基于Logistic统计方法的煤粉爆炸下限研究

粉尘云爆炸下限是表征粉尘易燃易爆危险性的主要参数，相对精确地测试并表示粉尘云爆炸下限对评估和预防粉尘爆炸灾害是十分重要的。基于统计分析的Logistic回归模型，应用以概率表示粉尘云爆炸下限的计算方法，在20 L球形爆炸罐中对不同粒径的煤粉-空气混合物进行爆炸下限测试实验，利用SPSS统计分析软件计算得到不同粒径、不同实验次数下煤粉点火成功概率-浓度分布曲线，结果表明不同点火概率下的爆炸下限均随粒径的减小而呈现逐渐减小的趋势，且粉尘粒径越小，点火成功概率从p=10%增至p=90%的浓度区间越窄，即其燃爆特性越稳定。实验次数对爆炸下限概率分布存在影响，实验次数越多，爆炸下限概率分布的浓度区间越窄，但点火概率为50%的浓度值与实验次数无关，是研究粉尘爆炸下限的关键值。与其他计算方法的结果相比，以概率表示特定物质的爆炸下限更符合实际情况，更能满足不同生产环境对安全控制的需要。

Research of the lower explosion limit of coal dust based on the statistical method of Logistic regression

The lower explosion limit of dust cloud is a basic characterization of the dangers of inflammable and explosive dust.Accurately test and show the lower explosion limit is important for the assessment and prevention of dust explosion disaster.According to Logistic regression model based on statistical analysis，using the calculation method of the lower explosion limit of dust cloud which represented by probability，the experiments on the lower explosion limit of coal dust with different diameters were conducted in 20 L spherical explosion test apparatus.The test results were analyzed using statistical software (SPSS) to obtain probability distributions for ignition versus dust concentrations of coal dust with different diameters and different experimental frequency.The results show that the lower explosion limit of coal dust under different ignition probability has a tendency to decrease with reducing particle size.And the smaller the particle size，the narrower the range of concentration of ignition probability from 10% to 90%，which means the deflagrating characteristic of coal dust is becoming much more stable.The lower explosive limit probability distribution is affected by experimental frequency，the more the experiments，the narrower the range of lower explosive limit concentration.When the ignition probability is 50%，the corresponding concentration has nothing to do with the number of experiments，which is the key to the research of dust explosion experiment.Compared with other standard calculations，the viewpoint of ignition as a statistical phenomenon appears to be more consistent with the test data in engineering，can also meet the needs of different production environment for security control.