High-pressure large-diameter natural gas pipeline jet fire thermal radiation test method and system

Abstract

The present invention provides a method and system for testing the thermal radiation of jet fire in a high-pressure and large-diameter natural gas pipeline, and belongs to the technical field of gas transportation safety. The method for testing the thermal radiation of jet fire in a high-pressure and large-diameter natural gas pipeline of the present invention obtains a first position by obtaining a rough flame shape by combining factors such as the size, leakage point, wind speed and direction of the natural gas pipeline, and further considers the inclination of the flame on this basis to obtain a second position, and finally further screens the uncovered third position by analyzing historical simulation data, thereby realizing efficient and accurate sensor arrangement, which not only reduces the number of sensor arrangements, but also improves the arrangement accuracy, ensuring that the thermal radiation generated by the flame can be fully monitored, thereby improving safety and emergency response efficiency.

Description

Technical Field

[0001] The present invention relates to the technical field of gas transportation safety, and in particular to a method and system for testing the thermal radiation of jet fire in a high-pressure and large-diameter natural gas pipeline. Background Art

[0002] After a natural gas pipeline leaks and the gas is ignited, the radiation of the flame has a significant impact on the temperature of the surrounding environment, the fire resistance of the structure, and the safety of personnel. The high-pressure large-diameter natural gas pipeline jet fire thermal radiation test usually includes artificial simulation of natural gas leakage, ignition and burning for a period of time, during which the intensity and distribution of thermal radiation generated by the flame are recorded by thermal radiation measuring instruments. By simulating the jet fire thermal radiation, the hazards of the fire to the surrounding area of ​​the pipeline can be accurately evaluated, helping to optimize the safety design.

[0003] At present, there is no completely unified standard for the propagation mode of high-pressure large-diameter natural gas pipeline leakage fire. In particular, under different environments and climatic conditions, the dynamic changes of flame propagation and thermal radiation are difficult to be fully described by simple models. The flame after leakage and ignition is not always stable. Irregular flame fluctuations or instantaneous combustion enhancement may occur, resulting in uncertainty in the prediction of thermal radiation distribution. The thermal radiation distribution at the flame site is relatively complex, and a large number of thermal radiation sensors and other sensors are usually required to be deployed. The shape and temperature of the flame will change with the development of the combustion process, and this change is affected by many factors, especially wind speed, wind direction, fuel type, etc. These changes make the thermal radiation distribution of the fire very dynamic, and a large number of sensors need to be deployed on site for detection, but this requires a lot of hardware costs and installation work. Under the premise of ensuring data quality, minimizing the number of sensors deployed is a key method to improve monitoring efficiency and reduce costs. Therefore, how to predict the hot spots of thermal radiation during combustion without the need for a large number of sensors, thereby streamlining the number of sensor deployments, is an urgent problem to be solved. Summary of the invention

[0004] The present invention provides a method and system for testing the thermal radiation of jet fire in a high-pressure and large-diameter natural gas pipeline, which is used to solve the defects in the prior art that too many sensors are deployed, resulting in high test costs and low efficiency, and to achieve the effect of reducing the number of deployed sensors by improving the arrangement accuracy of the sensors.

[0005] The present invention provides a method for testing the thermal radiation of jet fire in a high-pressure and large-caliber natural gas pipeline, comprising:

[0006] Based on the size of the natural gas pipeline, the leakage location and the leakage diameter, the morphological characteristics of the flame development are determined; the morphological characteristics of the flame development include the shape and size of the flame at different times;

[0007] Determine the center position and the front position of the flame based on the morphological characteristics of the flame development, and determine the first position based on the center position and the front position of the flame;

[0008] Based on the morphological characteristics of the flame development and the wind speed and wind direction at the test site, the flame inclination angle during the flame development process is determined to obtain the morphological characteristics of the flame development after the flame inclination angle is superimposed;

[0009] Determining a second position based on the morphological characteristics of flame development after superimposing the flame inclination angle;

[0010] Identify a heat radiation hotspot area in a historical heat radiation layered map obtained by computational fluid dynamics (CFD) simulation, and determine a third position from the hotspot area not covered by the first position and the second position in the heat radiation hotspot area;

[0011] Sensors are deployed at the first position, the second position, and the third position to test the thermal radiation of the natural gas pipeline jet fire.

[0012] According to a high-pressure large-diameter natural gas pipeline jet fire thermal radiation test provided by the present invention, the thermal radiation hot spot area is identified in the historical thermal radiation layered diagram obtained by computational fluid dynamics (CFD) simulation, including:

[0013] Selecting a historical thermal radiation layered diagram that matches the size, leakage location, and leakage diameter of the natural gas pipeline from the historical data of CFD simulation;

[0014] Find the peak area of ​​thermal radiation intensity from the historical thermal radiation layered map by local maximum detection; determine the spatial range of different thermal radiation ranges by connected domain analysis; identify the thermal radiation change area by thermal radiation gradient analysis;

[0015] The thermal radiation hot spot area is determined based on the peak area, the spatial ranges of different thermal radiation ranges, and the thermal radiation change area.

[0016] According to a high-pressure large-diameter natural gas pipeline jet fire thermal radiation test provided by the present invention, the thermal radiation hot spot area is determined based on the peak area, the spatial range of different thermal radiation ranges and the thermal radiation change area, including:

[0017] The peak area, the spatial extent of different thermal radiation ranges, and the spatial distribution and temporal evolution of the thermal radiation variation area within the time period were analyzed by sliding windows;

[0018] The thermal radiation hot spot area is determined based on the peak area, the spatial ranges of different thermal radiation ranges, and the existence duration of the thermal radiation change area.

[0019] According to a high-pressure large-diameter natural gas pipeline jet fire thermal radiation test provided by the present invention, the flame inclination angle in the flame development process is determined based on the morphological characteristics of the flame development and the wind speed and wind direction at the test site, and the morphological characteristics of the flame development after the flame inclination angle is superimposed are obtained, including:

[0020] Based on the morphological characteristics of the flame development, modeling the flame morphology at different stages of the flame development process;

[0021] Based on the flame shape, wind speed and wind direction at different stages of the flame development process, the flame inclination angle at different stages of the flame development process is calculated;

[0022] Based on the flame inclination angles at different stages of the flame development process, and superimposed on the flame morphology models at different stages of the flame development process, the morphological characteristics of the flame in the entire development process are obtained.

[0023] According to a high-pressure large-diameter natural gas pipeline jet fire thermal radiation test provided by the present invention, the second position is determined based on the morphological characteristics of the flame development after superimposing the flame inclination angle, including:

[0024] Based on the morphological characteristics of flame development after superimposing the flame inclination angle, the maximum flame extension range is predicted, and the maximum flame extension range includes the range in the vertical and horizontal directions;

[0025] The second position is determined based on the maximum extension range of the flame, wind speed and wind direction.

[0026] According to a high-pressure large-diameter natural gas pipeline jet fire thermal radiation test provided by the present invention, the morphological characteristics of flame development are determined based on the size, leakage location and leakage diameter size of the natural gas pipeline, including:

[0027] Calculating the leakage flow rate using a flow model based on the size of the natural gas pipeline, the leakage location, and the leakage diameter size;

[0028] Calculating the combustion rate based on the leakage flow rate and determining the energy release rate and intensity of the flame;

[0029] Based on the energy release rate and intensity of the flame, computational fluid dynamics (CFD) is used to simulate the gas leakage and flame propagation process, and the morphological characteristics of the flame development are simulated.

[0030] According to a high-pressure large-diameter natural gas pipeline jet fire thermal radiation test provided by the present invention, the sensors are deployed at the first position, the second position and the third position to test the natural gas pipeline jet fire thermal radiation, including:

[0031] Based on the distances of the first position, the second position, and the third position from the leakage port, a target position is obtained by screening the first position, the second position, and the third position;

[0032] A movable sensor is deployed at the target position, and during the test process, the movable sensor deployed at the target position is controlled to move along the thermal radiation diffusion direction to perform dynamic detection of the thermal radiation.

[0033] The present invention also provides a high-pressure large-caliber natural gas pipeline jet fire thermal radiation test system, comprising:

[0034] The first simulation module is used to determine the morphological characteristics of flame development based on the size of the natural gas pipeline, the leakage location and the leakage diameter size; the morphological characteristics of flame development include the shape and size of the flame at different times;

[0035] A first processing module, configured to determine a center position and a front position of the flame based on the morphological characteristics of the flame development, and determine a first position based on the center position and the front position of the flame;

[0036] The second simulation module is used to determine the flame inclination angle during the flame development process based on the morphological characteristics of the flame development and the wind speed and wind direction at the test site, and obtain the morphological characteristics of the flame development after the flame inclination angle is superimposed;

[0037] A second processing module, used for determining a second position based on the morphological characteristics of flame development after superimposing the flame inclination angle;

[0038] A third processing module is used to identify a thermal radiation hot spot area in a historical thermal radiation layered map obtained by computational fluid dynamics (CFD) simulation, and determine a third position from the hot spot area not covered by the first position and the second position in the thermal radiation hot spot area;

[0039] The test module is used to deploy sensors at the first position, the second position and the third position to test the thermal radiation of the natural gas pipeline jet fire.

[0040] The present invention also provides an electronic device, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, any of the above-described methods for testing the jet fire thermal radiation of a high-pressure and large-diameter natural gas pipeline is implemented.

[0041] The present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements any of the above-described high-pressure large-diameter natural gas pipeline jet fire thermal radiation testing methods.

[0042] The present invention also provides a computer program product, comprising a computer program, which, when executed by a processor, implements any of the above-mentioned high-pressure large-diameter natural gas pipeline jet fire thermal radiation testing methods.

[0043] The high-pressure large-diameter natural gas pipeline jet fire thermal radiation testing method and system provided by the present invention obtains the approximate flame shape by combining factors such as the size, leakage point, wind speed and direction of the natural gas pipeline to obtain the first position, and further considers the inclination of the flame on this basis to obtain the second position, and finally further screens the uncovered third position by analyzing the historical simulation data, thereby realizing efficient and accurate sensor layout, which not only reduces the number of sensor layouts, but also improves the layout accuracy, ensuring that the thermal radiation generated by the flame can be fully monitored, thereby improving safety and emergency response efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] In order to more clearly illustrate the technical solutions in the present invention or the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0045] Figure 1 This is one of the flow diagrams of the high-pressure large-diameter natural gas pipeline jet fire thermal radiation test method provided by the present invention;

[0046] Figure 2 This is the second flow diagram of the high-pressure large-diameter natural gas pipeline jet fire thermal radiation testing method provided by the present invention;

[0047] Figure 3 It is a structural schematic diagram of a high-pressure large-caliber natural gas pipeline jet fire thermal radiation test system provided by the present invention;

[0048] Figure 4 It is a structural schematic diagram of the electronic device provided by the present invention. DETAILED DESCRIPTION

[0049] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the drawings of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0050] Combine the following Figure 1-Figure 4The invention describes a method and system for testing the thermal radiation of jet fire in a high-pressure and large-diameter natural gas pipeline.

[0051] The high-pressure large-diameter natural gas pipeline jet fire thermal radiation testing method according to the embodiment of the present invention mainly includes step 110 , step 120 , step 130 , step 140 , step 150 and step 160 .

[0052] Step 110, determining the morphological characteristics of the flame development based on the size of the natural gas pipeline, the leakage location and the leakage diameter size.

[0053] The morphological characteristics of flame development include the shape and size of the flame at different times.

[0054] Factors such as the diameter of the gas pipeline, the specific location of the leak point, and the size of the leak hole will affect the shape and development of the flame.

[0055] The size of the pipeline, the leak location, and the size of the leak diameter can be taken into consideration, and theoretical models or experimental data can be used to predict the flame morphology after a natural gas leak, including the flame's height, width, and size that changes over time.

[0056] In this embodiment, by preliminarily predicting the morphological characteristics of the flame, basic data can be provided for subsequent sensor arrangement and thermal radiation analysis, thereby improving the accuracy and efficiency of the test.

[0057] In some embodiments, determining the morphological characteristics of flame development based on the size of the natural gas pipeline, the leakage location, and the leakage diameter may include the following process.

[0058] The leakage flow rate can be calculated using a flow model based on the size of the natural gas pipeline, the leakage location, and the leakage diameter. The combustion rate can then be calculated based on the leakage flow rate, and the energy release rate and intensity of the flame can be determined. Based on the energy release rate and intensity of the flame, computational fluid dynamics (CFD) can be used to simulate the gas leakage and flame propagation process, and the morphological characteristics of the flame development can be simulated.

[0059] Based on these pipeline parameters, flow models can be used to estimate the rate at which natural gas leaks out of the pipeline, i.e., the leakage flow rate. Flow models usually consider factors such as the flow rate and pressure of natural gas to predict the scale of the leakage.

[0060] The combustion rate refers to the rate at which the leaked natural gas reacts with oxygen in the air to produce flames, which is closely related to the leakage flow rate. The energy release rate refers to the amount of heat released per unit time during the flame combustion process, which can be calculated using the combustion rate and the calorific value of natural gas.

[0061] The intensity of the flame's thermal radiation is usually related to the flame's temperature, volume, and the amount of gas burned. Once the leakage flow is determined, the combustion model is used to calculate the rate at which the leaked natural gas burns after it comes into contact with air. Based on the combustion rate, the flame's energy release rate (the amount of heat released by the flame) and flame intensity (the strength of the thermal radiation) can be further calculated.

[0062] Computational Fluid Dynamics (CFD) simulation is a simulation technology based on numerical methods, which is used to predict the distribution of heat, velocity, temperature, etc. in fluids (such as natural gas, air, etc.) and gases. Through the CFD model, it is possible to predict how the flame will spread from the leak location to the surrounding areas, as well as the temperature distribution and affected area of ​​the flame.

[0063] By determining the energy release rate and intensity of the flame, it can be input into the CFD simulation to simulate the flame expansion process after a natural gas leak. CFD simulation can not only predict the shape and size of the flame, but also the flame propagation speed, direction, and intensity distribution of thermal radiation.

[0064] It should be noted that this process can obtain the approximate morphological characteristics of the flame at different time points, including the temperature distribution, expansion speed, front position, etc. of the flame. These data are not accurate enough, but can be used as a reference for the arrangement of sensors.

[0065] Step 120, determining the center position and the front position of the flame based on the morphological characteristics of the flame development, and determining the first position based on the center position and the front position of the flame.

[0066] The center of the flame is the geometric center of the flame, usually the most intense part of the flame. The leading edge of the flame is the edge of the flame, usually the farthest point the flame travels.

[0067] Based on the determined flame morphology characteristics, the center and front positions of the flame can be determined. The center position is usually the highest heat area of ​​the flame, while the front position marks the expansion boundary of the flame.

[0068] In this embodiment, by clarifying the center and front position of the flame, the flame impact area can be effectively determined, providing a preliminary reference for sensor layout to ensure that the key area of ​​the flame can be covered.

[0069] Step 130, based on the morphological characteristics of flame development and the wind speed and wind direction at the test site, determine the flame inclination during the flame development process, and obtain the morphological characteristics of flame development after superimposing the flame inclination.

[0070] Flame inclination refers to the inclination angle of the flame due to the influence of wind. Wind speed and direction will cause the propagation direction of the flame to change, thus affecting the flame shape.

[0071] According to the actual wind speed and direction information at the test site, combined with the development characteristics of the flame, the flame inclination is calculated and the flame morphology prediction is adjusted.

[0072] Taking into account the influence of ambient wind speed and direction can make the prediction of flame morphology more accurate, thereby optimizing the subsequent flame radiation thermal analysis and sensor layout plan.

[0073] Step 140, determining a second position based on the morphological characteristics of the flame development after superimposing the flame inclination angle.

[0074] The second position is the flame position after considering the flame inclination, which is usually the edge of the flame or a key point in the affected area after the flame is tilted.

[0075] On the basis of step 130, the second position of the flame is further determined in combination with the shape after the flame inclination is adjusted. By considering the position after the flame inclination, the influence range of the flame can be judged more accurately, ensuring that all possible high-temperature areas are covered when the sensor is deployed.

[0076] Step 150 , identifying a heat radiation hotspot area in a historical heat radiation layered map obtained by computational fluid dynamics (CFD) simulation, and determining a third position from the hotspot area in the heat radiation hotspot area that is not covered by the first position and the second position.

[0077] CFD simulation is used to predict the distribution of thermal radiation during flame propagation. Thermal radiation hotspots refer to areas that require special attention for thermal radiation. These areas will produce strong thermal radiation and are prone to develop thermal radiation characteristics that are different from the surrounding areas, which may cause greater safety hazards.

[0078] It is understood that the development of the flame is simulated using a CFD tool, and a heat radiation distribution map is obtained through simulation. The heat radiation hotspot area is analyzed, and the uncovered area that may exist between the positions determined in step 120 and step 140 is identified.

[0079] CFD simulations usually provide a spatiotemporal distribution diagram of thermal radiation, that is, the intensity of thermal radiation at different locations at a certain point in time (or over a period of time). This diagram can be a 3D data set, representing the intensity of thermal radiation at various spatial locations such as spatial grid nodes.

[0080] Thermal radiation intensity data can be discrete point data such as temperature or radiation intensity collected at grid points or more detailed continuous data, which can be stored according to different CFD simulation tools and output methods.

[0081] A fixed radiation intensity value can be selected as the threshold, such as the temperature is higher than a certain value or the radiation intensity exceeds a predetermined value. According to the radiation intensity distribution in the historical data, a percentile is selected, such as the top 10% of high heat radiation areas, or it can be determined according to the heat radiation damage criterion.

[0082] The thermal radiation intensity data are stratified by time or space to identify which areas have higher thermal radiation intensity at different time points or spatial locations.

[0083] These areas are thermal radiation hot spots and can be identified through image or numerical processing methods such as threshold screening and cluster analysis.

[0084] The first location and the second location are hot spots that have been paid attention to or monitored, and it is assumed that these two types of locations have covered certain known hot spots.

[0085] Geometric or spatial analysis methods can be used to check the overlap between the thermal radiation hotspot area and the first and second positions. If some parts of the thermal radiation hotspot area already cover the first or second position, these areas are considered to be "covered" areas.

[0086] Spatial overlapping algorithms, such as rectangular boxes, circular boxes, or polygonal boxes, can be used to mark these covered areas.

[0087] On this basis, the historical thermal radiation hotspot area is subtracted from the coverage area of ​​the first and second positions, that is, the covered part is excluded. The remaining part is the uncovered hotspot area, which requires extra attention. The third position refers to those areas that have not been covered by the first and second positions and have high thermal radiation intensity.

[0088] In some embodiments, the third position can be determined by spatially sorting the uncovered hotspot areas to find out the position with the strongest thermal radiation intensity.

[0089] In other embodiments, cluster analysis (such as K-means or DBSCAN algorithm) can be used to further analyze the distribution of thermal radiation intensity in the uncovered area to determine the center of the hot spot cluster as a candidate area for the third position. Heat map visualization can also be used to color-code the thermal radiation intensity of the uncovered area to intuitively determine the third position.

[0090] Step 160 , deploying sensors at the first position, the second position, and the third position to test the thermal radiation of the natural gas pipeline jet fire.

[0091] Sensor deployment refers to placing thermal radiation sensors at the locations determined in the above steps to monitor the thermal radiation generated by the flame in real time. Sensors are deployed at the first location, the second location, and the third location to test and monitor the thermal radiation of the natural gas pipeline jet fire. These sensors will detect the thermal radiation intensity of the flame in real time and provide data support.

[0092] It is understandable that by properly arranging sensors, the number of sensors can be reduced while ensuring coverage of all key thermal radiation areas, improving the accuracy and efficiency of monitoring. Optimizing sensor layout helps reduce costs and improve the accuracy of data collection, ultimately improving the ability to warn of leaks.

[0093] According to the high-pressure large-diameter natural gas pipeline jet fire thermal radiation testing method provided by the embodiment of the present invention, the approximate flame shape is obtained by combining factors such as the size of the natural gas pipeline, the leakage point, wind speed and direction, etc. to obtain the first position, and on this basis, the inclination of the flame is further considered to obtain the second position, and finally, by analyzing the historical simulation data, the uncovered third position is further screened, thereby achieving efficient and accurate sensor layout, which can not only reduce the number of sensor layouts, but also improve the layout accuracy, ensuring that the thermal radiation generated by the flame can be fully monitored, thereby improving safety and emergency response efficiency.

[0094] In some embodiments, Figure 2 As shown, identifying the heat radiation hot spot area in the historical heat radiation layered map obtained by computational fluid dynamics (CFD) simulation includes step 210, step 220 and step 230.

[0095] Step 210, selecting a historical thermal radiation layered diagram that matches the size, leakage location, and leakage diameter of the natural gas pipeline from the historical data of the CFD simulation;

[0096] Step 220, find the peak area of ​​thermal radiation intensity from the historical thermal radiation layered map by local maximum detection; determine the spatial range of different thermal radiation ranges by connected domain analysis; identify the thermal radiation change area by thermal radiation gradient analysis;

[0097] Step 230 , determining the thermal radiation hotspot area based on the peak area, the spatial range of different thermal radiation ranges, and the thermal radiation change area.

[0098] The specific implementation process of identifying thermal radiation hotspots in the historical thermal radiation layered map obtained by computational fluid dynamics (CFD) simulation can be divided into three main steps: screening relevant historical data, local maximum detection and analysis, and determining thermal radiation hotspots based on multiple analysis results.

[0099] Thermal radiation layer map data can be extracted from CFD simulations. This data usually contains time, space (such as coordinates) and thermal radiation intensity information. Depending on the simulation settings, historical thermal radiation layer map data may contain data for multiple time points or multiple different locations.

[0100] The corresponding thermal radiation layer diagram can be selected by the known size of the natural gas pipeline. The size of the pipeline will affect the thermal radiation distribution when a leak occurs, so it is necessary to ensure that the selected historical data matches the pipeline size. Similarly, the data that meets the leak conditions can be filtered out by the known leak location and leak diameter size.

[0101] By screening out historical thermal radiation layered map data that matches the size, leak location and caliber of the natural gas pipeline, it is ensured that the analyzed thermal radiation data can reflect the thermal radiation distribution associated with the leak.

[0102] The local maximum detection is to find the peak area of ​​radiation intensity from the thermal radiation intensity map, which can represent the hottest point of thermal radiation.

[0103] A local maximum detection algorithm can be used to identify peak regions in an image. Local maximum detection methods can include Gaussian filtering, peak detection, and neighborhood comparison processes.

[0104] Gaussian filtering is to smooth the thermal radiation intensity map to remove noise and unimportant small fluctuations. After that, the local neighborhood value of each point in the image can be calculated to determine whether it is a maximum value. Peak detection detects local maximum values ​​by looking for a value greater than the current point in the neighborhood of each point. Neighborhood comparison checks the values ​​within a certain range around each point. If the thermal radiation intensity value of the point is the maximum value in the neighborhood, it is considered a local maximum.

[0105] Connected domain analysis is used to determine the spatial range of areas with high thermal radiation intensity (i.e., the distribution area of ​​thermal radiation hotspots). Connected domain analysis is performed on local maximum areas to find continuous areas with high thermal radiation intensity. Commonly used connected domain analysis methods include four-neighborhood and eight-neighborhood connection methods, region growing algorithms, and morphological analysis.

[0106] The four-neighborhood and eight-neighborhood connection methods are to determine whether the thermal radiation intensity of the adjacent nodes around each pixel (or spatial node) exceeds a certain threshold. In this way, the adjacent areas with higher thermal radiation intensity are merged. The region growing algorithm starts from the local maximum point and expands outward within a certain threshold range to merge the areas with high thermal radiation intensity in the neighborhood until the conditions are met. Morphological analysis is to further analyze the connected domain through morphological operations such as expansion, corrosion, opening and closing operations, etc.

[0107] Thermal radiation gradient analysis is to identify areas of thermal radiation change, especially areas of sharp thermal radiation change near leaks, or areas where sharp temperature changes occur after encountering some obstacles.

[0108] It is also possible to draw a thermal radiation variation curve of the monitoring point, and then obtain the gradient distribution of thermal radiation intensity in different areas at different times based on the thermal radiation variation curve.

[0109] Thermal radiation changes can be analyzed by the gradient of thermal radiation intensity. Gradients can be used to describe the rate of change of temperature or radiation intensity in space. Gradient calculations for thermal radiation layered graphs can be performed using numerical differentiation methods such as the central difference method to calculate the thermal radiation gradient corresponding to the value of each point in the curve.

[0110] Areas with larger thermal radiation gradients usually correspond to areas with more dramatic thermal radiation changes, which may be hot spots around the leak site or in the leak propagation path.

[0111] Comprehensively analyze the peak area, the spatial range of different thermal radiation ranges, and the thermal radiation change area. The above three types of information can be combined through logical operations such as union and intersection. Generally speaking, the thermal radiation hotspot area can be an area that meets the following conditions at the same time: the thermal radiation intensity is high enough, the thermal radiation intensity distribution is coherent and continuous in space, and the thermal radiation changes significantly.

[0112] Based on the results of the above analysis, hot spots are marked in the thermal radiation layered diagram. These areas may represent leakage points or key areas in the leakage propagation process and require special attention.

[0113] In practical applications, it may be necessary to adjust the thresholds or algorithm parameters in the above steps according to specific requirements or scenarios, for example, adjusting the threshold for local maximum detection or adjusting the neighborhood range in connected domain analysis.

[0114] It can be understood that through the analysis of the above three steps, the thermal radiation hotspot areas can be identified from the historical thermal radiation stratification diagram of the CFD simulation, which can provide a basis for subsequent safety monitoring, risk assessment, etc.

[0115] In some embodiments, the thermal radiation hotspot area is determined based on the peak area, the spatial range of different thermal radiation ranges, and the thermal radiation change area, including: analyzing the spatial distribution and time evolution of the peak area, the spatial range of different thermal radiation ranges, and the thermal radiation change area within a time period through a sliding window; determining the thermal radiation hotspot area based on the peak area, the spatial range of different thermal radiation ranges, and the duration of existence of the thermal radiation change area.

[0116] You can set an appropriate time window size. For example, if each time step is 1 minute, you can set a 5-minute window, which means analyzing the hotspots in the past 5 minutes. Move the window forward step by step, and update the hotspot analysis results in the window in real time. For example, if the current time step is t, the window analyzes the data between the interval [t-5, t].

[0117] Aggregating the data in the window can be done by calculating the average thermal radiation intensity of each area in the window to identify the area with the largest change, or by calculating the variance of the radiation intensity of each area in the window to identify the area with the most dramatic change.

[0118] In each window, the hotspot area is identified by the aforementioned local maximum detection, connected domain analysis and other methods. The hotspot area of ​​the current window is compared with the hotspot area of ​​the previous window to observe the changing trend of the hotspot area.

[0119] Draw a heat map of thermal radiation intensity for each time step. Each heat map shows the distribution of radiation intensity in different spatial regions at a certain moment. Finally, display the heat maps of all time steps in chronological order as an animation, or stack them up to form a time series heat map. This can help observe the changing trend of hot spots over time.

[0120] On this basis, a thermal radiation intensity threshold needs to be set. Only when the radiation intensity of a certain area exceeds this threshold and the area remains unchanged or continues to increase over a period of time, it is considered a persistent hotspot.

[0121] Identify whether each hotspot area exists in each time step (i.e., whether the radiation intensity exceeds the threshold). For each hotspot area, calculate its duration, i.e., the time period during which the area appears continuously in multiple time steps.

[0122] Duration analysis helps assess whether a hotspot area is a stable hotspot or just a temporary fluctuation. Hotspots that persist for a long time may require special attention and the deployment of sensors.

[0123] For each hotspot identified in the sliding window, record their persistence in different time windows. If an area exists and maintains a high radiation intensity in multiple consecutive time windows, it indicates that the area is a stable and persistent thermal radiation hotspot.

[0124] In this embodiment, the most representative thermal radiation hotspot areas can be identified in large-scale CFD simulation data with a long time span, thereby providing valuable basis for subsequent safety assessment, leakage treatment or optimization.

[0125] In some embodiments, based on the morphological characteristics of flame development and the wind speed and wind direction at the test site, the flame inclination during flame development is determined to obtain the morphological characteristics of flame development after superimposing the flame inclination, including the following process.

[0126] Based on the morphological characteristics of flame development, the flame morphology at different stages of the flame development process can be modeled; based on the flame morphology, wind speed and wind direction at different stages of the flame development process, the flame inclination at different stages of the flame development process can be calculated; finally, based on the flame inclination at different stages of the flame development process, it is superimposed on the flame morphology model at different stages of the flame development process to obtain the morphological characteristics of the flame in the entire development process.

[0127] In other words, the core of this process is to determine the flame's inclination angle (flame inclination) by analyzing the flame's development morphology, wind speed and wind direction at the scene, and to superimpose the influence of this inclination angle on the flame morphology model, thereby more accurately describing the morphological changes of the flame at different stages of development.

[0128] First, the morphology of the flame at different development stages is modeled to describe the changes of the flame in time and space. According to the flame morphology, wind speed and wind direction at the scene, the inclination angle of the flame at each development stage (i.e., the flame inclination angle) is calculated. The calculated flame inclination angle is superimposed on the flame morphology model, and the flame morphology is adjusted to obtain the morphological characteristics of the flame development process that are more in line with the actual situation, thereby obtaining a more accurate flame development process model.

[0129] In some embodiments, the second position is determined based on the morphological characteristics of the flame development after superimposing the flame inclination angle, including: predicting the maximum expansion range of the flame based on the morphological characteristics of the flame development after superimposing the flame inclination angle, the maximum expansion range including the range in the vertical and horizontal directions; determining the second position based on the maximum expansion range of the flame, wind speed and wind direction.

[0130] Based on the flame morphology characteristics after the inclination angle is adjusted, the maximum expansion range of the flame is predicted. The maximum expansion range refers to the maximum size of the flame in the vertical direction (i.e. the height of the flame) and the horizontal direction (i.e. the horizontal range of the flame) when the flame expands most strongly.

[0131] When predicting the maximum spread, it is necessary to consider the wind speed and direction at the scene, because the effect of wind will affect the direction and speed of flame spread. The greater the wind speed, the faster the flame may spread, and the wind direction determines the main direction of flame spread.

[0132] Based on the predicted maximum spread and the effect of wind, a second location is determined. This location can be a specific area or location where the flame may spread, taking into account the actual development trend of the flame and the effect of wind.

[0133] It can be understood that the process is to predict the maximum extension range of the flame based on the adjusted flame morphological characteristics, and then further determine the second position to which the flame may extend through the influence of wind speed and wind direction.

[0134] In some embodiments, sensors are deployed at a first location, a second location, and a third location to test the thermal radiation of a natural gas pipeline jet fire, including the following process.

[0135] The target position can be screened out from the first position, the second position and the third position based on the distances of the first position, the second position and the third position from the leakage port; a movable sensor is deployed at the target position, and during the test, the movable sensor deployed at the target position is controlled to move along the direction of thermal radiation diffusion to dynamically detect the thermal radiation.

[0136] A movable sensor is deployed at the selected target location. Unlike a fixed sensor, this sensor can be moved along the diffusion direction of thermal radiation during the test, so that the intensity and distribution of thermal radiation can be more comprehensively monitored and recorded.

[0137] It should be noted that the target location can be a location far away from the leak, where the temperature may not be high and is less affected by high temperatures. Therefore, complex drones and mobile robots can be deployed to carry sensors to achieve dynamic monitoring. In addition, this area with low temperature is far away, wide and has slow temperature fluctuations. Deploying mobile sensors can achieve detection of a large range during movement, which improves efficiency while meeting monitoring requirements.

[0138] During the test, the sensor moves along the diffusion direction of the thermal radiation. Thermal radiation generally spreads from the fire source to the surrounding area, so the movement of the sensor can help obtain radiation data at different locations. This dynamic detection method can track the changes in thermal radiation in real time and provide continuous monitoring data, thereby ensuring that the impact of flames or thermal radiation on the environment can be evaluated in a timely manner.

[0139] The high-pressure large-diameter natural gas pipeline jet fire thermal radiation test system provided by the present invention is described below. The high-pressure large-diameter natural gas pipeline jet fire thermal radiation test system described below and the high-pressure large-diameter natural gas pipeline jet fire thermal radiation test method described above can be referenced to each other.

[0140] like Figure 3 As shown, the high-pressure large-diameter natural gas pipeline jet fire thermal radiation test system of the embodiment of the present invention mainly includes a first simulation module 310, a first processing module 320, a second simulation module 330, a second processing module 340, a third processing module 350 and a test module 360.

[0141] The first simulation module 310 is used to determine the morphological characteristics of flame development based on the size of the natural gas pipeline, the leakage location and the leakage diameter size; the morphological characteristics of flame development include the shape and size of the flame at different times;

[0142] The first processing module 320 is used to determine the center position and the front position of the flame based on the morphological characteristics of the flame development, and determine the first position based on the center position and the front position of the flame;

[0143] The second simulation module 330 is used to determine the flame inclination angle during the flame development process based on the morphological characteristics of the flame development and the wind speed and wind direction at the test site, and obtain the morphological characteristics of the flame development after the flame inclination angle is superimposed;

[0144] The second processing module 340 is used to determine the second position based on the morphological characteristics of the flame development after the flame inclination angle is superimposed;

[0145] The third processing module 350 is used to identify a heat radiation hot spot area in the historical heat radiation layered map obtained by computational fluid dynamics (CFD) simulation, and determine a third position from the hot spot area not covered by the first position and the second position in the heat radiation hot spot area;

[0146] The test module 360 ​​is used to deploy sensors at the first position, the second position and the third position to test the thermal radiation of the natural gas pipeline jet fire.

[0147] According to the high-pressure large-diameter natural gas pipeline jet fire thermal radiation test system provided by the embodiment of the present invention, the approximate flame shape is obtained by combining factors such as the size of the natural gas pipeline, the leakage point, wind speed and direction, etc. to obtain the first position, and on this basis, the inclination of the flame is further considered to obtain the second position, and finally, by analyzing the historical simulation data, the uncovered third position is further screened, thereby realizing efficient and accurate sensor layout, which can not only reduce the number of sensor layouts, but also improve the layout accuracy, ensuring that the thermal radiation generated by the flame can be fully monitored, thereby improving safety and emergency response efficiency.

[0148] Figure 4 An example of a physical structure diagram of an electronic device is shown in FIG. Figure 4As shown, the electronic device may include: a processor (processor) 410 , a communication interface (Communications Interface) 420 , a memory (memory) 430 and a communication bus 440 , wherein the processor 410 , the communication interface 420 , and the memory 430 communicate with each other through the communication bus 440 . The processor 410 can call the logic instructions in the memory 430 to execute a high-pressure large-diameter natural gas pipeline jet fire thermal radiation test method, the method comprising: determining the morphological characteristics of flame development based on the size of the natural gas pipeline, the leakage location and the leakage diameter size; the morphological characteristics of flame development include the shape and size of the flame at different times; determining the center position and the front position of the flame based on the morphological characteristics of flame development, and determining the first position based on the center position and the front position of the flame; determining the flame inclination during the flame development process based on the morphological characteristics of flame development and the wind speed and wind direction at the test site, and obtaining the morphological characteristics of flame development after superimposing the flame inclination; determining the second position based on the morphological characteristics of flame development after superimposing the flame inclination; identifying the thermal radiation hotspot area in the historical thermal radiation layered map obtained by computational fluid dynamics (CFD) simulation, and determining the third position from the hotspot area not covered by the first position and the second position in the thermal radiation hotspot area; deploying sensors at the first position, the second position and the third position to test the thermal radiation of the natural gas pipeline jet fire.

[0149] In addition, the logic instructions in the above-mentioned memory 430 can be implemented in the form of a software functional unit and can be stored in a computer-readable storage medium when it is sold or used as an independent product. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art or the part of the technical solution, can be embodied in the form of a software product, and the computer software product is stored in a storage medium, including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to perform all or part of the steps of the method described in each embodiment of the present invention. The aforementioned storage medium includes: U disk, mobile hard disk, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), disk or optical disk, etc. Various media that can store program codes.

[0150] On the other hand, the present invention also provides a computer program product, which includes a computer program, which can be stored on a non-transitory computer-readable storage medium. When the computer program is executed by a processor, the computer can execute the high-pressure large-diameter natural gas pipeline jet fire thermal radiation test method provided by the above methods, the method including: determining the morphological characteristics of flame development based on the size of the natural gas pipeline, the leakage location and the leakage diameter size; the morphological characteristics of flame development include the shape and size of the flame at different times; determining the center position and the front position of the flame based on the morphological characteristics of flame development, and determining the first position based on the center position and the front position of the flame; determining the flame inclination during the flame development process based on the morphological characteristics of flame development and the wind speed and wind direction at the test site, and obtaining the morphological characteristics of flame development after superimposing the flame inclination; determining the second position based on the morphological characteristics of flame development after superimposing the flame inclination; identifying the thermal radiation hotspot area in the historical thermal radiation layered map obtained by computational fluid dynamics (CFD) simulation, and determining the third position from the hotspot area not covered by the first position and the second position in the thermal radiation hotspot area; deploying sensors at the first position, the second position and the third position to test the thermal radiation of the natural gas pipeline jet fire.

[0151] On the other hand, the present invention also provides a non-transitory computer-readable storage medium having a computer program stored thereon, which is implemented by a processor to execute the high-pressure large-diameter natural gas pipeline jet fire thermal radiation test method provided by the above-mentioned methods when the computer program is executed, the method comprising: determining the morphological characteristics of flame development based on the size of the natural gas pipeline, the leakage location and the leakage diameter size; the morphological characteristics of flame development include the shape and size of the flame at different times; determining the center position and the front position of the flame based on the morphological characteristics of flame development, and determining the first position based on the center position and the front position of the flame; determining the flame inclination during the flame development process based on the morphological characteristics of flame development and the wind speed and wind direction at the test site, and obtaining the morphological characteristics of flame development after superimposing the flame inclination; determining the second position based on the morphological characteristics of flame development after superimposing the flame inclination; identifying the thermal radiation hotspot area in the historical thermal radiation layered map obtained by computational fluid dynamics (CFD) simulation, and determining the third position from the hotspot area not covered by the first position and the second position in the thermal radiation hotspot area; deploying sensors at the first position, the second position and the third position to test the thermal radiation of the natural gas pipeline jet fire.

[0152] The device embodiments described above are merely illustrative, wherein the units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the scheme of this embodiment. Ordinary technicians in this field can understand and implement it without paying creative labor.

[0153] Through the description of the above implementation methods, those skilled in the art can clearly understand that each implementation method can be implemented by means of software plus a necessary general hardware platform, and of course, can also be implemented by hardware. Based on this understanding, the above technical solution is essentially or the part that contributes to the prior art can be embodied in the form of a software product, and the computer software product can be stored in a computer-readable storage medium, such as ROM / RAM, a disk, an optical disk, etc., including a number of instructions for a computer device (which can be a personal computer, a server, or a network device, etc.) to execute the methods described in each embodiment or some parts of the embodiments.

[0154] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for testing the thermal radiation of jet fire in a high-pressure and large-diameter natural gas pipeline, characterized in that: include: Determine the morphological characteristics of flame development based on the size of the natural gas pipeline, the leak location, and the leak diameter; The morphological characteristics of flame development include the shape and size of the flame at different moments; Determine the center position and the front position of the flame based on the morphological characteristics of the flame development, and determine the first position based on the center position and the front position of the flame; Based on the morphological characteristics of the flame development and the wind speed and wind direction at the test site, the flame inclination angle during the flame development process is determined to obtain the morphological characteristics of the flame development after the flame inclination angle is superimposed; Determining a second position based on the morphological characteristics of flame development after superimposing the flame inclination angle; Identify a heat radiation hotspot area in a historical heat radiation layered map obtained by computational fluid dynamics (CFD) simulation, and determine a third position from the hotspot area not covered by the first position and the second position in the heat radiation hotspot area; Sensors are deployed at the first position, the second position, and the third position to test the thermal radiation of the natural gas pipeline jet fire.

2. The high-pressure large-diameter natural gas pipeline jet fire thermal radiation test method according to claim 1 is characterized in that: The step of identifying the thermal radiation hotspot area in the historical thermal radiation layered diagram obtained by computational fluid dynamics (CFD) simulation includes: Selecting a historical thermal radiation layered diagram that matches the size, leakage location, and leakage diameter of the natural gas pipeline from the historical data of CFD simulation; Find the peak area of ​​thermal radiation intensity from the historical thermal radiation layered map by local maximum detection; determine the spatial range of different thermal radiation ranges by connected domain analysis; identify the thermal radiation change area by thermal radiation gradient analysis; The thermal radiation hot spot area is determined based on the peak area, the spatial ranges of different thermal radiation ranges, and the thermal radiation change area.

3. The high-pressure large-diameter natural gas pipeline jet fire thermal radiation test method according to claim 2 is characterized in that: The determining of the thermal radiation hotspot area based on the peak area, the spatial range of different thermal radiation ranges, and the thermal radiation change area includes: The peak area, the spatial extent of different thermal radiation ranges, and the spatial distribution and temporal evolution of the thermal radiation variation area within the time period were analyzed by sliding windows; The thermal radiation hot spot area is determined based on the peak area, the spatial ranges of different thermal radiation ranges, and the existence duration of the thermal radiation change area.

4. The high-pressure large-diameter natural gas pipeline jet fire thermal radiation test method according to claim 1 is characterized in that: The method of determining the flame inclination angle during the flame development process based on the morphological characteristics of the flame development and the wind speed and wind direction at the test site, and obtaining the morphological characteristics of the flame development after superimposing the flame inclination angle, includes: Based on the morphological characteristics of the flame development, modeling the flame morphology at different stages of the flame development process; Based on the flame shape, wind speed and wind direction at different stages of the flame development process, the flame inclination angle at different stages of the flame development process is calculated; Based on the flame inclination angles at different stages of the flame development process, and superimposed on the flame morphology models at different stages of the flame development process, the morphological characteristics of the flame in the entire development process are obtained.

5. The high-pressure large-diameter natural gas pipeline jet fire thermal radiation test method according to claim 4 is characterized in that: The determining of the second position based on the morphological characteristics of the flame development after superimposing the flame inclination angle comprises: Based on the morphological characteristics of flame development after superimposing the flame inclination angle, the maximum flame extension range is predicted, and the maximum flame extension range includes the range in the vertical and horizontal directions; The second position is determined based on the maximum extension range of the flame, wind speed and wind direction.

6. The high-pressure large-diameter natural gas pipeline jet fire thermal radiation test method according to claim 1 is characterized in that: Determining the morphological characteristics of flame development based on the size of the natural gas pipeline, the leakage location and the leakage diameter size includes: Calculating the leakage flow rate using a flow model based on the size of the natural gas pipeline, the leakage location, and the leakage diameter size; Calculating the combustion rate based on the leakage flow rate and determining the energy release rate and intensity of the flame; Based on the energy release rate and intensity of the flame, computational fluid dynamics (CFD) is used to simulate the gas leakage and flame propagation process, and the morphological characteristics of the flame development are simulated.

7. The high-pressure large-diameter natural gas pipeline jet fire thermal radiation test method according to claim 1 is characterized in that: The step of deploying sensors at the first position, the second position, and the third position to test the thermal radiation of the natural gas pipeline jet fire includes: Based on the distances of the first position, the second position, and the third position from the leakage port, a target position is obtained by screening the first position, the second position, and the third position; A movable sensor is deployed at the target position, and during the test process, the movable sensor deployed at the target position is controlled to move along the thermal radiation diffusion direction to perform dynamic detection of the thermal radiation.

8. A high-pressure large-diameter natural gas pipeline jet fire thermal radiation test system, characterized in that: include: A first simulation module is used to determine the morphological characteristics of flame development based on the size of the natural gas pipeline, the leakage location and the leakage diameter size; The morphological characteristics of flame development include the shape and size of the flame at different moments; A first processing module, configured to determine a center position and a front position of the flame based on the morphological characteristics of the flame development, and determine a first position based on the center position and the front position of the flame; The second simulation module is used to determine the flame inclination angle during the flame development process based on the morphological characteristics of the flame development and the wind speed and wind direction at the test site, and obtain the morphological characteristics of the flame development after the flame inclination angle is superimposed; A second processing module, used for determining a second position based on the morphological characteristics of flame development after superimposing the flame inclination angle; A third processing module is used to identify a thermal radiation hot spot area in a historical thermal radiation layered map obtained by computational fluid dynamics (CFD) simulation, and determine a third position from the hot spot area not covered by the first position and the second position in the thermal radiation hot spot area; The test module is used to deploy sensors at the first position, the second position and the third position to test the thermal radiation of the natural gas pipeline jet fire.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and capable of running on the processor, characterized in that: When the processor executes the program, the high-pressure large-diameter natural gas pipeline jet fire thermal radiation testing method as described in any one of claims 1 to 7 is implemented.

10. A non-transitory computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the high-pressure large-diameter natural gas pipeline jet fire thermal radiation testing method as described in any one of claims 1 to 7 is implemented.

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