聚乙烯薄膜对可燃气云爆炸影响的实验研究与数值模拟

聚乙烯薄膜作为约束物，对可燃气云爆炸有着重要的影响.采用7.8%的乙炔/空气混合气进行了实验研究，薄膜厚度分别为0.02、0.04 mm和0.06 mm，层数为1～4层.结果显示，当采用单层厚度0.02 mm的薄膜时，半径0.5 m的半球形气云爆炸可产生2.410 kPa的最大超压;厚度0.06 mm时，最大超压达到3.642 kPa;薄膜层数为4层时，最大超压上升到13.125 kPa.建立了描述气云爆炸的理论模型，模型考虑了薄膜强度、层数对爆炸的影响，采用SIMPLE算法进行了数值求解.计算结果与实验值相比较，最大相对偏差14.8%，平均相对偏差4.73%.提出的方法对有弱约束物存在时，气云爆炸的灾害预测具有重要的指导意义.

Experimental and simulated study of effect of polythene film on flammable vapor cloud explosion

Polythene film used as confinement plays an important role in flammable cloud explosion.Experiments of C₂H₂/air cloud explosion were performed at 7.8% ethyne concentration.Polythene film with different thicknesses(0.02, 0.04 mm and 0.06 mm) and different layers (1—4) were adopted in the experiments.The results showed that, the maximum overpressure was 2.410 kPa in the explosion of hemisphere cloud with radius 0.5 m, while, as the thickness of film was 0.06 mm,the maximum overpressure reached 3.642 kPa.When 4 layers of film were adopted, the maximum overpressure reached 13.125 kPa.A theoretical model, considering the influences of intensity and layers of polythene film on explosion, was established and solved by SIMPLE algorithm.Compared with the test data, the maximum and average relative deviations of calculation results were 14.8% and 4.73% respectively.The results are of great significance on forecasting gas cloud explosion with weak confinements.