<p>可燃气体爆炸防控始终是工业安全生产领域的重要内容，氢气/甲烷混合燃料作为向氢能源迈进的关键一步，其利用的有效性已得到证实，但在其安全使用方面引起许多学者的关注。因此本文以氢气/甲烷预混气体为研究对象，采用实验研究、理论分析和数值计算相结合的手段开展研究。利用20L球型爆炸装置结合纹影仪、光谱仪等设备进行氢气/甲烷爆燃及抑爆实验研究，通过改变惰性气体的体积分数、粉体的质量浓度及气/固两相抑制剂的配比，开展单相惰性气体、粉体和气/固两相抑制剂对氢气/甲烷爆燃特性的影响。分析了氢气/甲烷爆燃过程中的爆炸极限参数、压力参数、火焰结构参数、层流火焰传播速度和自由基的变化规律，获得了抑爆关键控制参数；分析了惰性气体和粉体协同抑制氢气/甲烷爆炸的相互耦合作用，揭示了气固两相介质抑制氢气/甲烷爆炸的协同机理，为主动抑爆装置中抑爆剂的开发以及抑爆技术的发展提供了科学支撑。</p> <p>在氢气/甲烷爆燃参数方面，本文获取了爆燃过程中的爆炸极限参数、压力参数、火焰结构参数、层流火焰传播速度和自由基的变化情况。惰性气体的加入使氢气/甲烷预混气体的爆炸上限降低，下限升高。当氢气添加比例小于30%时，氢气/甲烷预混气体的爆炸危险性较小。在富氧条件下，氢气/甲烷预混气体中氢的比例越高，预混气体越容易产生胞状结构的火焰。当氢气添加比例大于30%时，爆炸破坏力开始增加，且这一规律不随氢气/甲烷预混气体当量比的变化而变化。氢气/甲烷预混气体中的氢气添加比例对火焰层流传播起主导作用，当量比的变化起次要作用。本文实验计算的层流火焰传播速度与GRI Mech 3.0计算的氢气/甲烷预混气体的层流速度基本一致。氢气/甲烷预混气体的爆燃反应动力学中，R38：H+O₂=O+OH、R84：OH+H₂=H+H₂O为氢气/甲烷预混气体爆燃过程中的关键反应步骤，对反应整体起到关键作用，OH自由基可作为研究氢气/甲烷爆燃过程中的关键自由基。</p> <p>在单一惰性气体抑制氢气/甲烷爆燃方面，惰性气体抑制作用下，当惰性气体添加量超过15%时，氢气/甲烷预混气体层流火焰受到浮力不稳定性的影响。二氧化碳对氢气/甲烷预混气体层流速度的抑制效果比氮气好。当惰性气体添加量于10%时，惰性气体的添加对氢气/甲烷预混气体爆燃压力峰值的影响与氢气添加比例的变化基本无关。在火焰发展的初始阶段，惰性气体的加入降低了拉伸火焰的传播速度和拉伸速率。惰性气体添加比越大，初期拉伸速率越低。惰性气体对氢气添加比例在70%以上的氢气/甲烷预混气体的爆燃影响较小。从爆燃极限、层流燃烧速度和爆燃指数等爆燃参数，氢气/甲烷预混气体在氢气添加比例超过70%时发生突变，即&phi;=0.7是氢气/甲烷预混气体爆炸特性的转折点。</p> <p>在两相抑制剂抑制氢气/甲烷爆燃方面，气相二氧化硅、聚磷酸铵粉体、纯干水材料、10%APP改性干水材料、20%APP改性干水材料对纯甲烷最佳抑制浓度分别为65g/m³、225g/m³、500g/m³、500g/m³和500g/m³。CO₂-气相二氧化硅两相抑制剂在所有工况条件下都无完全抑制状态。对于CO₂-聚磷酸铵两相抑制剂，5%以下的CO₂添加下无法完全抑制，10%CO₂添加下在氢气添加比小于30%时能够完全抑制，15%CO₂添加下在氢气添加比例小于50%时能够完全抑制。在CO₂-干水材料两相抑制剂作用下，氢气添加比例为70%的预混气体的爆燃指数偏小，即危险性偏小；氢气添加比例小于30%时，爆燃指数的大小基本不发生变化，爆炸危险性基本不变；三种干水材料都是在15%CO₂添加下，当氢气添加比例小于30%时能够完全抑制。此外，当氢气添加比例不超过70%时，气固两相抑制剂对氢气/甲烷预混气体的实际抑制效果大于理论上的叠加值；两相抑制剂对氢气添加比70%的氢气/甲烷预混气体爆燃的抑制效果等同于两种单相抑制剂的抑制效果叠加。</p> <p>综合爆燃极限、层流传播速度、爆炸危险性和抑制剂的抑制效果等方面，依照氢气添加比，氢气/甲烷预混气体爆燃存在两个转折点，即氢气添加比例为30%和70%。两相抑制剂作用下，氢气/甲烷预混气体爆燃过程中OH特征波长辐射强度整体减弱，具体表现为辐射信号出现时间逐渐延迟，辐射强度峰值逐渐减小，峰值时间也逐渐延后。两相抑制剂减少了氢气/甲烷预混气体爆燃过程中OH的生成，直接反映出对氢气/甲烷燃爆反应的抑制作用。此外，氢气/甲烷预混气体爆燃及抑制过程中，压力上升速率峰值时间与OH自由基峰值信号峰值时间之间存在着时间上的一致性。</p>

<p>Flammable gas explosion prevention and control is an important element in the field of industrial safety and production. Hydrogen/methane mixed fuel, as a key step towards hydrogen energy, have proven their effectiveness in utilisation, but have attracted the attention of many scholars in terms of their safe use. Therefore, this paper takes hydrogen / methane mixed fuel as the research object, using experimental research as the main and theoretical analysis as the auxiliary means to carry out the research. Therefore, this paper takes the hydrogen / methane premixed gas as the research object, and carries out the research by means of experimental research, theoretical analysis and numerical calculation. The experimental study on hydrogen / methane deflagration and explosion suppression was carried out by using 20L spherical explosive device combined with schlieren meter and spectrometer. By changing the volume fraction of inert gas, the mass concentration of powder and the ratio of gas / solid two-phase inhibitor, the effects of single-phase inert gas, powder and gas / solid two-phase inhibitor on hydrogen / methane deflagration characteristics were carried out. The variation rules of explosion limit parameters, pressure parameters, flame structure parameters, laminar flame propagation velocity and free radicals in the process of hydrogen / methane deflagration are analyzed, and the key control parameters of explosion suppression are obtained. the coupling effect of inert gas and powder on hydrogen / methane explosion is analyzed, and the synergistic mechanism of gas-solid two-phase medium inhibiting hydrogen / methane explosion is revealed. It provides scientific support for the development of explosion suppressants and explosion suppression technology in active explosion suppression devices.</p> <p>In terms of hydrogen / methane deflagration parameters, the explosion limit parameters, pressure parameters, flame structure parameters, laminar flame propagation velocity and free radicals in the deflagration process are obtained. With the addition of inert gas, the explosion upper limit of hydrogen / methane premixed gas decreases and the lower limit increases. When the hydrogen addition ratio is less than 30%, the explosion risk of hydrogen / methane premixed gas is less. Under the condition of rich oxygen, the higher the proportion of hydrogen in hydrogen / methane premixed gas, the easier it is to produce cellular flame. When the hydrogen addition ratio is more than 30%, the explosive destructive force begins to increase, and this law does not change with the change of hydrogen / methane premixed gas equivalent ratio. The hydrogen addition ratio in hydrogen / methane premixed gas plays a leading role in flame laminar propagation, while the change of equivalent ratio plays a secondary role. The laminar flame propagation velocity calculated in this paper is basically consistent with the laminar flow velocity of hydrogen / methane premixed gas calculated by GRI Mech 3.0. In the deflagration reaction kinetics of hydrogen / methane premixed gas, R38:H+O₂=O+OH and R84:OH+H₂=H+H₂O are the key reaction steps in the deflagration process of hydrogen / methane premixed gas, which play a key role in the whole reaction. OH radical can be used as the key free radical in the process of hydrogen / methane deflagration.</p> <p>In the case of single inert gas suppression of hydrogen/methane deflagration, the hydrogen/methane premixed gas laminar flame is affected by buoyancy instability when the inert gas addition exceeds 15% in the presence of inert gas. Carbon dioxide suppresses the laminar flame propagation rate of hydrogen/methane premixed gases better than nitrogen. At 10% inert gas addition, the effect of inert gas addition on the peak hydrogen/methane premixed gas deflagration pressure is largely independent of changes in the proportion of hydrogen added. In the initial stages of flame development, the addition of inert gas reduces the rate of propagation of the stretching flame and the rate of stretching. The higher the inert gas addition ratio, the lower the initial stretching rate. The inert gas has less effect on the deflagration of hydrogen/methane premixed gases with hydrogen addition ratios above 70%. In terms of deflagration parameters such as deflagration limit, laminar burning rate and deflagration index, the hydrogen/methane premixed gas undergoes a sudden change at hydrogen addition ratios above 70%, that is, &phi; = 0.7 is the turning point in the explosive characteristics of the hydrogen/methane premixed gas.</p> <p>For the inhibition of hydrogen/methane deflagration by two-phase inhibitors, the best inhibition concentrations for pure methane were 65 g/m³, 225 g/m³, 500 g/m³, 500 g/m³ and 500 g/m³ for fumed silica, ammonium polyphosphate powder, pure dry water material, 10% APP modified dry water material and 20% APP modified dry water material, respectively. No complete inhibition under all operating conditions. For CO₂-ammonium polyphosphate two-phase inhibitors, complete inhibition is not possible with less than 5% CO₂ addition, complete inhibition is possible with 10% CO₂ addition at less than 30% hydrogen addition, and complete inhibition is possible with 15% CO₂ addition at less than 50% hydrogen addition. In the CO₂ - dry water materials under the action of two-phase inhibitor, hydrogen addition ratio of 70% of the premixed gas deflagration index is small, that is, the danger is small; hydrogen addition ratio of less than 30%, the size of the deflagration index basically does not change, the explosion risk is basically unchanged; all three dry water materials are under the 15% CO₂ addition, when the hydrogen addition ratio of less than 30% can be completely inhibited. In addition, when the hydrogen addition ratio does not exceed 70%, the actual inhibition effect of the gas-solid two-phase inhibitor on the hydrogen/methane premixed gas is greater than the theoretical superposition value; the inhibition effect of the two-phase inhibitor on the hydrogen addition ratio of 70% of the hydrogen/methane premixed gas deflagration is equivalent to the inhibition effect of the two single-phase inhibitor superposition.</p> <p>Combined with the overall situation, the deflagration characteristics of hydrogen / methane premixed fuel can be divided into two turning points: 30% and 70% hydrogen addition according to deflagration limit, laminar propagation speed, explosion hazard and inhibitor inhibition effect. that is, the three stages are 0-30% hydrogen content in the premixed fuel, 30-70% and more than 70% respectively. Under the action of two-phase inhibitor, the radiation intensity of OH characteristic wavelength decreases during the deflagration of hydrogen / methane premixed fuel with different amount of hydrogen, which is shown by the gradual delay of the occurrence time of radiation signal, the decrease of the peak radiation intensity and the delay of peak time. The two-phase inhibitor reduces the production of OH during hydrogen/methane premixed gas deflagration, which directly reflects the inhibition of the hydrogen/methane deflagration reaction. In addition, there is a temporal agreement between the peak time of the pressure rise rate and the peak time of the OH radical signal during hydrogen/methane premixed gas deflagration and inhibition.</p>