A method for predicting flame inclination angle, an electronic device, and a storage medium

Abstract

The present invention discloses a method for predicting the inclination angle of a flame, an electronic device, and a storage medium. When an oil pool fire occurs in a current tunnel, the stoichiometric air-fuel ratio of the fuel is obtained through the chemical equation of the fuel under complete combustion; based on the dimension types included in the parameters, the parameters are divided to obtain basic physical quantities and remaining parameters; the wind speed, stoichiometric air-fuel ratio, and remaining parameters are respectively made dimensionless with the basic physical quantities to obtain target values; based on the target stoichiometric air-fuel ratio, target wind speed, mass loss rate of the target fuel, and basic physical quantities in the target values, dimensionless processing is carried out to obtain a target ratio; and based on the target ratio, the target tunnel cross-section width, target fire source size, target specific heat capacity of air, and target fire source release rate in the target values, the inclination angle of the flame is determined. The present invention can accurately predict the inclination angle of the flame considering the tunnel space effect.

Description

Technical Field

[0001] The present invention relates to the field of highway and waterway transportation, and relates to, but is not limited to, a method for predicting flame inclination angle, an electronic device, and a storage medium. Background Art

[0002] Pool fires in tunnels are mostly caused by traffic accidents of fuel transportation vehicles in tunnels. This type of fire has characteristics such as large combustion power and difficulty in extinguishing, and is an important object of concern in the safety design of tunnel fires. Currently, longitudinal ventilation is generally used in tunnel fire protection design to control the smoke in tunnel fires. When the tunnel ventilation speed is greater than the critical ventilation speed of the fire, all the smoke will flow towards the downstream of the fire source. At this time, accurately predicting the inclination angle of the flame has important value, because the inclination angle of the flame at this time can be used to assist in determining the maximum temperature of the tunnel ceiling and its specific position, and further can assist in determining the structural disaster area of the tunnel fire and assist in optimizing the layout plan of fire protection measures such as water spray.

[0003] In the related art, pool combustion experiments based on open spaces or small-scale pool combustion experiments in large enclosed spaces are used, but the flame inclination angle prediction method obtained by this method does not consider the confinement effect of the confined space or only considers the confinement effect of a single side wall. Because when a pool fire occurs in a tunnel, the flame is affected by both the tunnel ceiling and the side walls at the same time, and the space confinement effect is obvious, so the flame inclination angle prediction methods currently available in the industry are not applicable to the tunnel pool fire scenario.

[0004] Therefore, how to accurately predict the flame inclination angle while considering the tunnel space confinement effect has become an urgent problem to be solved. Summary of the Invention

[0005] In view of this, an embodiment of the present invention provides a method for predicting flame inclination angle, which at least solves the problem of accurately predicting the flame inclination angle in the related art considering the tunnel space effect.

[0006] According to the first aspect of the embodiment of the present invention, a method for predicting flame inclination angle is provided, including:

[0007] When a pool fire occurs in the current tunnel, obtain the stoichiometric air-fuel ratio of the fuel through the chemical equation of the fuel under complete combustion;

[0008] Based on the dimensional types included in the parameters, divide the parameters to obtain basic physical quantities and remaining parameters; the parameters include tunnel parameters, the wind speed of longitudinal ventilation in the tunnel, environmental parameters during the pool fire, and fire source parameters;

[0009] Nondimensionalize the wind speed, the stoichiometric air-fuel ratio, and the remaining parameters with respect to the basic physical quantities respectively to obtain target values;

[0010] Based on the stoichiometric air-fuel ratio, target wind speed, mass loss rate of the target fuel, and the basic physical quantities among the target values, dimensionless processing is performed to obtain a target ratio; and based on the target ratio, the target tunnel cross-sectional width, target fire source size, target specific heat capacity of air, and target fire source release rate among the target values, the inclination angle of the flame is determined.

[0011] According to the second aspect of the embodiments of the present invention, an electronic device is provided, including: a processor, a memory, a communication interface, and a communication bus. The processor, the memory, and the communication interface complete communication with each other through the communication bus; the memory is used to store at least one executable instruction, and the executable instruction causes the processor to perform the operations corresponding to the method described in the first aspect.

[0012] According to the third aspect of the embodiments of the present invention, a computer storage medium is provided, on which a computer program is stored, and when the program is executed by a processor, the method described in the first aspect is implemented.

[0013] According to the solution provided by the embodiments of the present invention, when a pool fire occurs in the current tunnel, the stoichiometric air-fuel ratio of the fuel is obtained through the chemical equation of the fuel under complete combustion. Based on the dimensional types included in the parameters, the parameters are divided to obtain basic physical quantities and remaining parameters; the parameters include tunnel parameters, the wind speed of longitudinal ventilation in the tunnel, environmental parameters during the pool fire, and fire source parameters. By determining the basic physical quantities among multiple parameters, the complexity of data processing is simplified, and the prediction result of the subsequent flame inclination angle is improved. The wind speed, stoichiometric air-fuel ratio, and remaining parameters are respectively subjected to dimensionless processing with the basic physical quantities to obtain target values. Based on the stoichiometric air-fuel ratio, target wind speed, mass loss rate of the target fuel, and basic physical quantities among the target values, dimensionless processing is performed to obtain a target ratio; by performing dimensionless processing on the values, the data can be scaled to a relatively stable range, reducing the risk of numerical instability and further improving the prediction accuracy. And based on the target ratio, the target tunnel cross-sectional width, target fire source size, target specific heat capacity of air, and target fire source release rate among the target values, the inclination angle of the flame is determined. For a tunnel including sidewalls and a ceiling, this process takes the tunnel cross-sectional area, tunnel cross-sectional length, and width as important features of the confined space, and combines the fire source parameters, environmental parameters, and the ratio of the vertical flame momentum to the horizontal ventilation air flow momentum (target ratio) during fuel combustion to predict the inclination angle of the flame, enabling accurate prediction of the flame inclination angle considering the tunnel space effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] To more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the accompanying drawings required for the description of the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can be obtained based on these drawings, where:

[0015] Figure 1 It is a schematic flowchart of a method for predicting the flame inclination angle provided by an embodiment of the present invention;

[0016] Figure 2 It is a schematic diagram of the effect of the flame inclination angle under the influence of lateral wind in a tunnel provided by an embodiment of the present invention;

[0017] Figure 3 It is a schematic diagram of the effect of a transverse section of a tunnel provided by an embodiment of the present invention;

[0018] Figure 4 It is a schematic diagram of the effect of the comparison result of the flame inclination angle obtained by numerical calculation and the prediction by the method of the present invention provided by an embodiment of the present invention;

[0019] Figure 5 It is a schematic structural diagram of an electronic device provided according to an embodiment of the present invention. Detailed Embodiments

[0020] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the following will clearly and completely describe the technical solutions in the embodiments of the present invention with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention. The following embodiments are used to illustrate the present invention, but do not limit the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts belong to the scope of protection of the present invention.

[0021] In the following description, reference is made to "some embodiments", which describe a subset of all possible embodiments. However, it can be understood that "some embodiments" can be the same subset or different subsets of all possible embodiments, and can be combined with each other without conflict.

[0022] It should be noted that the terms "first / second / third" involved in the embodiments of the present invention are only used to distinguish similar objects, and do not represent a specific order for the objects. It can be understood that "first / second / third" can be interchanged with a specific order or sequence when permitted, so that the embodiments of the present invention described here can be implemented in an order other than that illustrated or described here.

[0023] Those skilled in the art of the present technology can understand that, unless otherwise defined, all terms used herein (including technical terms and scientific terms) have the same meaning as the general understanding of those of ordinary skill in the art to which the embodiments of the present invention belong. It should also be understood that terms such as those defined in a general dictionary should be understood to have a meaning consistent with the meaning in the context of the prior art, and will not be interpreted with an idealized or overly formal meaning unless specifically defined as here.

[0024] Figure 1 FIG. is a schematic flowchart of a method for predicting the flame inclination angle provided by an embodiment of the present invention. The method for predicting the flame inclination angle provided by the embodiment of the present invention can be executed by an electronic device, and the electronic device can be, for example, a computer, a server, etc.

[0025] As Figure 1 shown, the method for predicting the flame inclination angle includes:

[0026] S101. When an oil pool fire occurs in the current tunnel, obtain the stoichiometric air-fuel ratio of the fuel through the chemical equation of the fuel in the case of complete combustion in the oil pool.

[0027] In the embodiments of the present invention, the fuel in the oil pool is mainly used to generate heat and flames. The fuel in the oil pool is mainly liquid fuel, including hydrocarbon fuels and alcohol fuels, etc. The stoichiometric air-fuel ratio refers to the mass ratio of air to fuel when the fuel is completely burned. When the fuel burns in the air, the oxygen in a certain mass of air just makes a certain mass of fuel completely burned. At this time, the mass ratio of air to fuel is called the stoichiometric air-fuel ratio. First, determine the type of oil pool combustion, and then obtain the corresponding chemical equation in the case of complete combustion of the fuel in the oil pool, as shown in the following formula (1):

[0028] (1)

[0029] In the above formula (1), , , are the stoichiometric constants required to balance the chemical equation.

[0030] In the embodiments of the present invention, the cross-sectional form of the current tunnel is rectangular or oblong, the fuel for the oil pool fire is a pure liquid hydrocarbon fuel, the shape of the fire source in the current tunnel is square, and the fire source is located on the tunnel center line.

[0031] S102. Perform parameter division based on the dimension type included in the parameters to obtain basic physical quantities and remaining parameters; the parameters include tunnel parameters, the wind speed of longitudinal ventilation in the tunnel, environmental parameters during an oil pool fire, and fire source parameters.

[0032] In an embodiment of the present invention, the dimension types include basic dimensions and derived dimensions. The basic dimensions, that is, the basic physical quantities, refer to the physical quantities with independent dimensions in the International System of Units (SI). The derived dimensions refer to the physical quantities whose dimensions can be expressed as a combination of basic dimensions. The dimensions of the derived quantities can be expressed as a product of powers of the basic quantities. The basic physical quantities can be determined by steps such as clarifying the basic physical quantities, identifying the dimensions of the parameters, classifying the parameters according to their dimension types, and directly extracting from the classified parameters those parameters that directly correspond to the basic physical quantities. Among them, the parameters refer to the tunnel parameters of the current tunnel, the wind speed of the longitudinal ventilation in the tunnel, the environmental parameters during an oil pool fire, and the fire source parameters. The remaining parameters refer to the parameters obtained by removing the basic physical quantities from the parameters.

[0033] In an embodiment of the present invention, the wind speed during the longitudinal ventilation of the current tunnel is greater than the critical ventilation wind speed in the tunnel.

[0034] S103. Nondimensionalize the wind speed, the stoichiometric air-fuel ratio, and the remaining parameters respectively with the basic physical quantities to obtain target values.

[0035] In an embodiment of the present invention, the nondimensionalization process is to transform those physical quantities with units (such as meters, seconds, kilograms, etc.) into pure numbers without units through a certain mathematical transformation. The target values are multiple values. The wind speed, the stoichiometric air-fuel ratio, and the remaining parameters can be respectively subjected to a ratio operation with the basic physical quantities to achieve the purpose of nondimensionalization and obtain the target values including multiple values.

[0036] S104. Nondimensionalize based on the target stoichiometric air-fuel ratio, the target wind speed, the mass loss rate of the target fuel, and the basic physical quantities in the target values to obtain a target ratio; and determine the inclination angle of the flame based on the target ratio, the target tunnel cross-sectional width, the target fire source size, the target specific heat capacity of air, and the target fire source release rate in the target values.

[0037] In an embodiment of the present invention, the target ratio is the nondimensionalized value corresponding to the ratio of the vertical flame momentum to the transverse ventilation air flow momentum during fuel combustion. The flame momentum refers to the momentum at the front edge of the flame, that is, the momentum carried during the flame propagation process. It can be used to describe the propagation ability of the flame in the medium, especially during the combustion process of gaseous or liquid fuels. The flame momentum reflects the kinetic energy and momentum transfer at the front edge of the flame and is a function of the flame propagation speed and the flame thickness. The mass loss rate of the fuel (Mass Loss Rate, MLR) refers to the amount of fuel mass reduction per unit time and is usually used to describe the consumption speed of the fuel during the combustion process. The transverse ventilation air flow momentum refers to the product of the air quality passing through the ventilation system per unit time and its speed. It reflects the dynamic characteristics of the ventilation air flow.

[0038] Among them, the inclination angle of the flame refers to the angle between the line connecting the center point and the end point of the fire source and the vertical direction after the connection.

[0039] It can be understood that in the embodiments of the present invention, when an oil pool fire occurs in the current tunnel, the stoichiometric air-fuel ratio of the fuel is obtained through the chemical equation of the fuel in the oil pool under complete combustion, and parameter division is performed based on the dimension type included in the parameters to obtain basic physical quantities and remaining parameters; the parameters include tunnel parameters, the wind speed of longitudinal ventilation in the tunnel, environmental parameters during the oil pool fire, and fire source parameters. By determining the basic physical quantities among multiple parameters, the complexity of data processing is simplified, and the prediction result of the subsequent flame inclination angle is improved. The wind speed, stoichiometric air-fuel ratio, and remaining parameters are respectively made dimensionless with the basic physical quantities to obtain target values, and dimensionless processing is performed based on the target stoichiometric air-fuel ratio, target wind speed, target mass loss rate of the fuel, and basic physical quantities in the target values to obtain a target ratio; by making the numerical values dimensionless, the data can be scaled to a relatively stable range, reducing the risk of numerical instability and further improving the prediction accuracy. Based on the target ratio, the inclination angle of the flame is determined from the target tunnel cross-sectional width, target fire source size, target specific heat capacity of air, and target fire source release rate in the target values. For a tunnel including side walls and a ceiling, this process takes the tunnel cross-sectional area, tunnel cross-sectional length, and width as important characteristics of the confined space, and combines the fire source parameters, environmental parameters, and the ratio of the vertical flame momentum to the horizontal ventilation air flow momentum during fuel combustion (target ratio) to predict the inclination angle of the flame, improving the prediction accuracy.

[0040] In some embodiments of the present invention, S101 can be implemented through S1011, and the specific description is as follows through the following steps.

[0041] S1011. Balance the chemical equation of the fuel in the oil pool under complete combustion to obtain the balanced chemical equation, and calculate the stoichiometric air-fuel ratio through the stoichiometric constants of the balanced chemical equation and a preset stoichiometric air-fuel ratio formula.

[0042] In some embodiments of the present invention, the chemical equation is as shown in the above formula (1), and for , , Balance to make formula (1) hold. The preset stoichiometric air-fuel ratio formula is as follows:

[0043] (2)

[0044] In the above formula (2), S is the stoichiometric air-fuel ratio of the fuel, representing burning 1 kg of fuel The ratio of the required consumption air quality to the fuel quality.

[0045] Among them, after calculating , , values, substitute , , values into formula (2) to calculate the stoichiometric air-fuel ratio of the fuel.

[0046] It can be understood that in some embodiments of the present invention, the chemical equation of the fuel in the oil pool under complete combustion is balanced, and the stoichiometric air-fuel ratio is calculated through the stoichiometric constants in the balanced chemical equation. Calculating the stoichiometric air-fuel ratio through the chemical equation can fully understand the specific situation of the current tunnel in case of fire, and improve the prediction accuracy of the subsequent inclination angle.

[0047] In some embodiments of the present invention, S102 can be implemented through S1021 to S1022, and is implemented through the following steps.

[0048] S1021. Statistically count the number of basic dimensions included in the parameters by dimension type to obtain the dimension number.

[0049] S1022. Based on the dimension number and the theorem in the dimension analysis method, select the same number of physical quantities as the basic physical quantities, and regard the parameters other than the basic physical quantities in the parameters as the remaining parameters; the basic physical quantities include the air density in the environmental parameters, the environmental temperature, the tunnel cross-section height in the tunnel parameters, and the acceleration of gravity.

[0050] In some embodiments of the present invention, the basic physical quantities include the air density in the environmental parameters, the environmental temperature, the tunnel cross-section height in the tunnel parameters, and the acceleration of gravity. The number of basic dimensions included in the parameters is statistically counted by dimension type to obtain the number of basic dimensions. The π theorem is an important principle in dimension analysis. It states that in a system with n physical quantities, if there are k basic dimensions among them, then k physical quantities can be selected as the basic physical quantities, and the remaining physical quantities can be expressed as functions of these k basic physical quantities. The basic physical quantities can be selected according to the number of basic dimensions statistically obtained previously. The selection of these basic physical quantities needs to meet certain conditions, that is, their dimensions should be able to represent all the basic dimensions respectively, and they should be independent of each other (that is, the dimension of one basic physical quantity cannot be expressed by the combination of the dimensions of other basic physical quantities).

[0051] It can be understood that in some embodiments of the present invention, by counting the number of basic dimensions included in the parameters according to the dimension type, the dimension number is obtained. Based on the dimension number and the theorem in the dimensional analysis method, the same number of physical quantities are selected as the basic physical quantities, which simplifies the complexity of data processing and improves the accuracy of the data processing process.

[0052] In some embodiments of the present invention, the remaining parameters include the tunnel cross-section width in the tunnel parameters, the heat release rate of the fire source, the fire source size, the mass loss rate of the fuel, the fuel stoichiometric number in the fire source parameters, and the specific heat capacity of air in the environmental parameters. S103 can be implemented through S1031 to S1036 and is implemented through the following steps.

[0053] S1031. Determine the target tunnel cross-section width through the tunnel cross-section height, the tunnel cross-section width, and a preset first non-dimensionalization calculation formula.

[0054] In some embodiments of the present invention, the preset first non-dimensionalization calculation formula is as shown in the following formula (3):

[0055] (3)

[0056] In the above formula (3), is the target tunnel cross-section width, is the tunnel cross-section width, H is the tunnel cross-section height.

[0057] S1032. Determine the target wind speed through the wind speed, the acceleration due to gravity, the tunnel cross-section height, and a preset second non-dimensionalization calculation formula.

[0058] In some embodiments of the present invention, the preset second non-dimensionalization calculation formula is as shown in the following formula (4):

[0059] (4)

[0060] In the above formula (4), is the target wind speed, is the wind speed, is the acceleration due to gravity.

[0061] S1033. Determine the target fire source size through the fire source size, the tunnel cross-section height, and a preset third non-dimensionalization calculation formula.

[0062] In some embodiments of the present invention, the preset third non-dimensionalization calculation formula is as shown in the following formula (5):

[0063] (5)

[0064] In the above formula (5), is the target fire source size, is the fire source size.

[0065] S1034. Determine the target air specific heat capacity by using the air specific heat capacity, gravitational acceleration, tunnel cross-section height, ambient temperature, and a preset fourth non-dimensionalization calculation formula.

[0066] In some embodiments of the present invention, the preset fourth non-dimensionalization calculation formula is as shown in (6) below:

[0067] (6)

[0068] In the above formula (6), is the target air specific heat capacity, is the air specific heat capacity, is the ambient temperature.

[0069] S1035. Determine the target mass loss rate of the fuel by using the mass loss rate of the fuel, gravitational acceleration, tunnel cross-section height, air density, and a preset fifth non-dimensionalization calculation formula.

[0070] In some embodiments of the present invention, the preset fifth non-dimensionalization calculation formula is as shown in (7) below:

[0071] (7)

[0072] In formula (7), is the target mass loss rate of the fuel, is the mass loss rate of the fuel, is the air density.

[0073] S1036. Determine the target fire source release rate by using the heat release rate of the fire source, gravitational acceleration, tunnel cross-section height, air density, and a preset sixth non-dimensionalization calculation formula.

[0074] In some embodiments of the present invention, the preset sixth non-dimensionalization calculation formula is as shown in (8) below:

[0075] (8)

[0076] In the above formula (8), is the target heat release rate of the fire source, is the heat release rate of the fire source.

[0077] It can be understood that in some embodiments of the present invention, the remaining parameters include the tunnel cross-section width in the tunnel parameters, the heat release rate of the fire source, the fire source size, the mass loss rate of the fuel, the fuel stoichiometric number in the fire source parameters, and the specific heat capacity of air in the environmental parameters. By performing non-dimensionalization processing on the utilization wind speed, stoichiometric air-fuel ratio, remaining parameters, and basic physical quantities respectively, the target tunnel cross-section width, target wind speed, target fire source size, target specific heat capacity of air, target mass loss rate of the fuel, and target fire source release rate are obtained. By non-dimensionalizing the numerical values, this method can scale the data to a relatively stable range, reduce the risk of numerical instability, and further improve the prediction accuracy.

[0078] In some embodiments of the present invention, the non-dimensionalization processing based on the target stoichiometric air-fuel ratio, target wind speed, target mass loss rate of the fuel, and the basic physical quantities in S104 to obtain the target ratio can be achieved through S104a. The determination of the flame inclination angle based on the target ratio, target tunnel cross-section width, target fire source size, target specific heat capacity of air, and target fire source release rate in the target numerical values in S104 can be achieved through S104A by the following steps.

[0079] S104a: Perform non-dimensionalization processing through the target stoichiometric air-fuel ratio, target wind speed, target mass loss rate of the fuel, air density, gravitational acceleration, and the seventh non-dimensionalization calculation formula in the basic physical quantities to obtain the target ratio.

[0080] In the embodiments of the present invention, the target ratio can be calculated by the following formula (9):

[0081] (9)

[0082] In the above formula (9), is the target ratio, S is the stoichiometric air-fuel ratio, is the air density, is the wind speed, is the gravitational acceleration, is the target mass loss rate of the fuel, is the target wind speed, is the target stoichiometric air-fuel ratio.

[0083] S104A: Determine the inclination angle through the target ratio, target tunnel cross-section width, target fire source size, target specific heat capacity of air, target fire source release rate in the target numerical values, and a preset inclination angle calculation formula.

[0084] In some embodiments of the present invention, the preset inclination angle calculation formula is as shown in the following (10):

[0085] (10) The above formula (10), , , = = , is the ratio of the target heat release rate of the fire source to the specific heat capacity of the target air, W is the width of the tunnel cross-section, is the target tunnel cross-section width, is the target fire source size, is the fire source size, H is the height of the tunnel cross-section, is the target ratio, is the specific heat capacity of the target air, is the target heat release rate of the fire source.

[0086] It can be understood that in some embodiments of the present invention, for a tunnel including side walls and a ceiling, the tunnel cross-sectional area, the tunnel cross-sectional length, and the width are used as important features of the confined space, and the inclination angle of the flame is predicted by combining the target fire source release rate, the target fire source size, the specific heat capacity of the target air, and the ratio of the vertical flame momentum to the horizontal ventilation air flow momentum during fuel combustion (target ratio), improving the accuracy of the prediction.

[0087] In the embodiments of the present invention, Example 1 is the specific process of predicting the inclination angle of the flame when a fire occurs in the tunnel:

[0088] Exemplarily, as Figure 2 shown, Figure 2 is a schematic diagram of the inclination angle of the flame under the influence of a lateral wind in a tunnel provided by an embodiment of the present invention, is the inclination angle of the flame, as Figure 3 shown, Figure 3 is a schematic diagram of the transverse cross-section of a tunnel provided by an embodiment of the present invention. Specifically, Figure 2 and Figure 3 Taking a tunnel with a longitudinal length of 300 m and cross-sectional dimensions of 8 m × 8 m or 9.6 m × 9.6 m shown as an example for analysis. Assuming that an oil pool fire with a heat release rate of 22.6 MW occurs in the tunnel, the oil pool area is 2.4 m × 2.4 m, the fuel of the fire source is n-heptane, the environmental temperature is 20 °C, and four scenarios of longitudinal ventilation wind speeds in the tunnel of 4 m / s, 5 m / s, 6 m / s, and 7 m / s are considered.

[0089] S1: Determine the fuel type of the oil pool and calculate the stoichiometric air-fuel ratio of the fuel by balancing the chemical reaction equation under the condition of complete combustion of the fuel.

[0090] Among them, the chemical formula of n-heptane is C7H16, and the corresponding stoichiometric air-fuel ratio is 15.14.

[0091] S2: Substitute the stoichiometric air-fuel ratio obtained in S1 into formula (9) to calculate the ratio of the vertical flame momentum to the horizontal ventilation air flow momentum during fuel combustion (this ratio is an important parameter affecting the flame tilt angle).

[0092] S3: Obtain the main physical parameters affecting the flame tilt angle of the oil pool fire in the current tunnel, including: the tunnel cross-section height H , the tunnel cross-section width W , the longitudinal ventilation air speed in the tunnel U (m / s), the heat release rate of the fire source Q (kW), the fire source size D (m), the air density (kg / m 3 ), the ambient temperature (K), the specific heat capacity of air (kJ / (K·kg)), the acceleration due to gravity (m / s 2 ), the mass loss rate of the fuel (kg / s), and the fuel combustion and the stoichiometric air-fuel ratio of the fuel S .

[0093] In this embodiment, the statistical results of each parameter are shown in Table 1.

[0094] Table 1 Statistical results of parameters required for calculation

[0095]

[0096] S4: Analyze the dimension types included in the parameters obtained in S3, and count the number of basic dimensions included.

[0097] It can be seen from this that the dimension types included in the above physical parameters are length L, mass M, temperature T, and time t, a total of 4 items.

[0098] S5: Based on the number of dimensions obtained in S4, combined with the π theorem in the dimensional analysis method, select the same number of physical quantities as the basic physical quantities, and the selected basic physical quantities should include all the dimension types in S3.

[0099] Among them, select the air density obtained in S1 , the tunnel height H, the ambient temperature , and the acceleration due to gravity as the basic physical quantities, and their respective dimensions are: ; ; ; 。

[0100] S6: Use the dimensional analysis method to express the remaining parameters obtained in S3 in dimensionless form using the basic physical quantities obtained through formulas (3), (4), (5), (6), (7), and (8).

[0101] S7: Combine the dimensionless parameters obtained in S6 and construct dimensionless numbers that are the same as or approximate to those in S2 through formula (9).

[0102] S8: Deduct the dimensionless parameters involved in the combination of S7 from S6 and use the remaining dimensionless parameters as the correction items for reflecting the spatial confinement effect of the reaction tunnel. Among them, the items for correction include formulas (3), (5), and formula (8).

[0103] S9: Use numerical simulation or combustion test methods to obtain the flame inclination angles under different heat source powers, different ventilation wind speeds, and different tunnel cross-section forms, and use the fitting method to determine the flame inclination angle prediction method with the momentum ratio given in S2 and the correction items given in S8 as the main parameters. Among them, the inclination angle prediction formula finally determined by combining numerical simulation and experimental methods is the above formula (10).

[0104] Substituting each parameter into the above calculation formula can predict the flame inclination angle under given conditions:

[0105] U = 4 m / s:

[0106] ;

[0107] U = 5 m / s:

[0108] ;

[0109] U = 6 m / s:

[0110] ;

[0111] U = 7 m / s:

[0112] ;

[0113] ( W = 8 m) ( W = 9.6 m)

[0114] ( W = 8 m): ;

[0115] ( W = 9.6 m): ;

[0116] When the tunnel area is 8 m × 8 m:

[0117] U When = 4 m / s, , U When = 5 m / s, , When, , U When = 7 m / s, .

[0118] When the tunnel area is 9.6 m × 9.6 m:

[0119] U When = 4 m / s, , U When = 5 m / s, , U When = 6 m / s, , U When = 7 m / s, .

[0120] Figure 4 This is a schematic diagram showing the comparison result of the flame inclination angle obtained by the numerical calculation provided in the embodiment of the present invention and the prediction of the method of the present invention. In order to verify the method of the present invention, a tunnel fire model in the example was established using the fire dynamics simulation software FDS, and the flame inclination angle within the range of longitudinal wind speed from 4 to 7 m / s was analyzed through the post-processing method. As Figure 4 is known, the maximum difference between the two is only 7%.

[0121] Referring to Figure 5 , a schematic diagram of the structure of an electronic device according to an embodiment of the present invention is shown. The specific implementation of the electronic device is not limited in the specific embodiment of the present invention.

[0122] As Figure 5 shown, the electronic device may include: a processor 502, a communication interface 504, a memory 506, and a communication bus 508.

[0123] Among them:

[0124] The processor 502, the communication interface 504, and the memory 506 communicate with each other through the communication bus 508.

[0125] A communication interface 504 for communicating with other electronic devices or servers.

[0126] A processor 502 for executing a program 510, and specifically can execute relevant steps in the above method embodiments.

[0127] Specifically, the program 510 may include program code, and this program code includes computer operation instructions.

[0128] The processor 502 may be a central processing unit (CPU), or a specific integrated circuit (ASIC, Application Specific Integrated Circuit), or one or more integrated circuits configured to implement the embodiments of the present invention. One or more processors included in the intelligent device may be of the same type of processor, such as one or more CPUs; or may be of different types of processors, such as one or more CPUs and one or more ASICs.

[0129] A memory 506 for storing the program 510. The memory 506 may include a high-speed RAM memory, and may also include a non-volatile memory, such as at least one disk memory.

[0130] The program 510 is specifically used to cause the processor 502 to execute the operations corresponding to the methods described in the above method embodiments.

[0131] For the specific implementation of each step in the program 510, reference may be made to the corresponding steps and descriptions in the above method embodiments, which will not be elaborated here. Those skilled in the art can clearly understand that for the convenience and brevity of description, the specific working processes of the above-described devices and modules can refer to the corresponding process descriptions in the foregoing method embodiments, which will not be elaborated here.

[0132] It should be noted that according to the needs of implementation, each component / step described in the embodiments of the present invention can be split into more components / steps, or two or more components / steps or partial operations of components / steps can be combined into new components / steps to achieve the purpose of the embodiments of the present invention.

[0133] The method according to the embodiments of the present invention can be implemented in hardware, firmware, or be implemented as software or computer code that can be stored in a recording medium (such as a CD ROM, RAM, floppy disk, hard disk, or magneto-optical disk), or be implemented as computer code that is originally stored in a remote recording medium or a non-transitory machine-readable medium and downloaded through a network and will be stored in a local recording medium, so that the method described herein can be stored in such software processing on a recording medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware (such as an ASIC or FPGA). It can be understood that a computer, a processor, a microprocessor controller, or programmable hardware includes a storage component (such as RAM, ROM, flash memory, etc.) that can store or receive software or computer code, and when the software or computer code is accessed and executed by the computer, the processor, or the hardware, the method described herein is implemented. In addition, when a general-purpose computer accesses the code for implementing the method shown herein, the execution of the code converts the general-purpose computer into a dedicated computer for executing the method shown herein.

[0134] Those of ordinary skill in the art can realize that the units and method steps of each example described in combination with the embodiments disclosed herein can be implemented in electronic hardware, or in a combination of computer software and electronic hardware. Whether these functions are executed in a hardware or software manner depends on the specific application and design constraints of the technical solution. A professional person can use different methods to implement the described functions for each specific application, but such implementation should not be considered to exceed the scope of the embodiments of the present invention.

[0135] The above embodiments are only used to illustrate the embodiments of the present invention, rather than to limit the embodiments of the present invention. Those of ordinary skill in the relevant technical field can also make various changes and modifications without departing from the spirit and scope of the embodiments of the present invention. Therefore, all equivalent technical solutions also belong to the scope of the embodiments of the present invention. The patent protection scope of the embodiments of the present invention shall be defined by the claims.

Claims

1. A method for predicting the flame inclination angle, characterized in that, including: When a pool fire occurs in the current tunnel, obtaining the stoichiometric air-fuel ratio of the fuel through the chemical equation of the fuel in the pool under complete combustion; Based on the dimension types included in the parameters, dividing the parameters to obtain basic physical quantities and remaining parameters; the parameters include tunnel parameters, the wind speed of longitudinal ventilation in the tunnel, environmental parameters during a pool fire, and fire source parameters; Performing non-dimensionalization processing on the wind speed, the stoichiometric air-fuel ratio, and the remaining parameters respectively with the basic physical quantities to obtain target values; Based on the target stoichiometric air-fuel ratio, target wind speed, mass loss rate of the target fuel, and the basic physical quantities in the target values, performing non-dimensionalization processing to obtain a target ratio; Determining the inclination angle through the target ratio, the target tunnel cross-section width, target fire source size, target specific heat capacity of air, target fire source heat release rate in the target values, and a preset inclination angle calculation formula; where the preset inclination angle calculation formula is: ； Among them, , ， ， In the above formula, is the ratio of the target heat release rate of the fire source and the target specific heat capacity of air, W is the width of the tunnel cross-section, is the target tunnel cross-section width, is the target fire source size, is the fire source size, H is the height of the tunnel cross-section, is the target ratio, is the target specific heat capacity of air, is the target heat release rate of the fire source.

2. The method according to claim 1, wherein The obtaining the stoichiometric air-fuel ratio of the fuel through the chemical equation of the fuel in the pool under complete combustion includes: Balancing the chemical equation of the fuel in the pool under complete combustion to obtain a balanced chemical equation, and calculating the stoichiometric air-fuel ratio through the stoichiometric constants of the balanced chemical equation and a preset stoichiometric air-fuel ratio formula; where the chemical equation is: ； wherein, , , are the stoichiometric constants of the balanced chemical equation; The preset stoichiometric air-fuel ratio formula is: ； In the formula, S is the stoichiometric air-fuel ratio, representing the ratio of the mass of air required for burning 1 kg of fuel to the mass of the fuel.

3. The method according to claim 1, wherein The based on the dimension types included in the parameters, dividing the parameters to obtain basic physical quantities and remaining parameters includes: Counting the number of basic dimensions included in the parameters through the dimension types to obtain the dimension number; Based on the dimensional quantity and in the dimensional analysis method The theorem selects the same number of physical quantities as the basic physical quantities, and in the parameters, the parameters other than the basic physical quantities are used as the remaining parameters; the basic physical quantities include the air density in the environmental parameters, the environmental temperature, the tunnel cross-section height in the tunnel parameters, and the acceleration of gravity.

4. The method according to claim 3, wherein The remaining parameters include the tunnel cross-section width in the tunnel parameters, the fire source heat release rate, fire source size, mass loss rate of the fuel, fuel stoichiometric number in the fire source parameters, and the specific heat capacity of air in the environmental parameters; The performing non-dimensionalization processing on the wind speed, the stoichiometric air-fuel ratio, and the remaining parameters respectively with the basic physical quantities to obtain target values includes: Determining the target tunnel cross-section width through the tunnel cross-section height, the tunnel cross-section width, and a preset first non-dimensionalization calculation formula; Determining the target wind speed through the wind speed, the acceleration of gravity, the tunnel cross-section height, and a preset second non-dimensionalization calculation formula; Determining the target fire source size through the fire source size, the tunnel cross-section height, and a preset third non-dimensionalization calculation formula; Using the specific heat capacity of air, the acceleration of gravity, the tunnel cross-section height, the environmental temperature, and a preset fourth non-dimensionalization calculation formula to determine the target specific heat capacity of air; Using the mass loss rate of the fuel, the acceleration of gravity, the tunnel cross-section height, the air density, and a preset fifth non-dimensionalization calculation formula to determine the target mass loss rate of the fuel; Determining the target fire source heat release rate through the fire source heat release rate, the acceleration of gravity, the tunnel cross-section height, the air density, and a preset sixth non-dimensionalization calculation formula.

5. The method according to claim 4, wherein: The first dimensionless calculation formula is as follows: ; The second non-dimensionalization calculation formula is as follows: ; In the formula, is the target wind speed, is the wind speed, is the acceleration due to gravity; The third dimensionless calculation formula is as follows: ; The fourth non-dimensionalization calculation formula is as follows: ; In the formula, is the specific heat capacity of the air, is the ambient temperature; The fifth dimensionless calculation formula is as follows: ; In the formula, is the mass loss rate of the target fuel, is the mass loss rate of the fuel, is the air density; The sixth dimensionless calculation formula is as follows: ; In the formula, is the heat release rate of the fire source.

6. The method according to claim 5, characterized in that, The dimensionless processing based on the target stoichiometric air-fuel ratio, target wind speed, mass loss rate of the target fuel, and the basic physical quantities in the target values to obtain a target ratio includes: Performing dimensionless processing through the target stoichiometric air-fuel ratio, the target wind speed, the mass loss rate of the target fuel, the air density, gravitational acceleration among the basic physical quantities, and a preset seventh dimensionless calculation formula to obtain the target ratio; wherein, the seventh dimensionless calculation formula is: ； In the formula, S is the stoichiometric air-fuel ratio, is the target stoichiometric air-fuel ratio.

7. The method according to any one of claims 1 to 6, characterized in that, The inclination angle is the angle between the line connecting the fire source center point and the fire source end point and the vertical direction. The fuel is a pure liquid hydrocarbon fuel. The wind speed is greater than the critical ventilation wind speed. The shape of the fire source in the current tunnel is square. The fire source is located on the tunnel center line. The cross-section form of the current tunnel is rectangular. The current tunnel includes side walls and a ceiling.

8. An electronic device, comprising: A processor, a memory, a communication interface, and a communication bus. The processor, the memory, and the communication interface complete communication with each other through the communication bus; The memory is used to store at least one executable instruction, and the executable instruction causes the processor to perform the operations corresponding to the method according to any one of claims 1-7.

9. A computer storage medium, on which a computer program is stored, and when the program is executed by a processor, it implements the method according to any one of claims 1-7.

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