基于20 L球罐的多相混合物扩散模拟

为更好地探索多相混合物的爆炸特性,以铝粉、乙醚、空气为研究对象,基于20 L球型爆炸罐建立三维计算模型,对气固两相和气液固三相混合物的分散过程进行数值模拟,以分析不同多相混合物分散过程的差异,并为测量多相混合物爆炸下限时的点火延迟时间设定提供参考。监测分析铝粉浓度粒子分布、流场内部湍流动能以及液相体积百分数等的演化过程,讨论混合物分散效果的差异,并确定测量爆炸下限的点火延迟时间。研究结果表明:实验工况下,液相的存在会降低粉尘云团的湍流动能、降低其扩散速度,并使粉尘云内部浓度更均匀。测量多相混合物爆炸下限时,三相混合物的最佳点火延迟时间早于气固两相混合物10～20 ms。

Diffusion simulation of multiphase mixture based on 20 L spherical vessel

In order to explore the multiphase mixture explosion characteristics, the three dimensional calculation model with aluminum powder, ethyl ether, air as research materials was built up based on 20 L spherical explosion tank. This research simulated dispersion process of gas solid two phase mixture and gas liquid solid three phase mixture. It analyzed the differences in the dispersion processes of different polyphase mixtures and provided a reference for the set of ignition delay time at measuring the lower limit of explosion of multiphase mixture. The evolution process of aluminum powder concentration particle distribution, turbulent kinetic energy in the flow field and liquid phase volume percentage were monitored and analyzed. The difference of mixture dispersion effects and determining the ignition delay time to measure the lower limit of explosion was discussed. The results show that the presence of liquid phase can reduce the turbulent kinetic energy of dust clouds and their diffusion rate and make the concentration more even inside the dust cloud under the same working conditions. When the lower explosive limit of explosion of multiphase mixture is measured, the optimum ignition delay time of three phase mixture is 10-20 ms earlier than that of the gas solid two phase mixture.