风蚀性粒子降尘浓度的动力学预报模式

为探求开放源露天煤尘在自然风力作用下的扩散情况,本研究采用空气动力学的数值计算方法,以离散相拉格朗日随机轨道为计算模型,预测了原煤、大矿、水洗和精煤4类煤种料堆的降尘浓度分布,并采用风洞试验对结果进行了对比验证.结果表明:动力学模式对风蚀粒子的预报误差在±25%,其中原煤种的预报度最高,误差10%.动力学模式与高斯沉降模式相比,高斯模式对尘源处的降尘浓度预报误差过大,动力学预报模式是基于颗粒群的运动轨迹的行为预报,能准确地描述粗大颗粒的跃移运动状态,对于满足Rosin-Rammler粒径分布的固体粒子降尘浓度的预报良好.

Dynamic prediction mode of particle ground concentration in open-air coal yard

To investigate the particles diffusion caused by natural wind in open-air coal yard, the stochastic trajectory modeling was employed based on the dynamical computational method. The ground concentrations were calculated for the four kinds of coal powder named as crude coal, blocked coal, watered coal and refined coal. Afterwards, wind-tunnel experiment was conducted and comparison was made between the measured values and predicted ones. The results illustrated that the calculated error was limited within ±25%, especially, for crude coal powder the error range was 10%. Comparison with the dynamical mode, the Gauss mode predicted much larger values than the actual conditions for ground concentration where coal particle sources. By contrast, the dynamical mode focused on the particle travelling behaviors during the diffusion in the air, consequently, could accurately describe the coarse particle statement. For particles within Rosin-Rammler size distribution, the dynamical mode had good prediction.