Nuclear power plant pipeline temperature wireless monitoring system based on SAW technology

Abstract

The application discloses a nuclear power plant pipeline temperature wireless monitoring system based on SAW technology and relates to the technical field of nuclear power plants.The technical scheme is as follows: a temperature sensor group comprises a plurality of SAW temperature sensors arranged at different measuring point positions of a nuclear power plant pipeline, so as to measure temperature data of different measuring point positions of the same section of the nuclear power plant pipeline; a temperature acquisition and processing unit is used for collecting a temperature data set of the measuring point positions corresponding to at least one pipeline section of the nuclear power plant pipeline; and a temperature reconstruction processing unit is used for obtaining the monitoring temperature of the corresponding pipeline section after temperature field reconstruction of the corresponding pipeline section according to the temperature data set.The application uses SAW temperature sensors, does not need power supply and electrical connection cables, has simple structure, small volume and low maintenance cost, can adapt to the high-temperature and strong radiation environment of the nuclear power plant, and can obtain more accurate monitoring temperature of the pipeline section through the pipeline temperature analysis by the temperature field reconstruction method.

Description

Technical Field

[0001] This invention relates to the field of nuclear power plant technology, and more specifically, to a wireless monitoring system for pipeline temperature in nuclear power plants based on SAW technology. Background Technology

[0002] The management of severe accidents at nuclear power plants is receiving increasing attention, and the concept of severe accident management has been strengthened in the design of nuclear power plants, along with the increased application of fatigue monitoring systems. To achieve condition monitoring of key equipment components in nuclear power plants and to complete automated statistical analysis of transient operating conditions, it is necessary to monitor the temperature of nuclear power plant pipelines.

[0003] Currently, the primary method for monitoring the temperature of pipelines in nuclear power plants is through traditional wired temperature sensors (thermocouples / resistance temperature detectors). While these sensors can accurately and reliably acquire temperature values ​​at relevant locations and display trends, they require transmission cables and a power supply, making installation, disassembly, and maintenance quite difficult. Furthermore, monitoring the temperature of pipelines in nuclear power plants necessitates deploying numerous temperature sensors at different locations. The transmission signals from these sensors must pass through the containment structure via cables, occupying a significant number of containment penetration ports.

[0004] Therefore, how to research and design a wireless monitoring system for nuclear power plant pipeline temperature that can overcome the above-mentioned defects is an urgent problem that we need to solve. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the purpose of this invention is to provide a wireless monitoring system for nuclear power plant pipeline temperature based on SAW technology. This system uses a surface acoustic wave (SAW) temperature sensor, eliminating the need for power supply and electrical connection cables. It features a simple structure, small size, and low maintenance costs, and can adapt to the high-temperature and high-radiation environments of nuclear power plants. Furthermore, by using a temperature field reconstruction method for pipeline temperature analysis, more accurate monitoring temperatures of pipeline cross-sections can be obtained.

[0006] The above-mentioned technical objective of this invention is achieved through the following technical solution: a wireless monitoring system for pipeline temperature in nuclear power plants based on SAW technology, comprising:

[0007] The temperature sensor array includes multiple SAW temperature sensors arranged at different measuring points on the pipeline of the nuclear power plant to measure temperature data at different measuring points on the same cross section of the pipeline of the nuclear power plant.

[0008] The temperature acquisition and processing unit is used to acquire temperature data at the location of the measuring point corresponding to at least one cross section of a pipeline in a nuclear power plant pipeline.

[0009] The temperature reconstruction processing unit is used to reconstruct the temperature field of the corresponding pipe section based on the temperature dataset to obtain the monitoring temperature of the corresponding pipe section.

[0010] Furthermore, the specific process of reconstructing the temperature field of the corresponding pipe cross-section based on the temperature dataset is as follows:

[0011] Extract multiple temperature data sequences from the temperature dataset according to a preset sequence length;

[0012] The least squares method was used to interpolate different temperature data sequences, and multiple temperature data curves were obtained by fitting.

[0013] Temperature data at the same measuring point location is extracted from multiple temperature data curves to obtain a temperature data set for the corresponding measuring point location.

[0014] The average value of each temperature data in the temperature data set is used as the monitoring value of the corresponding measuring point. After removing outliers from all monitoring values ​​with the minimum fluctuation threshold, and inputting the remaining monitoring values ​​into the matching temperature field model, the average temperature of the reconstructed temperature field is calculated, and the monitoring temperature of the corresponding pipe section is obtained.

[0015] Furthermore, the specific process of extracting the temperature data sequence is as follows:

[0016] Randomly select the measurement point location corresponding to a temperature data point from the temperature dataset as the starting point;

[0017] The initial temperature data sequence is extracted along a single circumferential direction from the starting point according to the preset sequence length.

[0018] The initial temperature data sequence is shifted one sequence interval along a single circumference until the last temperature data sequence is the same as the initial temperature data sequence, resulting in multiple different temperature data sequences.

[0019] Furthermore, the specific process of extracting the temperature data sequence is as follows:

[0020] Select the location of a measurement point corresponding to a temperature data point from the temperature dataset as the starting point;

[0021] A set of temperature data sequences is sequentially extracted along a single circumferential direction from the starting point according to the preset sequence length. The temperature data sequences in the same set cover all temperature data in the temperature dataset, and the end point of the previous extracted temperature data sequence is adjacent to the start point of the next extracted temperature data sequence.

[0022] By selecting different starting points, multiple sets of different temperature data sequences can be obtained.

[0023] Furthermore, the process of clearing outliers from all monitored values ​​using the minimum fluctuation threshold specifically involves:

[0024] The average of all monitored values ​​is used as the standard value;

[0025] Determine whether the absolute value of the difference between the monitored value and the standard value exceeds the minimum fluctuation threshold. If it does, the corresponding monitored value is removed as an outlier.

[0026] Furthermore, the temperature acquisition and processing unit includes multiple temperature readers and multiple front-end antennas;

[0027] Multiple temperature readers transmit signals to the temperature reconstruction processing unit via a bus.

[0028] The SAW temperature sensor transmits temperature signals wirelessly to the front-end antenna.

[0029] The main body of the temperature reader has multiple radio frequency inputs, and the front-end antenna is connected to the main body of the temperature reader via a radio frequency cable.

[0030] Furthermore, the temperature reader sends a query signal to the SAW temperature sensor via a front-end antenna;

[0031] The query signal is received by the built-in antenna of the SAW temperature sensor.

[0032] When the temperature of the nuclear power plant pipeline changes, the SAW temperature sensor responds to the query signal and then transmits a wireless signal carrying the temperature information of the measuring point of the nuclear power plant pipeline through its built-in antenna.

[0033] The front-end antenna of the temperature reader receives wireless signals.

[0034] Furthermore, the front-end antenna adopts a one-to-many wireless transmission method, which enables the transmission of query signals from multiple SAW temperature sensors and the reception of wireless signals through a single front-end antenna.

[0035] Furthermore, the SAW temperature sensor includes a sensor body, a sensor base, and a sensor pedestal;

[0036] The sensor body is connected to the sensor base;

[0037] The sensor base is welded onto a pipeline in a nuclear power plant.

[0038] The contact surface between the sensor base and the nuclear power plant pipeline is machined into an arc shape corresponding to the outer diameter of different pipelines.

[0039] The sensor base has a slot in the middle to accommodate a tuning fork-shaped sensor base;

[0040] A countersunk hole is provided at the center of the sensor base for installing fastening bolts.

[0041] Furthermore, the matching process of the temperature field model is as follows:

[0042] The temperature field distribution model of different pipeline locations under different operating conditions was obtained through simulation.

[0043] By comparing the model adaptability using multi-point temperature data collected from the pipe cross-section, the optimal temperature field model was obtained.

[0044] Compared with the prior art, the present invention has the following beneficial effects:

[0045] 1. The wireless monitoring system for nuclear power plant pipeline temperature based on SAW technology provided by this invention uses a surface acoustic wave (SAW) temperature sensor, which does not require power supply or electrical connection cables. It has a simple structure, small size, and low maintenance cost, and can adapt to the high temperature and strong radiation environment of nuclear power plants. Furthermore, by using the temperature field reconstruction method to analyze pipeline temperature, more accurate monitoring temperature of pipeline cross-sections can be obtained.

[0046] 2. This invention constructs multiple temperature data sequences from a temperature dataset and establishes temperature data curves after interpolation of the temperature data sequences. This not only provides detailed temperature data at different locations on a single pipe cross-section, but also allows the calculation of temperature data at the same measuring point location using the average of multiple temperature data. This enhances the stability and accuracy of the average temperature of the reconstructed temperature field in terms of data volume, and effectively avoids the impact of large deviations in the temperature data curve construction process on the accuracy of the average temperature calculation of the reconstructed temperature field.

[0047] 3. This invention achieves a significant reduction in the number of cables at the output end of pipeline temperature measurement in nuclear power plants through one-to-many wireless communication technology and the design of a multi-channel reader. Attached Figure Description

[0048] The accompanying drawings, which are included to provide a further understanding of embodiments of the invention and form part of this application, do not constitute a limitation thereof. In the drawings:

[0049] Figure 1 This is a system block diagram in an embodiment of the present invention;

[0050] Figure 2 This is a schematic diagram of the SAW temperature sensor in an embodiment of the present invention.

[0051] The attached diagram shows the markings and corresponding component names:

[0052] 101. Temperature sensor group; 102. SAW temperature sensor; 103. Sensor body; 104. Sensor base; 105. Temperature acquisition and processing unit; 106. Temperature reader; 107. Front-end antenna; 108. Temperature reconstruction processing unit. Detailed Implementation

[0053] To make the objectives, technical solutions, and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the embodiments and accompanying drawings. The illustrative embodiments and descriptions of the present invention are only used to explain the present invention and are not intended to limit the present invention.

[0054] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly or indirectly attached to that other component. When a component is referred to as being "connected to" another component, it can be directly or indirectly connected to that other component.

[0055] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention.

[0056] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0057] Example: A wireless monitoring system for pipeline temperature in nuclear power plants based on SAW technology, such as... Figure 1 As shown, the system includes a temperature sensor group 101, a temperature acquisition and processing unit 105, and a temperature reconstruction processing unit 108. The temperature sensor group 101 includes multiple SAW temperature sensors 102 arranged at different measuring points along the same cross-section of the nuclear power plant pipeline to measure temperature data at different measuring points. The monitoring system may contain multiple annular temperature sensor groups 101, with sensors in each group spaced circumferentially and different groups arranged spaced along the pipeline's axis. The temperature acquisition and processing unit 105 collects temperature data sets corresponding to measuring points along at least one cross-section of the nuclear power plant pipeline. The temperature reconstruction processing unit 108 reconstructs the temperature field of the corresponding pipeline cross-section based on the temperature data sets to obtain the monitored temperature of that cross-section.

[0058] Surface acoustic waves (SAWs) possess extremely low propagation speeds and extremely short wavelengths, hundreds of thousands of times shorter than the propagation wavelengths of corresponding electromagnetic waves. Within the same frequency band, SAW devices are also significantly smaller than their electromagnetic counterparts, enabling the miniaturization of electronic devices. Because SAWs propagate slowly along solid surfaces, time-varying signals can be fully represented on the crystal substrate surface at a given instant. Therefore, signal sampling and transformation are easy when transmitting signals at the device's input and output terminals. Furthermore, since SAW devices are fabricated on single-crystal materials using semiconductor planar technology, they exhibit excellent consistency and repeatability, facilitating mass production. When using certain single-crystal or composite materials, SAW devices demonstrate extremely high temperature stability. In addition, SAW devices possess high temperature resistance and radiation resistance.

[0059] This invention uses a surface acoustic wave (SAW) temperature sensor 102, which requires no power supply or electrical connection cables, has a simple structure, small size, and low maintenance cost, and can adapt to the high temperature and strong radiation environment of nuclear power plants; and by using the temperature field reconstruction method to analyze the pipe temperature, more accurate monitoring temperature of the pipe cross section can be obtained.

[0060] To improve the accuracy and reliability of temperature monitoring, the specific process of reconstructing the temperature field of the corresponding pipe section based on the temperature dataset in this invention is as follows: Multiple temperature data sequences are extracted from the temperature dataset according to a preset sequence length; the least squares method is used to interpolate different temperature data sequences to obtain multiple temperature data curves; temperature data at the same measuring point is extracted from the multiple temperature data curves to obtain a temperature data group for the corresponding measuring point; the mean value of each temperature data in the temperature data group is used as the monitoring value for the corresponding measuring point, and after removing outliers from all monitoring values ​​using a minimum fluctuation threshold, the remaining monitoring values ​​are input into a matching temperature field model to calculate the average temperature of the reconstructed temperature field, thus obtaining the monitoring temperature of the corresponding pipe section.

[0061] As an optional implementation method, the temperature data sequence extraction process is as follows: randomly select a measurement point corresponding to a temperature data from the temperature dataset as the starting point; extract the initial temperature data sequence along a single circumferential direction from the starting point according to the preset sequence length; move the initial temperature data sequence one sequence interval along the single circumferential direction until the last temperature data sequence is the same as the initial temperature data sequence, thus obtaining multiple different temperature data sequences.

[0062] As another optional implementation method, the temperature data sequence extraction process is as follows: select the measurement point position corresponding to a temperature data in the temperature dataset as the starting point; extract a set of temperature data sequences sequentially along a single circumferential direction from the starting point according to the preset sequence length. The temperature data sequences in the same set cover all temperature data in the temperature dataset, and the end point of the previous extracted temperature data sequence is adjacent to the starting point of the next extracted temperature data sequence; select different starting points to obtain multiple sets of different temperature data sequences.

[0063] The process of removing outliers from all monitored values ​​using the minimum fluctuation threshold is as follows: the average value of all monitored values ​​is used as the standard value; it is determined whether the absolute value of the difference between the monitored value and the standard value exceeds the minimum fluctuation threshold. If it does, the corresponding monitored value is removed as an outlier.

[0064] This invention constructs multiple temperature data sequences from a temperature dataset and establishes temperature data curves after interpolation of the temperature data sequences. This not only provides detailed temperature data at different locations on a single pipe cross-section, but also allows the calculation of temperature data at the same measuring point location using the average of multiple temperature data. This enhances the stability and accuracy of the average temperature of the reconstructed temperature field in terms of data volume, and effectively avoids the impact of large deviations in the temperature data curve construction process on the accuracy of the calculated average temperature of the reconstructed temperature field.

[0065] The temperature acquisition and processing unit 105 includes multiple temperature readers 106 and multiple front-end antennas 107; the multiple temperature readers 106 transmit signals to the temperature reconstruction processing unit 108 via a bus; the SAW temperature sensor 102 and the front-end antenna 107 transmit temperature signals wirelessly; the main body of the temperature reader 106 has multiple radio frequency interfaces, and the front-end antenna 107 is connected to the main body of the temperature reader 106 via a radio frequency cable.

[0066] Temperature reader 106 sends a query signal to SAW temperature sensor 102 via front-end antenna 107; the query signal is received by the built-in antenna of SAW temperature sensor 102; when the temperature of the nuclear power plant pipeline changes, SAW temperature sensor 102 responds to the query signal by transmitting a wireless signal carrying the temperature information of the measuring point of the nuclear power plant pipeline through its built-in antenna; front-end antenna 107 of temperature reader 106 receives the wireless signal.

[0067] The front-end antenna 107 adopts a one-to-many wireless transmission method, and completes the transmission of query signals and the reception of wireless signals from multiple SAW temperature sensors 102 through a single front-end antenna 107.

[0068] like Figure 1 and Figure 2As shown, the SAW temperature sensor 102 includes a sensor body 103, a sensor base 104, and a sensor base; the sensor body 103 is connected to the sensor base 104; the sensor base is welded to the nuclear power plant pipeline; the contact surface between the sensor base and the nuclear power plant pipeline is machined into an arc shape corresponding to the outer diameter of different pipelines; a groove is cut in the middle of the sensor base to fit the tuning fork-shaped sensor base 104; a countersunk through hole is provided at the center of the sensor base for installing fastening bolts.

[0069] The matching process of the temperature field model is as follows: the temperature field distribution model of different pipeline locations under different operating conditions is obtained through simulation; the model adaptability is compared using the collected multi-point temperature data of the pipeline cross-section, and the optimal adaptive temperature field model is obtained by matching.

[0070] Working Principle: This invention uses a surface acoustic wave (SAW) temperature sensor 102, which requires no power supply or electrical connection cables. It features a simple structure, small size, and low maintenance costs, making it suitable for the high-temperature and high-radiation environments of nuclear power plants. Furthermore, by using a temperature field reconstruction method for pipe temperature analysis, more accurate monitoring temperatures of pipe cross-sections can be obtained. In addition, this invention constructs multiple temperature data sequences from a temperature dataset and establishes temperature data curves after interpolation of these sequences. This allows for detailed temperature data at different locations on a single pipe cross-section, and the calculation of the temperature data at the same measuring point can be performed by averaging multiple temperature data. This enhances the stability and accuracy of calculating the average temperature of the reconstructed temperature field from the perspective of data volume, and effectively avoids the impact of large deviations in the temperature data curve construction process on the accuracy of the calculated average temperature of the reconstructed temperature field.

[0071] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A wireless monitoring system for pipeline temperature in nuclear power plants based on SAW technology, characterized in that: include: A temperature sensor group (101) includes multiple SAW temperature sensors (102) arranged at different measuring points on the nuclear power plant pipeline to measure temperature data at different measuring points on the same cross section of the nuclear power plant pipeline. Each SAW temperature sensor (102) includes a sensor body (103), a sensor base (104), and a sensor pedestal. The sensor body (103) is connected to the sensor base (104). The sensor pedestal is welded to the nuclear power plant pipeline. The contact surface between the sensor pedestal and the nuclear power plant pipeline is machined into an arc shape corresponding to the outer diameter of different pipelines. A groove is cut in the center of the sensor pedestal to accommodate the tuning fork-shaped sensor base (104). A countersunk hole is provided at the center of the sensor pedestal for installing fastening bolts. Temperature acquisition and processing unit (105) is used to acquire temperature data sets at the measurement point locations corresponding to at least one pipe section in a nuclear power plant pipeline; The temperature reconstruction processing unit (108) is used to reconstruct the temperature field of the corresponding pipe section based on the temperature dataset to obtain the monitoring temperature of the corresponding pipe section. The specific process of reconstructing the temperature field of the corresponding pipe section based on the temperature dataset is as follows: multiple temperature data sequences are extracted from the temperature dataset according to a preset sequence length; the least squares method is used to perform interpolation processing on different temperature data sequences to fit multiple temperature data curves; temperature data at the same measuring point location is extracted from the multiple temperature data curves to obtain a temperature data group at the corresponding measuring point location; the mean value of each temperature data in the temperature data group is used as the monitoring value at the corresponding measuring point location, and after clearing outliers in all monitoring values ​​with the minimum fluctuation threshold, and inputting the remaining monitoring values ​​into the matching temperature field model, the average temperature of the reconstructed temperature field is calculated to obtain the monitoring temperature of the corresponding pipe section.

2. The wireless monitoring system for nuclear power plant pipeline temperature based on SAW technology according to claim 1, characterized in that, The specific process of extracting the temperature data sequence is as follows: Randomly select the measurement point location corresponding to a temperature data point from the temperature dataset as the starting point; The initial temperature data sequence is extracted along a single circumferential direction from the starting point according to the preset sequence length. The initial temperature data sequence is shifted one sequence interval along a single circumference until the last temperature data sequence is the same as the initial temperature data sequence, resulting in multiple different temperature data sequences.

3. The wireless monitoring system for nuclear power plant pipeline temperature based on SAW technology according to claim 1, characterized in that, The specific process of extracting the temperature data sequence is as follows: Select the location of a measurement point corresponding to a temperature data point from the temperature dataset as the starting point; A set of temperature data sequences is sequentially extracted along a single circumferential direction from the starting point according to the preset sequence length. The temperature data sequences in the same set cover all temperature data in the temperature dataset, and the end point of the previous extracted temperature data sequence is adjacent to the start point of the next extracted temperature data sequence. By selecting different starting points, multiple sets of different temperature data sequences can be obtained.

4. The wireless monitoring system for nuclear power plant pipeline temperature based on SAW technology according to claim 1, characterized in that, The process of removing outliers from all monitored values ​​using the minimum fluctuation threshold is as follows: The average of all monitored values ​​is used as the standard value; Determine whether the absolute value of the difference between the monitored value and the standard value exceeds the minimum fluctuation threshold. If it does, the corresponding monitored value is removed as an outlier.

5. The wireless monitoring system for nuclear power plant pipeline temperature based on SAW technology according to claim 1, characterized in that, The temperature acquisition and processing unit (105) includes multiple temperature readers (106) and multiple front-end antennas (107); The multiple temperature readers (106) transmit signals to the temperature reconstruction processing unit (108) via a bus. The SAW temperature sensor (102) and the front-end antenna (107) transmit temperature signals wirelessly; The main body of the temperature reader (106) is a multi-RF interface, and the front-end antenna (107) is connected to the main body of the temperature reader (106) via an RF cable.

6. The wireless monitoring system for nuclear power plant pipeline temperature based on SAW technology according to claim 5, characterized in that, The temperature reader (106) sends a query signal to the SAW temperature sensor (102) via the front-end antenna (107); The query signal is received by the built-in antenna of the SAW temperature sensor (102); The SAW temperature sensor (102) has a built-in antenna that transmits a wireless signal carrying temperature information of the pipeline measuring point in the nuclear power plant. The front-end antenna (107) of the temperature reader (106) receives wireless signals.

7. The wireless monitoring system for nuclear power plant pipeline temperature based on SAW technology according to claim 5, characterized in that, The front-end antenna (107) adopts a one-to-many wireless transmission method, and completes the transmission of query signals and the reception of wireless signals from multiple SAW temperature sensors (102) through a single front-end antenna (107).

8. The wireless monitoring system for nuclear power plant pipeline temperature based on SAW technology according to claim 1, characterized in that, The matching process of the temperature field model is as follows: The temperature field distribution model of different pipeline locations under different operating conditions was obtained through simulation. By comparing the model adaptability using multi-point temperature data collected from the pipe cross-section, the optimal temperature field model was obtained.

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