撞击流强化煤气化过程中颗粒变化及流场的可视化研究

Coal gasification is one of the routes for efficient and clean use of coal. However, currently the coal gasification techniques used in our country mainly depend on import. It is feasible to use impinging stream for coal gasification, due to its simple layout, intensified heat and mass transfer, as well as good micro-mixing. This has drawn wide concerns for experts, scholars and industrial parts both local and oversea..Based on the recent research progresses and the achievements by our research group in the field of impinging stream theory and application, this project focuses on studying the feature of mass transfer of coal-gasification processes intensified by impinging streams, using naphthalene particle change by high speed CCD camera, and the flow field of impinging area by hydrogen iodide color reaction. The change rules of particle and flow field will be investigated. The effects of some factors, e.g. particle size of pulverized coal, inter-phase mass transfer, prolonged retention time, on the intensification of mass transfer will be studied to understand the mechanism of mass transfer intensified by impinging stream. The results may extend and deepen the impinging stream theory, and provide fundamental data and theoretical base for developing commercial coal gasification device using impinging stream technique.

煤气化技术是实现煤高效清洁利用的途径之一，但目前我国煤气化还是主要依赖国外进口技术。撞击流由于其简单的布置方式、强化的传热传质、良好的微观混合效果，应用于煤气化过程从理论上是可行的，也已引起国内外专家学者和企业界的日益关注。本项目将结合现有的国内外相关研究进展，以及本课题组在撞击流理论与应用领域的研究基础，采用高速摄像观察萘颗粒变化和碘化氢显色反应观察撞击区域流场变化研究撞击流强化煤气化过程中传质特性，寻找撞击过程中颗粒和流场的变化规律，分析强化传质的关键影响因素（例如煤粉破碎度、产物相间传递、停留时间延长等），探讨撞击流强化传质的机理，进一步扩展和深化撞击流理论，为撞击流煤气化的工业化提供基础数据和理论依据。

煤气化技术是实现煤高效清洁利用的途径之一，但目前我国煤气化还是主要依赖国外进口技术。本研究证明撞击流由于其简单的布置方式、强化的传热传质、良好的微观混合效果，应用于煤气化过程是可行的。粒子图像测速技术研究发现，气流速度对破碎萘颗粒尺寸及分布有明显影响。在撞击流条件下，煤粉颗粒的相向碰撞更有利于破碎，剪切力场的存在强化了宏观分散和微观混合，有利于煤炭颗粒的破碎。但碘化氢显色反应观察撞击区域流场变化未能实现，由于常温下分解速率过慢。为了了解撞击流煤气化整个流场的情况，还利用FLUENT软件对撞击流反应器中煤气化进行了流场的数值模拟，探讨了撞击流强化传质的机理，进一步扩展和深化撞击流理论，可为撞击流煤气化的工业化提供基础数据和理论依据。. 撰写了论文5篇，申请发明专利1项。参加了2次国内学术研讨会，并进行大会交流。培养相关领域的硕士研究生和本科生。