Coupling effect of fuel property parameters on gas/coal dust composite explosion
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摘要: 为研究瓦斯煤尘复合爆炸影响因素的耦合规律,对煤粉质量浓度、甲烷体积分数、煤粉粒径、煤粉种类等4种影响因素进行了多因素与单因素实验分析。通过正交实验,将各因素对爆炸的影响进行了定量分析,结果表明,4个因素对最大爆炸压力pmax的影响由强到弱依次为:甲烷体积分数、煤粉质量浓度、煤粉种类、煤粉粒径;对最大爆炸压力上升速率(dp/dt)max的影响程度由强到弱依次为:甲烷体积分数、煤粉质量浓度、煤粉粒径、煤粉种类。对于体积分数为9%、11%的甲烷,复合体系的pmax随煤粉的质量增加而减小。当煤粉质量浓度增加到100、200 g/m3时,在与体积分数为6%的甲烷耦合作用下,会产生更强的“激励”作用,且煤粉浓度较大时,挥发分低的煤种最佳瓦斯浓度会降低。甲烷体积分数存在临界值,该临界值会改变挥发分因素的影响方式:低于此临界值时,高挥发分煤尘体系的(dp/dt)max更高,(dp/dt)max来临时间更短;高于此临界值时,低挥发分体系具有更高的爆炸强度。粒径影响挥发分的作用,粒径越大,挥发分的影响差异越明显。当甲烷体积分数为11%时,挥发分高的煤尘更容易受粒径的影响,直径小的煤尘体系,爆炸系数Kst更小;而低挥发分煤粉在甲烷体积分数接近当量时受粒径影响更明显。Abstract: In order to reveal the coupling law of the influencing factors in gas/coal dust composite explosion, experiments were conducted in a 20 L spherical explosion device. Multi-factor and single-factor experimental analyses were conducted on four influencing factors according to explosion parameters, including coal concentration, methane volume fraction, coal particle size, and coal type. By conducting orthogonal experiments on the influencing factors, and using the explosion parameters as indicators to carry out range analysis and variance analysis, the influence of each factor on the explosion had been quantified. The experimental results show that the degree of influence of the four factor on pmax are (from strong to weak): methane volume fraction, coal dust mass concentration, coal dust type, and coal dust particle size; the effects on (dp/dt)max are (from strong to weak): methane volume fraction, coal dust mass concentration, coal dust particle size, and coal dust type. For methane concentrations of 9% and 11%, the value of pmax of the composite system decreases with increasing mass of coal dust. When the mass concentration of coal dust increases to 100 g/m3 and 200 g/m3, coupled with 6% volume fraction of methane, it will produce a stronger “incentive” effect, and when the concentration of coal dust is larger, the low volatility will reduce the optimal gas concentration. The existence of a certain critical value of methane concentration will change the influence mode of volatile factors. Below this value, the value of (dp/dt)max of the high volatile coal dust system is higher, and its arrival time is shorter, while above this value, the low volatile fraction system has a higher explosion intensity. Particle size implicates the influence of volatile fraction, the larger the particle diameter, the more obvious the difference produced by the volatile fraction factor. At 11% methane concentration, coal dust with high volatile fraction is more susceptible to the effect of particle size, and the smaller diameter coal dust system has smaller Kst value; at methane concentration close to equivalent, low volatile fraction coal dust is more significantly affected by the particle size factor.
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Key words:
- gas /
- coal dust /
- gas/dust explosion /
- influencing factor /
- coupling
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表 1 煤粉的工业分析
Table 1. Industrial analysis of coal dust
煤样 ω(挥发分)/% ω(水分)/% ω(灰分)/% ω(固定碳)/% 褐煤 38.02 6.68 4.98 54.75 无烟煤 7.97 2.58 10.59 79.91 表 2 正交实验各因素及水平参数
Table 2. Factors and level parameters of orthogonal experiment
水平 煤粉质量浓度/(g·m−3) 甲烷体积分数/% 煤粉粒径/μm 煤粉种类 1 30 6 39 褐煤 2 60 9 123 无烟煤 3 100 11 283 − 4 200 − − − 表 3 正交实验的极差分析结果
Table 3. Results of extreme difference analysis of orthogonal experiments
指标 因变量 煤粉质量浓度/(g·m−3) 甲烷体积分数/% 煤粉粒径/μm 煤粉种类 K1 pmax 6.119 7.752 8.048 12.256 (dp/dt)max 238.406 181.905 283.525 446.191 K2 pmax 6.132 8.489 8.153 12.041 (dp/dt)max 228.572 386.572 301.977 437.548 K3 pmax 6.137 8.056 8.096 — (dp/dt)max 220.595 315.262 298.237 — K4 pmax 5.909 — — — (dp/dt)max 196.166 — — — k1 pmax 0.680 0.646 0.671 0.681 (dp/dt)max 26.489 15.159 23.627 24.788 k2 pmax 0.681 0.707 0.679 0.669 (dp/dt)max 25.397 32.214 25.165 24.308 k3 pmax 0.682 0.671 0.675 — (dp/dt)max 24.511 26.272 24.853 — k4 pmax 0.657 — — — (dp/dt)max 21.796 — — — 极差R pmax 0.025 0.061 0.009 0.012 (dp/dt)max 4.693 17.055 1.538 0.480 最佳水平 pmax 100 9 138 褐煤 (dp/dt)max 30 9 138 褐煤 因素主次 pmax 甲烷体积分数、煤粉质量浓度、煤粉种类、煤粉粒径 (dp/dt)max 甲烷体积分数、煤粉质量浓度、煤粉种类、煤粉粒径 表 4 正交实验的方差分析结果
Table 4. Results of the variance analysis of orthogonal experiments
试验因素 因变量 平方和 均方 F 影响程度 煤粉质量浓度 pmax 0.005 0.002 1.307 — (dp/dt)max 108.575 36.192 3.597 显著 甲烷体积分数 pmax 0.023 0.012 10.037 高度显著 (dp/dt)max 1798.827 899.414 89.378 高度显著 煤粉粒径 pmax 0.001 0.001 0.201 — (dp/dt)max 15.859 7.930 0.788 — 煤粉种类 pmax 0.001 0.001 1.094 — (dp/dt)max 2.075 2.075 0.206 — 随机误差E pmax 0.031 0.001 — — (dp/dt)max 271.694 10.063 — — -
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