Method and device for predicting overpressure of gas explosion in underground space

Abstract

The invention relates to the technical field of fuel gas security and protection, in particular to a method and equipment for predicting fuel gas explosion overpressure in an underground space, and the method comprises the steps: obtaining inspection well parameters of a to-be-predicted underground space; the inspection well parameters comprise the well lid diameter, the well depth, the pipeline diameter, the gas concentration in the inspection well and the radius distance from an explosion point; determining the inspection well type of the to-be-predicted underground space, and selecting a corresponding gas explosion overpressure prediction model according to the inspection well type of the to-be-predicted underground space; the gas explosion overpressure prediction model comprises an external gas explosion overpressure prediction model and an internal gas explosion overpressure prediction model; inputting the diameter of the well lid, the well depth, the diameter of the pipeline, the gas concentration in the inspection well and the radius distance from the explosion point into an external gas explosion overpressure prediction model to obtain an external explosion gas overpressure prediction value; and inputting the well lid diameter, the well depth, the pipeline diameter and the gas concentration in the inspection well into the internal gas explosion overpressure prediction model to obtain an internal explosion gas overpressure prediction value.

Description

Technical Field

[0001] The present application relates to the field of gas safety technology, and in particular to a method and device for predicting overpressure of gas explosion in an underground space. Background Art

[0002] The gas industry is currently developing rapidly, especially with the completion and commissioning of a series of gas projects marked by the West-East Gas Transmission Project, pipeline gases such as natural gas, liquefied gas, and coal gas have been rapidly popularized.

[0003] The shock wave overpressure caused by gas explosion is one of the main causes of safety hazards, especially in closed or semi-closed environments such as connected manholes and independent manholes. In these environments, the impact of gas explosions is affected by the complex interaction of multiple factors, and the coupling of these factors significantly increases the catastrophic nature of the explosion and the difficulty of rescue. Therefore, achieving accurate pre-disaster prediction can effectively reduce accident losses and ensure public safety.

[0004] The existing technology still lacks sufficient research on gas explosions and lacks rapid prediction models, which makes disaster prediction and accident analysis difficult. Summary of the invention

[0005] In order to at least to some extent overcome the difficulties in disaster prediction and accident analysis of gas explosions in related technologies, the present application provides a method and device for predicting overpressure of gas explosions in underground spaces.

[0006] The scheme of this application is as follows:

[0007] According to a first aspect of an embodiment of the present application, a method for predicting overpressure of gas explosion in an underground space is provided, comprising:

[0008] Obtaining manhole parameters of the underground space to be predicted; the manhole parameters include: manhole cover diameter, well depth, pipe diameter, gas concentration in the manhole and radius distance from the explosion point;

[0009] Determine the type of the manhole of the underground space to be predicted, and select a corresponding gas explosion overpressure prediction model according to the type of the manhole of the underground space to be predicted; the gas explosion overpressure prediction model includes: an external gas explosion overpressure prediction model and an internal gas explosion overpressure prediction model;

[0010] The manhole cover diameter, well depth, pipe diameter, gas concentration in the manhole and radius distance from the explosion point are input into the external gas explosion overpressure prediction model to obtain the external explosion gas overpressure prediction value;

[0011] The manhole cover diameter, well depth, pipe diameter and gas concentration in the manhole are input into the internal gas explosion overpressure prediction model to obtain the predicted value of the internal explosion gas overpressure.

[0012] Preferably, the manhole categories include: connected manholes;

[0013] The overpressure prediction model for external gas explosion connected to the manhole is:

[0014]

[0015]

[0016] B=.0275*10 -6 *6.41087 V ;

[0017] C=2.5537*10 -11 *e 17.68663*L ;

[0018]

[0019] Wherein, P represents the predicted value of gas explosion overpressure; represents the gas concentration in the manhole; x represents the radius distance from the explosion point; D represents the manhole cover diameter; H represents the well depth; L represents the pipe diameter; A, B, C, and V all represent fitting parameters;

[0020] The prediction model for internal gas explosion overpressure in connected manholes is:

[0021]

[0022]

[0023]

[0024]

[0025] Preferably, the manhole categories include: independent manholes;

[0026] The external gas explosion overpressure prediction model for independent manholes is:

[0027] P=Ae Bx -0.00121073734;

[0028]

[0029]

[0030]

[0031] The prediction model for internal gas explosion overpressure of independent manholes is:

[0032]

[0033] Z = ln(0.8365 + 0.14998 * V);

[0034]

[0035] Where Z represents the fitting parameter.

[0036] Preferably, the method further comprises:

[0037] Construct a manhole gas explosion simulation environment using 3D computational fluid dynamics software;

[0038] Obtain the numerical simulation calculation results of the external gas explosion overpressure of the connected manholes with the radial distance, the numerical simulation calculation results of the internal gas explosion overpressure of the connected manholes with the radial distance, the numerical simulation calculation results of the external gas explosion overpressure of the independent manholes with the radial distance, and the numerical simulation calculation results of the internal gas explosion overpressure of the independent manholes with the radial distance under different manhole parameters;

[0039] The numerical simulation results of the external gas explosion overpressure of the connected manholes were nonlinearly fitted with the variation of the radius distance, and the external gas explosion overpressure prediction model of the connected manholes was obtained.

[0040] The nonlinear fitting was performed on the numerical simulation results of the variation of the internal gas explosion overpressure of the connected manhole with the radius distance, and the prediction model of the internal gas explosion overpressure of the connected manhole was obtained.

[0041] The nonlinear fitting is performed on the numerical simulation calculation results of the change of external gas explosion overpressure of independent manhole with radial distance, and the external gas explosion overpressure prediction model of independent manhole is obtained.

[0042] The nonlinear fitting was performed on the numerical simulation results of the variation of internal gas explosion overpressure of independent manholes with radial distance, and the prediction model of internal gas explosion overpressure of independent manholes was obtained.

[0043] Preferably, the method further comprises:

[0044] Each gas explosion overpressure prediction model is verified using the validation data set.

[0045] Preferably, a manhole gas explosion simulation environment is constructed by three-dimensional computational fluid dynamics software, including:

[0046] Construct a rectangular model as the underground space, and construct a manhole model in the center of the rectangular model;

[0047] An ignition source is set at the center of the manhole model, and the interior of the manhole model is filled with gas;

[0048] Set measuring points on the center line of the explosion vent;

[0049] A 0.10m grid is used to simulate the constructed simulation environment.

[0050] Preferably, a measuring point is set on the center line of the explosion vent, including:

[0051] Set multiple measuring points at intervals of 0.5m on the center line above the explosion vent;

[0052] Set multiple measuring points at intervals of 1m on the center line below the explosion vent.

[0053] Preferably, the three-dimensional computational fluid dynamics software describes the ideal fluid behavior of the compressible fluid through the mass conservation equation, momentum equation, enthalpy transport equation, fuel mass fraction transport equation and mixture mass fraction transport equation;

[0054] The three-dimensional computational fluid dynamics software also includes: a flame model and a turbulence model.

[0055] According to a second aspect of an embodiment of the present application, a device for predicting overpressure of gas explosion in an underground space is provided, comprising:

[0056] Processor and memory;

[0057] The processor and the memory are connected via a communication bus:

[0058] Wherein, the processor is used to call and execute the program stored in the memory;

[0059] The memory is used to store a program, and the program is used to execute at least a method for predicting overpressure of gas explosion in an underground space as described in any one of the above items.

[0060] The technical solution provided by the present application may include the following beneficial effects: the method for predicting gas explosion overpressure in underground space in the present application includes: obtaining manhole parameters of the underground space to be predicted; the manhole parameters include: manhole cover diameter, well depth, pipe diameter, gas concentration in the manhole and radius distance from the explosion point; determining the manhole type of the underground space to be predicted, and selecting a corresponding gas explosion overpressure prediction model according to the manhole type of the underground space to be predicted; the gas explosion overpressure prediction model includes: an external gas explosion overpressure prediction model and an internal gas explosion overpressure prediction model; the manhole cover diameter, well depth, pipe diameter, gas concentration in the manhole and radius distance from the explosion point are input into the external gas explosion overpressure prediction model to obtain an external explosion gas overpressure prediction value; the manhole cover diameter, well depth, pipe diameter and gas concentration in the manhole are input into the internal gas explosion overpressure prediction model to obtain an internal explosion gas overpressure prediction value.

[0061] This technical solution takes into account that the diameter of the manhole cover will affect the propagation path and intensity of the shock wave generated by the explosion in the manhole. A larger well depth will cause the shock wave to reflect and diffuse, increasing the degree of damage to surrounding buildings. The diameter of the pipeline directly affects the gas flow and the power of the explosion. The thicker the pipeline, the greater the gas leakage may be, and the explosion energy will also increase. The gas concentration in the manhole determines the intensity and range of the explosion. A higher concentration may lead to a greater explosive force. The radius distance from the explosion point also determines the power of the gas explosion. The closer to the ignition source, the stronger the shock wave overpressure of the explosion. Therefore, according to these influencing factors, a corresponding explosion gas overpressure prediction model is established to achieve accurate pre-disaster prediction. Pre-training the corresponding gas explosion overpressure prediction model for different manhole categories can make more accurate explosion gas overpressure predictions for different manholes. For each manhole category, external explosion gas overpressure predictions and internal explosion gas overpressure predictions are made. The prediction results are multifaceted and can better assist decision-making.

[0062] It should be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0064] Figure 1 It is a flow chart of a method for predicting overpressure of gas explosion in an underground space provided by an embodiment of the present application;

[0065] Figure 2 It is a schematic diagram of a manhole gas explosion simulation environment constructed by three-dimensional computational fluid dynamics software provided by an embodiment of the present application;

[0066] Figure 3 A graph showing the variation of the overpressure of the external gas explosion of the connected manhole with the radius distance provided by an embodiment of the present application;

[0067] Figure 4 It is a linear regression analysis schematic diagram of a connected manhole external gas explosion overpressure prediction model provided by an embodiment of the present application;

[0068] Figure 5 A graph showing the variation of the overpressure of a gas explosion in a connected manhole with the radius distance provided by an embodiment of the present application;

[0069] Figure 6 It is a linear regression analysis schematic diagram of a gas explosion overpressure prediction model inside a connected manhole provided by an embodiment of the present application;

[0070] Figure 7It is a curve diagram showing the variation of overpressure of external gas explosion of an independent manhole with radius distance provided by an embodiment of the present application;

[0071] Figure 8 It is a linear regression analysis schematic diagram of an independent manhole external gas explosion overpressure prediction model provided by an embodiment of the present application;

[0072] Fig. 9 It is a curve diagram showing the variation of overpressure of gas explosion inside an independent manhole with radial distance provided by an embodiment of the present application;

[0073] Fig.10 It is a linear regression analysis schematic diagram of a prediction model for overpressure of gas explosion inside an independent manhole provided by an embodiment of the present application;

[0074] Fig.11 It is a structural schematic diagram of a gas explosion overpressure prediction device in an underground space provided by an embodiment of the present application.

[0075] Reference numerals: processor-21; memory-22. DETAILED DESCRIPTION

[0076] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The implementations described in the following exemplary embodiments do not represent all implementations consistent with the present application. Instead, they are merely examples of devices and methods consistent with some aspects of the present application as detailed in the appended claims.

[0077] Embodiment 1

[0078] Figure 1 is a flow chart of a method for predicting overpressure of gas explosion in underground space provided by an embodiment of the present application, with reference to Figure 1 , a method for predicting overpressure of gas explosion in underground space, comprising:

[0079] S11: Obtaining manhole parameters of the underground space to be predicted; the manhole parameters include: manhole cover diameter, well depth, pipe diameter, gas concentration in the manhole and radius distance from the explosion point;

[0080] S12: determining the type of the manhole of the underground space to be predicted, and selecting a corresponding gas explosion overpressure prediction model according to the type of the manhole of the underground space to be predicted; the gas explosion overpressure prediction model includes: an external gas explosion overpressure prediction model and an internal gas explosion overpressure prediction model;

[0081] S13: inputting the manhole cover diameter, the well depth, the pipe diameter, the gas concentration in the manhole and the radius distance from the explosion point into the external gas explosion overpressure prediction model to obtain the external explosion gas overpressure prediction value;

[0082] S14: The manhole cover diameter, the well depth, the pipe diameter and the gas concentration in the manhole are input into the internal gas explosion overpressure prediction model to obtain the internal explosion gas overpressure prediction value.

[0083] It should be noted that manholes are an important part of urban infrastructure. They are underground spaces for the transfer and control of urban underground pipelines. All public water supply, sewage channels, telephone lines, optical fiber networks, etc. may be connected through underground passages under manholes. The design purpose of manholes is to make straight pipes less likely to be blocked and easy to install pipelines. In addition to being the inlet and outlet of pipelines, manholes also play a key role in the urban drainage system, ensuring that rainwater and wastewater can be discharged smoothly to avoid urban waterlogging.

[0084] The structures and materials of manholes are diverse. Generally, manholes include interconnected manholes and independent manholes that are independently set up and not connected to other manholes.

[0085] Different types of manholes have different effects on gas explosion overpressure, so the technical solution pre-trains corresponding gas explosion overpressure prediction models for different manhole types, which can make more accurate explosion gas overpressure predictions for different manholes.

[0086] It should be noted that in this technical solution, a manhole gas explosion simulation environment is constructed by using three-dimensional computational fluid dynamics software;

[0087] Obtain the numerical simulation calculation results of the external gas explosion overpressure of the connected manholes with the radial distance, the numerical simulation calculation results of the internal gas explosion overpressure of the connected manholes with the radial distance, the numerical simulation calculation results of the external gas explosion overpressure of the independent manholes with the radial distance, and the numerical simulation calculation results of the internal gas explosion overpressure of the independent manholes with the radial distance under different manhole parameters;

[0088] The numerical simulation results of the external gas explosion overpressure of the connected manholes were nonlinearly fitted with the variation of the radius distance, and the external gas explosion overpressure prediction model of the connected manholes was obtained.

[0089] The nonlinear fitting was performed on the numerical simulation results of the variation of the internal gas explosion overpressure of the connected manhole with the radius distance, and the prediction model of the internal gas explosion overpressure of the connected manhole was obtained.

[0090] The nonlinear fitting is performed on the numerical simulation calculation results of the change of external gas explosion overpressure of independent manhole with radial distance, and the external gas explosion overpressure prediction model of independent manhole is obtained.

[0091] The nonlinear fitting was performed on the numerical simulation results of the variation of internal gas explosion overpressure of independent manholes with radial distance, and the prediction model of internal gas explosion overpressure of independent manholes was obtained.

[0092] In specific practice, FLACS-CFD can be selected as the three-dimensional computational fluid dynamics software. FLACS-CFD includes multiple functions such as flammable gas diffusion, toxic gas diffusion, gas and dust explosion, explosion and shock wave propagation, etc., which can be used to perform engineering calculations related to industry and social security. FLACS-CFD uses the finite volume method to solve the Favre average transport equations of mass, momentum, enthalpy, turbulent kinetic energy, turbulent kinetic energy dissipation rate, fuel mass fraction and mixture fraction on a structured Cartesian grid. The RANS equations are closed by using the ideal gas state equation and the standard k-ε turbulence model. And by solving the velocity component on the staggered grid, the scalar variables such as density, pressure and temperature are solved on the unit-centered grid. Its accuracy and reliability in the field of gas explosion have been widely verified. Therefore, in this technical solution, the FLACS-CFD numerical simulation software is used to explore the characteristics of gas explosion in an independent manhole.

[0093] It should be noted that the FLACS-CFD software describes the ideal fluid behavior of compressible fluids through the mass conservation equation, momentum equation, enthalpy transport equation, fuel mass fraction transport equation, and mixture mass fraction transport equation;

[0094] The mass conservation equation:

[0095]

[0096] Momentum equation:

[0097]

[0098] The transport equation for enthalpy is:

[0099]

[0100] Fuel mass fraction transport equation:

[0101]

[0102] Mixture mass fraction transport equation:

[0103]

[0104] FLACS-CFD software also includes: flame model and turbulence model.

[0105] In industrial applications, the reaction zone in a premixed flame is thin compared to the actual grid resolution. Therefore, it is necessary to model the flame. In FLACS-CFD software, the flame zone is thickened by increasing the diffusion coefficient β and reducing the reaction rate coefficient 1 / β. Therefore, the flame model in FLACS-CFD software is called the β model. The equation is as follows:

[0106]

[0107]

[0108]

[0109] In terms of simulating industrial accident scenarios, FLACS-CFD software still relies on turbulence models based on RANS equations, such as the k-ε model. The turbulence model uses a two-equation model to solve two additional transport equations; one is the turbulent kinetic energy equation and the other is the turbulent kinetic energy dissipation equation. The Reynolds stress tensor is modeled using eddy viscosity based on the eddy viscosity assumption. The equation is as follows:

[0110] Turbulent kinetic energy transport equation:

[0111]

[0112] The transport equation of turbulent kinetic energy dissipation rate is:

[0113]

[0114] Turbulent Kinetic Energy:

[0115] P k =G s +G w +G b +G o ;

[0116] Reynolds stress tensor modeled using eddy viscosity:

[0117]

[0118] The parameters and symbols in the above equations are defined as shown in the following table:

[0119]

[0120]

[0121] Before using numerical methods to study gas explosions in pipelines, it is necessary to verify the selected numerical methods to ensure the reliability and accuracy of the final simulation results and conclusions. For FLACS-CFD software, mesh independence verification and reliability verification are required before conducting formal research. These two parts can ensure that an efficient, accurate and reliable model parameter is selected.

[0122] For explosion scenarios, based on previous research experience on the explosion characteristics of urban pipeline gas based on numerical simulation, 0.08 / 0.10 / 0.12m grid sizes were selected for independence verification. Methane is the main component of natural gas, usually accounting for more than 90%. Therefore, this technical solution regards natural gas as methane gas. The simulation experiment was carried out with a pipeline length of 200m, standard atmospheric pressure, and an ambient temperature of 20°C. The experimental results show that the calculation result errors corresponding to different grid sizes are all less than 10%. Taking into account the requirements of calculation accuracy and simulation efficiency, a 0.10m grid is selected in this technical solution to carry out research on the explosion characteristics of manholes and pipelines.

[0123] The FLACS-CFD numerical simulation was compared with the natural gas explosion experiment conducted by Tomlin. The numerical simulation setting parameters were the same as the experimental conditions.

[0124] The experimental results show that the FLACS-CFD numerical simulation can reproduce the experimental process well. Therefore, the technical solution of using FLACS-CFD software to simulate gas explosions in manholes and pipelines is scientific and reliable.

[0125] Specifically, a manhole gas explosion simulation environment is constructed using 3D computational fluid dynamics software, including:

[0126] Construct a rectangular model as the underground space, and construct a manhole model in the center of the rectangular model;

[0127] An ignition source is set at the center of the manhole model, and the interior of the manhole model is filled with gas;

[0128] Set measuring points on the center line of the explosion vent;

[0129] A 0.10m grid is used to simulate the constructed simulation environment.

[0130] Set measuring points on the center line of the explosion vent, including:

[0131] Set multiple measuring points at intervals of 0.5m on the center line above the explosion vent;

[0132] Set multiple measuring points at intervals of 1m on the center line below the explosion vent.

[0133] In specific practice, Figure 2As shown, the physical model used as the numerical calculation model of the underground space is a rectangular model of 200m (length) × 2m (width) × 4m (height). A manhole model is constructed in the center of the rectangular model, and the manhole model is filled with gas. An ignition source is set in the center of the manhole model. The influence of the ignition source on the explosion flow field is not considered. In order to study the impact of gas explosion release on the external space, the external calculation area is expanded to 8m along the Z-axis direction along the direction of the explosion vent. The initial ambient temperature is 20°C. All measuring points are located on the center line of the explosion vent, among which multiple measuring points are set at intervals of 0.5m on the center line above the explosion vent; and multiple measuring points are set at intervals of 1m on the center line below the explosion vent. Based on the results of numerical method verification, a 0.10m grid is used for simulation research. Reference Figure 2 , Figure 2 The middle measuring point 201 is located above the center of the manhole, measuring points 1-401 are arranged at an equal interval of 0.5m; measuring point 502 is located below the center of the manhole. Measuring points 402-602 are arranged at an equal interval of 1m.

[0134] This technical solution takes into account that the diameter of the manhole cover will affect the propagation path and intensity of the shock wave generated by the explosion in the manhole. A larger well depth will cause the shock wave to reflect and diffuse, increasing the degree of damage to surrounding buildings. The diameter of the pipeline directly affects the flow of gas and the power of the explosion. The thicker the pipeline, the greater the gas leakage may be, and the explosion energy will also increase. The gas concentration in the manhole determines the intensity and range of the explosion. A higher concentration may lead to a greater explosive force. The radius distance from the explosion point also determines the power of the gas explosion. The closer to the ignition source, the stronger the shock wave overpressure of the explosion. Therefore, a corresponding explosion gas overpressure prediction model is established based on these influencing factors to achieve accurate pre-disaster prediction.

[0135] In the experiment, different combinations of manhole parameters are set.

[0136] Example: The diameter of the manhole cover is 0.5m, the well depth is 2m, and the pipe diameter is 0.3m;

[0137] The manhole cover diameter is 1m, the well depth is 2.5m, and the pipe diameter is 0.8m;

[0138] The manhole cover diameter is 1.5m, the well depth is 2.9m, and the pipe diameter is 1.2m;

[0139] The gas concentration is 6%, 8%, 10%, 12% and 14%.

[0140] The numerical simulation calculation results of the external gas explosion overpressure of connected manholes changing with the radial distance under different manhole parameters, the numerical simulation calculation results of the internal gas explosion overpressure of connected manholes changing with the radial distance, the numerical simulation calculation results of the external gas explosion overpressure of independent manholes changing with the radial distance, and the numerical simulation calculation results of the internal gas explosion overpressure of independent manholes changing with the radial distance are obtained.

[0141] The curve of the overpressure of the gas explosion outside the connected manhole changing with the radius distance is as follows: Figure 3 shown.

[0142] The numerical simulation results of the external gas explosion overpressure of the connected manholes were nonlinearly fitted with the variation of the radius distance, and the external gas explosion overpressure prediction model of the connected manholes was obtained.

[0143] The overpressure prediction model for external gas explosion connected to the manhole is:

[0144]

[0145]

[0146] B=.0275*10 -6 *6.41087 V ;

[0147] C=2.5537*10 -11 *e 17.68663*L ;

[0148]

[0149] Wherein, P represents the predicted value of gas explosion overpressure; represents the gas concentration in the manhole; x represents the radius distance from the explosion point; D represents the manhole cover diameter; H represents the well depth; L represents the pipe diameter; A, B, C, and V all represent fitting parameters.

[0150] The external gas explosion overpressure prediction model of the connected manhole is verified by using the validation data set. Specifically, the evaluation model is verified by comparing and analyzing with any set of numerical calculation result data, such as Figure 4 As shown in the figure, linear regression analysis shows that when the variance values ​​of the two are in line with expectations, it means that the external gas explosion overpressure prediction model for connected manholes has significant credibility.

[0151] The curve of the overpressure of gas explosion in the connected manhole changing with the radius distance is as follows: Figure 5 shown.

[0152] The nonlinear fitting was performed on the numerical simulation results of the variation of the internal gas explosion overpressure of the connected manhole with the radius distance, and the prediction model of the internal gas explosion overpressure of the connected manhole was obtained.

[0153] The prediction model for internal gas explosion overpressure in connected manholes is:

[0154]

[0155]

[0156]

[0157]

[0158] The internal gas explosion overpressure prediction model of the connected manhole is verified by using the validation data set. Specifically, the evaluation model is verified by comparing and analyzing with any set of numerical calculation result data, such as Figure 6 As shown in the figure, linear regression analysis shows that when the variance values ​​of the two are in line with expectations, it means that the internal gas explosion overpressure prediction model of connected manholes has significant credibility.

[0159] The curve of the overpressure of gas explosion outside an independent manhole changing with the radius distance is as follows: Figure 7 shown.

[0160] The nonlinear fitting is performed on the numerical simulation calculation results of the change of external gas explosion overpressure of independent manhole with radial distance, and the external gas explosion overpressure prediction model of independent manhole is obtained.

[0161] The external gas explosion overpressure prediction model for independent manholes is:

[0162] P=Ae Bx -0.00121073734;

[0163]

[0164]

[0165]

[0166] The independent manhole external gas explosion overpressure prediction model is verified by using the validation data set. Specifically, the evaluation model is verified by comparing and analyzing with any set of numerical calculation result data, such as Figure 8 As shown in the figure, linear regression analysis shows that when the variance values ​​of the two are in line with expectations, it means that the independent manhole external gas explosion overpressure prediction model has significant credibility.

[0167] The curve of the overpressure of gas explosion in an independent manhole changing with the radius distance is as follows: Fig. 9 shown.

[0168] The nonlinear fitting is performed on the numerical simulation calculation results of the variation of internal gas explosion overpressure of independent manholes with radial distance, and the prediction model of internal gas explosion overpressure of independent manholes is obtained.

[0169] The prediction model for internal gas explosion overpressure of independent manholes is:

[0170]

[0171] Z = ln(0.8365 + 0.14998 * V);

[0172]

[0173] Where Z represents the fitting parameter.

[0174] The independent manhole internal gas explosion overpressure prediction model is verified by using the validation data set. Specifically, the evaluation model is verified by comparing and analyzing with any set of numerical calculation result data, such as Fig.10 As shown in the figure, linear regression analysis shows that when the variance values ​​of the two are in line with expectations, it means that the prediction model for overpressure of gas explosion inside independent manholes has significant credibility.

[0175] In this technical solution, the corresponding gas explosion overpressure prediction model is pre-trained for different manhole types, which can make more accurate explosion gas overpressure predictions for different manholes. For each manhole type, external explosion gas overpressure predictions and internal explosion gas overpressure predictions are made, and the prediction results are multifaceted, which can better assist decision-making.

[0176] Embodiment 2

[0177] Fig.11 This is a schematic diagram of a device for predicting overpressure of gas explosion in an underground space provided by an embodiment of the present application, referring to Fig.11 , a gas explosion overpressure prediction device in underground space, comprising:

[0178] Processor 21 and memory 22;

[0179] The processor 21 and the memory 22 are connected via a communication bus:

[0180] The processor 21 is used to call and execute the program stored in the memory 22;

[0181] The memory 22 is used to store a program, and the program is used to execute at least one of the methods for predicting overpressure of gas explosion in an underground space in the above embodiment.

[0182] It can be understood that the same or similar parts of the above embodiments can be referenced to each other, and the contents not described in detail in some embodiments can refer to the same or similar contents in other embodiments.

[0183] It should be noted that, in the description of this application, the terms "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, in the description of this application, unless otherwise specified, the meaning of "plurality" refers to at least two.

[0184] Any process or method description in a flowchart or otherwise described herein may be understood to represent a module, segment or portion of code that includes one or more executable instructions for implementing the steps of a specific logical function or process, and the scope of the preferred embodiments of the present application includes alternative implementations in which functions may not be performed in the order shown or discussed, including performing functions in a substantially simultaneous manner or in the reverse order depending on the functions involved, which should be understood by technicians in the technical field to which the embodiments of the present application belong.

[0185] It should be understood that the various parts of the present application can be implemented by hardware, software, firmware or a combination thereof. In the above-mentioned embodiments, multiple steps or methods can be implemented by software or firmware stored in a memory and executed by a suitable instruction execution system. For example, if implemented by hardware, as in another embodiment, it can be implemented by any one of the following technologies known in the art or their combination: a discrete logic circuit having a logic gate circuit for implementing a logic function for a data signal, a dedicated integrated circuit having a suitable combination of logic gate circuits, a programmable gate array (PGA), a field programmable gate array (FPGA), etc.

[0186] A person skilled in the art may understand that all or part of the steps in the method for implementing the above-mentioned embodiment may be completed by instructing related hardware through a program, and the program may be stored in a computer-readable storage medium, which, when executed, includes one or a combination of the steps of the method embodiment.

[0187] In addition, each functional unit in each embodiment of the present application may be integrated into a processing module, or each unit may exist physically separately, or two or more units may be integrated into one module. The above-mentioned integrated module may be implemented in the form of hardware or in the form of a software functional module. If the integrated module is implemented in the form of a software functional module and sold or used as an independent product, it may also be stored in a computer-readable storage medium.

[0188] The storage medium mentioned above can be a read-only memory, a magnetic disk or an optical disk, etc.

[0189] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0190] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in the field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A method for predicting overpressure of gas explosion in underground space, characterized in that: include: Obtaining manhole parameters of the underground space to be predicted; The manhole parameters include: manhole cover diameter, well depth, pipe diameter, gas concentration in the manhole and radius distance from the explosion point; Determine the type of the manhole of the underground space to be predicted, and select a corresponding gas explosion overpressure prediction model according to the type of the manhole of the underground space to be predicted; the gas explosion overpressure prediction model includes: an external gas explosion overpressure prediction model and an internal gas explosion overpressure prediction model; The manhole cover diameter, well depth, pipe diameter, gas concentration in the manhole and radius distance from the explosion point are input into the external gas explosion overpressure prediction model to obtain the external explosion gas overpressure prediction value; The manhole cover diameter, well depth, pipe diameter and gas concentration in the manhole are input into the internal gas explosion overpressure prediction model to obtain the predicted value of the internal explosion gas overpressure.

2. The method according to claim 1, characterized in that The categories of manholes include: connected manholes; The overpressure prediction model for external gas explosion connected to the manhole is: B＝.0275*10 -6 *6.41087 V ； C=2.5537*10 -11 *And 17.68663*L ; Wherein, P represents the predicted value of gas explosion overpressure; represents the gas concentration in the manhole; x represents the radius distance from the explosion point; D represents the manhole cover diameter; H represents the well depth; L represents the pipe diameter; A, B, C, and V all represent fitting parameters; The prediction model for internal gas explosion overpressure in connected manholes is:

3. The method according to claim 1, characterized in that The manhole categories include: independent manhole; The external gas explosion overpressure prediction model for independent manholes is: P=Ae Bx -0.00121073734; The prediction model for internal gas explosion overpressure of independent manholes is: Z = ln(0.8365 + 0.14998 * V); Where Z represents the fitting parameter.

4. The method according to claim 1, characterized in that: The method further comprises: Construct a manhole gas explosion simulation environment using 3D computational fluid dynamics software; Obtain the numerical simulation calculation results of the external gas explosion overpressure of the connected manholes with the radial distance, the numerical simulation calculation results of the internal gas explosion overpressure of the connected manholes with the radial distance, the numerical simulation calculation results of the external gas explosion overpressure of the independent manholes with the radial distance, and the numerical simulation calculation results of the internal gas explosion overpressure of the independent manholes with the radial distance under different manhole parameters; The numerical simulation results of the external gas explosion overpressure of the connected manholes were nonlinearly fitted with the variation of the radius distance, and the external gas explosion overpressure prediction model of the connected manholes was obtained. The nonlinear fitting was performed on the numerical simulation results of the variation of the internal gas explosion overpressure of the connected manhole with the radius distance, and the prediction model of the internal gas explosion overpressure of the connected manhole was obtained. The nonlinear fitting is performed on the numerical simulation calculation results of the change of external gas explosion overpressure of independent manhole with radial distance, and the external gas explosion overpressure prediction model of independent manhole is obtained. The nonlinear fitting was performed on the numerical simulation results of the variation of internal gas explosion overpressure of independent manholes with radial distance, and the prediction model of internal gas explosion overpressure of independent manholes was obtained.

5. The method according to claim 4, characterized in that The method further comprises: Each gas explosion overpressure prediction model is verified using the validation data set.

6. The method according to claim 4, characterized in that The manhole gas explosion simulation environment is constructed using 3D computational fluid dynamics software, including: Construct a rectangular model as the underground space, and construct a manhole model in the center of the rectangular model; An ignition source is set at the center of the manhole model, and the interior of the manhole model is filled with gas; Set measuring points on the center line of the explosion vent; A 0.10m grid is used to simulate the constructed simulation environment.

7. The method according to claim 6, characterized in that Set measuring points on the center line of the explosion vent, including: Set multiple measuring points at intervals of 0.5m on the center line above the explosion vent; Set multiple measuring points at intervals of 1m on the center line below the explosion vent.

8. The method according to claim 4, characterized in that The three-dimensional computational fluid dynamics software describes the ideal fluid behavior of the compressible fluid through the mass conservation equation, momentum equation, enthalpy transport equation, fuel mass fraction transport equation and mixture mass fraction transport equation; The three-dimensional computational fluid dynamics software also includes: a flame model and a turbulence model.

9. A device for predicting overpressure of gas explosion in underground space, characterized in that: include: Processor and memory; The processor and the memory are connected via a communication bus: Wherein, the processor is used to call and execute the program stored in the memory; The memory is used to store a program, and the program is used at least to execute a method for predicting overpressure of gas explosion in an underground space as described in any one of claims 1-8.

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