活性水音爆雾化的多尺度尘雾颗粒群碰撞团聚机理研究

The mine micro-scale dust has high concentration and hydrophobic behavior, meanwhile, the dust removal effect of traditional dedusting is limited, because of the dust-droplet coagulation mechanism is not perfect and the multiscale mechanical problems in bridging macroscopic characteristics and meso-mechanism. In order to reduce the dust concentration efficiently, the impact of factors can be summed up as size matching, well permeant and high relative velocity. Based on sonic boom and wettability theory, the activated water sonic blasting technology is built to reveal the atomization mechanism, which is different from the traditional dedusting. By solving the problem of smooth transition between particles behavior and incorporating the molecular dynamics approach into the smoothed particle hydrodynamics approach, the multiscale algorithm is established to analyze the particles dynamic evolution characteristics in the process of collecting dust, and the competitive adsorption model of activated fog-dust is established. Through theoretical analysis, the influences and relations of macro spraying dedusting on random variation such as collision, nucleation, coagulation and deposition is revealed to confirm the correlation between surfactant and dynamic characteristic of particles. The above theory research will be employed to form a theory of dust removal by spraying, and the research results will improve the development technology of dust removal efficiency to provide the fundamental data and theoretical foundation.

矿山微米级粉尘浓度高，憎水性强，传统喷雾技术降尘效率低，究其原因是尘雾颗粒群碰撞团聚机理不完善、喷雾降尘宏观表现和碰撞团聚细观机理内在联系不清晰。粒径匹配、浸润性好、相对速度高是实现高效捕集粉尘的三个基本条件，基于此，本项目在音爆原理、浸润性理论的基础上，提出一种有别于传统喷雾方式的活性水音爆雾化技术，分析活性水音爆破碎雾化机理；突破颗粒间各种力学、物理特性的平滑过渡难题，构建细观分子动力学与宏观光滑粒子流体动力学相结合的跨宏、细观多尺度算法，分析活性微雾捕集粉尘过程中颗粒群动力学演变特性，建立活性微雾-粉尘竞争吸附模型，揭示尘雾颗粒群细观随机变化特征（碰撞、成核、团聚、沉降）与宏观水雾除尘的内在联系，确定表面活性剂与尘雾颗粒群多尺度动力学特征的关联性，形成完整的活性水音爆微雾捕尘理论，为煤矿活性喷雾降尘技术的开发提供基础数据与理论支撑。

本项目是针对矿山微米级粉尘浓度高、憎水性强、传统喷雾技术降尘效率低等问题而提出的。首先，建立了4种拉瓦尔喷管内部侧壁曲线线型，分析了不同入口压力情况下音爆喷嘴内不同位置马赫数的变化情况，得到了DE-Laval喷管的扩张角度和缩扩比对喷嘴内流场的影响规律，确定了音爆喷嘴内部轴向气流速度大小与喷嘴内喉管长度之间的关系，得到了拉瓦尔结构参数对雾化特性影响研究，揭示了音爆雾化机理，研制出新型音爆雾化喷嘴。其次，分析了单一表面活性剂在添加到水中之后的气-液界面行为，考察了7个煤种9个煤样中矿物质所含无机盐离子种类和浓度，分析了无机盐的阴阳离子对不同类型表面活性剂极性头基的静电屏蔽作用、表面活性剂头基的水合作用以及对表面活性剂溶液的流变性能等性质的影响，构建了不同表面活性剂含有不同种类无机盐（NaCl，CaCl2，MgCl2）的一系列表面活性溶液模型。此外，构建了水在不同变质程度煤中的自扩散分子动力学模型，分析了纯水和在表面活性剂影响下水在不同变质程度煤中的自扩散系数，对水、表面活性剂和煤的分子表面静电势进行了计算，对分子表面静电势与表面活性剂影响下的水在煤中的润湿性进行了关联分析。最后，采用离散相模型的粒子跟踪技术分析了气路压力、喷嘴口径、喷嘴间距等影响因素对干涉区域雾化特性的影响，研究了多个音爆喷嘴联合布置产生的雾化干涉场的粒度特性，得到了不同布置方式对除尘效率的影响，为煤矿活性喷雾降尘技术的开发提供基础数据与理论支撑。