A simulation and prediction method for extreme fire outbreak behavior

Abstract

The present invention relates to the field of fire simulation prediction, and provides a simulation prediction method for extreme explosive fire behavior. The data of flame wall attachment behavior is determined by the flame airflow pressure difference value obtained by experiment, and then based on the flame wall attachment behavior data, it is judged whether the flame meets the critical occurrence condition of explosive fire behavior at the arc surface position corresponding to the detection device. When the critical condition of explosive fire is met at the arc surface position corresponding to the detection device, the arc surface position corresponding to the detection device is used as the critical occurrence position of explosive fire behavior. The present application is based on the flame wall attachment behavior data to judge the critical occurrence condition of explosive fire behavior, and can quantitatively characterize the explosive fire behavior. After obtaining the flame airflow pressure difference value, verifying it can improve the accuracy of the measured parameters, facilitate subsequent data processing and analysis, and provide effective support for the study of explosive fire behavior.

Description

Technical Field

[0001] The invention relates to the field of fire simulation prediction, and in particular to a simulation prediction method for extreme fire outbreak behavior. Background Art

[0002] Fire flare-ups are an extreme forest fire behavior that has an extremely fast spread speed and a high-intensity heat release rate, and is sudden. In the prior art, the study of fire flare-ups is still in its early stages, and there is a lack of quantitative characterization methods for fire flare-ups. Most of the existing simulation methods are suitable for flat terrain. Since the terrain in forest fire scenes is relatively complex, fires usually spread along curved terrain. The existing simulation methods lack the simulation of slope terrain with varying slopes, and the prediction accuracy of the potential location of fire flare-ups is low, which is not conducive to guiding forest fire prevention personnel to pre-isolate the potential location of fire flare-ups.

[0003] Based on this, it is necessary to provide a simulation and prediction method for extreme fire outbreak behavior to alleviate or solve the above problems. Summary of the invention

[0004] In order to solve the technical problems that the above-mentioned prior art lacks research on the behavior of explosive fires, lacks quantitative characterization means for explosive fires, and has low accuracy in predicting the potential location of explosive fires, the present invention provides a simulation prediction method for extreme explosive fire behavior, comprising the following steps:

[0005] S1, obtaining the ignition energy required to ignite the sample, and using the ignition energy as an ignition setting value;

[0006] S2, placing the sample on the induction simulation device, and igniting the sample with the ignition setting value; wherein the induction simulation device includes a frame, an ignition mechanism, an explosion fire induction mechanism and a detection device for detecting the pressure difference value of the flame airflow, the explosion fire induction mechanism has an arc-shaped surface for simulating a gradually steepening slope, the arc-shaped surface includes a low end and a high end relatively arranged along the bending direction, the ignition mechanism is arranged on the frame and close to the low end, the ignition mechanism is used to ignite the sample, the detection device includes a heat flux sensor and a mounting plate, the heat flux sensor is mounted on the mounting plate, the detection device is mounted on the frame and can be adjusted in position in the bending direction of the arc-shaped surface;

[0007] S3, obtaining the flame airflow pressure difference value detected by the detection device at the current position;

[0008] S4, determining flame wall attachment behavior data according to the flame airflow pressure difference value, and then judging whether the flame meets the critical occurrence condition of the fire explosion behavior at the arc surface position corresponding to the detection device according to the flame wall attachment behavior data;

[0009] S5, when the critical occurrence condition of the fire outbreak behavior is met at the arc surface position corresponding to the detection device, the arc surface position corresponding to the detection device is used as the critical occurrence position of the fire outbreak behavior.

[0010] In one embodiment, the step S4 specifically includes the following steps:

[0011] S41, using formula Calculate the Richardson number for the critical state of flame wall behavior ; Wherein, a coordinate system is established with the lower end of the arc surface as the coordinate origin, and the horizontal direction as x Axis, vertical direction y axis, x, y is the position of the detection device in the coordinate system; is the pressure difference of the flame airflow, g is the acceleration due to gravity, is the air temperature, is the ambient temperature at normal temperature, is the ambient density at room temperature, is the distance from the center of the heat flow sensor on the detection device to the mounting plate;

[0012] S42, determining the Richardson number whether it is established;

[0013] S431, in the Richardson number When it is established, it is determined that the flame meets the critical occurrence condition of the fire explosion behavior at the arc surface position corresponding to the detection device;

[0014] S432, in the Richardson number If the condition is established, it is determined that the fire at the arc surface position corresponding to the current position is too large, the detection device is moved downward along the curvature direction of the arc surface by a first preset distance, the position after the movement is taken as the current position, and the process returns to step S3;

[0015] S433, in the Richardson number When the fire is established, it is determined that the fire intensity at the arc surface position corresponding to the current position is too small, and it is determined whether the current position is the position corresponding to the high end;

[0016] S434, when the current position is not the position corresponding to the high end, move the detection device upward along the curvature direction of the arc surface by a second preset distance, take the position after the movement as the current position, and return to step S3;

[0017] S435, when the current position is the position corresponding to the high end, it is determined that the flame does not meet the critical occurrence condition of the fire explosion behavior at the arc surface position corresponding to the detection device.

[0018] In one embodiment, the step S432 specifically includes the following steps:

[0019] The detection device is moved along the surface of the arc-shaped curved surface toward the lower end, and each time the detection device moves, the detection device moves a first preset distance, and the first preset distance is x The step lengths in the axis directions are the same;

[0020] When the detection device moves, the inclination angle is set along the tangent direction of the arc-shaped surface.

[0021] In one embodiment, the step S434 specifically includes the following steps:

[0022] The detection device is moved along the surface of the arc-shaped curved surface toward the high end, and each time the detection device moves, the detection device moves a second preset distance, and the second preset distance is x The step lengths in the axis directions are the same;

[0023] When the detection device moves, the inclination angle is set along the tangent direction of the arc-shaped surface.

[0024] In one embodiment, the step S3 specifically includes the following steps:

[0025] S31, obtaining the total heat flux and the radiation heat flux measured by the detection device, and calculating the convective heat flux according to the total heat flux and the radiation heat flux;

[0026] S32, calculating a total Nusselt number according to the convective heat flux;

[0027] S33, calculate the Nusselt number under natural convection conditions and the Nusselt number under forced convection conditions;

[0028] S34, calculate the theoretical air flow rate ;

[0029] S35, obtain air flow velocity u , determine whether the following formula is true:

[0030] ;

[0031] S36, when the calculation formula in step S35 is established, determine the air flow speed u The measured data is qualified, and the air flow velocity u The measured data is used as the flame airflow pressure difference value.

[0032] In one embodiment, the ignition energy in step S1 is obtained by the following steps:

[0033]

[0034] in, For ignition energy, q is the ignition power, The time required for the sample to ignite.

[0035] In one embodiment, the air flow velocity is obtained in step S35 u The specific steps include:

[0036] Using formula Get air velocity u .

[0037] In one embodiment, the detection device moves along the surface of the arc-shaped surface, and the moving path satisfies ,in, R is the radius of the arc surface;

[0038] The detection device is rotatably mounted on the frame, and the frame includes a horizontal support frame, a first bracket and a second bracket;

[0039] The horizontal support frame is provided with a third slide rail extending along its own extension direction;

[0040] The first bracket includes a first slide rail and a first slider, the first slide rail extends vertically, the first slider is movably arranged along the third slide rail, and the first slider is connected to an end of the horizontal support frame away from the ignition mechanism;

[0041] The second bracket includes a second slide rail and a second slider, the second slide rail is arranged above the third slide rail in parallel, and the second slide rail extends from the top of the first slide rail toward the explosion fire inducing mechanism to the top of the arc surface, and the second slider is movably arranged along the first slide rail;

[0042] The detection device is installed on the second bracket.

[0043] In one embodiment, a heat insulating layer is further provided on the surface of the arc-shaped curved surface, and when the detection device moves, it moves along the surface of the heat insulating layer.

[0044] In one embodiment, the induced simulation device further includes a water cooling device, and before igniting the sample, the detection device is connected to the water cooling device.

[0045] Compared with the prior art, the present invention has the following beneficial effects:

[0046] This application can better simulate the behavior of fire outbreaks under slope terrain and more accurately predict the impact of complex terrain on fire outbreak behavior. Specifically, based on the flame wall behavior data, the critical occurrence conditions of fire outbreak behavior can be judged, the fire outbreak behavior can be quantitatively characterized, and verified after obtaining the flame airflow pressure difference value, which can improve the accuracy of the measured parameters. Compared with simple flat terrain, this scheme uses curved surfaces to more accurately simulate the occurrence scene of forest fire outbreak behavior, which is conducive to subsequent data processing and analysis, and provides effective support for the study of fire outbreak behavior. In practical applications, this method is conducive to guiding forest fire prevention personnel to set up firebreaks, pre-fire isolation of potential locations for fire outbreaks, and limiting the induction of fire outbreak behavior to a large extent, reducing the destructiveness of forest fires and the property losses caused. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0048] Figure 1 This is a schematic diagram of the structure of the device for inducing and simulating extreme explosive fire behavior in an embodiment of the present application;

[0049] Figure 2 for Figure 1 Schematic diagram of the structure of the middle rack;

[0050] Figure 3 This is a flow chart for simulating and predicting extreme fire outbreak behavior in an embodiment of the present application;

[0051] Description of the drawings: 1. Rack; 11. First bracket; 111. First slide rail; 12. Second bracket; 121. Second slide rail; 13. Horizontal support frame; 131. Third slide rail; 2. Ignition mechanism; 3. Explosion fire inducing mechanism; 31. Arc surface; 32. Insulation layer; 4. Detection device; 5. Water cooling device. DETAILED DESCRIPTION

[0052] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0053] Furthermore, the technical solutions between the various embodiments of the present invention may be combined with each other, but this must be based on the fact that they can be implemented by ordinary technicians in the field. When the combination of technical solutions is mutually contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0054] When numerical ranges are given in the embodiments, it should be understood that unless otherwise specified in the present invention, both endpoints of each numerical range and any value between the two endpoints can be selected. Unless otherwise defined, all technical and scientific terms used in the present invention are familiar to those skilled in the art and the description of the present invention, and any method, device and material of the prior art similar or equivalent to the method, device and material in the embodiments of the present invention can also be used to implement the present invention.

[0055] In the prior art, when studying extreme fire behavior, there is little quantitative characterization of fire behavior, and there is a lack of means to verify parameters, which makes it impossible to accurately evaluate the accuracy of parameters, difficult to perform precise theoretical modeling and prediction, and not conducive to data processing and analysis, resulting in difficulty in comparing and verifying experimental results.

[0056] Please see attached Figures 1 to 3 The present invention provides a simulation prediction method for extreme fire behavior, comprising the following steps:

[0057] S1, obtaining the ignition energy required to ignite the sample, and using the ignition energy as the ignition setting value;

[0058] S2, placing the sample on the induction simulation device, and igniting the sample with the ignition setting value; wherein the induction simulation device includes a frame 1, an ignition mechanism 2, an explosion fire induction mechanism 3 and a detection device 4 for detecting the pressure difference value of the flame airflow, the explosion fire induction mechanism 3 has an arc surface 31 for simulating a gradually steepening slope, the arc surface 31 includes a low end and a high end relatively arranged along the bending direction, the ignition mechanism 2 is arranged on the frame 1 and close to the low end, the ignition mechanism 2 is used to ignite the sample, the detection device 4 includes a heat flow sensor and a mounting plate, the heat flow sensor is mounted on the mounting plate, the detection device 4 is mounted on the frame 1 and can be adjusted in position in the bending direction of the arc surface 31;

[0059] S3, obtaining the flame airflow pressure difference value detected by the detection device 4 at the current position;

[0060] S4, determining the flame wall attachment behavior data according to the flame airflow pressure difference value, and then judging whether the flame at the position of the arc surface 31 corresponding to the detection device 4 meets the critical occurrence condition of the fire explosion behavior according to the flame wall attachment behavior data;

[0061] S5, when the position of the arc surface 31 corresponding to the detection device 4 meets the critical occurrence condition of the fire outbreak behavior, the position of the arc surface 31 corresponding to the detection device 4 is used as the critical occurrence position of the fire outbreak behavior.

[0062] In the embodiment of the present application, the flame wall attachment behavior data is determined by the flame airflow pressure difference value obtained by detection, and then based on the flame wall attachment behavior data, it is judged whether the position of the arc surface 31 corresponding to the detection device 4 meets the critical occurrence condition of the explosive fire behavior. In this way, the flame wall attachment behavior can be quantitatively characterized by the flame airflow pressure difference value, and whether the critical occurrence condition of the explosive fire behavior is met can be judged from the measured and calculated data, so that the experimental results can be intuitively evaluated through the data, making the data processing process more objective, accurate and simple.

[0063] Preferably, the arc surface 31 is a single curved surface.

[0064] In one embodiment, step S4 specifically includes the following steps:

[0065] S41, using formula Calculate the Richardson number for the critical state of flame wall behavior ; Wherein, a coordinate system is established with the lower end of the arc surface 31 as the coordinate origin, and the horizontal direction is x Axis, vertical direction y axis, x , y is the position of the detection device 4 in the coordinate system; is the flame airflow pressure difference value, g is the acceleration due to gravity, is the air temperature, is the ambient temperature at normal temperature, is the ambient density at room temperature, is the distance from the center of the heat flux sensor on the detection device 4 to the mounting plate;

[0066] S42, determine the Richardson number whether it is established;

[0067] S431, in Richardson number When it is established, it is determined that the flame meets the critical occurrence condition of the fire explosion behavior at the position of the arc surface 31 corresponding to the detection device 4;

[0068] S432, in Richardson number When the condition is established, it is determined that the fire at the arc surface 31 corresponding to the current position is too large, and the detection device 4 is moved downward along the bending direction of the arc surface 31 by a first preset distance, and the moved position is used as the current position, and the process returns to step S3;

[0069] S433, in Richardson number When it is established, it is determined that the fire intensity at the arc surface 31 position corresponding to the current position is too small, and it is determined whether the current position is the position corresponding to the high end;

[0070] S434, when the current position is not the position corresponding to the high end, the detection device 4 is moved upward along the bending direction of the arc surface 31 by a second preset distance, the position after the movement is taken as the current position, and the process returns to step S3;

[0071] S435, when the current position is the position corresponding to the high end, it is determined that the flame at the position of the arc surface 31 corresponding to the detection device 4 does not meet the critical occurrence condition of the fire explosion behavior.

[0072] It should be noted that a coordinate system is established with the lower end of the arc surface 31 as the coordinate origin, wherein the coordinate origin specifically refers to the end position of the arc surface on the lower end.

[0073] Under the critical conditions of fire behavior, the convective heat transfer mode is often in mixed convection. Under this condition, the Richardson number Usually between 0.1 and 10, this application uses the Richardson number As the critical condition for flame attachment to the wall, that is, the critical condition for the occurrence of explosive fire, when When the fire breaks out, , it is determined that no fire explosion occurs.

[0074] When the detection device 4 is moved downward along the curved surface 31, the gas flow rate gradually decreases, that is, the Richardson number gradually increases, so in When the detection device 4 is moved upward, the critical position of the flame adhering to the wall is found. Similarly, When the detection device 4 needs to be moved down.

[0075] In the present application, the Richardson number is used Characterizing the critical conditions for the occurrence of explosive fire, it is possible to predict whether the explosive fire has reached the critical conditions through calculation, so that the behavior of the explosive fire can be intuitively expressed through data. At the same time, it can also be based on the Richardson number. The position of the detection device 4 is adjusted to find the critical position where the fire breaks out.

[0076] In one embodiment, step S432 specifically includes the following steps:

[0077] The detection device 4 is moved toward the lower end along the surface of the arc surface 31. Each time the detection device 4 moves, it moves a first preset distance. The first preset distance is x The step lengths in the axis directions are the same;

[0078] When the detection device 4 moves, the inclination angle is set along the tangent direction of the arc-shaped curved surface 31 .

[0079] It should be noted that the first preset distance is the distance that the detection device 4 moves on the arc surface 31. x The step lengths in the axial direction are equal. For example, during the movement, the step length of the first preset distance is 25 mm, that is, each time the detection device 4 moves, x The moving distance in the axial direction is 25mm, and the moving process meets x=x -25mm.

[0080] In the present application embodiment, each time x The step length of the first preset distance moved in the axial direction is the same. In the subsequent data analysis and processing process, the position of the detection device 4 is approximated as the occurrence position of the fire explosion, so that the error between the measured position and the actual occurrence position of the fire explosion is not greater than the step length of the first preset distance, thereby improving the accuracy of the data. The detection device 4 is set at an inclined angle along the tangent direction of the arc surface 31 during the movement process, so that the flame airflow pressure difference value can be measured more accurately, so that a more accurate Richardson number can be calculated, which is convenient for subsequent data processing and analysis.

[0081] In one embodiment, step S434 specifically includes the following steps:

[0082] The detection device 4 is moved toward the high end along the surface of the arc surface 31. Each time the detection device 4 moves, it moves a second preset distance. The second preset distance is x The step lengths in the axis directions are the same;

[0083] When the detection device 4 moves, the inclination angle is set along the tangent direction of the arc-shaped curved surface 31 .

[0084] It should be noted that the second preset distance is the distance that the detection device 4 moves on the arc surface 31. x The step lengths in the axial direction are equal. For example, during the movement, the step length of the second preset distance is 25 mm, that is, each time the movement is performed, x The moving distance in the axial direction is 25mm, and the moving process meets x=x -25mm.

[0085] In the present application embodiment, each time x The step length of moving the second preset distance in the axial direction is also the same. In the subsequent data analysis and processing, the position of the detection device 4 is approximated to the location where the fire broke out. In this way, the error between the measured position and the actual location where the fire broke out is no more than a step length of the second preset distance, thereby improving the accuracy of the data.

[0086] In one embodiment, step S3 specifically includes the following steps:

[0087] S31, obtaining the total heat flux and the radiation heat flux measured by the detection device 4, and calculating the convective heat flux according to the total heat flux and the radiation heat flux;

[0088] S32, calculation of the total Nusselt number based on the convective heat flux;

[0089] S33, calculate the Nusselt number under natural convection conditions and the Nusselt number under forced convection conditions;

[0090] S34, calculate the theoretical air flow rate ;

[0091] S35, obtain air flow velocity u , determine whether the following formula is true:

[0092] ;

[0093] S36, when the calculation formula in step S35 is established, determine the air flow speed u The measured data is qualified, and the air flow velocity u The measured data is used as the flame airflow pressure difference value.

[0094] It should be noted that in the process of simulating explosive fire behavior, due to the large amount of particulate matter generated during the explosive combustion of the fire, the detection device may be blocked, and the measured parameters are usually not accurate enough. Before using the measured flame airflow pressure difference value to calculate the Richardson number, the accuracy of the flame airflow pressure difference value needs to be verified. Only when the data is accurate can the data be used, otherwise the data will not be used.

[0095] Exemplarily, the total heat flux and the radiant heat flux are expressed as and The convective heat flux is expressed as Indicated in kW / m 2 , the calculation formula for convective heat flux is: .

[0096] According to the convective heat flux The total Nusselt number is calculated and expressed as Indicates that the calculation formula is:

[0097]

[0098] Where D is the characteristic diameter of the heat flow meter window, which is 10 mm in this embodiment. is the thermal conductivity of gas;

[0099] Under extreme fire outbreak conditions, the convective heat transfer relationship can be described by the combined natural convection and forced convection, further expressed as:

[0100]

[0101] in, is the Nusselt number under natural convection, is the Nusselt number under forced convection.

[0102] Using the natural convection relationship, calculate the Nusselt number under natural convection :

[0103]

[0104] in, is the thermal diffusion coefficient, is the kinematic viscosity, and both are the air temperatures function.

[0105] Using the forced convection relation, calculate the Nusselt number under forced convection :

[0106]

[0107] In the above calculation formula, only the theoretical air flow rate The above equations are closed. By combining the above equations, we can get the theoretical air flow velocity. Theoretical calculation formula:

[0108]

[0109] Considering that the maximum error in the fire research process is within the range of ±30%, this embodiment uses ±25% as the judgment standard.

[0110] In the embodiment of the present application, the flame airflow pressure difference value is verified, so that the error of the experimental data can be controlled within the allowable range, the influence of erroneous data on the analysis results can be reduced, and the accuracy and rigor of the data analysis can be improved.

[0111] In one embodiment, the ignition energy in step S1 is obtained by the following steps:

[0112]

[0113] in, For ignition energy, q is the ignition power, The time required for the sample to ignite.

[0114] In the embodiment of the present application, the ignition energy required to ignite the sample is used as the ignition setting value, so that the sample can be ignited with the ignition setting value in subsequent experimental processes, reducing the impact of the ignition process on the experimental data and improving the accuracy of the data.

[0115] In one embodiment, the air flow velocity is obtained in step S35 u The specific steps include:

[0116] Using formula Get air velocity u .

[0117] What you need to know is that the flame airflow pressure difference and air velocity u These are all data directly measured by the measuring device.

[0118] In the embodiment of the present application, the flame airflow pressure difference value is With air velocity u Connecting and verifying each other can effectively improve the accuracy of experimental measurements and facilitate subsequent data analysis and processing.

[0119] In one embodiment, the detection device 4 moves along the surface of the arc-shaped curved surface 31, and the moving path satisfies, wherein R is the radius of the arc-shaped curved surface 31;

[0120] The detection device 4 is rotatably mounted on the frame 1, and the frame 1 includes a horizontal support frame 13, a first bracket 11 and a second bracket 12;

[0121] The horizontal support frame 13 is provided with a third slide rail 131 extending along its own extension direction;

[0122] The first bracket 11 includes a first slide rail 111 and a first slider, the first slide rail 111 extends vertically, the first slider is movably arranged along the third slide rail 131, and the first slider is connected to the end of the horizontal support frame 13 away from the ignition mechanism 2;

[0123] The second bracket 12 includes a second slide rail 121 and a second slider. The second slide rail 121 is arranged above the third slide rail 131 in parallel, and the second slide rail 121 extends from the top of the first slide rail 111 toward the explosion fire inducing mechanism 3 to the top of the arc surface 31. The second slider is movably arranged along the first slide rail 111.

[0124] The detection device 4 is mounted on the second bracket 12 .

[0125] In the embodiment of the present application, the detection device 4 is rotatably mounted on the frame 1, and the frame 1 is movable in the x-axis and y-axis directions, so that the detection device 4 can be placed at any position on the arc surface 31, which can adapt to various testing conditions and has high flexibility.

[0126] In one embodiment, a heat insulating layer 32 is further provided on the surface of the arc-shaped curved surface 31 , and when the detection device 4 moves, it moves along the surface of the heat insulating layer 32 .

[0127] In the embodiment of the present application, a heat insulating layer 32 is provided on the arc surface 31, which can reduce the heat loss of the explosive fire, reduce the impact of the environment on the explosive fire, and make the test result more accurate.

[0128] In one embodiment, the induced simulation device further includes a water cooling device 5 , and before the sample is ignited, the detection device 4 is connected to the water cooling device 5 .

[0129] In the embodiment of the present application, before igniting the sample, the detection device 4 is connected to the water cooling device 5, which can cool the detection device 4 more efficiently, protect the detection device 4, and reduce the impact of the high temperature environment on the accuracy of the detection device 4.

[0130] The above are only preferred embodiments of the present invention, and the protection scope of the present invention is not limited thereto. Any equivalent structure or equivalent process transformation made by using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the protection scope of the present invention.

Claims

1. A simulation and prediction method for extreme fire outbreak behavior, characterized in that: The steps include: S1, obtaining the ignition energy required to ignite the sample, and using the ignition energy as an ignition setting value; S2, placing the sample on the induction simulation device, and igniting the sample with the ignition setting value; wherein the induction simulation device includes a frame, an ignition mechanism, an explosion fire induction mechanism and a detection device for detecting the pressure difference value of the flame airflow, the explosion fire induction mechanism has an arc-shaped surface for simulating a gradually steepening slope, the arc-shaped surface includes a low end and a high end relatively arranged along the bending direction, the ignition mechanism is arranged on the frame and close to the low end, the ignition mechanism is used to ignite the sample, the detection device includes a heat flux sensor and a mounting plate, the heat flux sensor is mounted on the mounting plate, the detection device is mounted on the frame and can be adjusted in position in the bending direction of the arc-shaped surface; S3, obtaining the flame airflow pressure difference value detected by the detection device at the current position; S4, determining flame wall attachment behavior data according to the flame airflow pressure difference value, and then judging whether the flame meets the critical occurrence condition of the fire explosion behavior at the arc surface position corresponding to the detection device according to the flame wall attachment behavior data; S5, when the critical occurrence condition of the fire outbreak behavior is met at the arc surface position corresponding to the detection device, the arc surface position corresponding to the detection device is used as the critical occurrence position of the fire outbreak behavior.

2. The method for simulating and predicting extreme fire behavior according to claim 1, characterized in that: The step S4 specifically comprises the following steps: S41, using formula Calculate the Richardson number for the critical state of flame wall behavior ; Wherein, a coordinate system is established with the lower end of the arc surface as the coordinate origin, and the horizontal direction as x Axis, vertical direction y axis, x , y is the position of the detection device in the coordinate system; is the pressure difference of the flame airflow, g is the acceleration due to gravity, is the air temperature, is the ambient temperature at normal temperature, is the ambient density at room temperature, is the distance from the center of the heat flow sensor on the detection device to the mounting plate; S42, determining the Richardson number whether it is established; S431, in the Richardson number When it is established, it is determined that the flame meets the critical occurrence condition of the fire explosion behavior at the arc surface position corresponding to the detection device; S432, in the Richardson number When the condition is established, it is determined that the fire intensity at the arc surface position corresponding to the current position is too large, the detection device is moved downward along the bending direction of the arc surface by a first preset distance, the position after the movement is taken as the current position, and the process returns to step S3; S433, in the Richardson number When the fire is established, it is determined that the fire intensity at the arc surface position corresponding to the current position is too small, and it is determined whether the current position is the position corresponding to the high end; S434, when the current position is not the position corresponding to the high end, move the detection device upward along the curvature direction of the arc surface by a second preset distance, take the position after the movement as the current position, and return to step S3; S435, when the current position is the position corresponding to the high end, it is determined that the flame does not meet the critical occurrence condition of the fire explosion behavior at the arc surface position corresponding to the detection device.

3. The simulation prediction method of extreme fire outbreak behavior according to claim 2, characterized in that: The step S432 specifically includes the following steps: The detection device is moved along the surface of the arc-shaped curved surface toward the lower end, and each time the detection device moves, the detection device moves a first preset distance, and the first preset distance is x The step lengths in the axis directions are the same; When the detection device moves, the inclination angle is set along the tangent direction of the arc-shaped surface.

4. The method for simulating and predicting extreme fire behavior according to claim 2, characterized in that: The step S434 specifically includes the following steps: The detection device is moved along the surface of the arc-shaped curved surface toward the high end, and each time the detection device moves, the detection device moves a second preset distance, and the second preset distance is x The step lengths in the axis directions are the same; When the detection device moves, the inclination angle is set along the tangent direction of the arc-shaped surface.

5. The method for simulating and predicting extreme fire behavior according to claim 2, characterized in that: The step S3 specifically comprises the following steps: S31, obtaining the total heat flux and the radiation heat flux measured by the detection device, and calculating the convective heat flux according to the total heat flux and the radiation heat flux; S32, calculating a total Nusselt number according to the convective heat flux; S33, calculate the Nusselt number under natural convection conditions and the Nusselt number under forced convection conditions; S34, calculate the theoretical air flow rate ; S35, obtain air flow velocity u , determine whether the following formula is true: ； S36, when the calculation formula in step S35 is established, determine the air flow speed u The measured data is qualified, and the air flow velocity u The measured data is used as the flame airflow pressure difference value.

6. The method for simulating and predicting extreme fire behavior according to claim 1, characterized in that: The ignition energy in step S1 is obtained specifically through the following steps: in, For ignition energy, q is the ignition power, The time required for the sample to ignite.

7. The method for simulating and predicting extreme fire behavior according to claim 5, characterized in that: In step S35, the air flow velocity is obtained u The specific steps include: Using formula Get air velocity u .

8. The method for simulating and predicting extreme fire behavior according to claim 2, characterized in that: The detection device moves along the surface of the arc surface, and the moving path satisfies ,in, R is the radius of the arc surface; The detection device is rotatably mounted on the frame, and the frame includes a horizontal support frame, a first bracket and a second bracket; The horizontal support frame is provided with a third slide rail extending along its own extension direction; The first bracket includes a first slide rail and a first slider, the first slide rail extends vertically, the first slider is movably arranged along the third slide rail, and the first slider is connected to an end of the horizontal support frame away from the ignition mechanism; The second bracket includes a second slide rail and a second slider, the second slide rail is arranged above the third slide rail in parallel, and the second slide rail extends from the top of the first slide rail toward the explosion fire inducing mechanism to the top of the arc surface, and the second slider is movably arranged along the first slide rail; The detection device is installed on the second bracket.

9. The method for simulating and predicting extreme fire behavior according to claim 8, characterized in that: A heat insulating layer is also provided on the surface of the arc-shaped curved surface, and when the detection device moves, it moves along the surface of the heat insulating layer.

10. The method for simulating and predicting extreme fire behavior according to claim 9, characterized in that: The induction simulation device also includes a water cooling device, and before igniting the sample, the detection device is connected to the water cooling device.

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