压力微泡沫与煤尘耦合降尘机理及应用基础研究

Pressure microfoam refers to water-based two-phase foam with micron scale and certain bearing capacity. Compared with large size foam, pressure microfoam has the characteristics of good pipeline transportation stability, good jet orientation, strong impact force and strong ability to capture fine dust, which is more suitable for dust removal in mining face. However, the existing studies do not have clear understandings of pressure microfoam and coal dust coupling dust removal mechanism and the relationship between the pressure microfoam properties, such as foam size, foam liquid content, thickness of liquid film, viscoelasticity, apparent viscosity and foam stability, and the preparation parameters and dust removal effects, leading to the blindness in dust removal. In order to improve the dust removal efficiencies of microfoam, by means of experimental observation, interface mechanics analysis and molecular dynamics simulation, the dynamic decay and fracture process of microfoam under the action of coal dust and the dynamic wetting mechanism of surfactants on coal dust are studied, and the pressure microfoam dust removal mechanism is revealed. Based on the jet mechanics theory and fluid mechanics simulation technology, a self-designed microfoam jet test platform is used to explore the influence mechanism of microfoam characteristics on dust removal efficiencies. Based on the theory of fluid mechanics and interfacial chemistry, a quantitative model is proposed to characterize the relationship between the preparation parameters of turbulence structure and the properties of foam by using the self-designed microfoam preparation test system. Through the above research, the coupling dust removal mechanism between microfoam and coal dust can be revealed, and the optimal pressure microfoam characteristic parameters and preparation equation can be obtained to improve the effects of microfoam dust removal.

压力微泡沫是指尺寸为微米级的具有一定承压能力的水基两相泡沫。相较于大尺寸泡沫，压力微泡沫具有管路输送稳定性和射流定向性好，冲击力强，捕捉微细粉尘能力强的特点，更适用于采掘工作面降尘。但现有研究对压力微泡沫与煤尘的耦合降尘机理和泡沫尺寸分布、含液率、液膜厚度、粘弹性、表观粘度、稳定性等泡沫特性与制备参数和降尘效果的关系认识不清，使降尘存在盲目性。本项目拟采用实验观测、界面力学分析和分子动力学模拟，研究煤尘冲击作用下压力微泡沫动态衰变破裂润湿煤尘过程，揭示压力微泡沫捕尘机理。采用射流力学理论和流体力学模拟，利用自行设计的压力微泡沫射流试验平台，探究压力微泡沫特性对泡沫射流和降尘效率的影响机制。应用流体力学和界面化学理论，采用自制的压力微泡沫制备系统，建立表征扰流机构制备参数与泡沫特性关系的量化模型。通过以上研究可探明微泡沫与煤尘的耦合降尘机理，获得最优的压力微泡沫特性和制备方程，提高降尘效果。

本项目针对压力微泡沫与煤尘耦合降尘机理及应用基础展开研究，采用分子动力学模拟方法，成功建立了压力微泡沫液膜稳定性以及泡沫液膜与煤尘耦合的分子动力学模型；创新性地提出以固液最大铺展因子和震荡次数作为衡量润湿性的参数，探究了表面活性剂的离子性质、种类、浓度和初始速度等性质对表面活性液滴铺展、回缩及震荡次数的影响；为提高泡沫的稳定性和喷射定向性，成功研发了纳米颗粒增强型的压力微泡沫，增加了液膜的机械强度，起到增强泡沫喷射稳定性的作用。运用Fluent模拟软件探究了压力微泡沫在管道中泡沫运动过程及泡沫喷射情况，对不同气水比下的压力微泡沫在管道中的压力损失、出口速度、射程和射高进行研究，揭示了压力微泡沫管道流动及喷射的流体动力学过程。