High-reliability compensation type cable type liquid level meter

Abstract

The invention belongs to the technical field of nuclear power station spent pool liquid level detection, and particularly relates to a high-reliability compensation type cable liquid level meter which comprises an on-site measurement assembly and an on-site instrument box, and the on-site measurement assembly is connected with the on-site instrument box through a coaxial cable. The field measurement assembly is used for measuring the liquid level of the spent fuel pool in real time, generating a high-frequency electromagnetic wave analog signal and transmitting the high-frequency electromagnetic wave analog signal to the on-site instrument box; and the in-situ instrument box is used for receiving the high-frequency electromagnetic wave analog signal, converting the analog signal into a digital signal, processing the digital signal to obtain liquid level information of the spent fuel pool, and outputting the liquid level information of the spent fuel pool to the main control room. The liquid level of the spent pool in the nuclear power station can be accurately monitored.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of nuclear power plant spent pool liquid level detection, and particularly relates to a high-reliability compensating cable type liquid level meter. BACKGROUND

[0002] The ordinary nuclear power plant spent pool liquid level meter is applied to the spent pool of a nuclear power plant to monitor the water level height in the spent pool, but the monitoring precision is easily affected by external interference; when the detected water level height is affected by external influence and incorrectly displayed, the main control of the nuclear power plant cannot correctly determine the spent pool water level, and the control system of the nuclear power plant and the power generation process of the entire unit and possible critical conditions cannot be timely known.

[0003] At present, the ordinary nuclear power plant spent pool liquid level meter has low display precision and is easily affected by external interference; when the water level rapidly rises or falls, the cable is unstable and has a shaking phenomenon, at this time, the liquid level meter is easily affected by the rapid change of the water level, leading to incorrect liquid level monitoring of the liquid level meter, so that the liquid level of the spent pool cannot be correctly monitored, and thus a major accident can be caused.

[0004] Therefore, it is urgent to develop a liquid level meter for monitoring the liquid level of a nuclear power plant spent pool to solve the problems of the ordinary nuclear power plant spent pool liquid level. SUMMARY

[0005] The application aims to provide a high-reliability compensating cable type liquid level meter capable of accurately monitoring the liquid level of a spent pool in a nuclear power plant.

[0006] The technical scheme for achieving the application is as follows:

[0007] The high-reliability compensating cable type liquid level meter comprises a field measurement assembly and an on-site instrument box, and the field measurement assembly is connected with the on-site instrument box through a coaxial cable; the field measurement assembly is used to measure the liquid level of the spent pool in real time, generate a high-frequency electromagnetic wave analog signal, and transmit the high-frequency electromagnetic wave analog signal to the on-site instrument box; the on-site instrument box is used to receive the high-frequency electromagnetic wave analog signal, convert the analog signal into a digital signal, process the digital signal to obtain spent pool liquid level information, and output the spent pool liquid level information to a main control room.

[0008] Further, the spent pool liquid level information is output to the main control room through a digital signal and an analog signal.

[0009] Further, the field measurement assembly comprises a flange, an antenna, an antenna sleeve, a PEEK assembly, and a sealing element; the flange is fixedly connected to the antenna sleeve, the PEEK assembly is fixedly connected to the flange, the antenna is arranged in the antenna sleeve, the coaxial cable penetrates the flange through the PEEK assembly, one end of the coaxial cable is connected with the antenna, and the sealing element is arranged between the coaxial cable and the PEEK assembly.

[0010] Further, the on-site instrument box comprises a radio frequency board card, an algorithm processing board card, and a connection between the radio frequency board card and the algorithm processing board card, the radio frequency board card receives high-frequency electromagnetic wave analog signals, processes the analog signals, and converts the analog signals into digital signals, and the algorithm processing board card processes the digital signals through a lead prediction algorithm, a pattern recognition algorithm, and an active noise reduction algorithm to obtain accurate spent pool liquid level information and output the spent pool liquid level information to a main control room.

[0011] Further, the radio frequency board card comprises a radio frequency transceiver component, a frequency mixer, a hardware filter circuit, and a sampler, which are connected in sequence, the radio frequency transceiver component is used for transmitting and receiving high-frequency electromagnetic wave analog signals, the frequency mixer is used for adjusting the frequency of the analog signals, the hardware filter circuit is used for processing the analog signals and removing interference signals, and the sampler is used for converting the analog signals into digital signals.

[0012] Further, the hardware filter circuit comprises a high-frequency filter and a Butterworth filter.

[0013] Further, the on-site instrument box further comprises a display board card, which is used for displaying the actual liquid level, setting various parameters of the radio frequency board card and the algorithm processing board card, and debugging parameters.

[0014] Further, the on-site instrument box further comprises a power supply board card, which is used for power supply of the entire liquid level meter system.

[0015] Further, the on-site instrument box further comprises an alarm board card, which is used for alarming when the spent pool liquid level height exceeds a preset liquid level threshold and generating an alarm signal to be transmitted to the main control room.

[0016] Further, the spent pool liquid level information is output to the main control room through a continuous liquid level signal transmission cable, and the alarm signal is transmitted to the main control room through a liquid level alarm signal transmission cable.

[0017] The beneficial technical effects of the present application are as follows:

[0018] 1. The high-reliability and compensation type cable liquid level meter provided by the present application can effectively identify the accurate position of the liquid level and actively avoid false liquid levels through the lead prediction algorithm, the pattern recognition algorithm, and the active noise reduction algorithm, so that the accurate liquid level of the liquid level collection and echo curve processing is realized, the measurement accuracy of the spent pool liquid level is greatly improved, and the stable operation of the nuclear power plant is effectively ensured.

[0019] 2. The high-reliability compensation cable type liquid level meter provided by the application effectively shields external interference by adding an antenna sleeve; reduces the error and false liquid level generated by the antenna during shaking; the design of the antenna sleeve improves the transmission stability of electromagnetic waves; reduces the distortion of the measurement echo; directly ensures the accuracy of the electronic circuit part of the on-site instrument box in processing the spent pool liquid level echo signal; indirectly ensures the accuracy of the output liquid level.

[0020] 3. The high-reliability compensation cable type liquid level meter provided by the application accurately transmits the liquid level to the main control room of the nuclear power plant through analog signals and digital communication; when the analog signal fails, the digital signal can transmit the spent pool liquid level; when the digital signal fails, the analog signal can transmit the accurate spent pool liquid level; through the dual redundancy mode, the accuracy and safety of the transmission of the spent pool liquid level are greatly improved. It effectively avoids the loss and danger caused by the power generation process of the nuclear power plant.

[0021] 4. The high-reliability compensation cable type liquid level meter provided by the application adopts a structure with separate measurement and transmission processing, the transmission processing part is installed in an environment and buffer area, and the measurement part has no electronic components, thereby improving the degree of resistance of the liquid level meter to harsh environments and prolonging the service life of the liquid level meter.

[0022] 5. The high-reliability compensation cable type liquid level meter provided by the application resists the extremely harsh environment of high radiation and high temperature under severe accident conditions in the nuclear power plant reactor building, ensures the continuous and stable measurement of the liquid level in the spent pool under accident conditions and after the accident, protects the safety function of the power plant, and reduces the impact of the accident.

[0023] 6. The high-reliability compensation cable type liquid level meter provided by the application allows workers to debug and verify the instrument in an environment and buffer area, is convenient to maintain, and is conducive to the control of the collective dose of the work group. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 The high-reliability compensation cable type liquid level meter structure schematic diagram provided by the embodiment of the application;

[0025] Figure 2 The high-reliability compensation cable type liquid level meter local structure schematic diagram provided by the embodiment of the application;

[0026] Figure 3 The electronic circuit schematic diagram of the on-site instrument box in the high-reliability compensation cable type liquid level meter provided by the embodiment of the application.

[0027] In the figure: 1 - field measurement assembly; 2 - coaxial cable; 3 - on-site instrument box; 4 - on-site instrument box power supply cable; 5 - main control room; 6 - continuous liquid level signal transmission cable; 7 - liquid level alarm signal transmission cable; 8 - antenna sleeve. DETAILED DESCRIPTION

[0028] The application will be further described in detail below in combination with the drawings and examples.

[0029] The application provides a high-reliability compensation type cable liquid level meter, comprising a field measurement assembly 1 and an on-site instrument box 3, wherein the field measurement assembly 1 is connected with the on-site instrument box 3 through a coaxial cable 2; the field measurement assembly 1 is used for measuring the pool liquid level in real time, generating a high-frequency electromagnetic wave analog signal, and transmitting the high-frequency electromagnetic wave analog signal to the on-site instrument box 3.

[0030] The on-site instrument box 3 is used for receiving the high-frequency electromagnetic wave analog signal, converting the analog signal into a digital signal, processing the digital signal to obtain pool liquid level information, and outputting the pool liquid level information to a main control room.

[0031] The pool liquid level information is output through RS485 digital signals and analog 4-20mA signals, and the double-path output accurate liquid level signal is redundant to each other; when the analog signal fails, the digital signal can continue to transmit the pool liquid level height; when the digital signal fails, the analog signal can continue to output the pool liquid level height.

[0032] The field measurement assembly 1 comprises a flange, an antenna, an antenna sleeve, a PEEK assembly and a sealing element; the flange is fixedly connected to the antenna sleeve, the PEEK assembly is fixedly connected to the flange, the antenna is arranged in the antenna sleeve, the coaxial cable penetrates through the flange through the PEEK assembly, one end of the coaxial cable is connected with the antenna, and the sealing element is arranged between the coaxial cable and the PEEK assembly, so as to prevent external substances from entering the inside of the antenna sleeve and affecting the measurement effect.

[0033] In a specific embodiment, the antenna sleeve and the flange are linked through threads, and then are welded to firmly combine the two into one whole. After welding, the welding can be checked by a flaw detection device to confirm whether there is a crack.

[0034] The PEEK assembly and the flange are linked through threads, and then are welded to firmly combine the two into one whole.

[0035] The antenna is a cable antenna. The sealing element can be an O-shaped sealing ring.

[0036] The antenna sleeve can effectively shield external interference and greatly protect electromagnetic wave transmission. The electromagnetic wave is transmitted through the cable antenna, and the liquid level is measured by using the TDR principle. The application of the antenna sleeve effectively solves the influence of external factors on electromagnetic wave transmission, so that the on-site measurement assembly can generate a good high-frequency electromagnetic wave analog signal, and the high-frequency electromagnetic wave analog signal is transmitted to the on-site instrument box.

[0037] The electronic circuit of the on-site instrument box obtains a good high-frequency electromagnetic wave analog signal; the high-frequency electromagnetic wave analog signal is adjusted in frequency by a mixer, a hardware filter circuit and a sampler in the electronic circuit, the analog signal is processed and interference signals are removed, and the analog signal is converted into a digital signal; the digital signal is further processed by a lead prediction algorithm, a pattern recognition algorithm and an active noise reduction algorithm to accurately calculate the spent pool liquid level; and the nuclear power plant control room obtains accurate spent pool liquid level information, thereby ensuring the safe operation of the nuclear power plant.

[0038] Specifically, the electronic circuit of the on-site instrument box includes a radio frequency board card and an algorithm processing board card, the radio frequency board card and the algorithm processing board card are connected, the radio frequency board card receives a high-frequency electromagnetic wave analog signal, processes the analog signal, and converts the analog signal into a digital signal; and the algorithm processing board card processes the digital signal by a lead prediction algorithm, a pattern recognition algorithm and an active noise reduction algorithm to obtain accurate spent pool liquid level information, and outputs the spent pool liquid level information to the control room through analog signals and digital signals.

[0039] The spent pool liquid level information is output to the control room through a continuous liquid level signal transmission cable.

[0040] The radio frequency board card includes a radio frequency transceiver assembly, a mixer, a hardware filter circuit and a sampler, which are connected in sequence; the radio frequency transceiver assembly is used to transmit and receive a high-frequency electromagnetic wave analog signal; the mixer is used to adjust the frequency of the analog signal; the hardware filter circuit is used to process the analog signal and remove interference signals; and the sampler is used to convert the analog signal into a digital signal.

[0041] The hardware filter circuit can be a high-frequency filter or a Butterworth filter.

[0042] The electronic circuit of the on-site instrument box further includes a power supply board card, a display board card and an alarm board card.

[0043] The display board card is used to display the actual liquid level, including the height of the spent pool liquid level and the height of the liquid level to the upper edge of the spent pool; and is also used to set various parameters of the radio frequency board card and the algorithm processing board card, and to debug parameters. For example, the use parameters of the algorithm processing board card are set through a connector.

[0044] The power supply board card is used for power supply of the whole liquid level meter system, can accept 220VAC and 24VDC power supply, and then supply power to the whole liquid level meter system through a voltage reduction module such as LDO, to ensure good operation of the liquid level meter.

[0045] The alarm board card is used for alarming when the liquid level height of the spent pool exceeds the preset liquid level threshold, and generates an alarm signal transmitted to the main control room.

[0046] The alarm signal is transmitted to the main control room through a liquid level alarm signal transmission cable.

[0047] The measurement assembly part mainly plays a protective and transmission role for the conduction of electromagnetic waves, shields external interference, and provides a liquid level signal for the electronic circuit part of the on-site instrument box. The electronic circuit part of the on-site instrument box is mainly used for sampling, processing, prediction, identification, calculation of high-frequency electromagnetic wave analog signals, real-time monitoring of the spent pool liquid level, and providing liquid level information, alarm and other functions for the main control room.

[0048] The electronic circuit part of the on-site instrument box processes the spent pool liquid level signal returned by the on-site measurement assembly, processes through algorithms such as advanced prediction, pattern recognition, and active noise reduction, forms liquid level information and provides it to the client. Provide reliable, accurate and effective spent pool liquid level information for the customer.

[0049] Embodiment 1

[0050] In this embodiment, the on-site instrument box adopts GWR-BOX assembly; the on-site measurement assembly adopts GWR-SPD assembly; the flange adopts GWR-SL assembly; the PEEK piece adopts GWR-PEEK assembly; the antenna sleeve adopts GWR-DL assembly; the radio frequency board card adopts RF board card; the algorithm processing board card adopts MCU board card; the alarm board card adopts ALARM board card; the power supply board card adopts POWER board card; the display board card adopts UI board card. The main control room of the nuclear power plant adopts DCC system.

[0051] The digital computer controller (DCC) is a real-time control system used to control process variables, execute instructions, realize human-computer interaction, output alarms or correction information, and ensure the safe and stable operation of the nuclear power plant.

[0052] The cable type liquid level meter GWR includes an on-site instrument box GWR-BOX, an on-site measurement assembly GWR-SPD, and a coaxial cable. The on-site measurement assembly GWR-SPD is connected to the on-site instrument box through the coaxial cable. The cable type liquid level meter GWR is a subsystem of the nuclear power plant for monitoring the spent pool liquid level through the DCC system.

[0053] As Figure 1As shown, the embodiment provides a high-reliability, compensation type cable liquid level meter, comprising: a local instrument box and a field measurement component, namely GWR-BOX and GWR-SPD.

[0054] The field measurement component GWR-SPD contains a standard flange GWR-SL, an antenna sleeve GWR-DL, and a sealing element GWR-PEEK.

[0055] In the embodiment, the PEEK component, the antenna sleeve GWR-DL, and the standard flange GWR-SL in the field measurement component GWR-SPD are combined into a whole through threading and welding.

[0056] The antenna sleeve GWR-DL and the flange GWR-SL are linked through threading, then welded, and then subjected to flaw detection equipment to confirm whether the welding has cracks, so that the two can be firmly combined into a whole, as shown in Figure 2 As shown, it is a structural diagram of the cable liquid level meter.

[0057] In the embodiment, the coaxial cable can be a K1 level coaxial cable.

[0058] The local instrument box GWR-BOX contains an RF board card, an MUC board card, an ALARM board card, a POWER board card, a UI board card, and a peripheral auxiliary board card, and a link board card.

[0059] The local instrument box GWR-BOX contains various electronic circuit board cards, and the various board cards are connected through various carrier boards and backplanes, can output analog liquid level and digital liquid level, and has a 9-way alarm function. Although the nine-way alarm function cannot accurately display the actual liquid level, it can indicate the area where the liquid level is located, and plays a warning role.

[0060] The RF board card is the core module of the cable liquid level, connected with the MCU board through a wiring terminal, used for transmitting and receiving high-frequency electromagnetic wave analog signals, processing the analog signals through a hardware filter circuit, and converting the processed analog signals into digital signals through a sampler.

[0061] The MCU board card is the core of data processing, which obtains accurate spent pool liquid level information through a lead prediction algorithm, a Butterworth filter, and an active noise reduction algorithm; and transmits the spent pool liquid level information to the main control room of the nuclear power plant through analog signals, digital signals, and alarm signals.

[0062] The UI board card is a circuit board for displaying the actual liquid level, which can display the height of the spent pool liquid level and the height of the liquid level to the upper edge of the spent pool, and can set various parameters, set the use parameters of the MCU board through a connector, and debug.

[0063] The POWER board card is a power supply board card of the whole system, can accept 220VAC and 24VDC power supply, and then supplies power for the whole liquid level meter system through a LDO voltage reduction module, to ensure good operation of the liquid level meter.

[0064] In the embodiment, as shown in FIG. 1, the RF board card, the MCU board card, the POWER board card and the UI board card are combined into a whole through various adapter boards and connectors in the GWR-BOX. Figure 3

[0065] The application is described in detail above in combination with the drawings and the embodiments, but the application is not limited to the above embodiments, and various changes can be made within the knowledge of those skilled in the art without departing from the purpose of the application. The contents not described in detail in the application can adopt the prior art.​

Claims

1. A high reliability, compensating cable type liquid level gauge, characterized in that, The application relates to a liquid level measuring system for a spent fuel pool. The spent fuel pool liquid level information is output to a main control room through a digital signal and an analog signal.

2. A high reliability, compensating cable type liquid level meter according to claim 1, characterized in that, The field measurement component comprises a flange, an antenna, an antenna sleeve, a PEEK component and a sealing element; the flange is fixedly connected to the antenna sleeve, the PEEK component is fixedly connected to the flange, the antenna is arranged in the antenna sleeve, the coaxial cable penetrates through the flange through the PEEK component, one end of the coaxial cable is connected to the antenna, and the sealing element is arranged between the coaxial cable and the PEEK component.

3. The high reliability, compensated cable level gauge of claim 1, wherein, The on-site instrument box comprises a radio frequency board card and an algorithm processing board card, the radio frequency board card receives the high-frequency electromagnetic wave analog signal, processes the analog signal and converts the analog signal into a digital signal, the algorithm processing board card processes the digital signal through a lead prediction algorithm, a pattern recognition algorithm and an active noise reduction algorithm, obtains accurate spent fuel pool liquid level information and outputs the spent fuel pool liquid level information to the main control room.

4. The high reliability, compensated cable level gauge of claim 1, wherein, The radio frequency board card comprises a radio frequency transceiver component, a mixer, a hardware filtering circuit and a sampler which are sequentially connected; the radio frequency transceiver component is used for transmitting and receiving the high-frequency electromagnetic wave analog signal; the mixer is used for adjusting the frequency of the analog signal; the hardware filtering circuit is used for processing the analog signal and removing interference signals; and the sampler is used for converting the analog signal into a digital signal.

5. A high reliability, compensating cable level gauge according to claim 4, characterized in that, The hardware filtering circuit comprises a high-frequency filter and a Butterworth filter.

6. A high reliability, compensated cable level gauge according to claim 5, characterized in that, The on-site instrument box further comprises a display board card which is used for displaying an actual liquid level, setting various parameters of the radio frequency board card and the algorithm processing board card and adjusting parameters.

7. The high reliability, compensated cable level gauge of claim 1, wherein, The on-site instrument box further comprises a power supply board card which is used for power supply of the entire liquid level meter system.

8. The high reliability, compensated cable level gauge of claim 1, wherein, The on-site instrument box further comprises an alarm board card which is used for alarming when the spent fuel pool liquid level height exceeds a preset liquid level threshold and generating an alarm signal which is transmitted to the main control room.

9. The high reliability, compensated cable level gauge of claim 1, wherein, The spent fuel pool liquid level information is output to the main control room through a continuous liquid level signal transmission cable; and the alarm signal is transmitted to the main control room through a liquid level alarm signal transmission cable.

10. A high reliability, compensated cable level gauge according to claim 9, characterized in that, ​

Images