Special-shaped clinging type temperature sensing system for pipeline leakage heat release monitoring
By employing a dual-layer differential sensing architecture and three-dimensional thermal resistance compensation technology, the problem of decoupling from environmental thermal interference in leak monitoring of irregularly shaped pipe fittings was solved, enabling high-fidelity reconstruction of weak exothermic signals and accurate leak identification, thereby improving the sensitivity and reliability of the monitoring system.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- 中稀金龙(长汀)稀土有限公司
- Filing Date
- 2026-04-02
- Publication Date
- 2026-05-12
AI Technical Summary
Existing technologies struggle to effectively decouple environmental thermal interference when monitoring leaks in irregularly shaped pipe fittings. This results in weak heat release signals being masked by background noise, making it impossible to accurately identify leak characteristics and leading to missed or false alarms.
A dual-layer differential sensing architecture is adopted, including a first temperature field acquisition module, a flexible thermal isolation module, and a second temperature field acquisition module. Combined with a heat flow analysis module and a spatial geometry mapping module, the normal heat flux field is reconstructed through a three-dimensional digital model and dynamic thermal resistance compensation, and the vector polar reversal component is extracted to achieve high-fidelity reconstruction of weak heat release signals.
Improve the signal-to-noise ratio of temperature measurement under complex boundary conditions, eliminate thermal field analytical distortion, construct multi-dimensional judgment criteria, accurately identify leakage characteristics, reduce false alarm frequency, and improve system sensitivity.
Smart Images
Figure CN122016085A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to an irregularly shaped, close-fitting temperature sensing system for monitoring heat release from pipeline leaks, belonging to the field of temperature measurement technology. Background Technology
[0002] In the current maintenance of petrochemical and large-scale energy pipeline networks, leakage monitoring of irregularly shaped connections such as flanges, tees, and elbows is a key aspect of ensuring the safe operation of the system. Currently, this type of monitoring mainly uses temperature sensing components deployed close to the pipe wall to capture temperature rise signals caused by changes in the physical properties of the medium to achieve early warning. This method of monitoring absolute temperature difference based on contact temperature sensing components has basic application value in industrial scenarios with straight pipe sections.
[0003] However, when the monitoring target is an irregularly shaped pipe, its complex surface topology causes non-uniformly distributed air gaps to be generated during the bonding process of the temperature sensing component. These gaps create uncontrollable contact thermal resistance between the sensor and the measured surface. Furthermore, since such pipes are usually exposed in an open convective heat transfer environment, the disordered fluctuations of the ambient wind field will continuously carry away the heat flux from the pipe wall surface. This makes the original signal collected by the temperature sensing component a mixed superposition of pipe wall heat conduction, ambient heat dissipation, and medium bottom temperature fluctuations. The weak temperature rise signal in the early stage of leakage is easily covered by background thermal noise, making it impossible for the system to extract the true leakage characteristics from a single temperature amplitude. In addition to hardware bonding limitations, the bottleneck of irregularly shaped pipe monitoring also has shortcomings in the decoupling of thermal field analysis logic and environmental interference. For example, Chinese invention patent application CN112378538A discloses an ultra-low temperature thermometer installation device, which improves contact thermal resistance by brazing shape-matching heat-conducting components to the outer wall of curved pipes. This solution belongs to the static physical compensation method based on ideal geometric surface bonding and relies on heat conduction. While the components and the outer wall of the pipe are rigidly matched in processing dimensions, in actual industrial conditions, irregularly shaped pipe fittings are affected by stress deformation, material aging, and installation disturbances. The preset heat conduction path generates uncontrollable thermal resistance drift. The existing technology does not address the underlying thermodynamic mechanism of non-uniform wall thickness evolution of irregularly shaped fittings and environmental convection fluctuations. It only achieves point-to-point temperature transfer and cannot reconstruct the heat flux vector field perpendicular to the pipe wall under complex curvature topology. Faced with the dynamic evolution of multi-source thermal disturbances inside and outside the pipe, it is difficult to extract weak local heat release characteristics from high-frequency environmental noise, leading to false alarms or missed alarms. If we try to optimize performance by increasing the deployment density of temperature sensing nodes or improving the physical resolution of temperature sensing components, the system still faces the problem of analytical distortion due to the lack of thermal resistance spatial distribution information. Since the thickness gradient and curvature change of irregularly shaped fittings determine the complexity of their original heat transfer path, the two-dimensional planar calculation logic, which is free from three-dimensional geometric constraints, cannot accurately reconstruct the heat flow vector perpendicular to the pipe wall. This leads to false alarms when the medium is under normal temperature regulation, and missed alarms when real small-diameter leaks occur.
[0004] Therefore, how to combine the three-dimensional spatial topological features of the pipe fittings and realize the dynamic decoupling of environmental thermal interference in order to achieve high-fidelity reconstruction of weak heat release signals under non-ideal heat transfer boundaries has become the technical problem to be solved by this invention. Summary of the Invention
[0005] To address the problems mentioned in the background art, the technical solution of the present invention is as follows: A non-circular, close-fitting temperature sensing system for monitoring heat release from pipeline leaks, comprising:
[0006] The first temperature field acquisition module is used to acquire the first temperature field distribution data of the wall surface of the tested irregular pipe fitting.
[0007] A flexible thermal isolation module is attached to the side of the first temperature field acquisition module facing away from the tested irregular pipe fitting, and is used to establish a heat transfer barrier defined by the nominal thermal resistance in the normal direction.
[0008] The second temperature field acquisition module is attached to the side of the flexible thermal isolation module away from the first temperature field acquisition module, and is used to acquire the second temperature field distribution data on the outer surface of the flexible thermal isolation module.
[0009] The heat flux analysis module is connected to both the first and second temperature field acquisition modules. It stores wall thickness evolution parameters and curvature spatial distribution data characterizing the original geometric features of the tested irregular-shaped pipe fitting. Based on the wall thickness evolution parameters and curvature spatial distribution data, the heat flux analysis module performs nonlinear weighted correction on the temperature difference between the first and second temperature field distribution data, calculating and generating the normal heat flux field of the tested irregular-shaped pipe fitting wall. The heat flux analysis module extracts the vector polar reversal component from the normal heat flux field and, combined with the lateral spatial temperature gradient in the first temperature field distribution data, outputs a leakage state warning signal for the tested irregular-shaped pipe fitting.
[0010] Preferably, the system also includes an online thermal resistance calibration module; the online thermal resistance calibration module obtains the reference temperature difference between adjacent temperature measurement nodes under steady-state conditions, and uses the offset of the reference temperature difference with operating time to determine the material aging degradation factor; the heat flow analysis module performs dynamic compensation on the nominal thermal resistance based on the material aging degradation factor to offset the analysis deviation caused by the physical degradation of the flexible thermal isolation module.
[0011] Preferably, the system further includes a spatial geometry mapping module; the spatial geometry mapping module stores a three-dimensional digital model of the irregular pipe fitting being measured; the spatial geometry mapping module uses the three-dimensional digital model to map the two-dimensional topological coordinates of the first temperature field acquisition module and the second temperature field acquisition module to the three-dimensional coordinate system, so as to determine the wall thickness evolution parameters corresponding to the three-dimensional coordinate system.
[0012] Preferably, the heat flow analysis module captures the exothermic disturbance based on the time change rate of the first temperature field distribution data; when the time change rate exceeds 0.5°C / s, the sampling frequency of the first temperature field acquisition module and the second temperature field acquisition module is switched from 1Hz to 50Hz.
[0013] Preferably, both the first temperature field acquisition module and the second temperature field acquisition module include a thermistor array encapsulated in a flexible printed circuit substrate; the flexible printed circuit substrate covers the surface of the flexible thermal isolation module and conformally fits the elbow or tee portion of the irregular pipe fitting being tested.
[0014] Preferably, the system further includes an environmental convection compensation module; the environmental convection compensation module is connected to a wind speed sensing unit; the environmental convection compensation module determines the convective heat transfer intensity on the surface of the second temperature field acquisition module based on the local flow field data provided by the wind speed sensing unit, and uses the convective heat transfer intensity to offset the background noise of the second temperature field distribution data.
[0015] Preferably, the heat flux analysis module establishes a transverse temperature difference distribution matrix based on the first temperature field distribution data; when the normal heat flux field reverses direction away from the pipe wall and the transverse temperature difference distribution matrix exhibits a radial characteristic of decaying outward from the local temperature rise point, the heat flux analysis module generates a medium leakage alarm signal.
[0016] Preferably, the system also includes a power consumption scheduling module; when the fluctuation value of the normal heat flux field is consistently lower than... At that time, the power consumption scheduling module keeps the first temperature field acquisition module and the second temperature field acquisition module in a monitoring state with a low sampling duty cycle.
[0017] Preferably, the contact interface between the first temperature field acquisition module and the tested irregular pipe fitting is provided with a fastening strain sensing module; the heat flow analysis module calculates the interface contact thermal resistance based on the real-time pressure value provided by the fastening strain sensing module, and uses the interface contact thermal resistance to perform amplitude compensation on the analysis result of the normal heat flux.
[0018] Compared with the prior art, the beneficial effects of the present invention are:
[0019] 1. In irregularly shaped, close-fitting temperature sensors, to improve the signal-to-noise ratio of temperature measurement under complex boundary conditions, this invention constructs a dual-layer differential sensing architecture consisting of a first temperature sensing matrix, a structural thermal resistance isolation layer, and a second temperature sensing matrix. The structural thermal resistance isolation layer establishes a controlled heat transfer path between the pipe wall side and the environment side, enabling the system to obtain the physical basis for extracting the vertical temperature difference gradient. The heat flow decoupling calculation unit uses this vertical temperature difference gradient to invert and calculate the transient equivalent vertical heat flux, transforming the monitoring scale from a single absolute temperature value into a heat flow intensity with vector attributes. This physically filters out the same-direction interference signals generated by environmental wind field disturbances and the bottom temperature fluctuations of the medium inside the pipe. Even when the background temperature drift intensity far exceeds the leakage temperature rise amplitude, it can still accurately extract the weak local heat release characteristics of the pipe wall.
[0020] 2. Eliminating thermal field distortion caused by irregular structures: This invention introduces a three-dimensional digital model of the pipe section to be monitored into the sensing logic. By executing a spatial mapping operator, the two-dimensional logical coordinates of the temperature sensing matrix are projected onto the three-dimensional surface grid nodes, realizing the geometric correspondence between the monitoring data and the real physical space. The computing unit extracts the local structural wall thickness scalar and the spatial principal curvature tensor from the model, and generates specific dynamic thermal impedance compensation weights for each node accordingly. This fundamentally corrects the thermal flow calculation deviation caused by uneven heat capacity distribution and complex heat conduction paths in irregular parts such as flanges and tees, giving the system adaptive and faithful analytical capabilities for irregular curved surfaces, and avoiding the detection blind spots generated by traditional planar temperature measuring grids at curvature abrupt changes.
[0021] 3. Constructing a multi-dimensional collaborative leakage state judgment criterion: This invention extracts the two-dimensional temperature difference gradient distribution in the horizontal plane of the first temperature sensing matrix and combines it with the abrupt change characteristics of vertical heat flux to form a spatiotemporally coupled abnormal state identification closed loop; the local heat release generated by leakage is manifested as the polarity reversal of heat flux in the vertical dimension and as an asymmetric radial diffusion characteristic in the horizontal dimension. This multi-dimensional physical feature mapping constitutes a rigorous judgment logic, effectively distinguishing between global process temperature control and local medium leakage, ensuring the system's high sensitivity to minor leakage while reducing the false alarm frequency caused by complex heat transfer boundary coupling. Attached Figure Description
[0022] Figure 1 This is a diagram of the architecture of the irregularly shaped sensing system that integrates three-dimensional geometric mapping and dynamic thermal resistance compensation according to the present invention.
[0023] Figure 2 This is a logic diagram for leak monitoring based on the reconstruction of the normal heat flux field and the identification of polar reversal in this invention.
[0024] The objectives, features, and advantages of this invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation
[0025] The technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this application are within the scope of protection of this application.
[0026] An irregularly shaped, close-fitting temperature sensing system for monitoring heat release from pipeline leaks includes:
[0027] The first temperature field acquisition module is used to acquire the first temperature field distribution data of the wall surface of the tested irregular pipe fitting.
[0028] A flexible thermal isolation module is attached to the side of the first temperature field acquisition module facing away from the tested irregular pipe fitting, and is used to establish a heat transfer barrier defined by the nominal thermal resistance in the normal direction.
[0029] The second temperature field acquisition module is attached to the side of the flexible thermal isolation module away from the first temperature field acquisition module, and is used to acquire the second temperature field distribution data on the outer surface of the flexible thermal isolation module.
[0030] The heat flux analysis module is connected to both the first and second temperature field acquisition modules. It stores wall thickness evolution parameters and curvature spatial distribution data characterizing the original geometric features of the tested irregular-shaped pipe fitting. Based on the wall thickness evolution parameters and curvature spatial distribution data, the heat flux analysis module performs nonlinear weighted correction on the temperature difference between the first and second temperature field distribution data, calculating and generating the normal heat flux field of the tested irregular-shaped pipe fitting wall. The heat flux analysis module extracts the vector polar reversal component from the normal heat flux field and, combined with the lateral spatial temperature gradient in the first temperature field distribution data, outputs a leakage state warning signal for the tested irregular-shaped pipe fitting.
[0031] Preferably, the system also includes an online thermal resistance calibration module; the online thermal resistance calibration module obtains the reference temperature difference between adjacent temperature measurement nodes under steady-state conditions, and uses the offset of the reference temperature difference with operating time to determine the material aging degradation factor; the heat flow analysis module performs dynamic compensation on the nominal thermal resistance based on the material aging degradation factor to offset the analysis deviation caused by the physical degradation of the flexible thermal isolation module.
[0032] Preferably, the heat flow analysis module utilizes the material scaling factor λ and the temperature difference between the first and second temperature field acquisition modules in the same spatial coordinates. The nominal thickness d of the flexible thermal insulation module, the material aging degradation factor η, and the geometric correction coefficient ξ determined by the curvature space distribution data are used to analyze the normal heat flux according to the following formula. : .
[0033] Preferably, the system further includes a spatial geometry mapping module; the spatial geometry mapping module stores a three-dimensional digital model of the irregular pipe fitting being measured; the spatial geometry mapping module uses the three-dimensional digital model to map the two-dimensional topological coordinates of the first temperature field acquisition module and the second temperature field acquisition module to the three-dimensional coordinate system, so as to determine the wall thickness evolution parameters corresponding to the three-dimensional coordinate system.
[0034] Preferably, the heat flow analysis module captures the exothermic disturbance based on the time change rate of the first temperature field distribution data; when the time change rate exceeds 0.5°C / s, the sampling frequency of the first temperature field acquisition module and the second temperature field acquisition module is switched from 1Hz to 50Hz.
[0035] Preferably, both the first temperature field acquisition module and the second temperature field acquisition module include a thermistor array encapsulated in a flexible printed circuit substrate; the flexible printed circuit substrate covers the surface of the flexible thermal isolation module and conformally fits the elbow or tee portion of the irregular pipe fitting being tested.
[0036] Preferably, the system further includes an environmental convection compensation module; the environmental convection compensation module is connected to a wind speed sensing unit; the environmental convection compensation module determines the convective heat transfer intensity on the surface of the second temperature field acquisition module based on the local flow field data provided by the wind speed sensing unit, and uses the convective heat transfer intensity to offset the background noise of the second temperature field distribution data.
[0037] Preferably, the heat flux analysis module establishes a transverse temperature difference distribution matrix based on the first temperature field distribution data; when the normal heat flux field reverses direction away from the pipe wall and the transverse temperature difference distribution matrix exhibits a radial characteristic of decaying outward from the local temperature rise point, the heat flux analysis module generates a medium leakage alarm signal.
[0038] Preferably, the system also includes a power consumption scheduling module; when the fluctuation value of the normal heat flux field is consistently lower than... At that time, the power consumption scheduling module keeps the first temperature field acquisition module and the second temperature field acquisition module in a monitoring state with a low sampling duty cycle.
[0039] Preferably, the contact interface between the first temperature field acquisition module and the tested irregular pipe fitting is provided with a fastening strain sensing module; the heat flow analysis module calculates the interface contact thermal resistance based on the real-time pressure value provided by the fastening strain sensing module, and uses the interface contact thermal resistance to perform amplitude compensation on the analysis result of the normal heat flux.
[0040] Example 1: In a monitoring scenario of a high-pressure natural gas pipeline reducing tee node located outdoors in northern winter, the medium inside the pipe experiences a global temperature rise of 5.0℃ / min. Simultaneously, the external environment experiences convective interference due to sudden changes in wind speed. This causes significant fluctuations in the data acquired by the single-layer temperature sensor, obscuring the initial 0.2℃ / min local heat release associated with the leak within the background thermal disturbance. Under this condition, the irregularly shaped, close-fitting temperature sensing system of this invention for monitoring pipeline leak heat release activates an internal and external heat source separation mechanism. The spatial geometry mapping module retrieves the three-dimensional digital model of the measured irregularly shaped pipe fitting, mapping the two-dimensional topological coordinates of the first and second temperature field acquisition modules to a three-dimensional coordinate system. This determines the wall thickness evolution parameters at the corresponding location of the temperature measurement node and the geometric correction coefficient ξ derived from the curvature spatial distribution data. Simultaneously, the online thermal resistance calibration module extracts the offset of the reference temperature difference between adjacent temperature measurement nodes under leak-free steady-state conditions over time to determine the material aging attenuation factor η. The heat flow analysis module, based on the above parameters, combines the material proportionality coefficient λ, the nominal thickness d of the flexible thermal insulation module, and the first temperature field distribution data under the same spatial coordinates. With the second temperature field distribution data According to the formula The normal heat flux field of the wall surface of the tested irregular pipe fitting is calculated; among which, Where λ is the normal heat flux and λ is the material proportionality coefficient. This is the first temperature field distribution data. The second temperature field distribution data is given, where d is the nominal thickness, η is the dimensionless material aging degradation factor, and ξ is the dimensionless geometric correction coefficient. Based on Fourier's law of thermal conductivity, a steady-state heat transfer model is established under a non-ideal contact boundary. Under the assumption of one-dimensional normal heat flow conduction, the heat flow analysis module, according to the above parameters, combines the material scaling factor λ, the nominal thickness d of the flexible thermal insulation module, and the first temperature field distribution data under the same spatial coordinates. With the second temperature field distribution data Temperature difference ΔT, introducing a constant Perform dimension matching from millimeters to meters, according to the formula. The normal heat flux field of the wall surface of the tested irregular pipe fitting is calculated and generated, where η is the normal heat flux, λ is the material proportionality coefficient, d is the nominal thickness, and η and ξ are both dimensionless coefficients.
[0041] Based on the established heat flux reconstruction logic, the system couples physical quantity calculation with a spatiotemporal dynamic capture mechanism. When the heat flux analysis module detects a boundary condition with a time change rate greater than 0.5℃ / s based on the first temperature field distribution data, it triggers the sampling frequency of the first and second temperature field acquisition modules to jump from 1Hz to 50Hz. The heat flux analysis module extracts the vector polar reversal component away from the pipe wall direction in the normal heat flux field from the high-frequency data sequence and identifies that the first temperature field distribution data corresponding to this component presents a transverse spatial temperature gradient in the topological plane, decaying outward from the local temperature rise point. Under the dual thermal noise masking of the medium bottom temperature rise and the rapid cooling of the environment, it outputs a leakage status warning signal for the tested irregular pipe fitting. The judgment process is executed based on a ring FIFO buffer with a length of 512 data points, with a time window sliding every 20.0 milliseconds. When extracting the vector polar reversal component, the heat flux analysis... The module is pre-set with a dynamic noise envelope of 1.2 watts per square meter. The polar reversal judgment is activated only when the absolute value of the normal heat flux crosses the envelope for 15.0 consecutive sampling periods and the vector direction points to the space outside the tube. At the same time, for the identification of the lateral spatial temperature gradient, the system constructs a 3.0 by 3.0 sensor weight matrix with the local temperature rise point as the center, calculates the temperature difference gradient between the central node and the 8.0 peripheral nodes. If the gradient spatial integral value is continuously greater than 0.5℃ / cm within 10.0 seconds and shows a symmetrical decay towards the periphery, it is judged as a local heat release feature, thereby filtering out false alarm signals generated by global process temperature adjustment. The sensing system uses structural geometric prior data to perform spatial physical quantity compensation for nonlinear thermal resistance. By constructing a multidimensional differential topology to analyze the heat flux evolution path, the threshold judgment mechanism in the field of temperature measurement that relies on single-point energy accumulation is transformed into a dynamic vector field state reconstruction method that resists heat transfer boundary interference.
[0042] Example 2: This example verifies the weak heat release monitoring at a variable-diameter tee node in a high-pressure natural gas pipeline. It utilizes a physical simulation test platform with a temperature control accuracy of 0.05℃ and a wind speed adjustment range of 0m / s to 20m / s to acquire physical experimental data. The test platform deploys a fan array around the fluid pipeline, actively superimposing convective thermal disturbance caused by irregular wind speed fluctuations as background noise. The base temperature inside the pipe is increased at a rate of 5.0℃ / min to reproduce the bottom temperature drift interference in an industrial setting. The system sets a threshold for triggering a jump in the dynamic sampling frequency. The determination of the trigger threshold is based on the trade-off between the sensitivity of heat leakage feature capture and the load of the data processing bus. The main technical factors affecting the value of this threshold are the low-frequency drift rate of ambient temperature and the slope of the inherent heat leakage feature. The judgment rule is set as follows: when the low-frequency drift rate of ambient temperature approaches the upper edge of the preset envelope, the value that is greater than the maximum drift slope of ambient temperature and less than the lower limit of the characteristic heat release rate is extracted as the trigger threshold. Combined with the inherent 0.2℃ / min heat leakage feature at the variable diameter tee node, the system calibrates the jump trigger threshold of the time change rate to 0.5℃ / s.
[0043] To address the anti-interference capability and numerical range boundary effects under extreme heat transfer boundaries, the experiment established the present invention sample group, a partially missing control group, and an out-of-range control group. Wind speed perturbation parameters at three gradients of 5 m / s, 10 m / s, and 15 m / s were applied sequentially to construct a problem intensity gradient control system. The partially missing control group removed the geometric feature correction step determined by the curvature space distribution data. The sampling frequencies of the out-of-range control group were set to 10 Hz and 150 Hz, respectively, deviating from the preferred range. Under the condition of applying a 10 m / s wind speed perturbation and injecting a simulated leakage heat source, the initial first temperature field distribution data acquired by the first temperature field acquisition module exhibited irregular oscillations with an amplitude reaching 2.3℃, with weak heat release characteristics hidden in the background fluctuations. After the present invention sample group detected a transient temperature rise slope greater than 0.5℃ / s, it triggered the sampling frequencies of the first and second temperature field acquisition modules to increase to 50 Hz. (Heat flow solution...) The analysis module retrieves wall thickness evolution parameters and curvature spatial distribution data, and calculates a dimensionless geometric correction coefficient of 1.42 at the variable diameter tee node. Based on this geometric correction coefficient and material aging attenuation factor, the normal heat flux field analyzed by the sample group of this invention converges rapidly from the initial perturbation state, and the vector polar reversal component away from the pipe wall direction is extracted and stabilized at 12.5 W / m². Based on this, the system combines the transverse spatial temperature gradient and outputs a leakage state warning signal for the tested irregular pipe fitting 14.5 s after the leakage occurs. Under the same wind speed of 10 m / s, the partial missing control group uses the static thermal resistance algebraic model due to the lack of three-dimensional geometric feature correction. The normal heat flux analyzed by it produces characteristic distortion in the curvature maxima region, and the calculated vector polar reversal component diverges and fluctuates in the range of 4.2 W / m² to 18.7 W / m². The system cannot extract stable features and ultimately does not output a leakage state warning signal.
[0044] Under increasing wind speed disturbances of 5 m / s, 10 m / s, and 15 m / s, the vector polar reversal component extracted by the sample group of this invention remained at 12.8 W / m², 12.5 W / m², and 12.1 W / m², respectively, with corresponding warning response times of 12.1 s, 14.5 s, and 16.8 s. The warning response time exhibited a quantization hysteresis law with increasing convective disturbance intensity, but the vector component remained stable. In the out-of-range control group, when the sampling frequency was set to 150 Hz above the upper limit, the energy inversion of high-frequency convective noise produced a nonlinear saturation overload effect, and the signal-to-noise ratio of the vector polar reversal component decreased sharply. The warning response time deteriorated to 38.5s when the sampling frequency was set to 10Hz below the lower limit. Low-frequency discrete sampling caused the omission of transient time series features, and the warning response time was extended to 45.2s. The experimental data showed that the sensing system integrates topological geometric constraints into the dynamic frequency response logic and uses algebraic operations of the normal heat flux vector field to offset the temperature analysis error caused by the superposition of the three-dimensional nonlinear heat transfer boundary and high-frequency environmental disturbance. The above comparison and gradient verification established 50Hz as the optimal working boundary for dynamic sampling, and proved that the system can achieve stable reconstruction of weak heat release characteristics and state warning under severe thermal disturbance conditions.
[0045] Example 3: In the case of natural gas leakage monitoring in irregularly shaped pipeline networks, the heat transfer path of the pipe wall exhibits anisotropy, and the underlying temperature measurement reference experiences temperature drift. The spatial geometry mapping module of the irregularly shaped, close-fitting temperature sensing system used for pipeline leakage heat release monitoring retrieves the original three-dimensional digital model data of the irregularly shaped pipe fitting being measured, extracts the principal curvature parameters at the temperature measurement nodes, and then uses the maximum principal curvature at the location of the temperature measurement node as the basis for further analysis. With minimum principal curvature Based on the nominal thickness d of the flexible thermal insulation module, according to the formula Calculate the geometric correction coefficient ξ; where, For the maximum principal curvature, The minimum principal curvature is given by d, the nominal thickness is given by ξ, and the dimensionless geometric correction factor is given by ξ. The online thermal resistance calibration module collects a reference temperature difference sequence from adjacent temperature measurement nodes for 1000 consecutive sampling cycles within a steady-state window when the pipeline is leak-free and the fluid temperature remains constant. The online thermal resistance calibration module then extracts the time average value of the reference temperature difference sequence. averaging the time Compared with the initial temperature difference baseline value calibrated during initial deployment Compare according to the formula Determine the material aging degradation factor η; where, This represents the average time-to-base temperature difference during the current steady-state window. The initial temperature difference reference value is η, which is a dimensionless material aging degradation factor. The heat flow analysis module adjusts the nominal thermal resistance parameter in the heat flow analysis formula according to the material aging degradation factor η to compensate for the temperature analysis deviation caused by physical degradation.
[0046] The heat flux analysis module acquires the discretized normal heat flux field using the applied geometric correction coefficient ξ and the material aging attenuation factor η. It calculates the spatial derivative of the heat flux along the tangential spatial gradient direction parallel to the pipe wall. When the heat flux analysis module determines that the normal heat flux amplitude at a specific temperature measuring node exceeds the steady-state normal heat flux reference threshold, and the integral value of the spatial derivative of the normal heat flux within the closed loop formed by the surrounding adjacent nodes is within the preset zero tolerance range, it extracts the heat flux component pointing towards the outside of the pipe network at that specific temperature measuring node as the vector polar reversal component. The heat flux analysis module, in conjunction with the transverse spatial temperature gradient attenuating outward from the specific temperature measuring node in the first temperature field distribution data, outputs a leakage state warning signal for the tested irregular pipe fitting. This sensing system quantifies the physical distortion effect of curvature geometry on heat conduction and introduces the material aging attenuation factor in the time dimension, integrating spatial geometric constraints into the algebraic operation of the normal heat flux vector field, and outputs a monitoring and judgment result characterizing the local heat release characteristics.
[0047] Example 4: This example focuses on the calibration conditions of the system initially deployed at a newly commissioned variable-diameter tee node. The test platform injects constant-temperature natural gas into the control pipe and closes the upstream and downstream valves to maintain a fluid velocity of 0 m / s. Simultaneously, the external fan array is activated to apply a steady-state convective wind field with a constant wind speed. Under the constraint of heat flow balance inside and outside the pipe, the online thermal resistance calibration module continuously reads the temperature readings of the first and second temperature field acquisition modules over 1000 consecutive sampling periods. It then calculates the time series variance of the temperature difference between adjacent temperature measurement nodes. After determining that the variance is continuously below a preset variance threshold, the temperature data within that stable interval is averaged over time. The system thus generates an initial temperature difference benchmark value. And store it in the read-only memory of the heat flow analysis module, this initial temperature difference reference value. This serves as a physical reference baseline for deriving the aging and degradation factor of dimensionless materials.
[0048] The spatial geometry mapping module, in conjunction with a 3D scanner, scans the outer surface of the irregularly shaped pipe fitting being measured, which is attached to the first and second temperature field acquisition modules. Based on this, the system obtains a point cloud dataset containing the 3D spatial coordinates of the temperature measurement nodes, and uses a surface fitting algorithm to calculate the maximum principal curvature at the location of each temperature measurement node. With minimum principal curvature Based on the nominal thickness d of the flexible thermal isolation module and the topological mapping relationship of the temperature sensing nodes, a dimensionless geometric correction coefficient array ξ is generated. The heat flow analysis module then uses the calibrated initial temperature difference reference value. By introducing a dimensionless geometric correction coefficient ξ array and resetting the nonlinear heat transfer boundary conditions using heat flow analytical formulas, the sensor network completes spatial data alignment with the three-dimensional heat transfer physical entity based on the above physical parameter mapping.
[0049] Example 5: In the environmental baseline calibration condition for the initial deployment of the system, the online thermal resistance calibration module controls the first and second temperature field acquisition modules to acquire a continuous 24-hour base temperature sequence under conditions without natural gas flow. The heat flow analysis module calculates the rate of temperature change of the base temperature sequence within the sliding time window and extracts the global maximum positive value as the maximum drift slope of the ambient temperature. At the same time, the extreme value line of the base temperature sequence is established as the reference envelope. Based on this, the heat flow analysis module adds the inherent measurement deviation of the sensor to the upper edge value of the reference envelope to generate the preset upper edge parameter of the envelope. The system then writes various calibration parameters into the memory to establish the underlying quantitative benchmark for subsequent heat leakage judgment rules. In response to the abnormal heat transfer boundary caused by local detachment of the flexible thermal isolation module during long-term service, the heat flow analysis module constructs the spatial gradient matrix of normal heat flux based on the spatial coordinates of each node and calculates the normal heat flux of a single temperature measurement node. Average heat flux with adjacent temperature measurement nodes The absolute difference, according to the formula Extracting local mutation flux For single-node normal heat flux, The average heat flux is denoted as Δq, and the sudden change flux is denoted as Δq. When the local sudden change flux Δq is detected to be greater than 3 times the historical variance of the node and the current temperature rise rate of the node is in the zero range, the thermal resistance online calibration module determines that the temperature measuring node has experienced physical contact failure. The heat flow analysis module then removes the data link of the failed node and reconstructs the local temperature field by spatial interpolation using the real-time data collected from the surrounding normal nodes. This ensures that the analysis process of the normal heat flux vector field continues to output effective pipe wall characteristic quantities under the condition of local hardware failure.
[0050] When the system faces the sensor substrate noise calibration condition caused by the non-uniformity of the material surface before the pipeline network is put into operation, the heat flow analysis module outputs a constant power electrical signal to the uniform heating component set inside the tested irregular pipe fitting to construct an omnidirectional isotropic heat flow boundary condition. Simultaneously, it reads the no-load temperature response matrix of the first temperature field acquisition module. The heat flow analysis module traverses the outer surface of the tested irregular pipe fitting tangentially to calculate the static temperature spatial derivative between adjacent temperature measurement nodes, and writes the variance distribution data of this static temperature spatial derivative within a preset time window into the underlying knowledge base as a baseline feature vector characterizing the inherent spatial heat conduction dispersion of the sensor network. The heat flow analysis module extracts the baseline feature vector and combines it with the low-frequency drift rate of the real-time measured ambient temperature, according to the formula... Dynamically generate the upper limit parameter of the preset zero tolerance range. ,in, The upper limit parameter of the preset zero tolerance interval is β, where β is the dimensionless structural confidence coefficient. The variance of the static spatial derivative is extracted from the baseline feature vector, γ is the environmental drift sensitivity coefficient, and v is the low-frequency drift rate of the ambient temperature. Based on the upper limit parameter of the preset zero tolerance interval, the system compares the integral value of the spatial derivative of the normal heat flux within the closed loop formed by the surrounding adjacent nodes, establishes the cutoff boundary of the polar reversal component of the normal heat flux vector, and outputs the effective judgment result of the normal heat flux that meets the spatial heat conduction dispersion constraint of the temperature measurement node.
[0051] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the present invention can be implemented in other specific forms without departing from the spirit or essential characteristics of the present invention.
[0052] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention.
Claims
1. A non-circular, close-fitting temperature sensing system for monitoring heat release from pipeline leaks, characterized in that, include: The first temperature field acquisition module is used to acquire the first temperature field distribution data of the wall surface of the tested irregular pipe fitting. A flexible thermal isolation module is attached to the side of the first temperature field acquisition module facing away from the tested irregular pipe fitting, and is used to establish a heat transfer barrier defined by the nominal thermal resistance in the normal direction. The second temperature field acquisition module is attached to the side of the flexible thermal isolation module away from the first temperature field acquisition module, and is used to acquire the second temperature field distribution data on the outer surface of the flexible thermal isolation module. The heat flow analysis module is connected to the first temperature field acquisition module and the second temperature field acquisition module respectively; the heat flow analysis module stores wall thickness evolution parameters and curvature spatial distribution data that characterize the original geometric features of the tested irregular pipe fitting; The heat flux analysis module performs nonlinear weighted correction on the temperature difference between the first temperature field distribution data and the second temperature field distribution data based on the wall thickness evolution parameters and curvature spatial distribution data, and calculates and generates the normal heat flux field of the wall surface of the tested irregular pipe fitting. The heat flux analysis module extracts the vector polar reversal component in the normal heat flux field, and combines it with the lateral spatial temperature gradient in the first temperature field distribution data to output a leakage state warning signal for the tested irregular pipe fitting.
2. The irregularly shaped, close-fitting temperature sensing system for monitoring heat release from pipeline leaks according to claim 1, characterized in that, The system also includes an online thermal resistance calibration module; the online thermal resistance calibration module obtains the reference temperature difference between adjacent temperature measurement nodes under steady-state conditions, and uses the offset of the reference temperature difference with running time to determine the material aging degradation factor; The thermal flow analysis module dynamically compensates for the nominal thermal resistance based on the material aging degradation factor to offset the analysis deviation caused by the physical degradation of the flexible thermal isolation module.
3. The irregularly shaped, close-fitting temperature sensing system for monitoring heat release from pipeline leaks according to claim 1, characterized in that, The system also includes a spatial geometry mapping module; the spatial geometry mapping module stores a three-dimensional digital model of the irregular pipe fitting being tested; the spatial geometry mapping module uses the three-dimensional digital model to map the two-dimensional topological coordinates of the first temperature field acquisition module and the second temperature field acquisition module to the three-dimensional coordinate system, so as to determine the wall thickness evolution parameters corresponding to the three-dimensional coordinate system.
4. The irregularly shaped, close-fitting temperature sensing system for monitoring heat release from pipeline leaks according to claim 1, characterized in that, The heat flow analysis module captures exothermic disturbances based on the time change rate of the first temperature field distribution data; when the time change rate exceeds 0.5°C / s, the sampling frequency of the first temperature field acquisition module and the second temperature field acquisition module is switched from 1Hz to 50Hz.
5. The irregularly shaped, close-fitting temperature sensing system for monitoring heat release from pipeline leaks according to claim 1, characterized in that, Both the first temperature field acquisition module and the second temperature field acquisition module include a thermistor array encapsulated in a flexible printed circuit substrate; the flexible printed circuit substrate covers the surface of the flexible thermal isolation module and conformally fits the elbow or tee part of the irregular pipe fitting being tested.
6. The irregularly shaped, close-fitting temperature sensing system for monitoring heat release from pipeline leaks according to claim 1, characterized in that, The system also includes an environmental convection compensation module; the environmental convection compensation module is connected to a wind speed sensing unit; the environmental convection compensation module determines the convective heat transfer intensity on the surface of the second temperature field acquisition module based on the local flow field data provided by the wind speed sensing unit, and uses the convective heat transfer intensity to offset the background noise of the second temperature field distribution data.
7. A non-circular, close-fitting temperature sensing system for monitoring heat release from pipeline leaks according to claim 1, characterized in that, The heat flux analysis module establishes a transverse temperature difference distribution matrix based on the first temperature field distribution data. When the normal heat flux field reverses direction away from the pipe wall and the transverse temperature difference distribution matrix exhibits a radial characteristic of decaying outward from the local temperature rise point, the heat flux analysis module generates a medium leakage alarm signal.
8. A non-circular, close-fitting temperature sensing system for monitoring heat release from pipeline leaks according to claim 1, characterized in that, The system also includes a power consumption scheduling module; when the fluctuation value of the normal heat flux field is consistently lower than... At that time, the power consumption scheduling module keeps the first temperature field acquisition module and the second temperature field acquisition module in a monitoring state with a low sampling duty cycle.
9. A non-circular, close-fitting temperature sensing system for monitoring heat release from pipeline leaks according to claim 1, characterized in that, The contact interface between the first temperature field acquisition module and the tested irregular pipe fitting is equipped with a fastening strain sensing module; the heat flow analysis module calculates the interface contact thermal resistance based on the real-time pressure value provided by the fastening strain sensing module, and uses the interface contact thermal resistance to perform amplitude compensation on the analysis results of the normal heat flux.