Method, model and device for real-time risk assessment of gas-to-electricity pipeline diffusion coupling

Abstract

This invention discloses a real-time risk assessment method for the coupling of gas diffusion into power pipelines, belonging to the field of risk assessment. The steps are as follows: S1: Divide the gas pipeline and power pipeline into sections; S2: Determine the type of gas leak, obtain the hazard of different diffusion boundaries, and calculate soil permeability and road surface correction factors; S3: Obtain the risk impact factor of the coupling between gas pipelines and power pipelines; S4: Obtain the risk of the coupling between gas pipelines and power pipelines; S5: Set different correction coefficients for different power pipeline laying methods, calculate the cross-sectional area of ​​gas accumulation under different power pipeline laying methods, calculate the gas diffusion rate, obtain the sealing correction factor of the power pipeline, and calculate the maximum distance for gas diffusion to the dangerous concentration; S6: Obtain the risk of the power pipeline. This invention can provide a basis for the investigation, early warning, and handling of gas diffusion coupling accidents into power pipelines, preventing fire and explosion accidents and ensuring urban safety.

Description

Technical Field

[0001] This invention relates to the field of risk assessment, specifically to a coupled real-time risk assessment method, model, and device for the diffusion of gas into power pipelines. Background Technology

[0002] Urban gas pipelines and power lines are essential municipal infrastructure in modern cities, serving as vital lifelines. my country's urban gas and power pipeline networks are extremely complex, posing significant environmental risks. Due to limitations in early equipment, construction, technology, and management, many facilities have become aging and damaged. Furthermore, poor management, missing engineering data, high personnel turnover, and the increasing number of structures and buildings surrounding the pipelines have created substantial risks to urban safety.

[0003] Due to the flammable and explosive nature of natural gas, once a gas pipeline leaks, the combustible gas can easily spread and accumulate in adjacent underground spaces, making it highly susceptible to coupling accidents with nearby pipelines. When a gas leak spreads into adjacent power pipelines, short circuits, overloads, poor connections, and other factors in the power cables can lead to abnormal discharges and overheating. Therefore, the risk of cable tunnel explosions is relatively high under the combined effects of fuel leaks and power pipeline accidents.

[0004] Current risk assessments for gas and power pipelines are rather broad, failing to specifically consider the risks arising from their coupling effects. Existing risk assessment systems for gas pipelines divide the pipeline into several sections, scoring factors that could cause pipeline failure, such as third-party damage, pipeline corrosion, design flaws, and operational errors. Then, combining the probability of failure with the severity of the consequences, a relative risk value is formed. This assessment system only considers the risk factors present in the gas pipeline before the accident occurs, without taking into account the impact of a gas pipeline leak on nearby power pipelines.

[0005] For example, CN112633552B discloses a method and system for identifying and assessing the risks of coupling hazards between gas pipelines and surrounding pipelines. This method, through comprehensive analysis of gas leakage, gas diffusion and accumulation, vulnerability of surrounding pipelines, ignition probability, explosion consequences, and emergency response capabilities, can identify the coupling hazards between gas pipelines and surrounding pipelines, enabling qualitative and quantitative assessment of the risks associated with these connections. However, its assessment system still only considers gas pipelines and surrounding pipelines, with limited consideration for the impact of gas leakage diffusion and coupling with power lines. It lacks assessment of gas leakage types, the impact of diffusion processes, and the risk of gas diffusion within power lines. Summary of the Invention

[0006] The technical problem to be solved by this invention is how to conduct real-time assessment of the risks of gas leak diffusion and power channel coupling under the coupled effects of multiple factors, so as to prevent fire and explosion accidents and ensure the safety of cities and residents.

[0007] To address the above problems, this invention provides a coupled real-time risk assessment method for the diffusion of natural gas into power pipelines, comprising the following steps:

[0008] S1: Based on the underground pipeline network map of the city's gas pipelines and power pipelines, divide the pipelines into sections to obtain each division unit;

[0009] S2: Based on real-time monitoring data of the gas passages within each unit, determine the gas leak type T. Combined with the gas leak time t, obtain different diffusion boundary hazards P(T,t), and calculate the soil permeability Ks for different soil types and the pavement correction factor R for different pavement types. road ;

[0010] S3: Determine the coupling mode between gas pipelines and power pipelines, and obtain the risk impact factor R(d,h) of the coupling between gas pipelines and power pipelines. Where C is a constant, d is the horizontal distance between the gas pipeline and the power pipeline, i.e. the coupling distance, h is the burial depth of the gas pipeline, and λ is used to control the impact of coupling distance and burial depth on risk.

[0011] S4: Obtain the quantitative risk R of the coupling between gas pipelines and power pipelines, R = P(T,t)·Ks·R road ·R(d,h), and normalize R;

[0012] S5: Perform real-time monitoring of power pipelines in each unit, set different correction coefficients S for different power pipeline laying methods, and calculate the cross-sectional area A of gas accumulation under different power pipeline laying methods. m The power pipeline sensor monitors and calculates the gas diffusion rate, determines the pipeline blockage type (blocked or unblocked), and obtains the blockage correction factor L; it also calculates the maximum distance D from the gas diffusion point to the hazardous concentration. b , in Let be the average diffusion rate of the gas, t be the time of gas leakage, and φ be the environmental correction factor.

[0013] S6: Obtaining Quantitative Risks of Power Pipelines d R d =D b ·A m ·S·L, and for R d Normalize.

[0014] Preferably, in step S2, the process of determining the type of gas leak is as follows: select a monitoring point and calculate the rate of change v of the gas concentration at that point. n Define volume correction factor Where V0 is the standard well volume, V is the actual gas well volume, and v is the volume of the standard well. n Perform correction: v n修正 =k1·v n Define the rate of change thresholds α and β; compare v n Correction and change rate thresholds α and β, if v n修正 If ≤α, then the gas leak type T is a pinhole leak. <v n修正 ≤β, at this time the gas leak type T is a large hole leak, if v n修正 >β, at this time the gas leak type T is a rupture leak.

[0015] This invention corrects the rate of change of gas concentration by using a volume correction coefficient, which can eliminate the influence of volume on the rate of change of concentration and make the monitoring results of gas wells with different volumes comparable.

[0016] Preferably, the diffusion boundary hazard Where χ, ε, and γ are adjustment parameters, and Q small Q large Q rupture These represent the gas leakage amounts from small hole leaks, large hole leaks, and rupture leaks, respectively.

[0017] This invention determines the type of gas leak, specifically obtains the diffusion boundary hazard of different gas leak types, and calculates soil permeability for different soil types and pavement correction factors for different pavement types, enabling more accurate quantitative risk assessment of the coupling of gas pipelines and power pipelines.

[0018] Preferably, in step S2, the soil permeability Where D 10 Where ψ is the effective particle size, μ is the water unit weight, e is the hydrodynamic viscosity, and N is a constant; the pavement correction factor is... Where k hard >1.

[0019] Preferably, in step S3, the coupling method between the gas pipeline and the power pipeline includes parallel coupling and cross coupling.

[0020] Preferably, in step S5, the laying methods of the power pipeline include direct burial, conduit installation, and power trench installation, with a correction factor of S corresponding to the direct burial method. direct The correction factor corresponding to the bushing method is S. casing The correction factor corresponding to the power trench method is S.trench .

[0021] Preferably, in the sleeve configuration, the cross-sectional area A of the gas accumulation is... casing =n·πr 2 Where n is the number of pipes inside the casing, and r is the radius of the casing pipes; in the power trench method, the cross-sectional area A of the gas accumulation is... trench = w·h, where w is the width of the power trench and h is the height of the power trench.

[0022] Preferably, in step S5, the blocking correction factor Where L blocked >1, L unblocked <1.

[0023] Corresponding to the above method, the present invention also provides a coupled real-time risk assessment model for the diffusion of natural gas into power pipelines, comprising the following modules:

[0024] Unit segmentation module: used to divide pipe segments based on the underground pipeline network map of the city's gas pipelines and power pipelines, and obtain each segmentation unit;

[0025] The diffusion boundary hazard acquisition module is used to determine the gas leak type T based on real-time monitoring data of the gas passages within each unit, and, combined with the gas leak time t, obtain different diffusion boundary hazards P(T, t). It also calculates the soil permeability Ks for different soil types and the pavement correction factor R for different pavement types. road ;

[0026] The module for calculating the coupling risk impact factor is used to determine the coupling mode between gas pipelines and power pipelines, and to obtain the coupling risk impact factor R(d,h) between gas pipelines and power pipelines. Where C is a constant, d is the horizontal distance between the gas pipeline and the power pipeline, i.e. the coupling distance, h is the burial depth of the gas pipeline, and λ is used to control the impact of coupling distance and burial depth on risk.

[0027] The coupling risk acquisition module is used to obtain the quantitative real-time risk R of the coupling between gas pipelines and power pipelines, where R = P(T,t)·Ks·R. road ·R(d,h), and normalize R;

[0028] Power pipeline monitoring module: Used for real-time monitoring of power pipelines in various units. Different correction factors S are set for different power pipeline laying methods to calculate the cross-sectional area A of gas accumulation under different power pipeline laying methods. mThe gas diffusion rate is calculated based on real-time monitoring data, and the type of blockage in the power pipeline is determined, including whether it is blocked or not, and the blockage correction factor L is obtained; the maximum distance D from the gas diffusion to the dangerous concentration is calculated. b , in Let be the average diffusion rate of the gas, t be the time of gas leakage, and φ be the environmental correction factor.

[0029] The Power Pipeline Risk Acquisition Module is used to obtain the quantitative, real-time risk (R) of power pipelines. d R d =D b ·A m ·S·L, and for R d Normalize.

[0030] The present invention also provides a terminal device, including a memory and a processor, wherein the memory is used to store a computer program, and the processor is used to call and run the computer program stored in the memory to execute the coupled real-time risk assessment method for gas diffusion into power pipelines as described above.

[0031] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0032] (1) By correcting the rate of change of gas concentration by volume correction coefficient, different types of leaks can be distinguished more accurately, and the diffusion boundary hazards of different types of gas leaks can be obtained. Furthermore, by analyzing the influence of different soil types, road surface types and other factors on gas diffusion, a more comprehensive and accurate quantitative risk assessment of the coupling of gas pipelines and power pipelines can be conducted.

[0033] (2) Based on the detection data, the risk of gas leakage and power pipeline coupling during the gas diffusion process is evaluated in real time, realizing dynamic real-time risk assessment. This enables the assessment results to reflect the current risk situation in a timely manner, effectively improving the efficiency of pipeline safety management, effectively preventing accidents, and ensuring the safety of residents and property.

[0034] (3) By calculating the quantitative risk of power pipelines, the risk of gas diffusion in power pipelines can be assessed. With the help of monitoring equipment, the situation of gas diffusion and accumulation in power pipelines can be predicted, which can provide a basis for accident investigation, early warning and handling. Attached Figure Description

[0035] Figure 1 This is a flowchart of Embodiment 1 of the present invention;

[0036] Figure 2 This is a schematic diagram of the terminal intelligent device in Embodiment 3 of the present invention. Detailed Implementation

[0037] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0038] Example 1

[0039] like Figure 1 The diagram shown is a flowchart of the entire embodiment. This embodiment provides a coupled real-time risk assessment method for the diffusion of natural gas into power pipelines. The specific process is as follows:

[0040] Step 1: First, based on the underground pipeline network map of gas and electricity channels, divide the gas pipelines and electricity pipelines into different units. The division principle is as follows:

[0041] (1) Divided into different units based on differences in pipe diameter, pipe age, and pipe material;

[0042] (2) Divide into different units by road intersections or administrative boundaries;

[0043] (3) The pipes connected by the kit are divided into different units at the connection point;

[0044] (4) According to the different pipeline laying methods and ground hardening conditions, they are divided into different units.

[0045] The attributes of gas pipes and power pipelines within the divided units are extracted to obtain key factors affecting the spread of gas leaks, such as gas pipe pressure and burial depth, which are used as data support for the risk assessment of gas leak spread.

[0046] Perform steps 2-4 of this embodiment to obtain a quantitative real-time risk of gas leakage and coupling with adjacent power pipelines.

[0047] Step 2: Determine the gas leak type T based on real-time monitoring data of the gas passages within each unit. Combined with the gas leak time t, obtain the different diffusion boundary hazards P(T,t), and calculate the soil permeability Ks for different soil types and the pavement correction factor R for different pavement types. road The specific process is as follows:

[0048] S201: Determining the Type of Gas Leak: In current urban lifeline infrastructure projects, gas leak monitoring equipment is installed in gas wells. This equipment obtains real-time monitoring data of the gas passage and analyzes it to obtain the rate of change v of gas concentration after a leak. nThe functional relationship between the gas concentration M(t) and time t is linear or exponential. Discrete concentration data M(t1), M(t2), ..., M(t3) are obtained through monitoring equipment. n The rate of change of gas concentration per unit time is approximated using numerical differentiation methods:

[0049] Because the volume of the gas well affects the rate of change of gas concentration, this embodiment also uses a volume correction factor to adjust the monitored rate of change of gas concentration v. n Correction is performed: Let the volume of the gas well be V. Assume that the rate of concentration change is inversely proportional to the volume of the gas well, that is, the larger the volume, the smaller the concentration change per unit time. Define a volume correction coefficient k1. Where V0 is the standard well volume, V is the actual gas well volume, and then v n Perform correction:

[0050] Define the rate of change thresholds α and β, and compare v n Correction and change rate thresholds α and β, if v n修正 If ≤α, then the gas leak type T is a pinhole leak. <v n修正 ≤β, at this time the gas leak type T is a large hole leak, if v n修正 >β, at this time the gas leak type T is a rupture leak;

[0051] S202: By combining the gas leak type T and the gas leak time t, different diffusion boundary hazards P(T,t) are obtained. Where χ, ε, and γ are adjustment parameters reflecting the influence of environmental conditions on gas diffusion, Q small Q large Q rupture These represent the gas leakage amounts for small hole leaks, large hole leaks, and rupture leaks, respectively.

[0052] The diffusion of gas from a small hole leak is relatively slow. The longer the leakage time, the larger the diffusion radius. The formula for calculating the gas leakage amount from a small hole leak is: Where k is the gas adiabatic coefficient, which is 1.334 in this embodiment, R is the gas constant, and T B P is the temperature before the gas leak. B Let A be the pressure before the gas leak, and C be the area of ​​the leak. d The orifice flow correction coefficient is determined based on the shape of the leak: when the leak is circular, C... d =1.00, when the leak outlet is triangular, C d =0.95, when the leak outlet is rectangular, C d =0.90, when the leak point is an internally corroded constricting cavity, 0.9 <Cd <1.0, when the leakage outlet is a gradually expanding orifice damaged by external force, 0.6 <C d <0.9, where M is the molar mass of the gas;

[0053] When a large orifice leaks, the gas diffuses rapidly. For actual high-pressure or low-pressure gas transmission pipelines, as the orifice diameter further increases, the pressure P at the center of the leak increases. B Much less than the pressure P at the start of the pipeline A However, it is still greater than the critical pressure P. c At this point, the leakage process becomes a critical flow process where both the pipeline and the leak hole are in a state of critical flow. The formula for calculating the gas leakage rate in a large-hole leak is: Where T A P represents the gas temperature at the start of the pipeline. A The pressure at the starting point of the pipeline, where Ma A This is the Mach number at the start of the pipeline;

[0054] When a pipeline is subjected to external interference or overpressure, a large rupture may occur, leading to a large-scale gas leak. The leak point is typically 80%-100% of the pipeline's cross-sectional area. Due to the large area of ​​the leak point, the instantaneous gas leakage is substantial, causing a significant drop in pressure within the pipeline. For an ideal gas-insulated pipeline, the formula for calculating the gas leakage from a rupture is: Where m is the mass flow rate of the gas, Y g Where g is the gas expansion coefficient. c ρ is the gravitational constant. A Let P be the gas density inside the pipe. C P is the pressure at the beginning of the pipeline. D Let ∑K be the gas pressure at the leak point in the pipeline. f For the difference loss item, Where f is the friction coefficient, d is the inner diameter of the pipe, and L is the pipe length;

[0055] S203: Calculation of Soil Permeability: After a gas leak, it will diffuse in the soil. The properties of the soil will affect the diffusion rate of the gas. Therefore, the magnitude of the influencing factors on the soil depends on the soil properties. According to the permeability theory, the properties of different soils can be comprehensively expressed as soil permeability Ks, and the calculation formula is as follows: Where D 10 Where ψ is the effective particle size, μ is the water bulk density, e is the soil void ratio, and N is a constant. Soil permeability reflects the compactness of the soil. The more compact the soil, the worse its permeability. Conversely, the looser the soil, the better its permeability. After a gas leak, the diffusion movement is faster, and the diffusion and migration ability is also faster.

[0056] S204: Calculate the pavement correction factor R for different pavement typesroad There are significant differences in the impact of hardened surfaces (such as concrete or asphalt) and unhardened surfaces (such as sand or grass) on the diffusion of gas leaks.

[0057] Hardened pavements typically restrict the vertical diffusion of gases, causing them to diffuse primarily along the horizontal plane. Unhardened pavements, on the other hand, allow gases to diffuse more freely in the vertical direction. For hardened pavements, their diffusion inhibition is considered stronger; the gas struggles to penetrate the pavement, leading to more horizontal diffusion and an increased diffusion range. A correction factor is set for this. For unhardened pavements, the gas diffuses more readily, and the correction factor is set to 1, indicating no inhibition. Specifically, the pavement correction factor... Where k hard A constant representing the diffusion effect of hardened pavement, typically k hard >1.

[0058] Step 3: The coupling relationship between gas pipelines and power pipelines lies in the adjacent arrangement of the composite buried area, that is, the coupling method of gas pipelines and power pipelines in the composite buried area. The relationship between gas pipelines and power pipelines is that they are laid in parallel or cross-lay, and there is a certain distance between them. At the same time, the burial depth of the pipelines will also be considered when laying the pipelines.

[0059] To describe the coupling risk of gas leaks spreading to power transmission channels, a coupling risk impact factor is calculated: based on the relationship between burial depth and the coupling risk impact factor, generally the closer the distance and the shallower the burial depth, the greater the coupling risk.

[0060] Assume that the risk of gas leak spread has an exponentially inverse relationship with the coupling distance and burial depth of gas pipelines and power pipelines: Where R(d,h) is the magnitude of the coupling risk impact factor, C is a constant, d is the horizontal distance between the gas pipeline and the power pipeline, i.e. the coupling spacing, h is the burial depth of the gas pipeline, and λ is an undetermined coefficient used to control the impact of coupling spacing and burial depth on the risk.

[0061] For cross-layouts: Where C cross It is a constant for the cross-coupling of gas pipelines and power pipelines;

[0062] For parallel laying: Where C parallel It is a constant for the parallel coupling of gas pipelines and power pipelines.

[0063] Step 4: Conduct a risk assessment of the gas pipeline and adjacent power transmission line using soil properties, road surface type, and coupling risk impact factors as correction coefficients: Calculate the quantitative risk R of gas leakage and coupling between the gas pipeline and the adjacent power transmission line, R = P(T,t)·Ks·R roadFor R(d,h), to facilitate risk quantification and classification, the risk value R is normalized to the [0,1] interval. The normalization formula is as follows: Where R norm R is the normalized risk value. max and R min These are the maximum and minimum risk values, respectively. The maximum value is calculated by setting the most unfavorable gas leak scenario and the correction parameters, and the minimum value is calculated by setting the most favorable scenario. The minimum value takes 15 minutes, and the maximum value takes 24 hours.

[0064] The risk of gas diffusion within a power channel is affected by the size of the channel and the distance it can diffuse. The larger the channel area, the higher the relative risk. Power pipelines can be blocked or unblocked. When a power channel is blocked, gas will accumulate in a section of the pipeline. When the blockage is missing, the gas will continue to spread within the power channel, posing a relatively high risk. The area of ​​power pipelines is divided into conduit laying and cable trench laying, and the gas diffusion distance.

[0065] Perform steps 5-6 in this embodiment to obtain a quantitative real-time risk of the power pipeline.

[0066] Step 5: Perform real-time monitoring of power pipelines in each unit. For different power pipeline laying methods, set different correction coefficients S and calculate the cross-sectional area A of gas accumulation under different power pipeline laying methods. m The gas diffusion rate is calculated based on real-time monitoring data, and the type of blockage in the power pipeline is determined, including whether it is blocked or not, and the blockage correction factor L is obtained; the maximum distance D from the gas diffusion to the dangerous concentration is calculated. b , in Let φ be the average diffusion rate of the gas, t be the time of gas leakage, and φ be the environmental correction factor. The specific process is as follows:

[0067] S501: Different correction factors S are set for different power pipeline laying methods, specifically:

[0068] In direct burial, where the power conduit has no independent space and the cable is in direct contact with the soil, the possibility of gas spreading to the cable is low. However, when the gas concentration is high, it can still pose a danger. A correction factor of S is set for this situation. direct In this embodiment, S direct =1;

[0069] In the case of a casing system: the casing typically contains multiple circular channels (pipes), increasing the path and accumulation space for gas diffusion. In this situation, gas may accumulate inside the casing, leading to localized high concentrations, posing a moderate risk. A correction factor of S is set for this scenario. casing In this embodiment, Scasing =1.5;

[0070] In the case of an electrical trench: The space is relatively large (rectangular cross-section), and gas leaks easily accumulate and are difficult to dissipate quickly. Due to the enclosed nature of the channel and the large diffusion space, the risk is high. Therefore, a correction factor of S is set for this situation. trench In this embodiment, S trench =2;

[0071] Usually S direct casing trench ;

[0072] S502: Calculate the cross-sectional area A of gas accumulation under different power pipeline laying methods. m In the direct burial method, the cross-sectional area A of the gas accumulation is... direct =πr 2 Where r is the radius of the power pipeline; in the case of a bushing system, the cross-sectional area A of the gas accumulation is... casing =n·πl 2 Where n is the number of pipes inside the casing, and l is the radius of the casing pipes; in the power trench method, the cross-sectional area A of the gas accumulation is... trench = w·h, where w is the width of the power trench and h is the height of the power trench.

[0073] S503: Calculate the gas diffusion rate v(x) based on real-time monitoring data of the power pipeline: Assume that Z nodes are arranged along the power pipeline, and the position of each node is x. i The distance along the diffusion direction corresponds to a response time of t. i (The time required for the sensor to detect a certain concentration threshold), the formula for calculating the gas diffusion velocity v(x) is: Calculate the average diffusion velocity for all sensor locations in the response.

[0074] S504: Determine the type of blockage in power pipelines: including blocked and unblocked states; under blocked state, the gas diffusion range is limited, and it is easy to accumulate locally, resulting in a higher local concentration. The diffusion speed and range are significantly suppressed, but the risk may increase locally. Under unblocked state, the gas can diffuse freely along the power channel, with a larger diffusion range, but a lower concentration. The overall diffusion speed is faster, and the risk is more evenly distributed.

[0075] S505: Obtain the blocking correction factor L. Where L blocked >1, L unblocked <1.

[0076] ​​S506: Calculate the maximum distance D from gas diffusion to hazardous concentration. b , in denoted as the average diffusion rate of the gas, t as the time of gas leakage, and φ as the environmental correction factor, which is affected by environmental characteristics (such as temperature, humidity, power pipeline obstructions, etc.), and is usually 0 < φ < 10.

[0077] Step 6: Obtain the quantitative real-time risk R of the power pipeline d R d =D b ·A m ·S·L, and for R d Normalization is performed using the following formula: Where R norm 'Quantitative Risk R for Power Pipelines' d Normalized risk value, R d，max and R d，min Risk values ​​R d The maximum and minimum values ​​are calculated by setting the most unfavorable gas leakage and correction parameters, and the minimum value is calculated by setting the most favorable conditions. The minimum value takes 15 minutes, and the maximum value takes 24 hours.

[0078] This embodiment achieves rapid, real-time assessment of gas leakage and diffusion into power pipelines by using real-time monitoring data and considering both gas leakage and diffusion and power pipeline coupling factors. It can not only conduct a comprehensive risk assessment of gas pipelines and adjacent power channels, but also assess the risk of gas diffusion within power channels, providing a fundamental guarantee for the safe operation of urban lifelines.

[0079] Example 2

[0080] Corresponding to Example 1, this example provides a coupled real-time risk assessment model for the diffusion of natural gas into power pipelines, including the following modules:

[0081] Unit segmentation module: used to divide pipe segments based on the underground pipeline network map of the city's gas pipelines and power pipelines, and obtain each segmentation unit;

[0082] The diffusion boundary hazard acquisition module is used to determine the gas leak type T based on real-time monitoring data of the gas passages within each unit, and, combined with the gas leak time t, obtain different diffusion boundary hazards P(T, t). It also calculates the soil permeability Ks for different soil types and the pavement correction factor R for different pavement types. road Specifically, it includes the following units:

[0083] Leak Type Determination Unit: Used to determine the type of gas leak. It obtains real-time monitoring data from the gas leak monitoring equipment, and analyzes the rate of change (v) of gas concentration after the leak. n The functional relationship between the gas concentration M(t) and time t is linear or exponential. Discrete concentration data M(t1), M(t2), ..., M(t3) are obtained through monitoring equipment. n The rate of change of gas concentration per unit time is approximated using numerical differentiation methods:

[0084] Because the volume of the gas well affects the rate of change of gas concentration, this embodiment also uses a volume correction factor to adjust the monitored rate of change of gas concentration v. n Correction is performed: Let the volume of the gas well be V. Assume that the rate of concentration change is inversely proportional to the volume of the gas well, that is, the larger the volume, the smaller the concentration change per unit time. Define a volume correction coefficient k1. Where V0 is the standard well volume, V is the actual gas well volume, and then v n Perform correction:

[0085] Define the rate of change thresholds α and β, and compare v n Correction and change rate thresholds α and β, if v n修正 If ≤α, then the gas leak type T is a pinhole leak. <v n修正 ≤β, at this time the gas leak type T is a large hole leak, if v n修正 >β, at this time the gas leak type T is a rupture leak;

[0086] Analysis of diffusion boundary hazard elements: used to combine the gas leak type T and the gas leak time t to obtain different diffusion boundary hazard P(T,t). Where χ, ε, and γ are adjustment parameters, reflecting the influence of environmental conditions on gas diffusion, Q small Q large Q rupture These represent the gas leakage amounts for small hole leaks, large hole leaks, and rupture leaks, respectively.

[0087] The diffusion of gas from a small hole leak is relatively slow. The longer the leakage time, the larger the diffusion radius. The formula for calculating the gas leakage amount from a small hole leak is: Where k is the gas adiabatic coefficient, which is 1.334 in this embodiment, R is the gas constant, and T B P is the temperature before the gas leak. B Let A be the pressure before the gas leak, and C be the area of ​​the leak. d The orifice flow correction coefficient is determined based on the shape of the leak: when the leak is circular, C... d=1.00, when the leak outlet is triangular, C d =0.95, when the leak outlet is rectangular, C d =0.90, when the leak point is an internally corroded constricting cavity, 0.9 <C d <1.0, when the leakage outlet is a gradually expanding orifice damaged by external force, 0.6 <C d <0.9, where M is the molar mass of the gas;

[0088] When a large orifice leaks, the gas diffuses rapidly. For actual high-pressure or low-pressure gas transmission pipelines, as the orifice diameter further increases, the pressure P at the center of the leak increases. B Much less than the pressure P at the start of the pipeline A However, it is still greater than the critical pressure P. c At this point, the leakage process becomes a critical flow process where both the pipeline and the leak hole are in a state of critical flow. The formula for calculating the gas leakage rate in a large-hole leak is: Where T A P represents the gas temperature at the start of the pipeline. A The pressure at the starting point of the pipeline, where Ma A This is the Mach number at the start of the pipeline;

[0089] When a pipeline is subjected to external interference or overpressure, a large rupture may occur, leading to a large-scale gas leak. The leak point is typically 80%-100% of the pipeline's cross-sectional area. Due to the large area of ​​the leak point, the instantaneous gas leakage is substantial, causing a significant drop in pressure within the pipeline. For an ideal gas-insulated pipeline, the formula for calculating the gas leakage from a rupture is: Where m is the mass flow rate of the gas, Y g Where g is the gas expansion coefficient. c ρ is the gravitational constant. A Let P be the gas density inside the pipe. C P is the pressure at the beginning of the pipeline. D Let ∑K be the gas pressure at the leak point in the pipeline. f For the difference loss item, Where f is the friction coefficient, d is the inner diameter of the pipe, and L is the pipe length;

[0090] Obtaining soil permeability units: used to calculate soil permeability Ks, the formula is: Where D 10 Where ψ is the effective particle size, μ is the water bulk density, e is the soil void ratio, and N is a constant. Soil permeability reflects the compactness of the soil. The more compact the soil, the worse its permeability. Conversely, the looser the soil, the better its permeability. After a gas leak, the diffusion movement is faster, and the diffusion and migration ability is also faster.

[0091] The pavement correction factor acquisition unit is used to calculate the pavement correction factor R for different pavement types. road For hardened pavements, a correction factor is set to increase the diffusion range. For unhardened pavements, where gas diffusion is strong, the correction factor is set to 1, indicating no inhibition. Specifically, the pavement correction factor... Where k hard A constant representing the diffusion effect of hardened pavement, typically k hard >1.

[0092] The module for calculating the coupling risk impact factor is used to determine the coupling mode between gas pipelines and power pipelines, and to obtain the coupling risk impact factor R(d,h) between gas pipelines and power pipelines. Where C is a constant, d is the horizontal distance between the gas pipeline and the power pipeline, i.e. the coupling distance, h is the burial depth of the gas pipeline, and λ is used to control the impact of coupling distance and burial depth on risk.

[0093] The coupling risk acquisition module is used to obtain the quantitative real-time risk R of the coupling between gas pipelines and power pipelines, where R = P(T,t)·Ks·R. road ·R(d,h), and normalize R;

[0094] Power pipeline monitoring module: Used for real-time monitoring of power pipelines in various units. Different correction factors S are set for different power pipeline laying methods to calculate the cross-sectional area A of gas accumulation under different power pipeline laying methods. m The gas diffusion rate is calculated based on real-time monitoring data, and the type of blockage in the power pipeline is determined, including whether it is blocked or not, and the blockage correction factor L is obtained; the maximum distance D from the gas diffusion to the dangerous concentration is calculated. b , in Let be the average diffusion rate of the gas, t be the time of gas leakage, and φ be the environmental correction factor. Specifically, it includes the following units:

[0095] The correction factor setting unit is used to set different correction factors S for different power pipeline laying methods, specifically:

[0096] In direct burial, where the power conduit has no independent space and the cable is in direct contact with the soil, the possibility of gas spreading to the cable is low. However, when the gas concentration is high, it can still pose a danger. A correction factor of S is set for this situation. direct In this embodiment, S direct =1;

[0097] In the case of a casing system: the casing typically contains multiple circular channels (pipes), increasing the path and accumulation space for gas diffusion. In this situation, gas may accumulate inside the casing, leading to localized high concentrations, posing a moderate risk. A correction factor of S is set for this scenario. casing In this embodiment, S casing =1.5;

[0098] In the case of an electrical trench: The space is relatively large (rectangular cross-section), and gas leaks easily accumulate and are difficult to dissipate quickly. Due to the enclosed nature of the channel and the large diffusion space, the risk is high. Therefore, a correction factor of S is set for this situation. trench In this embodiment, S trench =2;

[0099] Usually S direct casing trench ;

[0100] Cross-sectional area calculation unit: used to calculate the cross-sectional area A of gas accumulation under different power pipeline laying methods. m In the direct burial method, the cross-sectional area A of the gas accumulation is... direct =πr 2 Where r is the radius of the power pipeline; in the case of a bushing system, the cross-sectional area A of the gas accumulation is... casing =n·πl 2 Where n is the number of pipes inside the casing, and l is the radius of the casing pipes; in the power trench method, the cross-sectional area A of the gas accumulation is... trench = w·h, where w is the width of the power trench and h is the height of the power trench;

[0101] The diffusion velocity calculation unit is used to calculate the diffusion velocity v(x) of the gas. It is assumed that Z nodes are arranged along the power pipeline, with each node located at position x. i The distance along the diffusion direction corresponds to a response time of t. i (The time required for the sensor to detect a certain concentration threshold), the formula for calculating the gas diffusion velocity v(x) is: Calculate the average diffusion velocity for all sensor locations in the response.

[0102] Blockage type determination unit: used to determine whether the power pipeline is blocked or not blocked;

[0103] Unit for obtaining blocking correction factor: Used to obtain blocking correction factor Where L blocked >1, L unblocked <1;

[0104] ​​Calculate the maximum diffusion distance unit: Used to calculate the maximum distance D that the gas can diffuse to a hazardous concentration. b , in denoted as the average diffusion rate of the gas, t as the time of gas leakage, and φ as the environmental correction factor, which is affected by environmental characteristics (such as temperature, humidity, power pipeline obstructions, etc.) and is usually 0 < φ < 10.

[0105] The Power Pipeline Risk Acquisition Module is used to obtain the quantitative, real-time risk (R) of power pipelines. d R d =D b ·A m ·S·L, and for R d Normalize.

[0106] This embodiment first uses a segmentation module to divide the gas pipeline and power pipeline into segments, obtaining each segmentation unit; then, through the diffusion boundary hazard acquisition module, the gas leak type T is determined based on real-time monitoring data, and combined with the gas leak time t, different diffusion boundary hazards are obtained, and soil permeability for different soil types and pavement correction factors for different pavement types are calculated; next, the coupling risk impact factor calculation module is used to obtain the coupling risk impact factor of the gas pipeline and power pipeline; finally, the coupling risk acquisition module is used to calculate the quantitative real-time risk of the coupling between the gas pipeline and power pipeline.

[0107] Using a power pipeline monitoring module, different correction coefficients were set for different power pipeline laying methods. The cross-sectional area of ​​gas accumulation under different power pipeline laying methods was calculated. Based on real-time monitoring data, the gas diffusion rate was calculated, the type of blockage in the power pipeline was determined, the blockage correction factor L was obtained, and the maximum distance D from gas diffusion to the dangerous concentration was calculated. b Then, by acquiring the power pipeline risk module, the quantitative real-time risk R of the power pipeline is calculated. d .

[0108] Example 3

[0109] like Figure 2 As shown, this embodiment provides an intelligent terminal device, including an input terminal, a memory, a processor, a display, a communication interface, and an output terminal. Real-time monitoring data of the gas pipeline is input into the terminal device through the input terminal and the communication interface. The memory is used to store a computer program for coupled real-time risk assessment of gas diffusion into the power pipeline. The processor is used to call and run the computer program stored in the memory to perform risk assessment. The specific assessment method is as described in Embodiment 1. The corresponding quantitative risk situation is displayed on the display, and finally the assessment result of the assessment unit is output through the output terminal.

[0110] The computer program for performing coupled real-time risk assessment of gas diffusion into power pipelines can also be stored on a computer-readable medium. When the processor controls the computer program to run, it performs risk assessment. The specific assessment process is also referred to in Embodiment 1 of the present invention.

[0111] The computer-readable medium may be a computer-readable signal medium or a computer-readable storage medium, or any combination of a computer-readable signal medium and a computer-readable storage medium;

[0112] The computer-readable storage medium can be any tangible medium containing a stored program that can be used by or in conjunction with an instruction execution system, apparatus, or device. The computer-readable storage medium includes electrical, magnetic, optical, electromagnetic, infrared, or semiconductor systems, apparatuses, and devices. More specifically, the computer-readable storage medium includes electrical connections with one or more wires, portable computer disks, hard disks, random access memory (RAM), erasable programmable read-only memory (EPROM), flash memory, optical fibers, optical storage devices, magnetic storage devices, etc., or any combination thereof.

[0113] A computer-readable signal medium can be a data signal propagated in baseband or as part of a carrier wave, carrying a computer-readable computer program. Such propagated data signals can take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A computer-readable signal medium can also be any computer-readable medium other than a computer-readable storage medium, which can send, propagate, or transmit a program for use by or in connection with an instruction execution system, apparatus, or device. The computer program contained on the computer-readable medium can be transmitted using any suitable medium, including but not limited to wireless, wired, or any suitable combination thereof.

[0114] 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 the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A coupled real-time risk assessment method for the diffusion of natural gas into power pipelines, characterized in that, Includes the following steps: S1: Based on the underground pipeline network map of the city's gas pipelines and power pipelines, divide the pipelines into sections to obtain each division unit; S2: Based on real-time monitoring data of the gas passages within each unit, determine the gas leak type T. Combined with the gas leak time t, obtain different diffusion boundary hazards P(T,t), and calculate the soil permeability Ks for different soil types and the pavement correction factor R for different pavement types. road ; S3: Determine the coupling mode between gas pipelines and power pipelines, and obtain the risk impact factors of gas pipeline and power pipeline coupling. Where C is a constant, d is the horizontal distance between the gas pipeline and the power pipeline, i.e. the coupling distance, h is the burial depth of the gas pipeline, and λ is used to control the impact of coupling distance and burial depth on risk. S4: Obtain the quantitative real-time risk R of gas leak and power pipeline coupling, R = P(T,t)·Ks·R road ·R(d,h), and normalize R; S5: Perform real-time monitoring of power pipelines in each unit, set different correction coefficients S for different power pipeline laying methods, and calculate the cross-sectional area A of gas accumulation under different power pipeline laying methods. m The power pipeline sensor monitors and calculates the gas diffusion rate and determines the type of blockage in the power pipeline, including the blocked state and the unblocked state, and obtains the blockage correction factor L; Calculate the maximum distance D from which the gas diffuses to the hazardous concentration. b , in Let be the average diffusion rate of the gas, t be the time of gas leakage, and φ be the environmental correction factor. S6: Obtaining Quantitative Real-Time Risk R of Power Pipelines d R d =D b ·A m ·S·L, and for R d Normalize.

2. The coupled real-time risk assessment method for the diffusion of natural gas into power pipelines according to claim 1, characterized in that, In step S2, the process of determining the type of gas leak is as follows: select a monitoring point and calculate the rate of change v of the gas concentration at that point. n Define volume correction factor Where V0 is the standard well volume, V is the actual gas well volume, and v is the volume of the standard well. n Perform correction: v n修正 =k1·v n Define the rate of change thresholds α and β; compare v n修正 With the rate of change thresholds α and β, if v n修正 If ≤α, then the gas leak type T is a pinhole leak. <v n修正 ≤β, at this time the gas leak type T is a large hole leak, if v n修正 >β, at this time the gas leak type T is a rupture leak.

3. The coupled real-time risk assessment method for the diffusion of natural gas into power pipelines according to claim 2, characterized in that, The aforementioned diffusion boundary hazard Where χ, ε, and γ are adjustment parameters, and Q small Q large Q rupture These represent the gas leakage amounts from small hole leaks, large hole leaks, and rupture leaks, respectively.

4. The coupled real-time risk assessment method for the diffusion of natural gas into power pipelines according to claim 1, characterized in that, In step S2, the soil permeability Where D 10 Where ψ is the effective particle size, μ is the water unit weight, e is the hydrodynamic viscosity, and N is a constant; the pavement correction factor is... Where k hard >1.

5. The coupled real-time risk assessment method for the diffusion of natural gas into power pipelines according to claim 1, characterized in that, In step S3, the coupling methods of the gas pipeline and the power pipeline include parallel coupling and cross coupling.

6. The coupled real-time risk assessment method for the diffusion of natural gas into power pipelines according to claim 1, characterized in that, In step S5, the laying methods of the power pipeline include direct burial, conduit installation, and power trench installation. The correction factor for direct burial is S. direct The correction factor corresponding to the bushing method is S. casing The correction factor corresponding to the power trench method is S. trench .

7. The coupled real-time risk assessment method for the diffusion of natural gas into power pipelines according to claim 6, characterized in that, In the sleeve configuration, the cross-sectional area A of the gas accumulation is... casing =n·πr 2 Where n is the number of pipes inside the casing, and r is the radius of the casing pipes; in the power trench method, the cross-sectional area A of the gas accumulation is... trench = w·h, where w is the width of the power trench and h is the height of the power trench.

8. The coupled real-time risk assessment method for the diffusion of natural gas into power pipelines according to claim 1, characterized in that, In step S5, the blocking correction factor Where L blocked >1, L unblocked <1.

9. A coupled real-time risk assessment model for the diffusion of natural gas into power pipelines, characterized in that, Includes the following modules: Unit segmentation module: used to divide pipe segments based on the underground pipeline network map of the city's gas pipelines and power pipelines, and obtain each segmentation unit; The diffusion boundary hazard acquisition module is used to determine the gas leak type T based on real-time monitoring data of the gas passages within each unit, and, combined with the gas leak time t, obtain different diffusion boundary hazards P(T, t). It also calculates the soil permeability Ks for different soil types and the pavement correction factor R for different pavement types. road ; The module for calculating the coupling risk impact factor is used to determine the coupling mode between gas pipelines and power pipelines, and to obtain the coupling risk impact factor R(d,h) between gas pipelines and power pipelines. Where C is a constant, d is the horizontal distance between the gas pipeline and the power pipeline, i.e. the coupling distance, h is the burial depth of the gas pipeline, and λ is used to control the impact of coupling distance and burial depth on risk. The coupling risk acquisition module is used to obtain the quantitative real-time risk R of the coupling between gas pipelines and power pipelines, where R = P(T,t)·Ks·R. road ·R(d,h), and normalize R; Power pipeline monitoring module: Used for real-time monitoring of power pipelines in various units. Different correction factors S are set for different power pipeline laying methods to calculate the cross-sectional area A of gas accumulation under different power pipeline laying methods. m The gas diffusion rate is calculated based on real-time monitoring data, and the type of blockage in the power pipeline is determined, including the blocked state and the unblocked state, and the blockage correction factor L is obtained. Calculate the maximum distance D from which the gas diffuses to the hazardous concentration. b , in Let be the average diffusion rate of the gas, t be the time of gas leakage, and φ be the environmental correction factor. The Power Pipeline Risk Acquisition Module is used to obtain the quantitative, real-time risk (R) of power pipelines. d R d =D b ·A m ·S·L, and for R d Normalize.

10. A terminal device, characterized in that, It includes a memory and a processor, the memory being used to store a computer program, and the processor being used to call and run the computer program stored in the memory to perform the method as described in any one of claims 1-8.

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