer device;

[0036] The first low-voltage power supply module supplies power to the main amplifier identification module, the first high-voltage power supply module and the first analog pre-processing module through the bus;

[0037] The first high-voltage power supply module is connected to the display transmission unit through a cable, and is used to transmit the high voltage to the first neutron detector after filtering by the display transmission unit;

[0038] The first analog preprocessing module is connected to the output end of the first signal switching device, and is used to convert the temperature current signal into a temperature voltage signal and output it in isolation to the first computer device. It is also used to collect the discrimination threshold voltage output by the main amplifier discrimination module and the high-voltage mirror signal output by the first high-voltage power supply module and output them in isolation to the first computer device.

[0039] As a possible design, the first computer device includes a first relay output board, a first analog output board, a pulse acquisition card, a first RS485 communication board, a first IO control board and a first analog input board.

[0040] The first relay output board is used to provide passive switching signals and output alarm information to the external main control device;

[0041] The first analog output board converts the boron concentration into a current signal and outputs it to an external main control device;

[0042] The input terminal of the pulse acquisition card is connected to the output terminal of the main amplifier discrimination module, and is used to collect the neutron square wave pulse signal output by the main amplifier discrimination module and to control the self-test calibration inside the signal processing unit;

[0043] The output end of the first RS485 communication board is connected to the display transmission unit for transmitting boron concentration, temperature and monitoring status information to the display transmission unit;

[0044] The first IO control board is connected to the external main control device, and is used to receive the boron concentration set value confirmation and remote self-test trigger signal of the external main control device, set the current boron concentration measurement value as the deviation alarm set value, and perform self-test calibration on the signal processing unit while performing boron concentration measurement;

[0045] The first analog input board input terminal is connected to the first analog pre-processing module output terminal, and is used to collect the high-voltage mirror signal, discrimination threshold pressure signal and temperature voltage signal output by the first analog pre-processing module, and process and display them.

[0046] As a possible design, the second NIM device includes a pulse signal processing module, a second low-voltage power supply module, a second high-voltage power supply module, and a second analog pre-processing module.

[0047] The output terminal of the pulse signal processing module is connected to the input terminal of the first signal switching device for outputting pulse count;

[0048] The second low-voltage power supply module supplies power to the pulse signal processing module, the second high-voltage power supply module and the second analog pre-processing module through the bus;

[0049] The second high-voltage power supply module is connected to the display transmission unit via a cable, and is used to transmit the high voltage to the second neutron detector after filtering by the display transmission unit;

[0050] The second analog preprocessing module is connected to the output end of the first signal switching device, and is used to convert the temperature current signal into a temperature voltage signal and output it in isolation to the second computer device. It is also used to collect the discrimination threshold voltage output by the pulse signal processing module and the high-voltage mirror signal output by the second high-voltage power supply module and output them in isolation to the second computer device.

[0051] As a possible design, the second computer device includes a second relay output board, a second analog output board, a second RS485 communication board, a second IO control board and a second analog input board.

[0052] The second relay output board is used to provide passive switch signals and output alarm information to external main control equipment;

[0053] The second analog output board converts the boron concentration into a current signal and outputs it to an external main control device;

[0054] The output end of the second RS485 communication board is connected to the display transmission unit for transmitting boron concentration, temperature and monitoring status information to the display transmission unit;

[0055] The second IO control board is connected to the external main control device, and is used to receive the boron concentration set value confirmation and remote self-test trigger signal of the external main control device, set the current boron concentration measurement value as the deviation alarm set value, and perform self-test calibration on the signal processing unit while performing boron concentration measurement;

[0056] The input end of the second analog input board is connected to the output end of the second analog preprocessing module, and is used to collect the high-voltage mirror signal, discrimination threshold pressure signal and temperature voltage signal output by the second analog preprocessing module, and process and display them.

[0057] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0058] The utility model connects the input pipeline, the output pipeline and the input end and the output end of the solution to be tested, and inputs the boron solution into the metal cavity from the bottom. Since the boron solution is measured from bottom to top and then returns to the nuclear sampling system loop, it can ensure that the boron solution fills the metal cavity, which can reduce the influence of bubbles on the measurement results. While reducing the complexity of the measurement, it can also reduce the error caused by external factors and improve the accuracy of the measurement. The entire detection does not require manual sampling and titration. At the same time, the metal cavity is wrapped in the outer shell, which can improve the shielding performance and protect the maintenance personnel. Moreover, since the entire device has a simple structure, it can be easily assembled back to its original appearance after disassembly, and the measuring part (metal cavity) is an integrated structure, which will not be affected by Disassembly produces changes, and it is made of metal and can withstand greater pressure, so that there is no risk of radioactive liquid leakage during measurement, which can greatly improve the detection stability of the device after maintenance and reduce the measurement error after long-term use; because the boron solution is continuously circulated during measurement, the boron concentration can be monitored online in real time, which is beneficial to monitoring the safe operation of the reactor; this device is equipped with a neutron detector group, which includes multiple neutron detectors and adopts a redundant diversity design concept to reduce the possibility of common cause failure causing two channels to be unavailable at the same time. Rapid switching between channels can realize uninterrupted measurement of boron concentration, and the faulty channel can be repaired online, which greatly improves the online availability time and measurement accuracy of the boron concentration monitoring device.

[0059] During use, this device can be connected to the device to be calibrated within a chemical sampling glove box to calibrate boron concentration. Calibration requires no disassembly of the device, thus avoiding unnecessary radiation exposure. Furthermore, the metal chamber within the device is designed to withstand a maximum pressure of 5.25 MPa, making it suitable for direct connection to the online pressurized circuit of a nuclear sampling system (designed for a 4.65 MPa circuit medium pressure). This simplifies the process flow, allows for real-time online measurement of boron solution concentration, and offers a fast response time, eliminating the risk of radioactive liquid contamination due to pressure-sensitive measurement pipelines.

[0060] The device of the utility model is suitable for 3.5Ci 238 The maximum neutron dose rate on the outer surface of the Pu-Be neutron source does not exceed 70μSv / h, and the maximum gamma dose rate does not exceed 40μSv / h, which fully meets the requirements of radiation technical indicators.

[0061] The utility model uses a temperature detector to make the temperature of the boron solution participate in the correction calculation of the boron concentration measurement. The temperature change of the boron solution has a significant impact on the boron concentration measurement result. By taking advantage of the fixed structure of the detection device, the relationship coefficient between the neutron count rate, the boron concentration and the temperature is obtained through experiments. The measurement software can correct the neutron count rate of the boron solution in the range of 20°C to 70°C to the neutron count rate at the calibration temperature in real time, greatly improving the measurement accuracy and response speed of the boron concentration, avoiding the measurement lag caused by introducing the boron solution into a constant temperature water tank for temperature control, and reducing the measurement error caused by the temperature fluctuation of the boron solution in the constant temperature water tank. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] The accompanying drawings described herein are used to provide a further understanding of the embodiments of the present invention, constitute a part of this application, and do not constitute a limitation of the embodiments of the present invention. In the accompanying drawings:

[0063] Figure 1 It is a schematic diagram of the local structure of the utility model;

[0064] Figure 2 A diagram showing the connection relationship between the display transmission unit and the signal processing unit of the present invention;

[0065] Figure 3 A diagram showing a connection relationship between a first NIM device and a first computer device of the present invention;

[0066] Figure 4 This is a connection diagram of the second NIM device and the second computer device of the present invention.

[0067] Markings and corresponding parts names in the accompanying drawings:

[0068] 1-Input pipeline; 2-Metal cavity; 3-Output pipeline; 4-Casing; 5-Neutron source; 6-Neutron source assembly; 7-Neutron detector group; 8-Temperature detector; 9-First neutron detector; 10-Second neutron detector; 11-Shielding body; 12-Bracket; 13-First preamplifier box; 14-Second preamplifier box; 15-Temperature transmitter box; 16-Display box; 17-First NIM device; 18-Second NIM device; 19-First computer device; 20-Second computer device; 21-First signal switching device; 22-Second signal switching device; 23-Main amplifier identification module; 24 -first low-voltage power supply module; 25-first high-voltage power supply module; 26-first analog pre-processing module; 27-pulse acquisition card; 28-first analog input board; 29-first relay output board; 30-first RS485 communication board; 32-first analog output board; 33-pulse signal processing module; 34-second low-voltage power supply module; 35-second high-voltage power supply module; 36-second analog pre-processing module; 37-second relay output board; 38-second analog output board; 39-second RS485 communication board; 40-second IO control board; 41-second analog input board. DETAILED DESCRIPTION

[0069] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with embodiments and drawings. The schematic implementation methods of the present invention and their descriptions are only used to explain the present invention and are not intended to limit the present invention.

[0070] Since the devices for measuring boron concentration in the prior art have problems such as complex structure, complex detection, large measurement error, high failure rate, and radiation exposure risk, the utility model provides a redundant and diverse online monitoring device for boron concentration to solve the above problems. Figure 1-4, including an input pipeline 1, which is connected to the external nuclear sampling circuit. The input pipeline 1 is connected to the bottom of the metal cavity 2, and the boron solution can be input into the metal cavity 2 from the bottom for monitoring. The input pipeline 1 can be a hose or a hard pipe, and the material can be a polymer, metal or other material, and the input pipeline 1 is tightly connected to the metal cavity 2; the metal cavity 2 is a hollow cavity inside, made of metal, preferably alloy, and its shape can be square, polygonal or elliptical. Preferably, the shape of the metal cavity 2 is elliptical, with the bottom connected to the input pipeline 1 and the top connected to the output pipeline 3, and a neutron source assembly 6 is installed in the internal water-proof channel to facilitate monitoring of the boron solution; the two ends of the output pipeline 3 are respectively connected to the top of the metal cavity 2 and the external nuclear sampling circuit. Under the circulation of the input pipeline 1, the metal cavity 2, the output pipeline 3 and the external nuclear sampling circuit, the boron solution will be continuously fed into the metal cavity 2 for monitoring. Since it is input from the bottom up, the internal air will be squeezed out, which can reduce the influence of environmental bubbles on the monitoring accuracy. The output pipeline 3 is made of the same material and shape as the input pipeline 1; the outer shell 4 is wrapped around the outside of the metal cavity 2 to shield neutrons. The outer shell can be made of metal or polymer material. The input pipeline 1 and the output pipeline 1 both pass through the outer shell 4 and are connected to the external nuclear sampling circuit; the neutron source 5 is located in the metal cavity 2 and is used to emit neutrons. It is fixed to the end of the neutron source assembly 6. The neutrons emitted by the neutron source 5 are moderated and absorbed by the boron solution in the metal cavity 2 and reach the neutron detector assembly 6; the neutron source assembly 6 is installed in the outer shell 4. Preferably, it is made of stainless steel. The neutron source assembly 6 is made of steel and embedded in the outer shell, and is transmitted into the metal cavity 2 through the water-proof channel of the metal cavity 2. The external space outside the metal cavity 2 is filled with a high-density boron-containing polyethylene block and a lead block with a stainless steel shell, which is used to shield neutron rays and gamma rays; the neutron detector group 7 is inserted into the metal cavity 2 to detect the neutron situation of the boron solution; the temperature detector 8 is installed on the end where the output pipeline 3 is connected to the metal cavity 2. Preferably, the temperature detector 8 is a PT temperature detector, which is used to detect the temperature of the measured boron solution.

[0071] Preferably, the metal cavity 2 has a maximum design pressure resistance of 5.25 MPa, which is suitable for being directly connected to the online pressurized loop of the nuclear sampling system with a loop medium design pressure of 4.65 MPa. This can simplify the process flow, measure the concentration of the boron solution online in real time, and has a fast measurement response, thus avoiding the risk of radioactive liquid contamination due to the non-pressure resistance of the measuring pipeline.

[0072] As a possible design, refer to Figure 1 The above-mentioned neutron detector group 7 includes multiple neutron detectors of different types. The neutron detector adopts a dual-channel redundant design, and the key signal processing components adopt a diversity design. While reducing the probability of common cause failure of the two measurement channels, when one of the measurement channels fails and becomes unavailable, the normal measurement channel can be switched to the application mode.

[0073] As a possible design, refer to Figure 1 The neutron detector assembly 7 includes a first neutron detector 9 and a second neutron detector 10. Preferably, the first neutron detector 9 is a BF3 proportional neutron counter tube or a boron-coated proportional neutron counter tube; the second neutron detector 10 is a BF3 proportional neutron counter tube or a boron-coated proportional neutron counter tube. More preferably, the first neutron detector 9 and the second neutron detector 10 are different detectors to improve detection accuracy.

[0074] As a possible design, refer to Figure 1 The device further comprises a shielding body 11, which is filled between the metal cavity 2 and the shell 4. Preferably, the shielding body 11 is a boron-containing polyethylene plate for moderating and shielding neutrons.

[0075] Preferably, refer to Figure 1 The above device also includes a bracket 12, which is fixed to the bottom of the shell 4 and is used to stabilize the shell 4.

[0076] As a possible design, refer to Figure 1-2 The above-mentioned display transmission unit is also included, which is used to output neutron detector pulse signals and temperature resistance signals. It adopts a redundant diversity design concept. The display transmission unit is connected to the first neutron detector 9, the second neutron detector 10, and the temperature detector 8 respectively. The display transmission unit adopts a dual-channel design, connecting to the first neutron detector 9 and the second neutron detector 10 respectively. In the event of a failure of the first neutron detector 9 or the second neutron detector 10, the display transmission unit quickly switches between channels to achieve uninterrupted measurement of boron concentration. The faulty channel can be repaired online, greatly improving the online availability of the device. The display transmission unit is located close to the neutron detector group 7, which facilitates the improvement of the signal-to-noise ratio of the neutron signal and facilitates the long-distance transmission of the neutron signal.

[0077] As a possible design, refer to Figure 1-2The display transmission unit includes a first preamplifier box 13, a second preamplifier box 14, a temperature transmitter box 15 and a display box 16. The input end of the first preamplifier box 13 is connected to the output end cable of the first neutron detector 9 through a coaxial multi-layer shielded cable, which is used to receive and amplify the pulse signal of the first neutron detector 9. Preferably, the first preamplifier box 13 includes a low-voltage power supply module and a pulse preamplifier. The preamplifier uses discrete components to realize functions such as pulse amplification, signal inversion, and DC isolation filtering. The low-voltage power supply module supplies power to the pulse preamplifier. The high-voltage signal of the high-voltage power supply module of the first NIM device 17 of the signal processing unit is filtered by the preamplifier and then input into the corresponding first neutron detector 9. The pulse signal output by the first neutron detector 9 is picked out and amplified by the DC isolation capacitor inside the first preamplifier box 13. The voltage pulse signal amplified by the first preamplifier box 13 is remotely transmitted to the main amplifier identification module of the first NIM device 17 of the signal processing unit via a coaxial shielded cable. Specifically, the first preamplifier box 13 and the second preamplifier box 14 are respectively connected to A / B signal channel, can switch to another channel for monitoring when one channel fails; the input end of the second preamplifier box 14 is connected to the output end cable of the second neutron detector 10 through a coaxial multi-layer shielded cable, which is used to receive and amplify the neutron detector pulse signal, and its structure is the same as the first preamplifier box 13; the input end of the temperature transmitter box 15 is connected to the output end cable of the temperature detector 8, and the temperature information of the boron solution in the metal cavity 2 is transmitted to the temperature transmitter box 15 by the PT100 resistance signal of the temperature detector 8, and is converted into a corresponding 4mA~20mA current signal. The current signal 16 is remotely transmitted to the first signal switching device 21 in the signal processing unit through a signal line with a shielded layer. The temperature transmitter box 15 can measure the temperature of the boron solution in real time, and the temperature value is involved in the temperature correction calculation of the boron concentration measurement; the display box 16 is docked with the signal processing unit, and is used to display the boron concentration, temperature, and monitoring status information of channel A or channel B. The signal transmission adopts the RS485 communication protocol.

[0078] As a possible design, refer to Figure 2 The above-mentioned device also includes a signal processing unit, which is respectively connected to the output end of the first preamplifier box 13, the output end of the second preamplifier box 14, the output end of the temperature transmitter box 15 and the input end of the display box 16, and is used to process the received boron concentration, temperature and monitoring status information and transmit it to the display box 16 for display.

[0079] As a possible design, refer to Figure 2The signal processing unit includes a first NIM device 17 , a second NIM device 18 , a first computer device 19 , a second computer device 20 , a first signal switching device 21 and a second signal switching device 22 .The input end of the first NIM device 17 and the input end of the second NIM device 18 are respectively connected to the display transmission unit. Specifically, the input end of the first NIM device 17 is respectively connected to the output end of the first preamplifier box 13 and the output end of the temperature transmitter box 15. The first NIM device 17 is used to transmit the pulse signal output from the first neutron detector 9 and the boron solution temperature transmitted by the temperature transmitter box 15. The input end of the second NIM device 18 is respectively connected to the output end of the second preamplifier box 14 and the output end of the temperature transmitter box 15. The second NIM device 18 is used to transmit the pulse signal output from the second neutron detector 10 and the boron solution temperature transmitted by the temperature transmitter box 15. When the first NIM device 17 is stopped, the second NIM device 18 can be used to The first computer device 19 is connected to the output of the first NIM device 17 and the output is connected to the input of the second signal switching device 22, for collecting and counting the pulse signal output by the first NIM device 17, and for converting the temperature current signal input from the first signal switching device 21 into a temperature voltage signal, obtaining the boron concentration and alarm logic through the pulse counting and temperature voltage signal, and the measurement software in the computer completes the boron concentration calculation and alarm logic analysis, and realizes the input, output and control of the signal through the function board in the computer device; the input of the second computer device 20 is connected to the output of the second NIM device 18 and the output is connected to the input of the second signal switching device 22, and the second computer device 20 is connected to the output of the second NIM device 18 and the output is connected to the input of the second signal switching device 22, through the US The B data line obtains the neutron count rate output by the pulse signal reprocessing module of the second NIM device 18, and is used to convert the temperature current signal input from the first signal switching device 21 into a temperature voltage signal. It is also used to obtain the boron concentration and alarm logic through the neutron count rate and temperature voltage signal; the input end of the first signal switching device 21 is connected to the temperature transmission box 15 to receive the temperature current signal output from the temperature detector 8. The output end of the first signal switching device 21 is connected to the input end of the first NIM device 17 and the second NIM device 18 respectively. During operation, only one temperature signal is allowed to be output. When either the A channel of the first NIM device 17 or the B channel of the second NIM device 18 fails and becomes unavailable, , by the action of the switching switch, the normal channel is switched to the use state; the input end of the second signal switching device 22 is connected to the output end of the first computer device 19 and the output end of the second computer device 20 respectively, which allows the signal of the first computer device 19 or the second computer device 20 to pass through the second signal switching device 22. The boron concentration and alarm signal of channel A or the boron concentration and alarm signal of channel B are transmitted to the relevant equipment in the main control room of the nuclear power plant through the selection of the switching switch of the second signal switching device 22. At the same time, through the selection of the switching switch of the signal switching device 19, the boron concentration, temperature and monitoring status information of channel A or the boron concentration, temperature and monitoring status information of channel B are transmitted to the display box 16 in the form of RS485 communication protocol and displayed.

[0080] Preferably, the first computer device 19 adopts a quadratic function relationship 1 / n=AP for the boron concentration calculation mathematical model. 2 +BP+C, n is the neutron counting rate obtained corresponding to the P concentration at the calibration temperature. Several groups of n~P data pairs are obtained through calibration tests, and the boron concentration calculation coefficients A, B, and C are fitted. In order to improve the measurement accuracy, the boron concentration measurement range is generally divided into two sections, and the coefficients A1, B1, C1 and A2, B2, C2 are fitted in sections.

[0081] As a possible design, the first NIM device 17 includes a main amplifier identification module 23, a first low-voltage power supply module 24, a first high-voltage power supply module 25, and a first analog pre-processing module 26, which adopt a bus design, and the internal functional modules communicate through the bus. The main amplifier identification module 23 is connected to the display transmission unit, and is used to receive the pulse signal output from the first neutron detector 9 and transmit the pulse signal to the first computer device 19. It is designed with discrete components and performs further amplification, pulse shaping, and amplitude identification on the output signal of the first pre-amplifier box 13 of channel A. The identified output square wave pulse signal is collected and counted by the pulse acquisition card in the first computer device 19 of channel A. The first low-voltage power supply module 24 supplies power to the main amplifier identification module 23 and the first analog pre-processing module 26 through the bus; the first high-voltage power supply module 25 is connected to the display transmission unit, and is used to receive the pulse signal output from the first neutron detector 9 and transmit the pulse signal to the first computer device 19. The cable is connected to the first preamplifier box 13 of the display transmission unit, which adopts a design method of discrete components, step-by-step multiplication, filtering control, and mechanical potentiometer to adjust the high-voltage output. The output high voltage is transmitted to the first preamplifier box 13 through a coaxial shielded cable for filtering and then reaches the first neutron detector 9 of channel A; the first analog preprocessing module 26 is connected to the output end of the first signal switching device 21, and is used to convert the temperature current signal into a temperature voltage signal and isolate it and output it to the first computer device 19, and is also used to collect the discrimination threshold pressure and high-voltage mirror signal and isolate it and output it to the first computer device 19.

[0082] As a possible design, the first computer device 19 includes a first relay output board 29, a first analog output board 32, a pulse acquisition card 27, a first RS485 communication board 30, a first IO control board 31 and a first analog input board 28. The first relay output board 29 is used to provide passive switch signals and output alarm information to the external main control device; the first analog output board 32 is used to convert the measured boron concentration within the range into a corresponding 4mA~20mA current signal and transmit it to the relevant equipment in the main control room; the input end of the pulse acquisition card 27 is connected to the output end of the main amplifier discrimination module 23, and is used to collect the neutron square wave pulse signal output by the main amplifier discrimination module 23; the output end of the first RS485 communication board 30 is transmitted to the display box 16 according to the RS485 communication protocol through the second signal switching device 22, and is used to transmit boron concentration, temperature and monitoring status information to the display box 16; the first IO control board 31 is connected to the external main control device, and is used to receive the external main control device boron concentration setting value confirmation and remote self-test trigger. A signal is sent to set the current boron concentration measurement value to the deviation alarm setting value, and the signal processing unit is self-checked and calibrated while the boron concentration measurement is being performed. Specifically, the boron concentration monitoring software controls the IO board to trigger the crystal oscillator frequency signal output inside the main amplifier discrimination module 23, replacing the neutron signal to complete the self-check; the input end of the first analog input board 28 is connected to the output end of the first analog preprocessing module 26, and is used to convert and isolate the current signal of the temperature transmitter box transmitted from the first NIM device 17 into voltage. The module also collects and isolates the threshold voltage and high-voltage mirror signal through the NIM bus for output. The three isolated output signals are sent to the pulse acquisition card 27 in the first computer device 19 of channel A and displayed by the first computer device 19 of channel A. Specifically, the high-voltage mirror signal, the discrimination threshold voltage signal and the temperature voltage signal are processed and displayed by the first analog input board 28 in the following manner: the first analog input board 28 multiplies the high-voltage mirror signal (a low-voltage value, through resistor voltage division, the high voltage range of 0-1500V is mirrored to a low voltage of 0-10V inside the high-voltage module for easy isolation and acquisition) by 150 through computer software, and the final display range is 0-1500V. The discrimination threshold voltage signal itself is a low-voltage signal, which is directly collected and displayed by the analog input board. After the temperature voltage signal is collected by the analog input module, it is multiplied by the corresponding calibration coefficient through computer software to convert it into temperature information and display it (displayed in units of ℃).

[0083] As a possible design, the second NIM device 18 has a different structure from the first NIM device 17 and includes a pulse signal processing module 33 , a second low-voltage power supply module 34 , a second high-voltage power supply module 35 and a second analog pre-processing module 36 . The output end of the pulse signal processing module 33 is connected to the input end of the first signal switching device 21 for outputting pulse counts. It adopts a large-scale integrated circuit design method based on FPGA and DSP, and the computer controls the amplification gain and shaping time to process the neutron signal into a digital signal. The second computer device 20 of the B channel obtains the neutron count rate through the USB interface; the second low-voltage power supply module 34 supplies power to the pulse signal processing module 33 and the second analog preprocessing module 36 through the bus; the second high-voltage power supply module 35 is connected to the second preamplifier box 14 through a cable, and is used to transmit the high voltage after filtering through the second preamplifier box 14 to the second neutron detector 10, providing the second neutron detector 10 with a working high-voltage power supply; the second analog preprocessing module 36 is connected to the output end of the first signal switching device 21, and is used to convert the temperature current signal into a corresponding 1V~5V DC voltage signal and isolate and output it to the second computer device 20 to collect and display the temperature value for temperature correction calculation of boron concentration.

[0084] As a possible design, the above-mentioned second computer device 20 includes a computer universal USB interface, a second relay output board 37, a second analog output board 38, a second RS485 communication board 39, a second IO control board 40 and a second analog input board 41. The second relay output board 37 is used to provide passive switching signals and output alarm information to the external main control device; the second analog output board 38 converts the boron concentration into a corresponding 4mA-20mA current signal, which is then converted into a boron concentration value for display within the relevant equipment in the main control room; the output end of the second RS485 communication board 39 is connected to the display box 16 of the display transmission unit through a second signal switching device, and is used to transmit data information such as the boron concentration, temperature, and monitoring status of the second computer device 20 to the display box 16 according to the RS485 communication protocol; the second IO control board 40 is connected to the external main control device, and is used to receive the external main control device's boron concentration set value confirmation and remote self-test trigger signal, set the current boron concentration measurement value to the deviation alarm set value, and perform self-test calibration on the signal processing unit while performing boron concentration measurement; the input end of the second analog input board 41 is connected to the output end of the second analog preprocessing module 36, and is used to collect the high-voltage mirror signal, discrimination threshold pressure signal, and temperature voltage signal output by the second analog preprocessing module 36, and process and display them. Specifically, the high-voltage mirror signal, the discrimination threshold pressure signal and the temperature voltage signal are processed and displayed by the second analog preprocessing module 36 in the following manner: the second analog preprocessing module 36 multiplies the high-voltage mirror signal (a low-voltage value, through resistor voltage division, the high-voltage range of 0-1500V is mirrored to a low voltage of 0-10V inside the high-voltage module for easy isolation and acquisition) by 150 through computer software, and the final display range is 0-1500V. The discrimination threshold pressure signal itself is a low-voltage signal, which is directly collected and displayed by the second analog input board 41. After the temperature voltage signal is collected by the analog input module, it is multiplied by the corresponding calibration coefficient through computer software to convert it into temperature information and display it (displayed in units of ℃).

[0085] The specific implementation methods described above further illustrate the purpose, technical solutions and beneficial effects of the utility model in detail. It should be understood that the above description is only a specific implementation method of the utility model and is not intended to limit the scope of protection of the utility model. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the utility model should be included in the scope of protection of the utility model.

Claims

1. A redundant and diverse boron concentration online monitoring device, characterized in that: include An input pipeline (1) is connected to the external nuclear sampling circuit and is used to receive the boron solution; A metal container (2) is connected to the input pipeline (1) and is used to contain the boron solution for monitoring; An output pipeline (3) is connected to the metal cavity (2) and the external nuclear sampling circuit respectively, and is used to send out the measured boron solution; A shell (4) wrapped around the outside of the metal cavity (2) for shielding neutrons; a neutron source (5), located in the metal cavity (2), for emitting neutrons; a neutron source assembly (6), installed in the housing (4) and used for shielding neutron rays and gamma rays; A neutron detector assembly (7) is inserted into the metal cavity (2) and is used to detect neutrons absorbed by the boron solution; The temperature detector (8) is installed on the output pipeline (3) and is used to detect the temperature of the boron solution being measured.

2. The redundant and diverse boron concentration online monitoring device according to claim 1, characterized in that: The neutron detector group (7) includes a plurality of neutron detectors of different types.

3. A redundant and diverse boron concentration online monitoring device according to claim 1 or 2, characterized in that: The neutron detector group (7) comprises a first neutron detector (9) and a second neutron detector (10).

4. The redundant and diverse boron concentration online monitoring device according to claim 1, characterized in that: It also includes a shielding body (11), which is filled between the metal cavity (2) and the shell (4).

5. The redundant and diverse boron concentration online monitoring device according to claim 3, characterized in that: It also includes a display transmission unit, which is connected to the first neutron detector (9), the second neutron detector (10) and the temperature detector (8) and is used to output a neutron detector pulse signal and a temperature resistance signal.

6. The redundant and diverse boron concentration online monitoring device according to claim 5, characterized in that: The display transmission unit comprises a first preamplifier box (13), a second preamplifier box (14), a temperature transmitter box (15) and a display box (16). The input end of the first preamplifier box (13) is connected to the output end of the first neutron detector (9) by a cable, and is used to receive and amplify the neutron detector pulse signal; The input end of the second preamplifier box (14) is connected to the output end of the second neutron detector (10) by a cable, and is used to receive and amplify the neutron detector pulse signal; The input end of the temperature transmitter box (15) is connected to the output end of the temperature detector (8) by a cable, and is used to receive the temperature resistance signal and convert the temperature resistance signal into a current signal; The display box (16) is used to display boron concentration, temperature and monitoring status information.

7. The redundant and diverse boron concentration online monitoring device according to claim 5, characterized in that: Also includes a signal processing unit, The input end of the signal processing unit is connected to the output end of the display transmission unit, and is used to collect and count pulse signals and receive temperature and current signals; The output end of the signal processing unit is connected to the input end of the display transmission unit, and is used to transmit the boron concentration, boron solution temperature and monitoring status information to the display transmission unit for display.

8. The redundant and diverse boron concentration online monitoring device according to claim 7, characterized in that: The signal processing unit includes a first NIM device (17), a second NIM device (18), a first computer device (19), a second computer device (20), a first signal switching device (21) and a second signal switching device (22), The first NIM device (17) input end and the second NIM device (18) input end are respectively connected to the display transmission unit, the first NIM device (17) is used to transmit the pulse signal output from the first neutron detector (9), and the second NIM device (18) is used to transmit the pulse signal output from the second neutron detector (10); The first computer device (19) has an input end connected to an output end of the first NIM device (17) and an output end connected to an input end of a second signal switching device (22), and is used to collect and count pulse signals output by the first NIM device (17), and to convert temperature current signals input from the first signal switching device (21) into temperature voltage signals, and to obtain boron concentration and alarm logic through pulse counting and temperature voltage signals; The second computer device (20) has an input end connected to an output end of the second NIM device (18) and an output end connected to an input end of a second signal switching device (22), and is used to read the neutron count rate output by the second NIM device (18), and to convert the temperature current signal input from the first signal switching device (21) into a temperature voltage signal, and further to obtain a boron concentration and an alarm logic through the neutron count rate and the temperature voltage signal; The input end of the first signal switching device (21) is connected to the display transmission unit and is used to receive the temperature current signal output from the temperature detector (8); the output end of the first signal switching device (21) is connected to the input end of the first NIM device (17) and the second NIM device (18) respectively, and is used to transmit the temperature current signal to the first NIM device (17) or the second NIM device (18) for processing; The input end of the second signal switching device (22) is connected to the output end of the first computer device (19) and the output end of the second computer device (20), respectively, and is used to transmit the boron concentration and alarm logic output by the first computer device (19) or the boron concentration and alarm logic output by the second computer device (20) to the external main control device, and is also used to transmit the boron concentration and alarm logic output by the first computer device (19) or the boron concentration, temperature and monitoring status information output by the second computer device (20) to the display transmission unit.

9. The redundant and diverse boron concentration online monitoring device according to claim 8, characterized in that: The first NIM device (17) includes a main amplifier identification module (23), a first low-voltage power supply module (24), a first high-voltage power supply module (25) and a first analog pre-processing module (26). The main amplification and discrimination module (23) is connected to the display transmission unit, and is used to receive the pulse signal output from the first neutron detector (9), and to transmit the pulse signal to the first computer device (19); The first low-voltage power supply module (24) supplies power to the main amplifier identification module (23), the first high-voltage power supply module (25) and the first analog pre-processing module (26) through a bus; The first high-voltage power supply module (25) is connected to the display transmission unit via a cable, and is used to transmit the high voltage to the first neutron detector (9) after filtering by the display transmission unit; The first analog preprocessing module (26) is connected to the output end of the first signal switching device (21), and is used to convert the temperature current signal into a temperature voltage signal and output it to the first computer device (19) in isolation. It is also used to collect the discrimination threshold voltage output by the main amplifier discrimination module (23) and the high-voltage mirror signal output by the first high-voltage power supply module (25), and output them to the first computer device (19) in isolation.

10. The redundant and diverse boron concentration online monitoring device according to claim 9, characterized in that: The first computer device (19) includes a first relay output board (29), a first analog output board (32), a pulse acquisition card (27), a first RS485 communication board (30), a first IO control board (31) and a first analog input board (28), The first relay output board (29) is used to provide a passive switching signal and output alarm information to an external main control device; The first analog output board (32) converts the boron concentration into a current signal and outputs it to an external main control device; The input end of the pulse acquisition card (27) is connected to the output end of the main amplification and discrimination module (23) and is used to acquire the neutron square wave pulse signal output by the main amplification and discrimination module (23); The output end of the first RS485 communication board (30) is connected to the display transmission unit and is used to transmit boron concentration, temperature and monitoring status information to the display transmission unit; The first IO control board (31) is connected to an external main control device and is used to receive a boron concentration setting value confirmation and a remote self-test trigger signal from the external main control device, set the current boron concentration measurement value as a deviation alarm setting value, and perform self-test calibration on the signal processing unit while performing boron concentration measurement; The input end of the first analog input board (28) is connected to the output end of the first analog pre-processing module (26) and is used to collect the high-voltage mirror signal, the discrimination threshold pressure signal and the temperature voltage signal output by the first analog pre-processing module (26), and process and display them.

11. The redundant and diverse boron concentration online monitoring device according to claim 8, characterized in that: The second NIM device (18) includes a pulse signal processing module (33), a second low-voltage power supply module (34), a second high-voltage power supply module (35) and a second analog pre-processing module (36). The output end of the pulse signal processing module (33) is connected to the input end of the first signal switching device (21) for outputting pulse counts; The second low-voltage power supply module (34) supplies power to the pulse signal processing module (33), the second high-voltage power supply module (35) and the second analog pre-processing module (36) via a bus; The second high-voltage power supply module (35) is connected to the display transmission unit via a cable, and is used to transmit the high voltage to the second neutron detector (10) after filtering by the display transmission unit; The second analog preprocessing module (36) is connected to the output end of the first signal switching device (21), and is used to convert the temperature current signal into a temperature voltage signal and output it in isolation to the second computer device (20). It is also used to collect the discrimination threshold voltage output by the pulse signal processing module (33) and the high-voltage mirror signal output by the second high-voltage power supply module (35), and output them in isolation to the second computer device (20).

12. The redundant and diverse boron concentration online monitoring device according to claim 11, characterized in that: The second computer device (20) includes a second relay output board (37), a second analog output board (38), a second RS485 communication board (39), a second IO control board (40) and a second analog input board (41), The second relay output board (37) is used to provide a passive switching signal and output alarm information to an external main control device; The second analog output board (38) converts the boron concentration into a current signal and outputs it to an external main control device; The output end of the second RS485 communication board (39) is connected to the display transmission unit and is used to transmit boron concentration, temperature and monitoring status information to the display transmission unit; The second IO control board (40) is connected to an external main control device and is used to receive a boron concentration setting value confirmation and a remote self-test trigger signal from the external main control device, set the current boron concentration measurement value as a deviation alarm setting value, and perform self-test calibration on the signal processing unit while performing boron concentration measurement; The input end of the second analog input board (41) is connected to the output end of the second analog pre-processing module (36) and is used to collect the high-voltage mirror signal, the discrimination threshold pressure signal and the temperature voltage signal output by the second analog pre-processing module (36), and process and display them.

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