双尘源耦合下呼吸性粉尘扩散的紊流系数求解

Solution of turbulence coefficient in the diffusion of respirable dust under the coupling of two dust sources

摘要:

为完善综采工作面呼吸性粉尘扩散模型, 解决模型中紊流扩散系数和紊流纵向弥散系数无法求解问题, 根据气溶胶力学和流体动力学理论, 结合综采工作面实际环境和呼吸性粉尘二次飞扬特点, 建立综采工作面移架产尘点与割煤产尘点耦合下的呼吸性粉尘扩散模型, 其中, 呼吸性粉尘二次飞扬采用镜像法.再通过相似实验, 按照原模比3:1, 搭建综采工作面实验场地, 确定采样点, 分别测出3种场景下各采样点的风速值与粉尘质量浓度值；结合实验数据, 采用梯度下降法求解紊流系数, 求解结果用于呼吸性粉尘质量浓度计算.将理论值与实验值对比, 结果表明, 在258个采样点中, 扩散模型的理论值与实测值的平均绝对误差率为29.66%, 证明了该理论模型的有效性, 可用于实际矿井下工作面呼吸性粉尘质量浓度的预测

Abstract:

To improve the respirable dust diffusion model in the fully mechanized working face, based on the theoretical model of aerosol mechanics and fluid dynamics and combined with the actual environment, the respirable dust diffusion model was established by coupling two dust sources of the frame shift and cutting coal. In this process, the treatment of two-time respirable dust was mirror image method. In order to solve the turbulent diffusion coefficient and longitudinal dispersion coefficient of the mathematical model, the experimental site was set up by the ratio of 3:1. Then some experiments were carried out and gradient descent method was used for parameter estimation. Turbulence coefficient value was applied to calculate the respirable dust mass concentration. Then comparing theoretical value with experimental value, results showed that: in the 258 sampling points, the average absolute error rate is 29.66%. It indicated the reliability of the theoretical model, which can be used to predict the dust mass concentration in the actual underground space