Self-extinguishing prediction method and device for plugging and fire extinguishing of underground space of deep well

Abstract

The invention relates to a deep well underground space plugging fire extinguishing self-extinguishing prediction method and device, and the method comprises the steps: determining flame self-extinguishing influence factors which influence the flame self-extinguishing moment in a deep well type underground space under a plugging condition, and the flame self-extinguishing influence factors can comprise the fire source depth, the deep well depth, the oxygen concentration and the fire source power; different fire source depth, deep well depth, oxygen concentration and fire source power may influence the combustion condition of flame in the deep well type underground space. Effective influence factors are determined based on the flame influence factors, the optimal influence factors are determined, and then more accurate prediction is carried out; therefore, a flame self-extinguishing moment prediction model can be constructed according to the effective influence factors, and a more accurate result can be predicted through the flame self-extinguishing moment prediction model after the detection values of the effective influence factors of the deep well type underground space at the current moment under the blocking condition are obtained. And therefore, rescue departments and personnel can perform effective processing according to the result.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of deep well fire extinguishing, and particularly relates to a deep well underground space plugging fire extinguishing and self-extinguishing prediction method and device. BACKGROUND

[0002] Deep well type underground space is a new solution for developing and utilizing underground space and relieving the problem of "parking difficulty". The deep well type underground space is usually in the form of a deep well type underground garage, which combines vertical shaft sinking and tunnelling technology (VSM) and mechanical three-dimensional intelligent parking technology, and has the characteristics of high space utilization, excellent anti-seismic performance, convenient access and intelligent operation and maintenance. However, the deep well type underground space inevitably brings fire safety problems. From the structure of the deep well type underground space, the deep well type underground space is usually a deep well-shaped building structure extending vertically downward, and this special structure determines the smoke dynamics characteristics when a fire occurs, that is, the smoke moves upward under the action of buoyancy, forming a strong "chimney effect", so that the facilities at each elevation in the space have the risk of being ignited. When a fire occurs in the deep well type underground space, conventional fire rescue facilities cannot enter in time, which can easily cause the fire to spread and reduce the efficiency of fire extinguishing and rescue.

[0003] When a fire occurs in the deep well type underground space, conventional fire rescue facilities cannot enter in time, which can easily cause the fire to spread and reduce the efficiency of fire extinguishing and rescue. Plugging is a common fire extinguishing strategy for limited space fires, which can cut off the oxygen supply and make the flame extinguish due to lack of oxygen. However, after plugging, the rescue department cannot confirm the extinguishing of the flame in the deep well type underground space, so that the disaster situation cannot be effectively handled in time.

[0004] Therefore, it is urgent to provide a deep well underground space plugging fire extinguishing and self-extinguishing prediction method and device to solve the technical problem that in the prior art, after plugging, the rescue department cannot confirm the extinguishing of the flame in the deep well type underground space, so that the disaster situation cannot be effectively handled in time. SUMMARY

[0005] Therefore, it is urgent to provide a deep well underground space plugging fire extinguishing and self-extinguishing prediction method and device to solve the technical problem that in the prior art, after plugging, the rescue department cannot confirm the extinguishing of the flame in the deep well type underground space, so that the disaster situation cannot be effectively handled in time.

[0006] In order to solve the above problems, in a first aspect, the present application provides a deep well underground space plugging fire extinguishing and self-extinguishing prediction method, comprising: Determine the flame self-extinguishing influencing factors affecting the flame self-extinguishing time in the deep well type underground space under the sealing condition, wherein the flame self-extinguishing influencing factors include the fire source depth, the deep well depth, the oxygen concentration and the fire source power; Determine the effective influencing factors based on the flame influencing factors, and construct a flame self-extinguishing time prediction model according to the effective influencing factors; Obtain the detection values of the effective influencing factors of the deep well type underground space under the sealing condition; Bring the detection values into the flame self-extinguishing time prediction model for prediction to obtain a prediction result.

[0007] In a possible implementation, the determination of the effective influencing factors based on the flame influencing factors includes: Analyze the influence of the flame self-extinguishing time of the deep well type underground space under the sealing condition according to the fire source depth and the fire source power in the deep well underground space experiment table to obtain a fire source analysis result; Analyze the influence of the flame self-extinguishing time of the deep well type underground space under the sealing condition according to the deep well depth and the fire source power in the deep well underground space experiment table to obtain a deep well analysis result; Obtain self-extinguishing effective influencing factors according to the fire source analysis result and the deep well analysis result, wherein the self-extinguishing effective influencing factors include the fire source power, the oxygen concentration and the fire source depth; Obtain effective influencing factors by algorithm analysis on the oxygen concentration, wherein the effective influencing factors include the fire source power and the fire source depth.

[0008] In a possible implementation, the analysis of the influence of the flame self-extinguishing time of the deep well type underground space under the sealing condition according to the fire source depth and the fire source power in the deep well underground space experiment table to obtain a fire source analysis result includes: Set the fire source power, multiple fire source depths and multiple oil pan sizes; Simulate the flame self-extinguishing conditions of the multiple fire source depths in the deep well type underground space under the sealing condition by the fire source power and each oil pan size to obtain all first flame self-extinguishing conditions of the multiple fire source depths of each oil pan size; Analyze the all first flame self-extinguishing conditions to obtain a fire source analysis result.

[0009] In a possible implementation, the analysis of the influence of the flame self-extinguishing time of the deep well type underground space under the sealing condition according to the deep well depth and the fire source power in the deep well underground space experiment table to obtain a deep well analysis result includes: setting a fire source power, a plurality of fire source depths, a plurality of deep well depths and a plurality of oil pan sizes; simulating, under the plugging condition, a flame self-extinguishing condition of the plurality of deep well depths in the deep well type underground space by the fire source power and each fire source depth corresponding to each oil pan size, to obtain all second flame self-extinguishing conditions of the plurality of deep well depths corresponding to the each fire source depth of the each oil pan size; analyzing the all second flame self-extinguishing conditions to obtain a deep well analysis result.

[0010] In a possible implementation, the fire source analysis result is that flame self-extinguishing is mainly caused by a decrease in oxygen concentration, and the deep well analysis result is that a deep well depth has no obvious influence on a flame self-extinguishing moment.

[0011] In a possible implementation, the algorithm analysis of the oxygen concentration is performed to obtain effective influencing factors, including: analyzing, based on an ethanol mass loss method and an oxygen consumption method, an influence of the oxygen concentration on a flame self-extinguishing moment under the plugging condition in the deep well type underground space to obtain corresponding algorithm analysis results; performing comparative analysis on the algorithm analysis results and the fire source analysis result to obtain a comparative analysis result; the comparative analysis result is that an influence error of the oxygen concentration on a flame self-extinguishing moment is large; removing, according to the comparative analysis result, the oxygen concentration in the self-extinguishing effective influencing factors to obtain effective influencing factors.

[0012] In a possible implementation, after the flame self-extinguishing moment prediction model is constructed according to the effective influencing factors, the method further includes: performing non-linear curved surface fitting on the fire source power and the plurality of fire source depths corresponding to the each oil pan size under the plugging condition according to the flame self-extinguishing moment prediction model to obtain a fitting result of the plurality of fire source depths of the each oil pan size; performing comparative analysis on the fitting result and the all first flame self-extinguishing conditions to obtain a comparative analysis result; the comparative analysis result is that a self-extinguishing time predicted by the fitting result is highly consistent with data obtained through experiments in the all first flame self-extinguishing conditions; determining, according to the comparative analysis result, that the flame self-extinguishing moment prediction model meets a requirement.

[0013] In a possible implementation, the deep-well underground space experiment table comprises a plurality of metal barrel sections, an electronic balance and an oil pool; a top seal is installed on the top of the prefabricated metal barrel section for sealing experiment, a camera is installed inside the top seal for obtaining experimental pictures during the experiment, a high-temperature-resistant glass door is installed on each metal barrel section for observing the experiment process, the inner wall of each metal barrel section is filled with asbestos for reducing heat loss of hot flue gas during flow, a plurality of circular holes are uniformly distributed on the side wall of the plurality of metal barrel sections for installing thermocouples to form a thermocouple tree for measuring the temperature at different positions, the supports of the electronic balance and the oil pool are inserted through the circular holes, the position of the fire source is changed by adjusting the position of the support to obtain the depth of the fire source, the oil pool is used to control the size of the flame to control the power of the fire source, the electronic balance is used to weigh the fuel in the oil pool to determine the relationship between oxygen concentration and fuel, and each metal barrel section is connected through a steel barrel section and a flange for assembly and disassembly to adjust the depth of the deep well.

[0014] In a possible implementation, the flame self-extinguishing time prediction model comprises:

[0015] wherein, k , and are fitting parameters, Q is the fire source power, h is the depth of the fire source, t is the flame self-extinguishing time.

[0016] In a second aspect, the present application further provides a deep-well underground space sealing and fire extinguishing self-extinguishing prediction device, comprising: a factor determination module configured to determine flame self-extinguishing influencing factors affecting the flame self-extinguishing time in a deep-well underground space under sealing conditions; the flame self-extinguishing influencing factors include the depth of the fire source, the depth of the deep well, the oxygen concentration and the fire source power; a model construction module configured to determine effective influencing factors based on the flame influencing factors, and construct a flame self-extinguishing time prediction model according to the effective influencing factors; a factor acquisition module configured to acquire detection values of the effective influencing factors of the deep-well underground space under the sealing conditions; a model prediction module configured to input the detection values into the flame self-extinguishing time prediction model for prediction to obtain a prediction result.

[0017] The beneficial effects of the present application are that the flame self-extinguishing influencing factors affecting the flame self-extinguishing time in the deep-well type underground space under the plugging condition can be determined, the flame self-extinguishing influencing factors can include the fire source depth, the deep-well depth, the oxygen concentration and the fire source power, and the different fire source depth, deep-well depth, oxygen concentration and fire source power can affect the combustion of the flame in the deep-well type underground space; the effective influencing factors can be determined based on the flame influencing factors, so that the optimal influencing factors can be determined, and then more accurate prediction can be carried out; and the flame self-extinguishing time prediction model can be constructed according to the effective influencing factors, after the detection values of the effective influencing factors of the deep-well type underground space under the plugging condition at the current time are obtained, the more accurate results can be predicted by the flame self-extinguishing time prediction model, and then the rescue departments and personnel can effectively handle the results. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 An embodiment structure schematic view of the deep-well underground space experiment table provided by the present application; Figure 2 An embodiment flow schematic view of the deep-well underground space plugging fire extinguishing and self-extinguishing prediction method provided by the present application; Figure 3 An embodiment structure schematic view of the development process of the flame from stable combustion to self-extinguishing provided by the present application; Figure 4 An embodiment structure schematic view of the deep-well underground space experiment table provided by the present application; Figure 2 An embodiment flow schematic view of step S202 in the present application; Figure 5 An embodiment coordinate schematic view of the flame self-extinguishing time under different deep-well depths when the fire source depth is-0.45m provided by the present application; Figure 6 An embodiment coordinate schematic view of the flame self-extinguishing time under different deep-well depths when the fire source depth is-1.05m provided by the present application; Figure 7 An embodiment coordinate schematic view of the nonlinear curved surface diagram provided by the present application; Figure 8 An embodiment structure schematic view of the deep-well underground space plugging fire extinguishing and self-extinguishing prediction device provided by the present application. DETAILED DESCRIPTION

[0019] The preferred embodiments of the present application will be specifically described below in combination with the drawings, wherein the drawings constitute a part of the present application, and are used to illustrate the principles of the embodiments of the present application, and are not used to limit the scope of the present application.

[0020] As Figure 1As shown in the specific embodiment of the present application, a deep well underground space plugging fire extinguishing self-extinguishing prediction method is disclosed, comprising: S101, determining the flame self-extinguishing influencing factors affecting the flame self-extinguishing time in the deep well type underground space under the plugging condition; the flame self-extinguishing influencing factors include the fire source depth, the deep well depth, the oxygen concentration and the fire source power.

[0021] Among them, in the deep well type underground space fire, the top plugging will cause the self-extinguishing of the flame. Flame self-extinguishing is a key phenomenon in the development process of fire, which refers to the phenomenon that the combustion is affected by various factors and cannot continue and is interrupted under certain conditions. Understanding the characteristics of flame self-extinguishing is of great significance to master the development law of deep well type underground space fire and develop effective fire prevention and extinguishing strategies. Figure 2 As shown, Figure 2 The development process of the flame from stable combustion to self-extinguishing is shown when the deep well depth is 3m, the fire source depth is 2.85m and the oil pan size is 10cm*10cm. It can be seen that the flame is from normal stable combustion to flame wandering and then self-extinguishing, and there is still remaining fuel. The influence law of the fire source depth and the deep well depth on the smoke transport characteristics of the deep well type underground space fire under the plugging condition can be summarized. The change of the fire source depth and the deep well depth may cause differences in the air entrainment mode around, the rising path of hot smoke, the velocity and temperature distribution in the deep well, and then affect the supply of oxygen concentration and the stability of combustion, and different fire source power combustion will also affect the combustion of the flame. The interaction of these factors determines the possibility of flame self-extinguishing and the characteristic time of self-extinguishing.

[0022] S102, determining the effective influencing factors based on the flame influencing factors, and constructing a flame self-extinguishing time prediction model according to the effective influencing factors.

[0023] Among them, the flame self-extinguishing of the deep well type underground space under the plugging condition can be carried out by scale size experiment, and the specific size experiment is carried out according to different fire source depths and different deep well depths, so that the corresponding experimental results can be obtained. Then the influence of the flame self-extinguishing time of the deep well type underground space under the plugging condition can be analyzed according to the experimental results, and the effective influencing factors can be obtained. After determining the effective influencing factors, the flame self-extinguishing time prediction model can be constructed based on the effective influencing factors. The flame self-extinguishing time prediction model is shown as formula (1): (1) In the formula, k , and are fitting parameters, Q is the fire source power, h is the fire source depth, t is the flame self-extinguishing time.

[0024] S103, acquire the detection value of the effective influencing factor of the deep-well type underground space under the plugging condition.

[0025] The effective influencing factor of the deep-well type underground space under the plugging condition at the current moment can be detected to obtain the detection value of each influencing factor. The detection process and detection instrument of different influencing factors can be different. For example, the effective influencing factor can include fire source depth and fire source power. The fire source depth can be detected by a depth vehicle instrument, and the fire source power can be detected by a power detection instrument or calculated by calculating the power of each vehicle burning in the deep-well type underground space. The specific setting can be made according to the actual situation, which is not limited in the embodiment of the application.

[0026] S104, bring the detection value into the flame self-extinguishing time prediction model to perform prediction to obtain a prediction result.

[0027] After obtaining the detection value of each effective influencing factor, the detection value can be brought into the flame self-extinguishing time prediction model to perform calculation, and a prediction result can be obtained. The prediction result can be the self-extinguishing time, so that rescue personnel can rescue the deep-well type underground space according to the self-extinguishing time.

[0028] Compared with the prior art, the embodiment provided can determine the flame self-extinguishing influencing factor affecting the flame self-extinguishing time in the deep-well type underground space under the plugging condition. The flame self-extinguishing influencing factor can include fire source depth, deep-well depth, oxygen concentration, and fire source power. Different fire source depths, deep-well depths, oxygen concentrations, and fire source powers can affect the combustion of the flame in the deep-well type underground space. The effective influencing factor can be determined based on the flame influencing factor, so that the optimal influencing factor can be determined, and more accurate prediction can be performed. Therefore, the flame self-extinguishing time prediction model can be constructed according to the effective influencing factor. After acquiring the detection value of the effective influencing factor of the deep-well type underground space under the plugging condition at the current moment, the flame self-extinguishing time prediction model can be used to predict a more accurate result, so that the rescue department and personnel can effectively handle the result.

[0029] In some embodiments of the application, as Figure 3As shown, the deep well underground space experiment table includes a plurality of metal barrel sections, electronic scales and oil pools; the top of the prefabricated metal barrel section is provided with a top block for blocking experiment, a camera is installed in the inside of the top block for obtaining experimental pictures during the experiment, a high-temperature-resistant glass door is installed on the inner wall of each metal barrel section for observing the experiment process, the inner wall of each metal barrel section is filled with asbestos for reducing heat loss of hot flue gas during flow, a plurality of round holes are uniformly distributed on the side wall of the plurality of metal barrel sections for installing thermocouples to form a thermocouple tree for measuring the temperature at different positions, the supports of the electronic scales and the oil pools are inserted through the round holes, the position of the fire source is changed by adjusting the position of the support to obtain the depth of the fire source, the oil pool is used to control the size of the flame to control the power of the fire source, the electronic scale is used to weigh the fuel in the oil pool to determine the relationship between the oxygen concentration and the fuel, and each metal barrel section is connected through a steel barrel section and a flange for assembly and disassembly to adjust the depth of the well.

[0030] In order to facilitate subsequent experiments, a deep well underground space experiment table is constructed, which is built by a plurality of prefabricated metal barrel sections with a thickness of 2mm, a height of 0.6m and a diameter of 0.6m, a top block is installed on the top of the prefabricated metal barrel section, so that the blocking experiment can be carried out, a CCD camera is installed in the inside of the top block, the CCD camera can be used to collect image information during the experiment, a high-temperature-resistant glass door is installed on each metal barrel section to observe the experimental phenomenon, in order to reduce the heat loss of hot flue gas during flow, the inner wall of each metal barrel section is filled with asbestos, and aluminum foil tape is used to seal the area that may exchange substances with the outside during the experiment. A plurality of round holes are uniformly distributed on the vertical interval of 0.1m of the side wall of each metal barrel section for installing thermocouples to form a thermocouple tree, the supports of the electronic scales and the oil pools are inserted through the round holes, the position of the fire source is changed by adjusting the position of the support, the depth of the fire source is obtained, the electronic scale can be used to weigh the weight of the oil pool, and the relationship between the oxygen concentration and the fuel can be determined, the fuel in the oil pool can control the size of the flame, and the power of the fire source can be controlled by the fuel, each metal barrel section is connected through a steel barrel section and a flange for assembly and disassembly to meet different experimental requirements, for example, the depth of the well can be 1.8m, 2.4m, 3m and 3.6m, so the number of barrel sections required is 3-6.

[0031] In some embodiments of the present application, as shown in Figure 4 As shown in step S102, the step S102 includes: S401, in the deep well underground space experiment table, the influence of the fire source depth and the fire source power on the flame self-extinguishing time of the deep well underground space under the blocking condition is analyzed, and a fire source analysis result is obtained.

[0032] Wherein, with the increase of the time of combustion, the fire source power (i.e. the fire source power) will gradually increase, in order to can carry out the experiment to the fire source depth, can set up a fixed fire source power, under the fire source power, to different fire source depth carries out the scale experiment, thereby can carry out the analysis to the influence of the flame self-extinguishing moment, obtains the fire source analysis result.

[0033] S402, in the deep well underground space experiment platform according to the depth of the deep well and the fire source power, the influence of the flame self-extinguishing moment of the deep well type underground space under the plugging condition is analyzed, and the deep well analysis result is obtained.

[0034] Wherein, for the same fire source depth, the space distribution under the fire source of different deep well depths is also different, therefore, the influence of the depth of the deep well on the flame self-extinguishing moment also needs to be considered. After setting a fixed fire source power, scale experiments can be carried out on different deep well depths of different fire source depths under the condition of the fire source power, so as to analyze the influence of the flame self-extinguishing moment and obtain the deep well analysis result.

[0035] S403, according to the fire source analysis result and the deep well analysis result, the self-extinguishing effective influence factor is obtained; the self-extinguishing effective influence factor includes the fire source power, the oxygen concentration and the fire source depth.

[0036] Wherein, through the scale experiment of multiple groups of different fire source depths, a certain amount of fuel residue is observed in all self-extinguishing working conditions, and the fire source analysis result is obtained that the flame self-extinguishing under the plugging condition is mainly caused by the reduction of oxygen concentration. Through the deep well analysis result of multiple deep well depths, it is not observed that the deep well depth has a significant influence on the flame self-extinguishing moment, therefore, the deep well depth is not considered in the subsequent research on the prediction of the flame self-extinguishing moment, so it can be determined that the self-extinguishing effective influence factor includes the fire source power, the oxygen concentration and the fire source depth.

[0037] S404, algorithm analysis is carried out on the oxygen concentration, and the effective influence factor is obtained; the effective influence factor includes the fire source power and the fire source depth.

[0038] In the specific embodiments of the present application, it is determined in the fire source analysis result in step S401 that the flame self-extinguishing is mainly caused by the reduction of oxygen concentration, so it can be determined that the self-extinguishing effective influence factor includes the oxygen concentration, but in order to further study the oxygen concentration, the prediction of the flame self-extinguishing moment is carried out through the "ethanol mass loss method" and "oxygen consumption method", so that the prediction value and the experimental value of the oxygen concentration have a large deviation, so the oxygen concentration is not taken as the effective influence factor, therefore, the effective influence factor includes the fire source power and the fire source depth.

[0039] In some embodiments of the present application, step S401 includes: setting the fire source power, multiple fire source depths and multiple oil pan sizes; Under blocking conditions, the flame self-extinguishing conditions at multiple fire source depths in a deep well-type underground space were simulated by using the fire source power and each oil pan size, and all the first flame self-extinguishing conditions at multiple fire source depths for each oil pan size were obtained; All first flame self-extinguishing situations are analyzed to obtain fire source analysis results.

[0040] In a specific embodiment of the present invention, scaled-down experiments revealed significant regularity in the self-extinguishing phenomenon of fires in deep underground spaces under sealed conditions. Fire source power, multiple fire source depths, and multiple oil pan sizes can be set. Then, under sealed conditions, the self-extinguishing behavior of flames at multiple fire source depths in the deep underground space can be simulated using the fire source power and each oil pan size. The first flame self-extinguishing behavior for each oil pan size at multiple fire source depths can be obtained, as shown in Table 1. Table 1. Flame self-extinguishing at different fire source depths and heat release rates

[0041] Note: “-” means “not self-extinguishing”.

[0042] Table 1 lists the flame self-extinguishing scenarios at different fire source depths and heat release rates for a deep well with a depth of 3 m. These scenarios represent all first flame self-extinguishing scenarios. It can be seen that as the distance from the fire source to the ceiling decreases, the probability of flame self-extinguishing increases, and the self-extinguishing time also decreases. In the case of an oil pan with dimensions of 10 cm × 10 cm, the flame self-extinguishing time decreased by 72.1% when the fire source depth decreased from 2.85 m to 0.45 m. In the case of an oil pan with dimensions of 10 cm × 15 cm, the flame self-extinguishing time decreased by 63.7% with decreasing fire source depth. The main reasons for the change in flame self-extinguishing time with changes in fire source depth are related to oxygen supply and heat transfer. When the fire source depth is deep, the flame can more easily obtain oxygen from the surrounding environment, and the oxygen concentration required to maintain combustion is relatively high, resulting in sustained combustion and a reduced self-extinguishing time. As the fire source depth decreases, air flow around the flame is restricted, making oxygen diffusion into the flame area more difficult. This reduces the oxygen concentration, weakens the flame's combustion intensity, and shortens the self-extinguishing time. In addition, changes in the depth of the fire source will also affect the efficiency of heat transfer to the surrounding environment, causing changes in the temperature distribution around the flame, thereby affecting the self-extinguishing characteristics of the flame.

[0043] Fire source power (i.e. heat release rate) QThe increase of the size of the oil pan also strengthens the self-extinguishing effect. The data in the table shows that in the working condition of a fire source depth of 1.05 m, when the size of the oil pan is increased from 6 cm x 6 cm (1 kW) to 10 cm x 15 cm (4 kW), the flame self-extinguishing time is shortened by 83.5%; in the working condition of a fire source depth of 0.45 m, with the increase of the fire source power, the flame self-extinguishing time is shortened by 77.1%. This is because the larger size of the oil pan has a larger fuel surface area, which can release more heat at the initial stage of combustion, so that the ambient temperature around the flame increases and the oxygen consumption speed accelerates. When the oxygen concentration decreases to a certain extent, the flame will reach the self-extinguishing state more quickly. At the same time, the change of the size of the oil pan can also affect the shape and stability of the flame, thereby affecting the self-extinguishing process.

[0044] As can be seen from Table 1, for a certain fire source power Q When Q corresponding to the oil pan size between 8 cm x 8 cm-10 cm x 10 cm, the corresponding full-size power is about 6.89 MW-10.34 MW, there is a critical fire source depth h (1.05 m h <1.65 m, corresponding to the full-size depth of 27.3-42.9 m) that just makes the flame self-extinguish. It is worth noting that a certain amount of fuel residue is observed in all self-extinguishing working conditions, which shows that the flame self-extinguishing under the sealing condition is mainly caused by the decrease of oxygen concentration.

[0045] In some embodiments of the present application, step S402 comprises: setting the fire source power, the plurality of fire source depths, the plurality of deep well depths, and the plurality of oil pan sizes; simulating the flame self-extinguishing conditions of the plurality of deep well depths under the sealing condition by the fire source power, each fire source depth corresponding to each oil pan size, to obtain all second flame self-extinguishing conditions of the plurality of deep well depths corresponding to each fire source depth of each oil pan size; analyzing all the second flame self-extinguishing conditions to obtain the deep well analysis result.

[0046] In specific embodiments of the present application, through detailed analysis of the flame self-extinguishing conditions under different fire source depths and fire source powers, it can be found that there is a complex functional relationship between the flame self-extinguishing time and the fire source depth and the fire source power. This relationship provides data support and research direction for establishing a flame self-extinguishing time prediction model. However, for the same fire source depth, the space distribution under the deep well source is also different, so the influence of the deep well depth on the flame self-extinguishing time also needs to be considered. Under the fixed fire source power, the experimental data of each deep well depth corresponding to each source depth of each oil pan size is shown in Table 2: Table 2, flame self-extinguishing conditions of each deep well depth

[0047]

[0048]

[0049] Table 2 supplements the self-extinguishing conditions of the other three deep wells, thus obtaining all the second flame self-extinguishing conditions, and finding that the fire source depth is h =0.45m and h =1.05m, the second flame self-extinguished at each depth. The data corresponding to the above two fire source depths are plotted into a bar graph, as shown in Figure 5 and Figure 6 As shown, Figure 5 The flame self-extinguishing time at different well depths when the fire source depth is -0.45m. Figure 6 The self-extinguishing moment of flames at different well depths when the fire source depth is -1.05m. The x-axis is the oil pan size, and the y-axis is the self-extinguishing moment. Figure 5 The depths of the deep wells are 1.8m, 2.4m and 3.6m respectively. Figure 6 The depths of the deep wells are 1.8m, 2.4m, 3.0m and 3.6m respectively. Figure 5 and Figure 6 As can be seen from the results, except for the case where the oil pan size was 6cm×6cm, there was no significant effect of the well depth on the flame self-extinguishing moment in the other cases. Therefore, the deep well analysis results show that the well depth has no significant effect on the flame self-extinguishing moment, and the well depth will not be considered in the subsequent research on the flame self-extinguishing moment prediction.

[0050] In some embodiments of the present invention, step S404 includes: Based on the ethanol mass loss method and oxygen consumption method, the influence of oxygen concentration in deep underground spaces under plugging conditions on the flame self-extinguishing moment was analyzed, and the corresponding algorithm analysis results were obtained.

[0051] Under standard conditions, the oxygen volume fraction in air is approximately 21%. In reality, when the oxygen volume fraction drops to 13%, ethanol combustion becomes difficult to sustain and the flame self-extinguishes. Therefore, the volume of oxygen consumed by the flame to self-extinguish accounts for 8% of the air.

[0052] From the chemical reaction equation for the combustion of a mixture of ethanol and oxygen, we know that burning 1 mol of ethanol requires 3 mol of oxygen. Therefore, the flame self-extinguishing moment can be calculated by the mass loss rate of ethanol, as shown in Formula 2: (2) Where, the amount of oxygen substance; represents the evaporation rate of ethanol; the volume of oxygen consumed; the heat value of ethanol. The known quantity is as shown in equation (3): (3) It is mentioned above that the flame self-extinguishing under the plugging condition is mainly caused by the decrease of oxygen concentration. In the deep well type underground space, the amount of oxygen above the fire source is certain, and in the case of sufficient fuel, the "oxygen consumption method" can be used to predict the self-extinguishing time, as shown in equation (4): (4) In the formula, the energy generated by the consumption of unit mass of oxygen, the value is 13.1 MJ / kg; the oxygen content consumed; Q the heat release rate of the fire source; the density of oxygen. The known quantity is as shown in equation (5): (5) The flame self-extinguishing time formula given by the above two methods is relatively approximate, so it can be seen that the "oxygen consumption method" is also applicable to the combustion of ethanol as fuel.

[0053] The self-extinguishing time of the working conditions in Table 1 is calculated by using the formula of the above two algorithms respectively, and Table 3 is obtained: Table 3, prediction of flame self-extinguishing time by two methods

[0054] The algorithm analysis results corresponding to the algorithms in Table 3 are included.

[0055] The algorithm analysis results are compared with the fire source analysis results to obtain the comparative analysis results; the comparative analysis results are that the influence error of oxygen concentration on the flame self-extinguishing time is large.

[0056] Among them, by comparing the algorithm analysis results of "ethanol mass loss method" and "oxygen consumption method" in Table 3, it can be seen that "ethanol mass loss method" and "oxygen consumption method" are relatively accurate for the prediction of flame self-extinguishing time of some working conditions, but for most working conditions, the predicted value and the experimental value have a large deviation. Considering the actual experimental scene and process, the reasons for the large analysis error may be as follows: (1) The volume fraction of oxygen in the calculation is a conclusion under the condition of uniform distribution of oxygen, while in the experiment, the oxygen above the fire source is usually not uniformly distributed, and the oxygen concentration near the fire source is larger due to the influence of gravity, so the time of flame self-extinguishing in the experiment is later than the theoretical value.

[0057] (2) In the process of combustion, the air under the fire source is sucked by the fire plume, which prolongs the duration of flame combustion.

[0058] (3) In the experiment, the power of the fire source is gradually increased to a stable value, while the above method is directly calculated according to the stable value of the power of the fire source, so that the calculated self-extinguishing time is earlier.

[0059] According to the comparative analysis result, the oxygen concentration in the self-extinguishing effective influencing factor is removed, and the effective influencing factor is obtained.

[0060] Among them, because the prediction value and the experimental value of the oxygen concentration have a large deviation, the oxygen concentration in the self-extinguishing effective influencing factor needs to be removed, and then the effective influencing factor including the fire source depth and the fire source power can be obtained.

[0061] In some embodiments of the present application, after step S102, the method further comprises: According to the flame self-extinguishing time prediction model, the fire source power and the plurality of fire source depths corresponding to each oil pan size are nonlinearly curved surface fitted under the plugging condition, and the fitting result of the plurality of fire source depths of each oil pan size is obtained; The fitting result is compared and analyzed with all the first flame self-extinguishing conditions, and the comparative analysis result is obtained; the comparative analysis result is that the self-extinguishing time predicted by the fitting result is highly consistent with the data obtained by experiment in all the first flame self-extinguishing conditions; According to the comparative analysis result, it is determined that the flame self-extinguishing time prediction model meets the requirements.

[0062] In specific embodiments of the present application, in order to more accurately predict the flame self-extinguishing time in the deep well type underground space under the plugging condition, a mathematical model related to the fire source depth h and the fire source power Q is established based on the scaled size experimental data. It is assumed that the self-extinguishing time t satisfies formula (1) between the last two, the plurality of oil pan sizes and the plurality of fire source depths in table 1 are brought into formula (1) for prediction and nonlinear curved surface fitting, and a nonlinear curved surface graph can be obtained as shown in Figure 7 , the x-axis is the fire source heat release rate (i.e. the fire source power), the y-axis is the fire source depth, and the z-axis is the flame self-extinguishing time. The fitting software can automatically generate fitting parameters, as shown in the formula for calculating Figure 7 in t , a is 879.07, k is 0.63, is -1.18, is -1.18, Figure 7The circles in the figure represent the experimental values of the self-extinguishing time in all first flame self-extinguishing cases, and through regression analysis on the nonlinear curved surface figure, the specific values of the parameters can be obtained, including the predicted self-extinguishing time. R 2 The value is 0.96, indicating that the flame self-extinguishing time prediction model has high prediction accuracy, and the flame self-extinguishing time prediction model meets the requirements.

[0063] In order to better implement the deep well underground space plugging fire extinguishing self-extinguishing prediction method in the embodiment of the application, on the basis of the deep well underground space plugging fire extinguishing self-extinguishing prediction method, correspondingly, the embodiment of the application also provides a deep well underground space plugging fire extinguishing self-extinguishing prediction device, as shown in Figure 8 The deep well underground space plugging fire extinguishing self-extinguishing prediction device 800 includes: A factor determination module 801 is configured to determine the flame self-extinguishing influencing factors affecting the flame self-extinguishing time in the deep well underground space under the plugging condition; the flame self-extinguishing influencing factors include the fire source depth, the deep well depth, the oxygen concentration and the fire source power. A model construction module 802 is configured to determine the effective influencing factors based on the flame influencing factors, and construct a flame self-extinguishing time prediction model according to the effective influencing factors. A factor acquisition module 803 is configured to acquire the detection values of the effective influencing factors of the deep well underground space under the plugging condition. A model prediction module 804 is configured to input the detection values into the flame self-extinguishing time prediction model for prediction to obtain a prediction result.

[0064] The deep well underground space plugging fire extinguishing self-extinguishing prediction device 800 provided by the above embodiment can realize the technical solutions described in the deep well underground space plugging fire extinguishing self-extinguishing prediction method embodiment, and the principles of the specific implementation of the above modules or units can be referred to the corresponding content in the deep well underground space plugging fire extinguishing self-extinguishing prediction method embodiment, which will not be described here.

[0065] The deep well underground space plugging fire extinguishing self-extinguishing prediction method and device provided by the application are described in detail above, and the principles and implementation modes of the application are described by applying specific examples; the above embodiment is only used to help understand the method and its core idea; meanwhile, for those skilled in the art, according to the idea of the application, the specific implementation mode and application range will be changed, and the above description should not be understood as limiting the application.

Claims

1. A method for predicting self-extinguishing of fire in deep underground space, characterized in that: include: Determine the factors affecting the flame self-extinguishing moment in deep underground spaces under blocking conditions; The factors affecting flame self-extinguishing include fire source depth, well depth, oxygen concentration and fire source power; Determining effective influencing factors based on the flame influencing factors, and constructing a flame self-extinguishing moment prediction model according to the effective influencing factors; Obtaining detection values ​​of the effective influencing factors of the deep well-type underground space under the blocking condition; The detection value is brought into the flame self-extinguishing moment prediction model for prediction to obtain a prediction result.

2. The method for predicting self-extinguishing of fire in deep well underground space according to claim 1, characterized in that: The determining of the effective influencing factors based on the flame influencing factors includes: In a deep well underground space test bench, the influence of the fire source depth and the fire source power on the flame self-extinguishing moment of the deep well underground space under the blocking condition is analyzed to obtain a fire source analysis result; In the deep well underground space test bench, the influence of the deep well depth and the fire source power on the flame self-extinguishing moment of the deep well underground space under the blocking condition is analyzed to obtain a deep well analysis result; Obtaining effective self-extinguishing influencing factors according to the fire source analysis results and the deep well analysis results; the effective self-extinguishing influencing factors include the fire source power, the oxygen concentration, and the fire source depth; An algorithmic analysis is performed on the oxygen concentration to obtain effective influencing factors; the effective influencing factors include the fire source power and the fire source depth.

3. The method for predicting self-extinguishing of fire in deep well underground space according to claim 2, characterized in that: The fire source analysis results obtained by analyzing the influence of the fire source depth and the fire source power on the flame self-extinguishing moment of the deep well underground space under the blocking condition in the deep well underground space test bench include: Set fire power, multiple fire depths, and multiple oil pan sizes; Under the blocking condition, the flame self-extinguishing conditions at the multiple fire source depths in the deep well-type underground space are simulated by using the fire source power and each oil pan size to obtain all first flame self-extinguishing conditions at the multiple fire source depths for each oil pan size; All the first flame self-extinguishing situations are analyzed to obtain a fire source analysis result.

4. The method for predicting self-extinguishing of fire in deep underground space according to claim 2, characterized in that: The deep well underground space test bench analyzes the influence of the deep well depth and the fire source power on the flame self-extinguishing moment of the deep well underground space under the blocking condition, and obtains deep well analysis results, including: Set fire power, multiple fire depths, multiple well depths, and multiple oil pan sizes; Under the blocking condition, the flame self-extinguishing conditions of the multiple deep well depths in the deep well-type underground space are simulated by using the fire source power and each fire source depth corresponding to each oil pan size, to obtain all second flame self-extinguishing conditions of the multiple deep well depths of each fire source depth corresponding to each oil pan size; All the second flame self-extinguishing situations are analyzed to obtain deep well analysis results.

5. The method for predicting self-extinguishing of fire in deep underground space according to claim 2, characterized in that: The fire source analysis results show that the flame self-extinguishing is mainly caused by the reduction of oxygen concentration, and the deep well analysis results show that the depth of the deep well has no obvious effect on the flame self-extinguishing time.

6. The method for predicting self-extinguishing of fire in deep underground space according to claim 2, characterized in that: The algorithm analysis of the oxygen concentration to obtain effective influencing factors includes: Based on the ethanol mass loss method and the oxygen consumption method, the influence of the oxygen concentration in the deep well-type underground space under the blocking condition on the flame self-extinguishing moment is analyzed respectively, and the corresponding algorithm analysis results are obtained; Comparing the algorithm analysis result with the fire source analysis result to obtain a comparative analysis result; the comparative analysis result shows that the influence of the oxygen concentration on the flame self-extinguishing moment has a large error; According to the comparative analysis result, the oxygen concentration in the effective self-extinguishing influencing factors is removed to obtain the effective influencing factors.

7. The method for predicting self-extinguishing of fire in deep underground space according to claim 3, characterized in that: After constructing the flame self-extinguishing time prediction model according to the effective influencing factors, the method further includes: Under the blocking condition, nonlinear surface fitting is performed on the fire source power and the multiple fire source depths corresponding to each oil pan size according to the flame self-extinguishing moment prediction model to obtain fitting results of the multiple fire source depths for each oil pan size; Comparing and analyzing the fitting result with all the first flame self-extinguishing conditions to obtain a comparative analysis result; the comparative analysis result indicates that the self-extinguishing time predicted by the fitting result is highly consistent with the data obtained through experiments in all the first flame self-extinguishing conditions; According to the comparative analysis results, it is determined that the flame self-extinguishing moment prediction model meets the requirements.

8. The method for predicting self-extinguishing of fire in deep underground space according to claim 2, characterized in that: The deep well underground space test bench includes multiple metal barrel sections, an electronic balance and an oil pool; a top seal is installed on the top of the prefabricated metal barrel section for conducting a sealing experiment, and a camera is installed inside the top seal for obtaining experimental pictures during the experiment. Each metal barrel section is installed with a high-temperature resistant glass door for observing the experimental process. The inner wall of each metal barrel section is filled with asbestos to reduce the heat loss of hot flue gas during the flow process. Several circular holes are evenly distributed on the side walls of the multiple metal barrel sections for installing thermocouples to form a thermocouple tree for measuring the temperature at different positions. The brackets of the electronic balance and the oil pool are inserted through the circular holes. The position of the fire source is changed by adjusting the position of the bracket to obtain the depth of the fire source. The oil pool is used to control the size of the flame and then control the power of the fire source. The electronic balance is used to weigh the fuel in the oil pool to determine the relationship between the oxygen concentration and the fuel. Each metal barrel section is connected to the steel barrel section and the flange for installation and disassembly, and for adjusting the depth of the deep well.

9. The method for predicting self-extinguishing of fire in deep underground space according to claim 1, characterized in that: The flame self-extinguishing moment prediction model includes: Where, k 、 and is the fitting parameter, Q is the fire source power, h is the depth of the fire source, t It is the flame self-extinguishing time.

10. A deep well underground space blocking fire extinguishing self-extinguishing prediction device, characterized in that: include: A factor determination module, used to determine factors affecting the flame self-extinguishing moment in a deep underground space under blocking conditions; The factors affecting flame self-extinguishing include fire source depth, well depth, oxygen concentration and fire source power; A model building module, configured to determine effective influencing factors based on the flame influencing factors, and to build a flame self-extinguishing moment prediction model according to the effective influencing factors; A factor acquisition module, configured to acquire detection values ​​of the effective influencing factors of the deep well-type underground space under the blocking condition; The model prediction module is used to bring the detection value into the flame self-extinguishing moment prediction model for prediction to obtain a prediction result.

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