Method for estimating synergistic inhibition efficiency of gas explosion by complex explosion inhibitor in closed space

Abstract

The application provides a method for estimating the synergistic inhibition efficiency of a complex explosion inhibitor in a closed space and an application method, wherein the complex explosion inhibitor is composed of explosion inhibitor 1 and explosion inhibitor 2, and the method comprises calculating a synergistic factor S , calculating a physical inhibition effect contribution factor and a chemical inhibition effect contribution factor of the complex explosion inhibitor when the complex explosion inhibitor synergistically inhibits combustible gas explosion, and calculating an explosion inhibition cost of the complex explosion inhibitor when the complex explosion inhibitor synergistically inhibits combustible gas explosion. The application is based on the synergistic inhibition efficiency of the complex explosion inhibitor in the closed space, and is used for screening the complex explosion inhibitor, i.e., screening the types and volume fractions of the explosion inhibitor 1 and the explosion inhibitor 2. The application estimates the synergistic inhibition effect of the complex explosion inhibitor through a theoretical calculation method from the perspective of actual application scenarios, reveals the physical and chemical inhibition effects of the complex explosion inhibitor when the complex explosion inhibitor synergistically inhibits combustible gas explosion through a numerical simulation method, reveals the synergistic inhibition principle of the complex explosion inhibitor, and effectively reduces the test amount.

Description

Technical Field

[0001] This invention belongs to the field of gas explosion suppression technology, specifically relating to a method for predicting and applying the synergistic suppression effect of compound explosion suppressants on gas explosions in a confined space. Background Technology

[0002] Combustible gases such as natural gas and hydrogen are important energy sources and fuels, widely used in industrial production and daily life. However, combustible gases are flammable and explosive. Leaks during their production, transportation, storage, and use can lead to serious explosions, posing a significant threat to industrial production and the safety of people and property. Therefore, research on combustible gas explosion suppression technologies is of great importance.

[0003] Technical measures for controlling combustible gas explosions mainly include inerting, explosion suppression, explosion containment, explosion pressure relief, and explosion sealing. Among these, explosion suppression technology involves adding a certain inert medium to the combustible gas / air mixture to effectively disrupt the combustion reaction conditions. Years of research have shown this to be a positive and effective technical measure. The main explosion suppressants studied include inert gases, halogenated hydrocarbons, fine water mist, solid powders, and composite explosion suppressants.

[0004] Inert gases have the advantages of being widely available, inexpensive, and environmentally friendly. They primarily suppress explosions by physically diluting oxygen and combustible gas concentrations. Halogenated hydrocarbon suppressants can react with reactive free radicals such as H, O, and OH produced during the explosion of combustible gases like natural gas and hydrogen, thus chemically inhibiting them. When using a single inert gas suppressant, a high concentration is required to completely suppress the explosion of natural gas, hydrogen, and other combustible gases. When using a single halogenated hydrocarbon suppressant, a lower concentration is required, but the unit price of halogenated hydrocarbon suppressants is high, leading to high costs for large-scale applications. When both are used together, the physical dilution effect of inert gases and the chemical inhibition effect of halogenated hydrocarbons can be combined, improving the suppression effect while reducing costs, thus overcoming the problems of low suppression efficiency, large dosage, and high cost associated with using a single suppressant. Furthermore, by using theoretical calculations and numerical simulations to predict the suppression effect of the compound suppressant and the critical concentration for synergistic suppression, the predicted results are first calculated, and then verified experimentally. This method effectively reduces the amount of experimentation required. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a method for predicting and applying the synergistic suppression effect of compound explosion suppressants in the confined space, addressing the shortcomings of the prior art. This method starts from the perspective of practical application scenarios, uses theoretical calculation methods to predict the synergistic suppression effect of compound explosion suppressants, and uses numerical simulation methods to reveal the physical and chemical suppression effects of compound explosion suppressants in the synergistic suppression of combustible gas explosions, revealing the synergistic suppression principle of compound explosion suppressants, and effectively reducing the amount of testing.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a method for predicting the synergistic effect of compound explosion suppressants in suppressing gas explosions in confined spaces, wherein the compound explosion suppressant consists of explosion suppressant 1 and explosion suppressant 2, and the method includes calculating a synergistic factor. S， Based on synergistic factors S The synergistic factor is used to quantitatively predict the effectiveness of compounded explosion suppressants in inhibiting gas explosions. S The calculation formula is as follows: ; In the formula, , These are the volume fractions of explosion suppressant 1 and explosion suppressant 2, respectively, when the compound explosion suppressant completely suppresses the explosion of flammable gas. To completely suppress the explosion of flammable gas using suppressant 1, the volume fraction of suppressant 1 used alone is... The volume fraction of explosion suppressant 2 used alone when it is used to completely suppress the explosion of flammable gas; when S When the value is greater than 1, it indicates that the explosion suppressant 1 and the explosion suppressant 2 have a negative synergistic inhibition effect, that is, when they are combined for inhibition, they inhibit each other, and the inhibition effect is less than the sum of the individual inhibition effects. when S When =1, it indicates that there is no synergistic suppression effect between explosion suppressant 1 and explosion suppressant 2; when S When the value is less than 1, it indicates that there is a positive synergistic inhibition effect between the explosion suppressant 1 and the explosion suppressant 2. That is, when they are combined for inhibition, they have a promoting effect on each other, and the inhibition effect is greater than the sum of the individual inhibition effects.

[0007] Preferably, the method further includes calculating the contribution factors of physical inhibition effect and chemical inhibition effect when the compound explosion suppressant synergistically inhibits the explosion of combustible gas, and predicting the physical inhibition effect and chemical inhibition effect when the compound explosion suppressant synergistically inhibits the explosion of gas based on the contribution factors of physical inhibition effect and chemical inhibition effect. The effects of the two contributing factors of the compound explosion suppressant on the laminar combustion rate of combustible gas explosion were studied using reaction kinetic simulation. The reaction kinetics simulation method is as follows: using CHEMKIN software, combining three mechanism files—gas phase kinetics file, surface kinetics file, and transmission data file—and a one-dimensional laminar combustion velocity model, the laminar combustion velocity of combustible gas explosion before and after the addition of the compound detonator is calculated. Assume the compound explosion suppressant used is m; To quantify the impact of different inhibition effects on laminar combustion velocity, a virtual substance, namely Vir1-m, was set up in the numerical simulation. Vir1-m has the same thermophysical parameters and transport characteristics as m, but does not participate in any reaction of combustible gas explosion. That is, Vir1-m only affects the physical suppression effect of combustible gas explosion. Assuming the laminar combustion velocity of the combustible gas flame without the addition of a knock suppressant is S0, and the laminar combustion velocity of the combustible gas with the addition of m is Su0; and the laminar combustion velocity with the addition of Vir1-m is Su1, the contribution factors of the two suppression effects are defined as follows: The formula for calculating the contribution factor ω1 of the physical inhibition effect is: ; The formula for calculating the contribution factor ω2 of the chemical inhibition effect is: .

[0008] Preferably, the method further includes calculating the suppression cost when the compounded explosion suppressant synergistically suppresses the explosion of flammable gas, based on a synergy factor. S Comprehensive screening and compounding of explosion suppressants based on explosion suppression costs ， Or based on synergistic factors S、 The contribution factors of physical inhibition effect, chemical inhibition effect, and explosion suppression cost were comprehensively considered to screen compound explosion suppressants. The formula for calculating the explosion suppression cost is as follows: Y=V1÷22.4×M1×X1+V2÷22.4×M2×X2; Where M1, V1, and X1 are the relative molecular mass, volume, and unit price per kilogram of the added explosion suppressant 1, respectively; M2, V2, and X2 are the relative molecular mass, volume, and unit price per kilogram of the added explosion suppressant 2, respectively; 22.4 is the molar volume constant under standard gas conditions, in L / mol; and Y is the explosion suppression cost of the compound explosion suppressant.

[0009] Preferably, in the compound explosion suppressant, explosion suppressant 1 is an inert gas and explosion suppressant 2 is a halogenated hydrocarbon.

[0010] Preferably, the inert gas is carbon dioxide, and the haloalkane is trifluoroiodomethane.

[0011] This invention also provides an application based on the synergistic suppression of gas explosions by compound explosion suppressants in a confined space. Based on the synergistic suppression of gas explosions by compound explosion suppressants in a confined space, compound explosion suppressants are screened, and the types and volume fractions of explosion suppressant 1 and explosion suppressant 2 are determined.

[0012] Preferably, compound explosion suppressants that require physical or chemical suppression effects are screened based on the contribution factors of physical suppression effect and chemical suppression effect. Alternatively, a combination of explosion suppressants can be screened based on the synergistic factor S and the explosion suppression cost. Alternatively, a combination of explosion suppressants can be screened based on the synergistic factor S, the contribution factor of physical inhibition effect, the contribution factor of chemical inhibition effect, and the explosion suppression cost.

[0013] Compared with the prior art, the present invention has the following advantages: 1. This invention first calculates the synergy factor S for the compound explosion suppressant composed of explosion suppressant 1 and explosion suppressant 2, and screens out compound explosion suppressants with positive synergistic inhibition effects, where the two components have a promoting effect on each other, and the inhibition effect is greater than the individual inhibition effect. This invention also calculates the contribution factors of physical inhibition effect and chemical inhibition effect when the compound explosion suppressant synergistically inhibits the explosion of flammable gases, and estimates the physical and chemical inhibition effects when the compound explosion suppressant synergistically inhibits the explosion of flammable gases based on the physical inhibition effect contribution factor ω1 and the chemical inhibition effect contribution factor ω2. This invention also includes calculating the explosion suppression cost when the compound explosion suppressant synergistically inhibits the explosion of flammable gases, and comprehensively screening compound explosion suppressants based on the synergy factor S and the explosion suppression cost, or comprehensively screening compound explosion suppressants based on the synergy factor S, the physical inhibition effect contribution factor, the chemical inhibition effect contribution factor, and the explosion suppression cost.

[0014] This invention simultaneously calculates the physical and chemical suppression effectiveness of the compound explosion suppressant using numerical simulation methods, revealing the principle of synergistic suppression. Finally, by calculating the usage cost, the optimal compound ratio of the compound explosion suppressant for synergistic suppression of flammable gas explosions is obtained. The compound explosion suppressant in this invention combines explosion suppressant 1 (which provides physical suppression) and explosion suppressant 2 (which provides chemical suppression), integrating the advantages of both suppressants to achieve a good synergistic suppression effect, improving the suppression efficiency and reducing usage costs. The evaluation method of this invention is a theoretical prediction method. By defining a synergistic factor S, the actual volume fractions of explosion suppressants 1 and 2 used alone when there is no explosion are compared with the actual volume fractions of explosion suppressants 1 and 2 in the compound explosion suppressant. The numerical simulation method of this invention is a reaction kinetic simulation method. By quantifying the contribution factors of the synergistic suppression effect of the compound explosion suppressant 1 and 2 on the physical and chemical suppression of flammable gas explosions, the principle of synergistic suppression is revealed.

[0015] 2. This invention, from the perspective of practical application scenarios, uses theoretical calculations to predict the synergistic suppression effect of compound explosion suppressants, and numerical simulations to reveal the physical and chemical suppression effects of compound explosion suppressants on flammable gas explosions, thus revealing the synergistic suppression principle and effectively reducing the amount of testing. Furthermore, by experimentally studying the suppression effect of compound explosion suppressants at different volume fractions and mixing ratios, the volume fraction and mixing ratio required for complete suppression of flammable gas explosions can be obtained. By introducing the unit price of the explosion suppressant, the volume fraction and mixing ratio corresponding to the lowest cost for complete suppression can be calculated, thus obtaining the optimal mixing ratio. In summary, through experimental research, theoretical calculations, and numerical simulations, the optimal mixing ratio of compound explosion suppressants for suppressing flammable gas explosions is obtained, improving the suppression effect while reducing the cost of using the explosion suppressant.

[0016] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. Attached Figure Description

[0017] Figure 1 These are the contributing factors to the physical and chemical effects of the single-component CO2 and CF3I explosion suppressants in suppressing hydrogen explosions in Example 1 of this invention. Among them, (a) is the contributing factor to the CO2 suppression effect at different hydrogen equivalence ratios, and (b) is the contributing factor to the CF3I suppression effect at different hydrogen equivalence ratios.

[0018] Figure 2 This is a graph showing the contribution factors of the physical and chemical effects of the compound explosion suppressant in Example 1 of the present invention. The horizontal axis represents the volume ratio of CF3I in the compound explosion suppressant, where (a) is the contribution factor of the physical and chemical suppression effect when the hydrogen equivalent ratio is 0.6, (b) is the contribution factor of the physical and chemical suppression effect when the hydrogen equivalent ratio is 1.0, (c) is the contribution factor of the physical and chemical suppression effect when the hydrogen equivalent ratio is 1.4, and (d) is the contribution factor of the physical and chemical suppression effect when the hydrogen equivalent ratio is 1.8. Detailed Implementation Example 1

[0019] This embodiment describes a method for predicting the synergistic effect of a compound explosion suppressor in suppressing gas explosions in a confined space. The compound explosion suppressor consists of explosion suppressor 1 and explosion suppressor 2. The method includes: (a) Calculate the synergy factor S (quantitative prediction method); The effectiveness of compounded explosion suppressants in inhibiting gas explosions is quantitatively estimated based on the synergistic factor S. The formula for calculating the synergistic factor S is as follows: ; In the formula, , These are the volume fractions of explosion suppressant 1 and explosion suppressant 2, respectively, when the compound explosion suppressant completely suppresses the explosion of flammable gas. To completely suppress the explosion of flammable gas using suppressant 1, the volume fraction of suppressant 1 used alone is... The volume fraction of explosion suppressant 2 used alone when it is used to completely suppress the explosion of flammable gas; when S When the value is greater than 1, it indicates that the explosion suppressant 1 and the explosion suppressant 2 have a negative synergistic inhibition effect, that is, when they are combined for inhibition, they inhibit each other, and the inhibition effect is less than the sum of the individual inhibition effects. when S When =1, it indicates that there is no synergistic suppression effect between explosion suppressant 1 and explosion suppressant 2; when S When the value is less than 1, it indicates that there is a positive synergistic inhibition effect between the explosion suppressant 1 and the explosion suppressant 2. That is, when they are combined for inhibition, they have a promoting effect on each other, and the inhibition effect is greater than the sum of the individual inhibition effects.

[0020] Explosion suppressant 1 is inert gas carbon dioxide, and explosion suppressant 2 is halogenated hydrocarbon explosion suppressant trifluoroiodomethane. Based on the above formula for calculating the synergistic factor, the synergistic factor of the compound explosion suppressants under different hydrogen equivalent ratios and different compounding ratios is calculated.

[0021] Table 1. Volume fraction of single-component explosion suppressant required to completely suppress hydrogen explosions. , Table 2 Synergistic Factors of Different Compound Knock Suppressants , , , , The data in Table 2 are only the results calculated using the synergistic factor calculation formula under a small number of different hydrogen equivalent ratios and different compounding ratios. The amount of data is related to the data gradient setting. Based on the multiple synergistic factors calculated in Table 2, it is possible to help screen out the appropriate volume fractions of trifluoroiodoform and carbon dioxide for chemical experiments. At the same time, the subsequent physical inhibition effect contribution factor, chemical inhibition effect contribution factor, and cost data can be referenced to select some data for chemical experiment verification, which reduces the amount of experimentation to a certain extent.

[0022] Chemical experiments were conducted to verify the explosion-suppressing performance of the compound explosion suppressant, specifically as follows: The compounding method of the compound explosion suppressant is as follows: trifluoroiodomethane and carbon dioxide are premixed in a certain proportion and then released into a closed experimental device; Premixing by proportion is to control the total volume fraction of the detonator and change the proportion of the halogenated hydrocarbon detonator. The volume proportion of the halogenated hydrocarbon detonator ranges from 0% to 100%. The compounded explosion suppressant is released into a closed experimental device containing hydrogen. The content of combustible gas is variable. The mixture explodes when ignited by a high-pressure pulse. At the same time, the total volume fraction of the detonator and the proportion of the halogenated hydrocarbon detonator can be changed to completely suppress the detonation of the combustible gas, thus obtaining compound detonators with different volume fractions and compounding ratios. In this embodiment, the combustible gas used in the experiment was hydrogen. The selected hydrogen equivalence ratios (φ) are shown in Table 1, with φ being 0.6, 1.0, 1.4, and 1.8, corresponding to volume fractions of 20.1%, 29.6%, 37.0%, and 43.1%. When carbon dioxide is used alone to suppress hydrogen explosions, the concentration gradient of carbon dioxide is set to 5%, and the concentration gradient of trifluoroiodomethane is set to 2%. The total integral of the compound explosion suppressant was set to 5%, 10%, 15% and 20%, with the volume ratio of trifluoroiodomethane in the compound explosion suppressant ranging from 0% to 100%, and the gradient set to 10%. Table 1 shows that the hydrogen equivalence ratio for complete suppression is 0.6–1.8. The volume fraction of CF3I used alone is less than that of CO2. The highest required CF3I volume fraction (18%) is needed when the hydrogen equivalence ratio is 0.6. Experiments revealed that when two detonators are used in combination, a total integral of 5% and 10% cannot completely suppress hydrogen with an equivalence ratio of 0.6. When the total integral of the combined detonator is 15%, the required CO2 volume fraction is 9%, and the required CF3I volume fraction is... When the total volume fraction is 6%, hydrogen with a hydrogen equivalence ratio of 0.6 can be completely suppressed. Therefore, when the hydrogen equivalence ratio is 0.6, the total volume fraction of the compound explosion suppressant is selected for analysis and calculation at 15% and 20%. Similarly, when the hydrogen equivalence ratio is 1.0, the total volume fraction of the compound explosion suppressant is selected at 10%; when the hydrogen equivalence ratio is 1.4, the total volume fraction of the compound explosion suppressant is selected at 5% and 10%; and when the hydrogen equivalence ratio is 1.8, the total volume fraction of the compound explosion suppressant is selected at 5%. When the total volume fraction continues to increase, even with the addition of a small amount of CF3I, hydrogen cannot explode. However, if the total volume fraction is too high, even if hydrogen explosion can be suppressed, the suppression efficiency per unit volume fraction of the compound explosion suppressant will decrease. Therefore, the hydrogen equivalence ratio and compound explosion suppressant in Table 3 were selected to calculate the synergy factor. Based on the chemical experimental results (significant suppression of hydrogen explosion) and the result that the calculated synergy factor is less than 1, it was verified that the synergy factor can be used as an evaluation index to predict the effectiveness of compound explosion suppressant in suppressing gas explosion.

[0023] Table 3. Volume fraction and synergistic factor of different compound explosion suppressants (CO2 / CF3I) at complete explosion suppression , Table 4 shows the experimental results of the suppression effect of the compound explosion suppressor on hydrogen explosions. It can be seen that when two explosion suppressors are used in combination, a synergistic suppression effect is achieved when the synergistic factor is less than 1.

[0024] Table 4. Synergistic effect of different compound explosion suppressants (i-C4H8 and CO2) on hydrogen explosions , To reveal the principle of synergistic suppression effect, the method for predicting the synergistic suppression performance of compound explosion suppressants in a confined space in this embodiment further includes: (ii) Calculate the contribution factors of physical inhibition effect and chemical inhibition effect when compound explosion suppressants synergistically suppress combustible gas explosions, and predict the physical inhibition effect and chemical inhibition effect when compound explosion suppressants synergistically suppress gas explosions based on the contribution factors of physical inhibition effect and chemical inhibition effect.

[0025] This method can be used to obtain the dynamic changes in the physical and chemical inhibition effects of compound explosion suppressants, and to verify whether the inhibition effect has been effectively improved.

[0026] The effects of the two contributing factors of the compound explosion suppressant on the laminar combustion rate of combustible gas explosion were studied using reaction kinetic simulation. The reaction kinetics simulation method is as follows: using CHEMKIN software, combining three mechanism files—gas phase kinetics file, surface kinetics file, and transmission data file—and a one-dimensional laminar combustion velocity model, the laminar combustion velocity of combustible gas explosion before and after the addition of the compound detonator is calculated. Assume the compound explosion suppressant used is m; To quantify the impact of different inhibition effects on laminar combustion velocity, a virtual substance, namely Vir1-m, was set up in the numerical simulation. Vir1-m has the same thermophysical parameters and transport characteristics as m, but does not participate in any reaction of combustible gas explosion. That is, Vir1-m only affects the physical suppression effect of combustible gas explosion. Assuming the laminar combustion rate of the combustible gas flame without the addition of a knock suppressor is S 0, when m is added, the laminar combustion rate of the combustible gas is S u0 The laminar combustion rate when Vir1-m is added is S u1 The contribution factors of the two inhibitory effects are defined as follows: Physical inhibition effect contribution factor ; Contributing factors of chemical inhibition effect ; By calculating the changes in the laminar combustion velocity of combustible gases after adding compound detonators with different volume fractions and compounding ratios, the physical and chemical inhibition effects of the compound detonators were calculated and compared with the inhibition effects of single-component detonators.

[0027] Figure 1 The contributing factors to the physical and chemical effects of single-component CO2 and CF3I explosion suppressants in inhibiting hydrogen explosions. Figure 1 (a) The contribution factors of CO2 inhibition effect at different hydrogen equivalence ratios. It can be seen that when the hydrogen equivalence ratio is 0.6, the contribution factors of both physical and chemical inhibition effects do not change significantly with increasing CO2 volume fraction, with the physical inhibition effect contributing 77% and the chemical inhibition effect contributing 23%. When the hydrogen equivalence ratio is greater than or equal to 1.0, the contribution factor of the physical inhibition effect gradually increases with increasing CO2 volume fraction; the higher the hydrogen equivalence ratio, the higher the contribution factor of the physical inhibition effect. The lowest physical inhibition effect is 65%, and the highest can reach 97.5%.

[0028] Figure 1 (b) shows the contribution factor of CF3I's suppression effect at different hydrogen equivalence ratios. It can be seen that at a hydrogen equivalence ratio of 0.6, as the volume fraction of CF3I increases, the contribution factor of the physical suppression effect gradually decreases, while the contribution of the chemical effect gradually increases. Specifically, with 2% CF3I as the detonator, the contribution factor of the chemical suppression effect is 71.3%, and with 8% CF3I, the contribution factor is 37.3%. This indicates that with a small amount of CF3I, chemical suppression is the primary effect. As the volume fraction continues to increase, the chemical suppression effect reaches saturation, the physical suppression effect gradually increases, and the chemical suppression effect ratio gradually decreases. Therefore, combining CF3I with CO2 can effectively exert its chemical suppression effect.

[0029] In addition, CF3I primarily exerts its chemical inhibition effect because it is relatively stable at room temperature but easily decomposes upon heating, and its decomposition products can react with H2 and O2 to achieve chemical inhibition. CO2 primarily exerts its physical inhibition effect because it is chemically stable and difficult to decompose even at high temperatures. However, adding a large amount of CO2 can dilute the O2 concentration, and CO2's specific heat capacity is higher than that of N2, allowing it to absorb some heat, thus resulting in a better physical inhibition effect. Of course, CF3I has a higher specific heat capacity than CO2, so when the same amount of CF3I is added, its physical and chemical inhibition effects are better than those of CO2. However, CF3I is significantly more expensive than CO2, so it is not suitable for large-scale use in industrial production. However, by using both types of detonators in combination, their advantages can be effectively combined to improve the inhibition efficiency.

[0030] Figure 2 The horizontal axis X in the figure represents the contribution factors of physical and chemical inhibition effects when two detonators are used in combination. CF3I This represents the proportion of CF3I in the total volume fraction of the two knock suppressors. It can be seen that, at different hydrogen equivalence ratios, as the volume ratio of CF3I increases, the contribution factor of the chemical suppression effect increases, while the contribution factor of the physical suppression effect decreases. For example... Figure 2 As shown in (a), when the hydrogen equivalence ratio is 0.6 and the total integral is 15%, the contribution factor of the chemical inhibition effect increases from 24.0% to 44.5% as the volume ratio of CF3I increases from 0 to 0.3. When the total integral is 20%, the chemical inhibition effect increases from 22.2% to 36.9% as the volume ratio of CF3I increases from 0 to 0.15. Compared with using 15% and 20% single-component CO2, the contribution factor of the chemical inhibition effect increases without changing the dilution effect. Figure 2 As shown in (b), when the hydrogen equivalence ratio is 1.0 and the total integral is 10%, the contribution factor of the chemical inhibition effect increases from 29.7% to 64.7% as the volume ratio of CF3I increases from 0 to 0.4. Compared with using 10% single-component CO2, the contribution factor of the chemical inhibition effect increases while the dilution effect remains unchanged. Figure 2 As shown in (c), when the hydrogen equivalence ratio is 1.4 and the total integral is 5%, the contribution factor of the chemical inhibition effect increases from 15.4% to 69.8% as the volume ratio of CF3I increases from 0 to 0.8. When the total integral is 10%, the chemical inhibition effect increases from 10.6% to 47.4% as the volume ratio of CF3I increases from 0 to 0.2. Compared with using 5% and 10% single-component CO2, the contribution factor of the chemical inhibition effect increases without changing the dilution effect. Figure 2 As shown in (d), when the hydrogen equivalence ratio is 1.8 and the total integral is 5%, the contribution factor of the chemical inhibition effect increases from 8.5% to 61.5% as the volume ratio of CF3I increases from 0 to 0.5. Compared with using 5% single-component CO2, the contribution factor of the chemical inhibition effect increases while the dilution effect remains unchanged. This indicates that the chemical inhibition effect is improved after adding CF3I.

[0031] In summary, when the volume fraction of the detonator is constant, the physical inerting effect on oxygen and combustible gases is constant. As the proportion of halogenated hydrocarbons CF3I increases, the laminar combustion rate of combustible gases decreases, and the chemical inhibition effect is improved.

[0032] To control costs, the method for predicting the synergistic effect of compound explosion suppressants in suppressing gas explosions in confined spaces, as described in this embodiment, further includes: (III) Calculate the suppression cost of compounded explosion suppressants synergistically suppressing flammable gas explosions, based on the synergy factor. S Comprehensive screening and compounding of explosion suppressants based on explosion suppression costs ， Or based on synergistic factors S、 The contribution factors of physical inhibition effect, chemical inhibition effect, and explosion suppression cost were comprehensively considered to screen compound explosion suppressants.

[0033] This embodiment introduces the prices of explosion suppressant 1 and explosion suppressant 2 in the compound explosion suppressant described on the market, calculates the price of the compound explosion suppressant under different volume fractions and compounding ratios when the combustible gas is completely suppressed, and finds the compounding ratio with the lowest price as the optimal compounding ratio. The formula for calculating the explosion suppression cost of the compound explosion suppressant under different volume fractions and compounding ratios is as follows: Y = V 1÷22.4× M 1 × X 1+ V 2÷22.4× M 2 × X 2; Where M1, V1, and X1 are the relative molecular mass, volume, and unit price per kilogram of the added explosion suppressant 1, respectively; M2, V2, and X2 are the relative molecular mass, volume, and unit price per kilogram of the added explosion suppressant 2, respectively; 22.4 is the gas standard condition molar volume constant; and Y is the explosion suppression cost of the compound explosion suppressant.

[0034] In this embodiment, the explosion suppressant 1 is carbon dioxide with a relative molecular mass M1 of 44 and a unit price (X1) of 30 yuan per kilogram; the explosion suppressant 2 is CF3I with a relative molecular mass M2 of 196 and a unit price (X2) of 2000 yuan per kilogram. Substituting these values ​​into the above formula for calculating the price of compound explosion suppressants under different volume fractions and compounding ratios: Y =0.06 V 1 +17.5 V 2; Table 5 shows the synergy factor and cost under different blending ratios when the hydrogen equivalence ratio is 1.0. It can be seen that by calculating the synergy factor and cost in advance, it is possible to effectively avoid conducting a large number of experiments. Experiments can be conducted by selecting a blending ratio with a smaller synergy factor.

[0035] Table 5. Synergistic factors and costs of different compounded knock suppressants (CO2 and CF3I) , The data in Table 6 are volume fractions, while the calculation formula contains... VSince this represents volume, calculations need to be performed in conjunction with a specific sealed container. The sealed container used in this experiment is 20L, requiring conversion. For example, a gas with a volume fraction of 10% has an actual volume of 2L. The actual cost is then calculated using the formula.

[0036] Table 6. Cost of complete explosion suppression with compound explosion suppressor (CO2 / CF3I) , As shown in Table 6, by calculating the optimal compounding ratio for complete suppression of explosions using the compounded explosion suppressant, the lowest cost (14.1 yuan) is achieved when the hydrogen equivalence ratio is 0.6, the total component of the compounded explosion suppressant is 20%, and the volume fraction of CF3I is 4%. The lowest cost (10.6 yuan) is achieved when the hydrogen equivalence ratio is 1.4, the total component of the explosion suppressant is 10%, and the volume fraction of CF3I is 3%. The lowest cost (10.5 yuan) is achieved when the hydrogen equivalence ratio is 1.8, the total component of the explosion suppressant is 5%, and the volume fraction of CF3I is 3%. Further increasing the total component will decrease the cost, but will also increase the required amount of explosion suppressant and reduce the suppression effect.

[0037] Based on the above three aspects, this invention can predict whether compounded explosion suppressants have a synergistic suppression effect, reveal the principle of synergistic suppression of compounded explosion suppressants, and calculate the optimal compounding ratio.

[0038] This embodiment also provides an application based on the synergistic effect of compound explosion suppressants in suppressing gas explosions in a confined space. Based on the synergistic effect of compound explosion suppressants in suppressing gas explosions in a confined space, compound explosion suppressants are screened, that is, the types and volume fractions of explosion suppressant 1 and explosion suppressant 2 are screened. Based on the contribution factors of physical inhibition effect and chemical inhibition effect, we screened compound explosion suppressants that require physical or chemical inhibition effect. Alternatively, a combination of explosion suppressants can be screened based on the synergistic factor S and the explosion suppression cost. Alternatively, a combination of explosion suppressants can be screened based on the synergistic factor S, the contribution factor of physical inhibition effect, the contribution factor of chemical inhibition effect, and the explosion suppression cost.

[0039] This invention addresses practical application scenarios by using theoretical calculations to predict the synergistic suppression effect of compound explosion suppressants. Numerical simulations reveal the physical and chemical suppression effects of the compound explosion suppressants on flammable gas explosions, elucidating the synergistic suppression principle and effectively reducing experimental workload. Furthermore, experimental studies investigate the suppression effects of different volume fractions and mixing ratios of the compound explosion suppressant, obtaining the volume fraction and mixing ratio required for complete suppression of flammable gas explosions. By incorporating the unit price of the explosion suppressant, the volume fraction and mixing ratio corresponding to the lowest cost for complete suppression can be calculated, thus obtaining the optimal mixing ratio. In summary, through experimental research, theoretical calculations, and numerical simulations, the optimal mixing ratio for suppressing flammable gas explosions with compound explosion suppressants is obtained, improving suppression efficiency while reducing the cost of using the suppressant.

[0040] This invention simultaneously calculates the physical and chemical suppression efficacy of the compounded explosion suppressant using numerical simulation methods, revealing the principle of synergistic suppression. Finally, by calculating the usage cost, the optimal compounding ratio of inert gas halogenated hydrocarbons for synergistic suppression of flammable gas explosions is obtained. The inert gas is carbon dioxide, which mainly plays an inertizing role, while the halogenated hydrocarbon is trifluoroiodomethane, which mainly plays a chemical suppression role. The compounding of the two explosion suppressants can combine the advantages of both, exhibiting a good synergistic suppression effect, improving the suppression efficiency, and reducing the usage cost. The evaluation method of this invention is a theoretical prediction method, which defines a synergistic factor. S The actual volume fractions of suppressants 1 and 2 used alone in a completely non-explosive scenario were compared with the ratio of the actual volume fractions of suppressants 1 and 2 in a compound suppressant. The numerical simulation method of this invention is a reaction kinetics simulation method. By quantifying the contribution factors of the physical and chemical suppression effects of the compound suppressant of inert gas and halogenated hydrocarbons in synergistically suppressing flammable gas explosions, the principle of synergistic suppression was revealed. The optimal compounding ratio is calculated by introducing the price of the suppressant on the basis of synergistic suppression, thus determining the minimum usage cost. Theoretical and numerical simulation calculations revealed that the compound use of carbon dioxide and trifluoroiodine methyl ether suppressants to suppress hydrogen explosions has a synergistic factor of less than 1, exhibiting a good synergistic suppression effect, with improved chemical suppression.

[0041] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any way. Any simple modifications, alterations, and equivalent changes made to the above embodiments based on the inventive essence shall still fall within the protection scope of the present invention.

Claims

1. A method for predicting the synergistic effect of a compound explosion suppressant in suppressing gas explosions in a confined space, wherein the compound explosion suppressant consists of explosion suppressant 1 and explosion suppressant 2, characterized in that, This method includes calculating the cooperability factor. S， Based on synergistic factors S The synergistic factor is used to quantitatively predict the effectiveness of compounded explosion suppressants in inhibiting gas explosions. S The calculation formula is as follows: ； In the formula, , These are the volume fractions of explosion suppressant 1 and explosion suppressant 2, respectively, when the compound explosion suppressant completely suppresses the explosion of flammable gas. To completely suppress the explosion of flammable gas using suppressant 1, the volume fraction of suppressant 1 used alone is... The volume fraction of explosion suppressant 2 used alone when it is used to completely suppress the explosion of flammable gas; when S When the value is greater than 1, it indicates that the explosion suppressant 1 and the explosion suppressant 2 have a negative synergistic inhibition effect, that is, when they are combined for inhibition, they inhibit each other, and the inhibition effect is less than the sum of the individual inhibition effects. when S When =1, it indicates that there is no synergistic suppression effect between explosion suppressant 1 and explosion suppressant 2; when S When <1, it indicates that there is a positive synergistic inhibition effect between explosion suppressant 1 and explosion suppressant 2. That is, when they are combined for inhibition, they have a promoting effect on each other, and the inhibition effect is greater than the sum of the individual inhibition effects. The method also includes calculating the contribution factors of physical inhibition effect and chemical inhibition effect when the compound explosion suppressant synergistically inhibits the explosion of combustible gas, and predicting the physical inhibition effect and chemical inhibition effect when the compound explosion suppressant synergistically inhibits the explosion of gas based on the contribution factors of physical inhibition effect and chemical inhibition effect. The effects of the two contributing factors of the compound explosion suppressant on the laminar combustion rate of combustible gas explosion were studied using reaction kinetic simulation. The reaction kinetics simulation method is as follows: using CHEMKIN software, combining three mechanism files—gas phase kinetics file, surface kinetics file, and transmission data file—and a one-dimensional laminar combustion velocity model, the laminar combustion velocity of combustible gas explosion before and after the addition of the compound detonator is calculated. Assume the compound explosion suppressant used is m; To quantify the impact of different inhibition effects on laminar combustion velocity, a virtual substance, namely Vir1-m, was set up in the numerical simulation. Vir1-m has the same thermophysical parameters and transport characteristics as m, but does not participate in any reaction of combustible gas explosion. That is, Vir1-m only affects the physical suppression effect of combustible gas explosion. Assuming the laminar combustion velocity of the combustible gas flame without the addition of a knock suppressant is S0, and the laminar combustion velocity of the combustible gas with the addition of m is Su0; and the laminar combustion velocity with the addition of Vir1-m is Su1, the contribution factors of the two suppression effects are defined as follows: The formula for calculating the contribution factor ω1 of the physical inhibition effect is: ; The formula for calculating the contribution factor ω2 of the chemical inhibition effect is: ; In the compound explosion suppressant, explosion suppressant 1 is an inert gas and explosion suppressant 2 is a halogenated hydrocarbon.

2. The method for predicting the synergistic suppression performance of compound explosion suppressants in a confined space according to claim 1, further comprising calculating the suppression cost of compound explosion suppressants synergistically suppressing combustible gas explosions, based on a synergistic factor. S Comprehensive screening and compounding of explosion suppressants based on explosion suppression costs ， Or based on synergistic factors S、 The contribution factors of physical inhibition effect, chemical inhibition effect, and explosion suppression cost were comprehensively considered to screen compound explosion suppressants. The formula for calculating the explosion suppression cost is as follows: Y = V 1÷22.4× M 1 × X 1+ V 2÷22.4× M 2 × X 2； in, M 1 、V 1 and X 1 represents the relative molecular mass, volume, and unit price per kilogram of the added explosion suppressant 1; M 2 、V 2 and X 2 represents the relative molecular mass, volume, and unit price per kilogram of the added detonator 2; 22.4 is the molar volume constant under standard gas conditions, in L / mol. Y The cost of suppressing explosions with compound explosion suppressants.

3. The method for predicting the synergistic effect of compound explosion suppressants in suppressing gas explosions in a confined space according to claim 1, characterized in that, The inert gas is carbon dioxide, and the halocarbon is trifluoroiodomethane.

4. An application method based on the synergistic suppression of gas explosions by compound explosion suppressants in confined spaces, characterized in that, Based on the method for predicting the synergistic effect of compound explosion suppressants in suppressing gas explosions in a confined space as described in claim 1, compound explosion suppressants are screened, namely, the types and volume fractions of explosion suppressant 1 and explosion suppressant 2 are screened.

5. The application method according to claim 4, characterized in that, Based on the contribution factors of physical inhibition effect and chemical inhibition effect, we screened compound explosion suppressants that require physical or chemical inhibition effect. Or, based on synergistic factors S Explosion suppressants were selected and compounded based on a comprehensive consideration of explosion suppression costs; Or, based on synergistic factors S、 The contribution factors of physical inhibition effect, chemical inhibition effect, and explosion suppression cost were comprehensively considered to screen compound explosion suppressants.

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