Flame inclination angle prediction method, electronic equipment and storage medium

Abstract

The invention discloses a flame inclination angle prediction method, electronic equipment and a storage medium, and the method comprises the steps: obtaining a stoichiometric air-fuel ratio of fuel through a chemical equation of the fuel of an oil pool under a complete combustion condition when the oil pool fire occurs in a current tunnel; performing parameter division based on dimension types included in the parameters to obtain basic physical quantities and residual parameters; the wind speed, the stoichiometric air-fuel ratio, the remaining parameters and the basic physical quantity are subjected to dimensionless processing, and target numerical values are obtained; non-dimensionalization processing is conducted on the basis of the target stoichiometric air-fuel ratio, the target wind speed, the mass loss rate of the target fuel and the basic physical quantity in the target numerical value, and a target ratio is obtained; and determining the inclination angle of the flame based on the target ratio, the target tunnel section width in the target value, the target fire source size, the target air specific heat capacity and the target fire source release rate. The flame inclination angle can be accurately predicted under the condition that the tunnel space effect is considered.

Description

Technical Field

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

[0002] Oil pool fires in tunnels are mostly caused by traffic accidents involving fuel transport vehicles in tunnels. This type of fire has the characteristics of high combustion power and difficulty in extinguishing, and is an important focus of tunnel fire safety design. Current tunnel fire protection design generally uses longitudinal ventilation to control smoke in tunnel fires. When the tunnel ventilation wind speed is greater than the critical ventilation wind speed of the fire, all smoke will flow toward the downstream of the fire source. At this time, it is of great value to accurately predict the inclination of the flame, because the inclination of the flame at this time can be used to assist in determining the maximum temperature of the tunnel ceiling and its specific location, which can then help determine the structural damage range of the tunnel fire and help optimize the layout of fire protection measures such as water spray.

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

[0004] Therefore, how to accurately predict the flame inclination angle while considering the space limitation effect of the tunnel becomes an urgent problem to be solved. Summary of the invention

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

[0006] According to a first aspect of an embodiment of the present invention, a flame inclination angle prediction method is provided, comprising:

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

[0008] Parameters are divided based on the dimension types contained in the parameters to obtain basic physical quantities and residual parameters; the parameters include tunnel parameters, wind speed of longitudinal ventilation in the tunnel, environmental parameters during oil pool fire, and fire source parameters;

[0009] The wind speed, the stoichiometric air-fuel ratio, the remaining parameters and the basic physical quantity are respectively dimensionally processed to obtain a target value;

[0010] A target ratio is obtained based on the target stoichiometric air-fuel ratio, target wind speed, target fuel mass loss rate and the basic physical quantities in the target values; and the inclination of the flame is determined based on the target ratio, the target tunnel section width, the target fire source size, the target air specific heat capacity and the target fire source release rate in the target values.

[0011] According to a second aspect of an embodiment of the present invention, there is provided an electronic device, comprising: a processor, a memory, a communication interface and a communication bus, wherein the processor, the memory and the communication interface communicate with each other via the communication bus; the memory is used to store at least one executable instruction, wherein the executable instruction enables the processor to perform an operation corresponding to the method described in the first aspect.

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

[0013] According to the scheme provided by the embodiment 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 the parameters are divided based on the dimension type contained in the parameters to obtain basic physical quantities and residual parameters; the parameters include tunnel parameters, 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 in multiple parameters, the complexity of data processing is simplified, and the prediction results of the subsequent flame inclination angle are improved. The wind speed, stoichiometric air-fuel ratio, and residual parameters are dimensionally processed with the basic physical quantities respectively to obtain the target numerical value, and the target stoichiometric air-fuel ratio, target wind speed, target fuel mass loss rate, and basic physical quantities in the target numerical value are dimensionally processed to obtain the target ratio; by dimensionally processing the numerical value, the data can be scaled to a relatively stable range, reducing the risk of numerical instability and further improving the accuracy of the prediction. And based on the target ratio, the target tunnel section width, target fire source size, target air specific heat capacity, and target fire source release rate in the target numerical value determine the flame inclination angle. For tunnels containing side walls and ceilings, this process takes the tunnel cross-sectional area and the tunnel cross-sectional length and width as important characteristics of the confined space, and predicts the flame inclination angle by combining the fire source parameters, environmental parameters, and the ratio of the vertical flame momentum to the horizontal ventilation wind flow momentum during fuel combustion (target ratio), so that the flame inclination angle is accurately predicted while considering the tunnel space effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative work, among which:

[0015] Figure 1 A schematic diagram of a flame inclination angle prediction method provided by an embodiment of the present invention;

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

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

[0018] Figure 4 A schematic diagram showing the effect of comparing the flame inclination angle obtained by numerical calculation and prediction by the method of the present invention provided in an embodiment of the present invention;

[0019] Figure 5 The present invention is a schematic diagram of the structure of an electronic device provided according to an embodiment of the present invention. DETAILED DESCRIPTION

[0020] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. The following embodiments are used to illustrate the present invention, but are not used to limit the scope of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within 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, but it will be understood that “some embodiments” may be the same subset or different subsets of all possible embodiments and may be combined with each other without conflict.

[0022] It should be pointed out 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 ordering of the objects. It can be understood that "first\second\third" can be interchanged in a specific order or sequence where 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] It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as those generally understood by those skilled in the art in the field to which the embodiments of the present invention belong. It should also be understood that terms such as those defined in general dictionaries should be understood to have meanings consistent with those in the context of the prior art, and will not be interpreted with idealized or overly formal meanings unless specifically defined as here.

[0024] Figure 1 The present invention provides a flowchart of a flame inclination angle prediction method according to an embodiment of the present invention. The flame inclination angle prediction method according to an embodiment of the present invention can be executed by an electronic device, such as a computer, a server, etc.

[0025] like Figure 1 As shown, the flame inclination angle prediction method includes:

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

[0027] In an embodiment of the present invention, the fuel of the oil pool is mainly used to generate heat and flames. The fuel of the oil pool is mainly liquid fuel, including hydrocarbon fuel and alcohol fuel. 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 burn. The mass ratio of air to fuel at this time is called the stoichiometric air-fuel ratio. First determine the combustion type of the oil pool, and then obtain the corresponding chemical equation when the fuel in the oil pool is completely burned, as shown in the following formula (1):

[0028]

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

[0030] In the embodiment of the present invention, the cross-section of the current tunnel is rectangular or oblong, the fuel of the oil pool fire is pure liquid hydrocarbon fuel, the fire source of the current tunnel is square, and the fire source is located at the center line of the tunnel.

[0031] S102. Parameters are divided based on the dimension types contained in the parameters to obtain basic physical quantities and remaining parameters; the parameters include tunnel parameters, wind speed of longitudinal ventilation in the tunnel, environmental parameters during oil pool fire, and fire source parameters.

[0032] In an embodiment of the present invention, the dimension type includes basic dimensions and derived dimensions. Basic dimensions, that is, basic physical quantities, refer to physical quantities with independent dimensions in the International System of Units (SI). Derived dimensions refer to physical quantities whose dimensions can be expressed as a combination of basic dimensions. The dimensions of derived quantities can be expressed by the power product of basic quantities. The basic physical quantities can be determined by clarifying the basic physical quantities, identifying the dimensions of the parameters, classifying the parameters according to their dimensional types, and directly extracting those parameters that directly correspond to the basic physical quantities from the classified parameters. These parameters are the basic physical quantities to be found, etc. 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 the 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 current longitudinal ventilation of the tunnel is greater than the critical ventilation wind speed in the tunnel.

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

[0035] In the embodiment of the present invention, dimensionless processing is to convert physical quantities with units (such as meters, seconds, kilograms, etc.) into pure numbers without units through certain mathematical transformations. The target value is a plurality of values, and the wind speed, stoichiometric air-fuel ratio, residual parameters and basic physical quantities can be respectively subjected to ratio calculations to achieve the purpose of dimensionless processing and obtain a target value containing a plurality of values.

[0036] S104. Dimensionally non-dimensionalizing the target stoichiometric air-fuel ratio, target wind speed, target fuel mass loss rate, and basic physical quantities in the target numerical values ​​to obtain a target ratio; and determining the inclination of the flame based on the target ratio, the target tunnel section width, target fire source size, target air specific heat capacity, and target fire source release rate in the target numerical values.

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

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

[0039] It can be understood that in the embodiment 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 the parameters are divided based on the dimension type contained in the parameters to obtain basic physical quantities and residual parameters; the parameters include tunnel parameters, 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 in multiple parameters, the complexity of data processing is simplified, and the prediction results of the subsequent flame inclination angle are improved. The wind speed, stoichiometric air-fuel ratio, and residual parameters are respectively processed dimensionlessly with the basic physical quantities to obtain the target values, and the target stoichiometric air-fuel ratio, target wind speed, target fuel mass loss rate, and basic physical quantities in the target values ​​are processed dimensionlessly to obtain the target ratio; by processing the values ​​dimensionlessly, the data can be scaled to a relatively stable range, reducing the risk of numerical instability and further improving the accuracy of the prediction. Based on the target ratio, the target tunnel section width, target fire source size, target air specific heat capacity, and target fire source release rate in the target values ​​determine the flame inclination angle. For tunnels containing side walls and ceilings, this process takes the tunnel cross-sectional area and the 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 wind flow momentum during fuel combustion (target ratio) to predict the flame inclination, thereby improving the prediction accuracy.

[0040] In some embodiments of the present invention, S101 can be implemented by S1011, which is specifically described by the following steps.

[0041] S1011. Balancing the chemical equation of the fuel in the oil pool under complete combustion conditions to obtain a balanced chemical equation, and calculating the stoichiometric air-fuel ratio using the stoichiometric constant 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 x, y, and z are balanced so that formula (1) is established. The preset stoichiometric air-fuel ratio formula is as follows:

[0043]

[0044] In the above formula (2), S is the stoichiometric air-fuel ratio of the fuel, which represents the combustion of 1 kg of fuel C x H y O z The ratio of the mass of air consumed to the mass of fuel required.

[0045] After the values ​​of x, y, and z are calculated, the values ​​of x, y, and z are substituted into formula (2) to calculate the stoichiometric air-fuel ratio of the fuel.

[0046] It is understandable 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 by the stoichiometric constant in the balanced chemical equation. By calculating the stoichiometric air-fuel ratio through the chemical equation, the specific situation of the current tunnel under fire can be fully understood, and the prediction accuracy of the subsequent inclination angle is improved.

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

[0048] S1021. Count the number of basic dimensions included in the parameter by dimension type to obtain the number of dimensions.

[0049] S1022. Based on dimensional quantity and the π theorem in the dimensional analysis method, the same number of physical quantities are selected as basic physical quantities, and the parameters other than the basic physical quantities are used as remaining parameters in the parameters; the basic physical quantities include air density and ambient temperature in the environmental parameters, and tunnel section height and gravitational acceleration in the tunnel parameters.

[0050] In some embodiments of the present invention, the basic physical quantities include air density and ambient temperature in environmental parameters, and tunnel section height and gravitational acceleration in tunnel parameters. The number of basic dimensions contained in the parameters is statistically analyzed by dimensional type to obtain the number of basic dimensions. The π theorem is an important principle in dimensional analysis, which points out that in a system with n physical quantities, if there are k basic dimensions, then k physical quantities can be selected as 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 obtained by the previous statistics. 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 a basic physical quantity cannot be represented by a combination of the dimensions of other basic physical quantities).

[0051] It can be understood that in some embodiments of the present invention, the number of basic dimensions contained in the parameters is counted by dimensional type to obtain dimensional quantity, and the same number of physical quantities are selected as basic physical quantities based on the dimensional quantity and the π theorem in the dimensional analysis method, 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 tunnel section width in tunnel parameters, fire source heat release rate, fire source size, fuel mass loss rate, fuel stoichiometric number in fire source parameters, and air specific heat capacity in environmental parameters. S103 can be implemented through S1031 to S1036, and is implemented through the following steps.

[0053] S1031. Determine a target tunnel section width by using the tunnel section height, the tunnel section width and a preset first dimensionless calculation formula.

[0054] In some embodiments of the present invention, the preset first dimensionless calculation formula is as follows (3):

[0055]

[0056] In the above formula (3), W * is the target tunnel section width, W is the tunnel section width, and H is the tunnel section height.

[0057] S1032. Determine the target wind speed by using the wind speed, gravity acceleration, tunnel section height and a preset second dimensionless calculation formula.

[0058] In some embodiments of the present invention, the preset second dimensionless calculation formula is as shown below (4):

[0059]

[0060] In the above formula (4), U * is the target wind speed, U is the wind speed, and g is the acceleration of gravity.

[0061] S1033. Determine the target fire source size by using the fire source size, tunnel section height and a preset third dimensionless calculation formula.

[0062] In some embodiments of the present invention, the preset third dimensionless calculation formula is as follows (5):

[0063]

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

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

[0066] In some embodiments of the present invention, the preset fourth dimensionless calculation formula is shown as follows (6):

[0067]

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

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

[0070] In some embodiments of the present invention, the preset fifth dimensionless calculation formula is as follows (7):

[0071]

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

[0073] S1036. Determine the target fire source release rate through the fire source heat release rate, gravity acceleration, tunnel section height, air density and the preset sixth dimensionless calculation formula.

[0074] In some embodiments of the present invention, the preset sixth dimensionless calculation formula is as follows (8):

[0075]

[0076] In the above formula (8), Q * is the target fire source size, and Q 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 section width in the tunnel parameters, the fire source heat release rate, fire source size, fuel mass loss rate, fuel stoichiometric number in the fire source parameters, and the air specific heat capacity in the environmental parameters. The wind speed, stoichiometric air-fuel ratio, and the remaining parameters are dimensionally processed with the basic physical quantities to obtain the target tunnel section width, target wind speed, target fire source size, target air specific heat capacity, target fuel mass loss rate, and target fire source release rate. This method can scale the data to a relatively stable range by dimensionlessly converting the numerical values, reducing the risk of numerical instability, and further improving the accuracy of the prediction.

[0078] In some embodiments of the present invention, the target stoichiometric air-fuel ratio, target wind speed, target fuel mass loss rate and the basic physical quantity in the target values ​​are dimensionlessly processed to obtain the target ratio in S104a, and the inclination of the flame based on the target ratio, the target tunnel section width, target fire source size, target air specific heat capacity and target fire source release rate in S104 can be determined by S104A through the following steps.

[0079] S104a, performing dimensionless processing on the target stoichiometric air-fuel ratio, the target wind speed, the target fuel mass loss rate, the air density among the basic physical quantities, the gravitational acceleration and the seventh dimensionless calculation formula to obtain a target ratio.

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

[0081]

[0082] In the above formula (9), is the target ratio, S is the stoichiometric air-fuel ratio, p a is the air density, U is the wind speed, g is the acceleration due to gravity, is the mass loss rate of the target fuel, U * is the target wind speed, S * is the target stoichiometric air-fuel ratio.

[0083] S104A, determining the inclination angle through the target ratio, the target tunnel section width in the target value, the target fire source size, the target air specific heat capacity, the target fire source release rate and a preset inclination angle calculation formula.

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

[0085]

[0086] In the above formula (10), is the target ratio.

[0087] 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, tunnel cross-sectional length and width are used as important characteristics of the confined space, and the inclination angle of the flame is predicted in combination with the target fire source release rate, target fire source size, target air specific heat capacity, and the ratio of the vertical flame momentum to the lateral ventilation wind flow momentum during fuel combustion (target ratio), thereby improving the accuracy of the prediction.

[0088] In the embodiment of the present invention, Example 1 is a specific process of predicting the flame inclination angle when a fire occurs in a tunnel:

[0089] For example, Figure 2 As shown, Figure 2 A schematic diagram of the flame inclination effect under the influence of lateral wind in a tunnel provided by an embodiment of the present invention, θ is the flame inclination angle, such as Figure 3 As shown, Figure 3 A schematic diagram of a tunnel cross-section effect provided by an embodiment of the present invention. Specifically, Figure 2 and Figure 3 A tunnel with a longitudinal length of 300m and a cross-sectional size of 8m×8m or 9.6m×9.6m is shown as an example for analysis. Assuming that an oil pool fire with a heat release rate of 22.6MW occurs in the tunnel, the oil pool area is 2.4m×2.4m, the fire source fuel is n-heptane, and the ambient temperature is 20℃, four scenarios are now considered: tunnel longitudinal ventilation wind speed of 4m / s, 5m / s, 6m / s and 7m / s.

[0090] S1: Determine the sump fuel type and calculate the stoichiometric air-fuel ratio of the fuel by balancing the chemical reaction equation for complete combustion of the fuel.

[0091] Among them, the chemical formula of n-heptane is C7H16, and the corresponding stoichiometric air-fuel ratio is 15.14.

[0092] 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 wind momentum during fuel combustion (this ratio is an important parameter affecting the flame inclination angle).

[0093] S3: Obtain the main physical parameters that affect the flame inclination of the oil pool fire in the current tunnel, including: tunnel section height H, tunnel section width W, tunnel longitudinal ventilation wind speed U (m / s), fire source heat release rate Q (kW), fire source size D (m), air density ρ a (kg / m 3 ), ambient temperature T a (K), specific heat capacity of air c p (kJ / (K·kg)), gravitational acceleration g(m / s 2 ), fuel mass loss rate (kg / s) and the stoichiometric air-fuel ratio S of the fuel combustion and the fuel.

[0094] In this embodiment, the statistical results of various parameters are shown in Table 1.

[0095] Table 1 Statistics of parameters required for calculation

[0096]

[0097] S4: Analyze and count the dimension types contained in the parameters obtained in S3, and count the number of basic dimensions contained.

[0098] From this, we can see 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.

[0099] S5: Based on the number of dimensions obtained in S4 and the π theorem in the dimensional analysis method, select the same number of physical quantities as basic physical quantities, and the selected basic physical quantities should include all dimensional types in S3.

[0100] Among them, the air density ρ obtained in S1 is selected a , tunnel height H, ambient temperature T a And gravitational acceleration g are basic physical quantities, and their dimensions are: ρ a =ML -3 ; H=L; T a =T; g = Lt -2 .

[0101] 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).

[0102] S7: Combine the dimensionless parameters obtained in S6 and construct a dimensionless number that is the same or similar to that in S2 through formula (9).

[0103] S8: Deduct the dimensionless parameters involved in the combination of S7 from S6, and use the remaining dimensionless parameters as correction items for the spatial confinement effect of the reaction tunnel. The items used for correction include formula (3), (5) and formula (8).

[0104] S9: numerical simulation or combustion test method is used to obtain the flame inclination angle under different fire source power, different ventilation wind speed and different tunnel cross-section conditions, and a fitting method is used to determine the flame inclination angle prediction method with the momentum ratio given by S2 and the correction item given by S8 as the main parameters. Among them, the inclination angle prediction formula finally determined by numerical simulation combined with experimental method is the above formula (10).

[0105] Substituting each parameter into the above calculation formula can predict the flame inclination angle under given conditions:

[0106] U=4m / s:

[0107]

[0108] U=5m / s:

[0109]

[0110] U=6m / s:

[0111]

[0112] U=7m / s:

[0113]

[0114]

[0115]

[0116]

[0117] When the tunnel area is 8m×8m:

[0118] When U=4m / s, cosθ1=0.31, when U=5m / s, cosθ1=0.27, when U=6m / s,

[0119] cosθ1=0.22, when U=7m / s, cosθ1=0.19.

[0120] When the tunnel area is 9.6m×9.6m:

[0121] When U=4m / s, cosθ1=0.32, when U=5m / s, cosθ1=0.28, when U=6m / s,

[0122] cosθ1=0.25, when U=7m / s, cosθ1=0.19.

[0123] Figure 4 The figure is a schematic diagram showing the effect of comparing the flame inclination angle obtained by numerical calculation and prediction by the method of the present invention provided in the embodiment of the present invention. In order to verify the method of the present invention, the fire dynamics simulation software FDS is used to establish the tunnel fire model in the example, and the flame inclination angle in the longitudinal wind speed range of 4-7m / s is analyzed by the post-processing method. Figure 4 As far as we know, the maximum difference between the two is only 7%.

[0124] Reference Figure 5 , shows a schematic diagram of the structure of an electronic device according to an embodiment of the present invention. The specific embodiment of the present invention does not limit the specific implementation of the electronic device.

[0125] like Figure 5As shown, the electronic device may include: a processor (processor) 502, a communication interface (Communications Interface 504, a memory (memory) 506, and a communication bus 508.

[0126] in:

[0127] The processor 502 , the communication interface 504 , and the memory 506 communicate with each other via a communication bus 508 .

[0128] The communication interface 504 is used to communicate with other electronic devices or servers.

[0129] The processor 502 is used to execute the program 510, and specifically can execute the relevant steps in the above method embodiment.

[0130] Specifically, the program 510 may include program codes, which include computer operation instructions.

[0131] The processor 502 may be a central processing unit (CPU), or an application-specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present invention. The one or more processors included in the smart device may be processors of the same type, such as one or more CPUs; or processors of different types, such as one or more CPUs and one or more ASICs.

[0132] The memory 506 is used to store the program 510. The memory 506 may include a high-speed RAM memory, and may also include a non-volatile memory (non-volatile memory), such as at least one disk memory.

[0133] The program 510 may be specifically used to enable the processor 502 to execute operations corresponding to the methods described in the above method embodiments.

[0134] The specific implementation of each step in program 510 can refer to the corresponding description of the corresponding steps and units in the above method embodiment, which will not be repeated here. Those skilled in the art can clearly understand that for the convenience and simplicity of description, the specific working process of the above-described devices and modules can refer to the corresponding process description in the above method embodiment, which will not be repeated here.

[0135] It should be pointed out that, according to the needs of implementation, the various components / steps 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.

[0136] The above-described method according to an embodiment of the present invention may be implemented in hardware, firmware, or as software or computer code that may be stored in a recording medium (such as a CD ROM, RAM, floppy disk, hard disk, or magneto-optical disk), or as computer code that is originally stored in a remote recording medium or a non-temporary machine-readable medium downloaded over a network and will be stored in a local recording medium, so that the method described herein may 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 is understood that a computer, processor, microprocessor controller, or programmable hardware includes a storage component (e.g., 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 a computer, processor, or 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.

[0137] Those of ordinary skill in the art will appreciate that the units and method steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of the embodiments of the present invention.

[0138] The above implementation methods are only used to illustrate the embodiments of the present invention, and are not limitations of the embodiments of the present invention. Ordinary technicians in the relevant technical field may 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 should be defined by the claims.

Claims

1. A flame inclination angle prediction method, characterized in that: include: When an oil pool fire occurs in the current tunnel, the stoichiometric air-fuel ratio of the fuel is obtained through a chemical equation of the fuel in the oil pool under complete combustion; Parameters are divided based on the dimension types contained in the parameters to obtain basic physical quantities and residual parameters; the parameters include tunnel parameters, wind speed of longitudinal ventilation in the tunnel, environmental parameters during oil pool fire, and fire source parameters; The wind speed, the stoichiometric air-fuel ratio, the remaining parameters and the basic physical quantity are respectively dimensionally processed to obtain a target value; Performing dimensionless processing based on the target stoichiometric air-fuel ratio, the target wind speed, the target fuel mass loss rate and the basic physical quantity in the target numerical value to obtain a target ratio; The inclination angle of the flame is determined based on the target ratio, the target tunnel section width in the target values, the target fire source size, the target air specific heat capacity, and the target fire source release rate.

2. The method according to claim 1, characterized in that The step of obtaining the stoichiometric air-fuel ratio of the fuel by using the chemical equation of the fuel in the oil pool under the condition of complete combustion includes: The chemical equation of the fuel in the oil pool under complete combustion is balanced to obtain a balanced chemical equation, and the stoichiometric air-fuel ratio is calculated by the stoichiometric constant of the balanced chemical equation and a preset stoichiometric air-fuel ratio formula; wherein the chemical equation is: Wherein, x, y, z are the stoichiometric constants of the balanced chemical equation; The preset stoichiometric air-fuel ratio formula is: Where S is the stoichiometric air-fuel ratio, representing the combustion of 1 kg of fuel C x H y O z The ratio of the mass of air consumed to the mass of fuel required.

3. The method according to claim 1, characterized in that The parameter division is performed based on the dimension type contained in the parameter to obtain basic physical quantities and remaining parameters, including: Counting the number of basic dimensions included in the parameter by the dimension type to obtain the dimension quantity; Based on the dimensional quantity and the π theorem in the dimensional analysis method, the same number of physical quantities are selected as the basic physical quantities, and the parameters other than the basic physical quantities in the parameters are used as the remaining parameters; the basic physical quantities include air density and ambient temperature in the environmental parameters, and tunnel section height and gravitational acceleration in the tunnel parameters.

4. The method according to claim 1, characterized in that: The remaining parameters include the tunnel section width in the tunnel parameters, the fire source heat release rate, fire source size, fuel mass loss rate, fuel stoichiometric number in the fire source parameters, and the air specific heat capacity in the environmental parameters; The step of performing dimensionless processing on the wind speed, the stoichiometric air-fuel ratio, the remaining parameters and the basic physical quantity to obtain a target value includes: Determining the target tunnel section width by using the tunnel section height, the tunnel section width and a preset first dimensionless calculation formula; Determining the target wind speed by using the wind speed, the gravitational acceleration, the tunnel section height and a preset second dimensionless calculation formula; Determining the target fire source size by using the fire source size, the tunnel section height and a preset third dimensionless calculation formula; Determine the target air specific heat capacity using the air specific heat capacity, the gravitational acceleration, the tunnel section height, the ambient temperature and a preset fourth dimensionless calculation formula; Determine the mass loss rate of the target fuel by using the mass loss rate of the fuel, the gravitational acceleration, the tunnel section height, the air density and a preset fifth dimensionless calculation formula; The target fire source release rate is determined by the fire source heat release rate, the gravitational acceleration, the tunnel section height, the air density and a preset sixth dimensionless calculation formula.

5. The method according to claim 4, characterized in that The first dimensionless calculation formula is: Where W * is the target tunnel section width, W is the tunnel section width, and H is the tunnel section height; The second dimensionless calculation formula is: Where U * is the target wind speed, U is the wind speed, and g is the gravitational acceleration; The third dimensionless calculation formula is: Where D * is the target fire source size, and D is the fire source size; The fourth dimensionless calculation formula is: In the formula, is the target air specific heat capacity, c p is the specific heat capacity of air, T a is the ambient temperature; The fifth dimensionless calculation formula is: In the formula, is the mass loss rate of the target fuel, is the mass loss rate of the fuel, p a is the air density; The sixth dimensionless calculation formula is: In the formula, Q * is the target fire source size, and Q is the heat release rate of the fire source.

6. The method according to claim 1, characterized in that The target ratio is obtained by performing dimensionless processing based on the target stoichiometric air-fuel ratio, the target wind speed, the target fuel mass loss rate and the basic physical quantity in the target numerical value, including: The target ratio is obtained by performing dimensionless processing on the target stoichiometric air-fuel ratio, the target wind speed, the mass loss rate of the target fuel, the air density in the basic physical quantity, the gravitational acceleration and a preset seventh dimensionless calculation formula; wherein the seventh dimensionless calculation formula is: In the formula, is the target ratio, S is the stoichiometric air-fuel ratio, S * is the target stoichiometric air-fuel ratio.

7. The method according to claim 1, characterized in that The step of determining the flame inclination angle based on the target ratio, the target tunnel section width in the target values, the target fire source size, the target air specific heat capacity, and the target fire source release rate includes: The inclination angle is determined by the target ratio, the target tunnel section width, the target fire source size, the target air specific heat capacity, the target fire source release rate and a preset inclination angle calculation formula; wherein the preset inclination angle calculation formula is: in, is the target ratio.

8. The method according to any one of claims 1 to 7, characterized in that: The inclination angle is the angle between the line connecting the center point of the fire source and the end point of the flame 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 of the current tunnel is a square. The fire source is located on the center line of the tunnel. The cross-section of the current tunnel is a rectangle or an oblong. The current tunnel includes side walls and a ceiling.

9. An electronic device, comprising: A processor, a memory, a communication interface and a communication bus, wherein the processor, the memory and the communication interface communicate with each other via the communication bus; The memory is used to store at least one executable instruction, and the executable instruction enables the processor to perform an operation corresponding to the method as described in any one of claims 1-8.

10. A computer storage medium having a computer program stored thereon, wherein the program, when executed by a processor, implements the method according to any one of claims 1 to 8.

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