Composite powder explosion suppressant and design method and preparation method thereof

Abstract

The invention relates to the technical field of explosion suppression, in particular to a composite powder explosion suppressant and a design method and a preparation method thereof. The composite powder explosion suppressant is prepared from the following components in parts by mass: 20 to 25 parts of aluminum oxide, 10 to 20 parts of magnesium oxide, 20 to 30 parts of silicon dioxide, 1 to 3 parts of cerium oxide, 10 to 15 parts of potassium bicarbonate, 10 to 15 parts of sodium bicarbonate, 3 to 8 parts of gas-phase hydrophobic white carbon black and 2 to 6 parts of talcum powder. The composite powder explosion suppressant disclosed by the invention is high in explosion suppression efficiency; the metal oxide component screened through quantum chemistry calculation has good explosion suppression performance, and all the components in the composite powder explosion suppressant have a synergistic effect, so that hydrogen explosion can be effectively inhibited.

Description

Technical Field

[0001] The present invention relates to the technical field of explosion suppression, and in particular to a composite powder explosion suppressant and a design method and a preparation method thereof. Background Art

[0002] Hydrogen energy is a clean, efficient, abundant, and widely used secondary energy source. It is considered one of the most promising alternative energy sources to traditional fossil fuels. It can play an important role in addressing energy crises and global warming. It is an ideal carrier for promoting the large-scale utilization of renewable energy and an important tool for achieving a green and low-carbon energy transition. However, due to the special physical and chemical properties of hydrogen, such as a wide range of explosion limits, low ignition energy, and fast laminar combustion speed, it is highly flammable and explosive. Once a leak occurs, it can easily induce an explosion, causing casualties and property damage. Spraying explosion suppressants can inhibit, interrupt, or slow down the hydrogen explosion reaction chain, weaken the intensity of hydrogen explosions, and protect places where the hydrogen concentration reaches the explosion limit. It is one of the means to prevent and control hydrogen explosion accidents.

[0003] A key issue in developing explosion suppression technology is the development or selection of appropriate suppression materials for the target combustibles. The high reactivity of hydrogen places stringent demands on the development of suitable suppression agents, including effectiveness, environmental friendliness, and cost.

[0004] Current research on hydrogen explosion suppression materials primarily focuses on ultrafine water mist, inert gases (such as CO2 and N2), halogenated hydrocarbons (such as heptafluoropropane and trifluoroiodomethane), and hydrocarbons (such as propane and ethylene). However, these efforts have been less than ideal, with drawbacks such as low explosion suppression efficiency, high cost, and negative environmental impacts. Powdered explosion suppressants are also widely used in gas explosion prevention due to their low cost, environmental friendliness, and ease of storage and transportation. However, because hydrogen reacts more rapidly than more common combustible gases like methane (the main component of gas), traditional single powdered explosion suppressants (such as ammonium phosphate dry powder, NaHCO3, and KHCO3) struggle to fully exert their chemical explosion suppression effectiveness, resulting in poor suppression results.

[0005] Therefore, it is necessary to provide a composite powder explosion suppressant with good explosion suppression effect. Summary of the Invention

[0006] To solve the above technical problems, the present invention provides a design method for a composite powder explosion suppressant. The method designs a composite powder explosion suppressant with good explosion suppression effect from a theoretical perspective.

[0007] A further technical problem to be solved by the present invention is to provide a composite powder explosion suppressant and a preparation method thereof.

[0008] In order to achieve the above object, the present invention adopts the following technical solutions:

[0009] A composite powder explosion suppressant comprises the following components, calculated by mass: 20-25 parts of aluminum oxide, 10-20 parts of magnesium oxide, 20-30 parts of silicon dioxide, and 1-3 parts of cerium oxide.

[0010] Preferably, the composite powder explosion suppressant further comprises 10-15 parts of potassium bicarbonate, 10-15 parts of sodium bicarbonate, 3-8 parts of fumed hydrophobic silica, and 2-6 parts of talc.

[0011] More preferably, 90% of the particle sizes of the composite powder explosion suppressant are less than or equal to 5 μm, that is, the composite powder explosion suppressant is an ultrafine composite powder explosion suppressant.

[0012] The design method of the composite powder explosion suppressant comprises the following steps:

[0013] S1: Structural optimization and frequency analysis of key elementary reactions in the application field of composite powder explosion suppressants are performed to obtain the correct optimized configuration;

[0014] S2: performing single-point energy calculation on the correct optimized configuration to obtain the energy difference of the key elementary reaction;

[0015] S3: Calculate the effect of the powder on the total energy of the reaction system under the correct optimized configuration to obtain the energy difference of the key elementary reaction under the condition of the powder;

[0016] S4: Compare the result of step S3 with the result of step S2 to obtain a ranking of the explosion suppression performance of the powder;

[0017] S5: Screening and obtaining the component formula of the composite powder explosion suppressant according to the result of step S4.

[0018] The step S1: structural optimization and frequency analysis of key elementary reactions in the application field of the composite powder explosion suppressant specifically includes the following steps:

[0019] S11: Structural optimization of key elementary reactions in the application field of composite powder explosion suppressants, wherein the structural optimization specifically involves continuously adjusting the geometric configuration of the system until the total energy of the system reaches a local minimum, thereby obtaining an optimized configuration;

[0020] S12: Perform frequency analysis on the optimized configuration to confirm that the correct optimized configuration is obtained.

[0021] The step S3: calculating the effect of the powder on the total energy of the reaction system under the correct optimized configuration specifically comprises the following steps:

[0022] S31: Calculate the isolated single point energy of the powder and the single point energy of the powder in various states in the key elementary reactions;

[0023] S32: Obtain the reaction path energy difference under the condition of the powder being present according to the single point energy calculated in step S31.

[0024] The step S5: screening and obtaining the component formula of the composite powder explosion suppressant according to the result of step S4 specifically comprises the following steps:

[0025] S51: Obtaining candidate powders with excellent explosion suppression performance according to the sorting results of step S4;

[0026] S52: A secondary screening is conducted from the two dimensions of safety and economy, and finally a component formula of a composite powder explosion suppressant with a balance of performance, safety and cost is obtained.

[0027] The composite powder explosion suppressant is used to suppress hydrogen explosions.

[0028] The preparation method of the composite powder explosion suppressant comprises the following steps:

[0029] S01: Weigh each component raw material according to the proportion;

[0030] S02: Drying the weighed raw materials; the drying conditions are: temperature 60-80°C, time 10-14h;

[0031] S03: Dry compounding the dried raw materials to obtain composite powder; this embodiment adopts ball milling for dry compounding;

[0032] S04: performing coating and modification treatment on the composite powder to obtain coated and modified powder;

[0033] S05: Drying the coated modified powder obtained in step S04 again;

[0034] S06: The composite powder material obtained in step S05 is subjected to sieving treatment to obtain an ultrafine composite powder explosion suppressant with a particle size of less than or equal to 5 μm. The sieving treatment is to place the composite powder material into a 3000 mesh filter screen for sieving.

[0035] Preferably, the coating modification treatment of the composite powder obtained in step S03 is specifically to place the composite powder obtained in step S03 into methyl hydrogen silicone oil for stirring, wherein the mass of the methyl hydrogen silicone oil is 0.5-2% of the mass of the composite powder, the stirring speed is 200-400 r / min, and the stirring time is 30-60 min.

[0036] The beneficial effects of the present invention are as follows:

[0037] (1) The design method of the composite powder explosion suppressant of the present invention is highly innovative. For the first time, the influence of metal oxide materials on the key elementary reactions of hydrogen combustion was systematically studied from the perspective of quantum chemical calculation, which provided a theoretical basis for the selection of explosion suppressant components, greatly saving experimental time and resources.

[0038] (2) The composite powder explosion suppressant of the present invention has high explosion suppression efficiency; the metal oxide components selected by quantum chemical calculation have good explosion suppression performance, and the components in the composite powder explosion suppressant work synergistically to effectively suppress hydrogen explosion.

[0039] (3) The composite powder explosion suppressant of the present invention is environmentally friendly and low-cost; the raw materials selected in the present invention are all common inorganic substances that are non-toxic and harmless and will not have a negative impact on the environment; the raw materials are widely available and low-priced, and have good prospects for engineering application.

[0040] (4) The preparation process of the composite powder explosion suppressant of the present invention is simple: it is prepared by dry compounding technology, which is simple to operate and easy to realize industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] Figure 1 is the IRC diagram of the key elementary reaction of hydrogen combustion in Example 1;

[0042] Figure 2 Result diagram comparing explosion overpressure-time curves before and after the composite powder explosion suppressant prepared in Examples 2 to 4;

[0043] Figure 3 Result diagram comparing the explosion overpressure rise rate-time curves before and after the composite powder explosion suppressant of Examples 2 to 4;

[0044] Figure 4 This is a result diagram comparing the explosion overpressure-time curves of the composite powder explosion suppressant prepared in the comparative example and the composite powder explosion suppressant prepared in Example 2 before and after the action.

[0045] Figure 5 This is a result diagram comparing the explosion overpressure rise rate-time curves of the composite powder explosion suppressant prepared in the comparative example and the composite powder explosion suppressant prepared in Example 2 before and after the action. DETAILED DESCRIPTION

[0046] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only intended to illustrate the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0047] The design method of the composite powder explosion suppressant of the present invention is the first to systematically study the influence of metal oxide materials on the key elementary reactions of hydrogen combustion from the perspective of quantum chemical calculation, providing a theoretical basis for the selection of explosion suppressant components, greatly saving experimental time and resources.

[0048] Single-point energy refers to the calculated energy of the electrons in a system, assuming the positions of the atomic nuclei of a molecule remain fixed. In this study, we first used a calculation method (B3LYP-D3(BJ) / 6-31G(d,p)) to optimize the most stable spatial structures of the reactants, transition states, and products. Then, we used a more precise calculation method (M06-2X / def2-TZVPP) to calculate the energy of these most stable spatial structures. This energy is known as the "single-point energy." This approach aims to obtain more reliable energy data at an acceptable computational cost.

[0049] Energy change is a key metric for evaluating the effectiveness of explosion suppressants. The effectiveness of an explosion suppressant is determined by comparing the energy difference (e5 - e3) between the key elementary reactions of hydrogen combustion with and without an explosion suppressant (metal oxide). If the addition of an explosion suppressant significantly alters the energy change of the reaction (for example, by increasing the reaction energy barrier or dramatically changing the reaction heat), it indicates that the inhibitor has effectively intervened in the reaction and thus has explosion suppression potential.

[0050] Example 1

[0051] A method for designing a composite powder explosion suppressant comprises the following steps:

[0052] S1: Structural optimization and frequency analysis of key elementary reactions in the application field of composite powder explosion suppressants. The correct optimized configuration obtained in step S1 is the most stable spatial structure of reactants, transition states, and products.

[0053] The composite powder explosion suppressant of this embodiment is used in the field of suppressing hydrogen explosions, so step S1 requires structural optimization and frequency analysis of key elementary reactions of hydrogen combustion.

[0054] Wherein, step S1 includes the following steps:

[0055] S11: Structural optimization of key elementary reactions in the application field of composite powder explosion suppressants, wherein the structural optimization specifically involves continuously adjusting the geometric configuration of the system until the total energy of the system reaches a local minimum, thereby obtaining an optimized configuration;

[0056] S12: Perform frequency analysis on the optimized configuration to confirm that the correct optimized configuration is obtained.

[0057] "Structure optimization" is a computational process that seeks the lowest energy point in a system to determine its most stable geometric configuration. Frequency analysis of the optimized structure verifies its structural properties: the stable structures of reactants and products should have no imaginary frequencies, while the transition state structure should have exactly one imaginary frequency, indicating that it is an energy saddle point connecting the reactants and products. All optimized structures in this paper were confirmed through frequency analysis.

[0058] Specifically, structural optimization is the process of automatically finding the "most stable" geometric configuration of a molecule or system during computation. The computational program continuously adjusts the positions of atoms (bond lengths and angles) until the total energy of the system reaches a local minimum. The result of this optimization is the equilibrium configuration of reactants, products, and transition states.

[0059] Frequency analysis is a check on the optimized configuration. Its results serve two important purposes: first, confirming the structural properties. For reactants and products, their vibrational frequencies should all be real frequencies (positive values); for the transition state, there must be exactly one imaginary frequency (negative value), the direction of which corresponds to the direction of the reaction crossing the energy barrier. Second, it verifies that the transition state found is indeed the correct saddle point connecting the reactants and products.

[0060] In the present invention, the key elementary reactions of hydrogen combustion include:

[0061] R7, H2+O2→H+HO2;

[0062] R1, H+O2→O+OH;

[0063] R2, O+H2→H+OH;

[0064] R3, OH+H2→H+H2O.

[0065] Specifically, the B3LYP-D3(BJ) / 6-31G(d,p) functional and basis set were first used to perform structural optimization and frequency analysis on the key elementary reactions of hydrogen combustion H2+O2=H+HO2(R7), H+O2=O+OH(R1), O+H2=H+OH(R2), and H2+OH=H2O+H(R3).

[0066] like Figure 1 As shown, the potential energy curves of these four elementary reactions were verified by IRC (intrinsic reaction coordinate) calculation. Figure 1 The horizontal axis represents the reaction coordinate, the vertical axis represents the relative energy, and the highest point on each curve corresponds to the transition state structure of the reaction. Figure 1 S1 in the figure is the potential energy curve of the R7 reaction. Figure 1 S2 in the figure is the potential energy curve of the R1 reaction. Figure 1 S3 in the figure is the potential energy curve of the R2 reaction. Figure 1S4 in the figure is the potential energy curve of the R3 reaction.

[0067] IRC calculations confirm that the resulting transition state connects the target reactants and products, and also provide information on the energy changes along the reaction path. R7 and R1 represent the chain initiation reactions during hydrogen combustion, while R2 and R3 represent the chain propagation reactions. These reactions constitute the key steps in the hydrogen explosion reaction chain.

[0068] S2: Single-point energy calculation is performed on the correctly optimized configuration to obtain the energy difference of the key elementary reaction, that is, the energy difference of the key elementary reaction under the condition of no additive (powder).

[0069] In this example, the M06-2X / def2-TZVPP functional and basis set were used to perform single-point energy calculations on the optimized configuration. The results are shown in Table 1.

[0070] Table 1 Energy values ​​of key elementary reactions of hydrogen combustion

[0071] S3: Calculate the effect of different powders on the total energy of the reaction system under the correct optimized configuration to obtain the energy difference of the key elementary reactions under the condition of the powder presence.

[0072] Specifically, step S3 includes the following steps:

[0073] S31: Calculates the single-point energy of isolated powders and the single-point energy of various powder states in key elementary reactions. Single-point energy is obtained through high-precision quantum chemical calculations, specifically single-point energy calculations for specific systems using the M06-2X / def2-TZVPP functional and basis set.

[0074] The single-point energies obtained in step S31 include e1 to e5. e1 refers to the single-point energy of the isolated powder (metal oxide additive), which is the basic energy value for calculating the additive itself. e2 refers to the total system energy when the metal oxide and the reactants of the key elementary reaction of hydrogen combustion coexist but do not form an interaction. e2 is equal to e1 (the energy of the metal oxide) plus the energy of the reactants. e3 refers to the system energy when the metal oxide and the reactants are considered as a whole (i.e., forming a complex). This is the energy after they interact and reach a stable structure. e4 refers to the total system energy when the metal oxide and the products of the elementary reaction coexist but do not form an interaction. e4 is equal to e1 (the energy of the metal oxide) plus the energy of the products. e5 refers to the system energy when the metal oxide and the products are considered as a whole (i.e., forming a complex). This is the energy after they interact and reach a stable structure.

[0075] S32: Based on the single point energy calculated in step S31, the reaction path energy difference (e5-e3) in the presence of the powder is calculated. Furthermore, step S32 also calculates the interaction energy between the metal oxide and the reactant (e3-e2) and the interaction energy between the metal oxide additive and the reaction product (e5-e4).

[0076] This example uses the M06-2X / def2-TZVPP functional and basis set to analyze the system energy changes under the conditions of the presence of additives (oxides) to evaluate its explosion suppression effect. The results are shown in Tables 2 to 5. Specifically,

[0077] e3-e2 reflects the interaction energy between metal oxides and reactants; e5-e4 represents the interaction energy between metal oxide additives and reaction products, and e5-e4 reflects the trend and strength of the combination of additives and products; e5-e3 represents the energy difference of the reaction path in the presence of additives (i.e., the energy difference of the key elementary reactions of hydrogen combustion in the two cases of "with metal oxides" and "without metal oxides").

[0078] Table 2 Effects of oxides on hydrogen combustion elementary reaction R7

[0079] Table 3 Effects of oxides on the elementary reaction R1 of hydrogen combustion

[0080] Table 4 Effects of oxides on the elementary reaction R2 of hydrogen combustion

[0081] Table 5 Effects of oxides on hydrogen combustion elementary reaction R3

[0082] S4: Compare the results of step S3 with the results of step S2 to obtain a ranking of the explosion suppression performance of different powders; that is, compare the energy difference of the key elementary reaction in the presence of powder obtained in step S3 with the energy difference of the key elementary reaction in the absence of powder obtained in step S2, and evaluate the explosion suppression performance of the powder by comparing the influence of the calculation result obtained in step S3 on the calculation result of step S2.

[0083] The explosion suppression performance of the 12 metal oxides studied was evaluated by comparing the reaction energy differences (e5-e3) in the presence of each metal oxide. As shown in Table 1, for the chain initiation reaction R7 (H2+O2→H+HO2), the energy difference without additives is 1.76683 eV. Here, the "energy difference without additives" refers to the energy change in the pure hydrogen combustion reaction itself, without any external interference. This value serves as the baseline for evaluating explosion suppression effectiveness. By comparing e5-e3 with the baseline, we can determine the impact of the additive on the reaction process. If the e5-e3 value changes significantly from the baseline, it means that the metal oxide has profoundly altered the energy path of this key reaction. This alteration in the energy path is precisely the manifestation of the inhibitory effect of the explosion suppressant—it interacts with the reactants or products, making the original reaction more difficult or taking a different path, thereby interrupting or slowing the explosive chain reaction. Therefore, the greater the difference between e5-e3 and the baseline energy difference, the greater the additive's ability to interfere with the reaction and the better its potential explosion suppression performance.

[0084] Therefore, for reaction R7 (Table 2), the metal oxides that exhibit an inhibitory effect (i.e., change the reaction energy) are ranked according to their intervention intensity on the reaction (based on | (e5-e3) - (original reaction energy difference) |) as follows: NiO |(-6.47558)-1.76683|= 8.24241 eV > Al2O3 (7.50748) > SrO (7.34463) > ZnO(7.21692) > SnO2 (6.74359) > CuO (6.21306) > CeO2 (5.65147) > ZrO2 (5.01401) >MgO (3.37051) > SiO2 (3.34173) > K2O (3.22797) > Na2O (3.08280).

[0085] For the chain initiation reaction R1 (H+O2→O+OH) (Table 3), the energy difference in the absence of additives is -1.18003 eV (Table 1). The metal oxides that show an inhibitory effect are ranked according to their intervention intensity on the reaction as follows: ZnO (3.78751) > CuO(3.39274) > K2O (3.28335) > NiO (2.68974) > CeO2 (2.18254) > Na2O (1.71834) >SnO2 (1.68218) > Al2O3 (1.37471) > SrO (0.68214) > ZrO2 (0.59479) > MgO(0.21838) > SiO2 (0.16501).

[0086] For the chain growth reaction R2 (O+H2→H+OH) (Table 4), the energy difference in the absence of additives is 0.24860 eV (Table 1). The metal oxides that show an inhibitory effect are ranked according to their intervention intensity on the reaction as follows: Al2O3 (9.27961) > SrO(5.81402) > ZrO2 (5.66586) > Na2O (5.55965) > CeO2 (5.09664) > MgO (4.72040) >SnO2 (4.49494) > K2O (4.49384) > SiO2 (4.13261) > CuO (3.64492) > NiO(1.22673) > ZnO (0.80150).

[0087] For the chain growth reaction R3 (H2+OH→H2O+H) (Table 5), the energy difference in the absence of additives is -0.60019 eV (Table 1). The metal oxides that show an inhibitory effect are ranked according to their intervention intensity on the reaction as follows: Al2O3 (3.75234) >CuO (3.66657) > K2O (1.59281) > ZrO2 (1.38903) > MgO (1.36654) > ZnO (1.32401)> CeO2 (1.20584) > Na2O (1.19086) > SiO2 (1.13358) > SrO (0.86793) > NiO(0.58319) > SnO2 (0.46371).

[0088] Based on the analysis of the above four key elementary reaction systems, a comprehensive inhibition performance evaluation of each metal oxide can be obtained. The analysis shows that different metal oxides exhibit their own advantages when intervening in different reaction steps, and there is no one oxide that is optimal in all reactions. Al2O3 exhibits the strongest intervention effect in the chain growth reactions R2 and R3, and ranks second in the R7 reaction, proving that it is the core component with the best comprehensive performance and is indispensable in the formulation system. NiO, ZnO, CuO, CeO2 and SrO, etc., show extremely excellent inhibition potential in specific reaction steps. For example, NiO ranks first in the R7 reaction, and ZnO ranks first in the R1 reaction. This series of calculation results shows that by compounding a variety of oxides with different advantages, a more comprehensive inhibition of the hydrogen explosion chain reaction can be achieved.

[0089] S5: Screening and obtaining the component formula of the composite powder explosion suppressant according to the result of step S4.

[0090] Specifically, step S5 includes the following steps:

[0091] S51: Obtaining candidate powders with excellent explosion suppression performance according to the sorting results of step S4;

[0092] S52: A secondary screening was conducted based on the two dimensions of safety and economy, and finally a component formula of a composite powder explosion suppressant with a balance of performance, safety and cost was obtained.

[0093] Based on the explosion suppression performance evaluation, this example further systematically evaluated metal oxides from the perspectives of safety and economics to determine the optimal explosion suppression component. The safety evaluation primarily examined the material's toxicity, chemical stability, environmental friendliness, and operational safety; the economic evaluation focused on raw material costs, preparation process, and feasibility of large-scale production.

[0094] Studies have found that while alkali metal oxides Na2O and K2O exhibit inhibitory effects on some elementary reactions, they are highly hygroscopic and react violently and exothermically when in contact with water, posing potential safety hazards during storage and use. Among transition metal oxides, NiO is unsuitable as an explosion suppressant component due to its high toxicity and carcinogenicity. While CuO and ZnO have relatively low toxicity and stable chemical properties, their raw material prices are high and their production processes are relatively complex, making them unsuitable for large-scale industrial applications. While SnO2 and ZrO2 have good chemical stability, their raw material prices are expensive, limiting their engineering applications. SrO is highly hygroscopic, and its preparation, storage, and use require special protection, increasing the cost of engineering applications.

[0095] In comparison, Al2O3, SiO2, MgO, and CeO2 all demonstrate significant advantages in terms of safety and cost-effectiveness. Al2O3 and SiO2 are ideal explosion suppression components due to their excellent chemical stability, non-toxicity, and environmental friendliness. Furthermore, their wide availability of raw materials, mature preparation processes, and manageable production costs are key factors. MgO not only offers excellent environmental compatibility and safety, but its low price and abundant raw material availability also ensure its large-scale application. While CeO2 may be relatively expensive, its significant explosion suppression properties and minimal usage make it an indispensable functional enhancement component.

[0096] Based on the above comprehensive evaluation results, the present invention obtains the component formula of the composite powder explosion suppressant, namely Al2O3, SiO2, MgO and CeO2.

[0097] To determine the specific dosages for the aforementioned components, the inventors conducted orthogonal experiments in a 20L spherical explosion device. By continuously adjusting the ratios of the components and using explosion suppression efficiency (peak overpressure reduction rate and overpressure rise rate reduction rate) as evaluation indicators, they ultimately determined a formula range that maximized synergy and achieved cost-effectiveness. This range resulted in a system with Al2O3 (20-25 parts), SiO2 (20-30 parts), MgO (10-20 parts), and CeO2 (1-3 parts) as the primary explosion suppression components.

[0098] In order to further enhance the explosion suppression effect, the present invention adds 10-15 parts of potassium bicarbonate, 10-15 parts of sodium bicarbonate, 3-8 parts of white carbon black and 2-6 parts of talc to the above raw materials.

[0099] Example 2

[0100] This embodiment provides a modified composite powder explosion suppressant. The preparation method is as follows:

[0101] S01: Weigh the following raw materials by mass: 20 parts aluminum oxide, 20 parts magnesium oxide, 20 parts silicon dioxide, 2 parts cerium oxide, 15 parts potassium bicarbonate, 15 parts sodium bicarbonate, 3 parts fumed hydrophobic silica, and 5 parts talc. S02: Place the above raw materials in a vacuum drying oven at 70°C and dry for 10 hours.

[0102] S03: The dried raw materials were put into a planetary ball mill, and the ball-to-material ratio was set to 8:1, the ball milling speed was 400 r / min, and the ball milling time was 3 h.

[0103] S04: The ball-milled composite powder is placed in a blender, and methyl hydrogenated silicone oil is added at a rate of 1% of the mass of the composite powder, with a stirring speed of 300 r / min and a stirring time of 45 min.

[0104] S05: Dry the modified composite powder at 60° C. for 12 h.

[0105] S06: Finally, the mixture was sieved through a 3000-mesh sieve to obtain an ultrafine modified composite powder explosion suppressant with a particle size of 90% less than 5 μm.

[0106] Ultrafineness is one of the key physical properties for achieving efficient explosion suppression. For hydrogen, an explosive reaction with extremely high speed, the explosion suppressant must be able to intervene in the reaction chain instantaneously and over a large area. The ultrafine modified composite powder explosion suppressant of the present invention has the following properties:

[0107] (1) Huge specific surface area: Ultrafine powder has a huge specific surface area, which means that at the same mass, it can provide more active sites for capturing key free radicals such as H• and OH•, and can absorb the heat generated by the explosion more efficiently.

[0108] (2) Excellent suspension and dispersibility: The smaller the particle size, the better the suspension performance of the powder in the air, and the easier it is to be rolled up by the driven airflow and evenly dispersed throughout the explosion area, forming an effective explosion suppression "cloud", thereby achieving global suppression of the explosion rather than local suppression.

[0109] (3) Faster reaction rate: Ultrafine powders can complete chemical explosion suppression processes such as endothermic decomposition (such as bicarbonate) and free radical capture more quickly, thereby fully intervening in the extremely fast reaction chain of hydrogen explosion.

[0110] Example 3

[0111] This embodiment provides an ultrafine modified composite powder explosion suppressant, the preparation method of which is as follows:

[0112] S01. Weigh the following raw materials by mass: 25 parts of aluminum oxide, 10 parts of magnesium oxide, 30 parts of silicon dioxide, 1 part of cerium oxide, 10 parts of potassium bicarbonate, 10 parts of sodium bicarbonate, 8 parts of fumed hydrophobic silica, and 6 parts of talc.

[0113] S02. Place the weighed raw materials in a vacuum drying oven and dry them at 60° C. for 10 h.

[0114] S03. Place the dried raw materials of each component in a planetary ball mill, set the ball-to-material ratio to 5:1, the ball mill speed to 300 r / min, and the ball milling time to 2 h for dry compounding.

[0115] S04. The obtained composite powder was subjected to a coating modification treatment with methyl hydrogen silicone oil, methyl hydrogen silicone oil was added at a rate of 0.5% by mass of the composite powder, and the mixture was stirred in a blender at a stirring speed of 200 r / min for 30 min.

[0116] S05. Place the modified composite powder in a vacuum drying oven again and dry it at 60° C. for 12 hours.

[0117] S06. The dried powder material is sieved through a 3000-mesh filter to obtain an ultrafine modified composite powder explosion suppressant having a particle size mainly distributed below 5 μm.

[0118] Example 4

[0119] This embodiment provides an ultrafine modified composite powder explosion suppressant, the preparation method of which is as follows:

[0120] S01. Weigh the following raw materials by mass: 22 parts of aluminum oxide, 15 parts of magnesium oxide, 25 parts of silicon dioxide, 3 parts of cerium oxide, 12 parts of potassium bicarbonate, 13 parts of sodium bicarbonate, 8 parts of fumed hydrophobic silica, and 2 parts of talc.

[0121] S02. Place the weighed raw materials in a vacuum drying oven and dry them at 80° C. for 14 h.

[0122] S03. Place the dried raw materials of each component in a planetary ball mill, set the ball-to-material ratio to 10:1, the ball mill speed to 500 r / min, and the ball milling time to 3 h for dry compounding.

[0123] S04. The obtained composite powder is subjected to a methyl hydrogen silicone oil coating modification treatment, methyl hydrogen silicone oil is added at a rate of 2% by mass of the composite powder, and stirred in a blender at a stirring speed of 400 r / min for 60 min.

[0124] S05. Place the modified composite powder in a vacuum drying oven again and dry it at 80° C. for 15 hours.

[0125] S06. The dried powder material is sieved through a 3000-mesh filter to obtain an ultrafine modified composite powder explosion suppressant having a particle size mainly distributed below 5 μm.

[0126] Comparative Example

[0127] This comparative example is designed to demonstrate the superiority of the composition ratio range defined in the present invention. The preparation method thereof, except for the formulation, is identical to that of Example 2 in terms of other process parameters (such as drying, ball milling, modification, screening, etc.).

[0128] The mass parts of the comparative example are: 5 parts of aluminum oxide, 5 parts of magnesium oxide, 60 parts of silicon dioxide, 5 parts of cerium oxide, 5 parts of potassium bicarbonate, 5 parts of sodium bicarbonate, 5 parts of fumed hydrophobic silica, and 10 parts of talc.

[0129] Explosion suppression performance test

[0130] In order to verify the actual performance of the composite powder explosion suppressant of the present invention, the explosion suppressant powders prepared in Example 2, Example 3 and Example 4 were tested for explosion suppression performance in a 20L standard spherical explosion test device. The test conditions were unified as follows: a 30% concentration of hydrogen-air mixture was filled into the device, and ignited using a 10J energy pulse ignition device at room temperature and pressure. 10g of explosion suppressant powder was added to each group of experiments, and a blank control group was set up without any explosion suppressant added. The test results are shown in the figure below. Figure 2 and Figure 3 shown.

[0131] Figure 2 The graphs are the explosion overpressure-time history curves under the action of different explosion suppressants. From the blank group (red line in the figure) without adding explosion suppressant, it can be seen that when the 30% hydrogen-air mixture explodes, its peak overpressure ( ) reached 0.7257 MPa. After adding 10g of the explosion suppressants prepared in Examples 2, 3, and 4, respectively, the peak explosion overpressures were significantly suppressed, decreasing to 0.5382 MPa (light blue line in the figure), 0.5292 MPa (green line in the figure), and 0.5182 MPa (dark blue line in the figure), respectively. Calculations show that the corresponding explosion suppression efficiencies (referring to the reduction in peak overpressure) for the three examples reached 25.8%, 27.1%, and 28.6%, respectively.

[0132] Figure 3 The explosion overpressure rise rate ( ). The peak overpressure rise rate in the blank group reached a high of 178.18 MPa / s, reflecting the severity of the hydrogen explosion. Adding the explosion suppressants of Examples 2, 3, and 4 effectively reduced this value to 152.26 MPa / s, 148.67 MPa / s, and 143.81 MPa / s, respectively. The corresponding decreases in the peak overpressure rise rate were 14.5%, 16.6%, and 19.3%, respectively.

[0133] In order to further verify the advantages of the component ratio defined in the present invention, the explosion suppression performance comparison test was conducted on the explosion suppression powder prepared in Example 2 and the powder of the comparative example under the same conditions. Figure 4 As shown in the figure, when no explosion suppressant is added, the explosion peak overpressure of the 30% hydrogen-air mixture reaches 0.7257 MPa, and the peak overpressure rising rate is as high as 178.18 MPa / s, showing extremely strong destructiveness. After adding 10g of the powder of Example 2 of the present invention, the explosion peak overpressure is significantly suppressed to 0.5382 MPa, and the explosion suppression efficiency reaches 25.8%; while after adding 10g of the comparative example powder, the peak overpressure is only reduced to 0.6621 MPa, and the explosion suppression efficiency is only 8.8%. Similarly, as Figure 5As shown, in terms of suppressing explosion growth, the powder in Example 2 effectively reduced the overpressure rise rate to 152.26 MPa / s, a 14.5% reduction; while the control powder achieved 165.68 MPa / s, a reduction of only approximately 7.0%. This demonstrates that Example 2 of the present invention outperforms the control powder in both reducing the final explosion intensity (peak overpressure) and slowing the explosion reaction (overpressure rise rate). This comparison strongly demonstrates that the component ratio range determined by theoretical calculation and experimental optimization in the present invention is the key to achieving efficient explosion suppression, not simply an obvious combination, but a significant inventive step. These experimental data strongly demonstrate the universal effectiveness of the technical solution proposed in this invention. Examples 2, 3, and 4, as different formulations within the scope of the present invention's claims, all exhibit excellent explosion suppression performance, directly confirming the scientific validity of the component ratio range of the present invention. The reduction in peak overpressure effectively weakens the ultimate destructive force of the explosion, which is attributed to the powder's efficient heat absorption effect and chemical interruption of the explosion chain reaction. At the same time, the slowdown in the rate of overpressure rise indicates that the severity of the explosion process is under control, which is of vital practical significance for protecting pressure-bearing equipment and buying precious time for safety measures to respond.

[0134] Therefore, the composite powder explosion suppressant designed and prepared based on quantum chemical calculations in this invention can significantly suppress violent hydrogen explosions even at relatively low dosages, making it a highly effective and cost-effective proactive safety measure within the hydrogen energy industry chain. To build a more comprehensive safety system, it is recommended that this explosion suppressant be deployed in conjunction with other preventative measures, such as hydrogen leak detection, anti-static measures, and forced ventilation.

[0135] The mechanism of action of the composite powder explosion suppressant based on quantitative calculation in this embodiment is:

[0136] (1) Suspended Al2O3, MgO, SiO2, CeO2, KHCO3 and NaHCO3 form a thermal barrier layer, which significantly reduces the efficiency of heat radiation transfer from the combustion zone to the unburned zone and effectively blocks heat conduction.

[0137] (2) Al2O3, MgO, SiO2 and CeO2 efficiently capture H• and OH• free radicals in the hydrogen explosion reaction through targeted binding, inhibiting their participation in chain transfer reactions, thereby blocking the continued progress of the hydrogen explosion reaction.

[0138] (3) KHCO3 and NaHCO3 undergo thermal decomposition when in contact with the hydrogen explosion flame. This endothermic process can significantly reduce the temperature of the explosion area, thereby inhibiting the explosion reaction rate.

[0139] (4) The decomposition products of KHCO3 and NaHCO3, CO2 and H2O, have a dual explosion suppression effect: CO2, as an inert gas, dilutes the O2 concentration in the explosion area, producing a flame suffocation effect; H2O not only has a significant heat absorption effect, but also can further dilute the O2 concentration after gasification, thereby enhancing the flame suffocation effect.

[0140] (5) K produced by the decomposition of KHCO3 and NaHCO3 + 、Na + As well as KO•, NaO•, etc., they can selectively combine with the key active groups (H•, OH•, and O•) of hydrogen explosion reaction, effectively interrupting the chain reaction process and significantly reducing the explosion pressure. The key reaction equation is as follows:

[0141] 2NaHCO3→Na2CO3+CO2+H2O;

[0142] Na2CO3→Na2O+CO2;

[0143] Na2O+H2O→2NaOH;

[0144] NaOH+OH→NaO+H2O;

[0145] NaOH+H→Na+H2O;

[0146] Na+OH+M→NaOH+M;

[0147] NaO+O→Na+O2;

[0148] NaO+H→Na+OH;

[0149] 2KHCO3→K2CO3+CO2+H2O;

[0150] K2CO3→K2O+CO2;

[0151] K2O+H2O→2KOH;

[0152] KOH+OH→KO+H2O;

[0153] KO+O→K+O2;

[0154] KOH+H→K+H2O;

[0155] K+OH+M→KOH+M;

[0156] K+O2+M→KO2+M;

[0157] KO2+H→KOH+O;

[0158] KO2+OH→KOH+O2.

[0159] The present invention not only realizes multiple inhibitions of key elementary reactions of hydrogen combustion, but also achieves an optimal balance in terms of safety and economy, and has significant engineering application value.

[0160] It will be easily understood by those skilled in the art that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

[0161] Any portions not described in detail in this specification are known in the art. The above embodiments are provided for illustrative purposes only and are not intended to limit the scope of the present invention. The scope of the present invention is defined by the appended claims. Any equivalent substitutions and modifications that do not depart from the spirit and principles of the present invention are intended to be encompassed within the scope of the present invention.

Claims

1. A composite powder explosion suppressant, characterized in that: The invention comprises the following components by weight: 20-25 parts of aluminum oxide, 10-20 parts of magnesium oxide, 20-30 parts of silicon dioxide and 1-3 parts of cerium oxide.

2. The composite powder explosion suppressant according to claim 1, characterized in that: The composite powder explosion suppressant further comprises 10-15 parts of potassium bicarbonate, 10-15 parts of sodium bicarbonate, 3-8 parts of fumed hydrophobic silica, and 2-6 parts of talc.

3. The composite powder explosion suppressant according to claim 1, characterized in that: 90% of the particle sizes of the composite powder explosion suppressant are less than or equal to 5 μm.

4. The method for designing a composite powder explosion suppressant according to any one of claims 1 to 3, characterized in that: The steps include: S1: Structural optimization and frequency analysis of key elementary reactions in the application field of composite powder explosion suppressants are performed to obtain the correct optimized configuration; S2: performing single-point energy calculation on the correct optimized configuration to obtain the energy difference of the key elementary reaction; S3: Calculate the effect of the powder on the total energy of the reaction system under the correct optimized configuration to obtain the energy difference of the key elementary reaction under the condition of the powder; S4: Compare the result of step S3 with the result of step S2 to obtain a ranking of the explosion suppression performance of the powder; S5: Screening and obtaining the component formula of the composite powder explosion suppressant according to the result of step S4.

5. The design method of composite powder explosion suppressant according to claim 4, characterized in that: Said S1: structural optimization and frequency analysis of key elementary reactions in the application field of composite powder explosion suppressant specifically includes the following steps: S11: Structural optimization of key elementary reactions in the application field of composite powder explosion suppressants, wherein the structural optimization specifically involves continuously adjusting the geometric configuration of the system until the total energy of the system reaches a local minimum, thereby obtaining an optimized configuration; S12: Perform frequency analysis on the optimized configuration to confirm that the correct optimized configuration is obtained.

6. The design method of composite powder explosion suppressant according to claim 4, characterized in that: The step S3: calculating the effect of the powder on the total energy of the reaction system specifically includes the following steps: S31: Calculate the isolated single point energy of the powder and the single point energy of the powder in various states in the key elementary reactions; S32: Obtain the reaction path energy difference under the condition of the powder being present according to the single point energy calculated in step S31.

7. The design method of composite powder explosion suppressant according to claim 4, characterized in that: The step S5: screening the component formula of the composite powder explosion suppressant according to the result of step S4 specifically comprises the following steps: S51: Obtaining candidate powders with excellent explosion suppression performance according to the sorting results of step S4; S52: A secondary screening was conducted based on the two dimensions of safety and economy, and finally a component formula of a composite powder explosion suppressant with a balance of performance, safety and cost was obtained.

8. The design method of composite powder explosion suppressant according to claim 4, characterized in that: The application field of the composite powder explosion suppressant is to suppress hydrogen explosion.

9. The method for preparing the composite powder explosion suppressant according to any one of claims 1 to 3, characterized in that: The steps include: S01: Weigh each component raw material according to the proportion; S02: Drying the weighed raw materials; the drying conditions are: temperature 60-80°C, time 10-14h; S03: Dry-blending the dried raw materials to obtain composite powder; S04: performing coating and modification treatment on the composite powder to obtain coated and modified powder; S05: Drying the coated modified powder obtained in step 04 again; S06: The composite powder material obtained in step S05 is sieved to obtain an ultrafine composite powder explosion suppressant with a particle size of less than or equal to 5 μm.

10. The method for preparing the composite powder explosion suppressant according to claim 9, characterized in that: The coating modification treatment of the composite powder obtained in step S03 is specifically to place the composite powder obtained in step S03 into methyl hydrogen silicone oil and stir it, wherein the mass of the methyl hydrogen silicone oil is 0.5-2% of the mass of the composite powder, the stirring speed is 200-400 r / min, and the stirring time is 30-60 min.

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