气固两相动态旋风分离的试验研究

发布时间：2018-05-28 04:01

本文选题：动态旋风分离器 + 数值模拟　；参考：《山东大学》2015年硕士论文

【摘要】：因为旋风分离器具有结构简单、安装成本低、操作维护简便、性能稳定等优点,自问世以来就在诸如,火力发电厂、焚烧厂、矿石冶炼厂、砂厂、水泥厂、粉体加工厂等领域发挥着举足轻重的作用。日益严苛的性能要求限制了普通旋风分离器的进一步发展,在过去的几十年中,大批学者在提高旋风分离器性能方面从事基础研究,这些工作基本上可以分成两部分：一方面,一些学者致力于改善旋风分离器的相关配置和几何形状；另一方面,一些学者开始在旋风分离器相关研究中添加额外的部件。本文延续加入额外部件的研究思路,在普通旋风分离器中增加了旋转叶片,设计了一种高效的动态旋风分离器,其分离性能与普通旋风分离器相比显著改善。在第2章中,使用Gambit软件对动态旋风分离器进行建模和网格划分,通过Fluent软件设置基本守恒方程、湍流模型、颗粒相模型、旋转模型及边界条件。进而研究了入口气速、叶片转速及叶片结构对动态旋风分离器装置切向速度场、压降分布和分离效率的影响。模拟结果表明,在某些试验工况下,动态旋风分离器分离性能远远优于普通旋风分离器,但动态旋风分离器的压降与普通旋风分离器相比也存在一定程度的提高。在第3章中,通过试验的方法验证了第2章中数值模拟计算模型的准确性。在实验室中搭建了试验台架,进口气速由导流阀门控制,通过ZRQF系列F30J型热球式风速仪测量；进出口总压通过SYT2000型数字微压计配合AS-T-1型皮托管测量；SAG 410气溶胶发生器控制颗粒的给料量;ELPI (Electrical Low Pressure Impactor)对动态旋风分离器进出口气体中不同粒径颗粒的质量分布进行分别测量,从而获得相应单一粒径颗粒的分级分离效率。试验结果与模拟结果相比略有差异,文中分析了产生偏差的可能原因,但总体而言,试验和模拟结果之间有相同的变化趋势。在第4章中,基于响应面分析和期望函数的多目标优化原理,使用Design-Expert这一软件对动态旋风分离器的叶片结构进行了优化。文中把装置的叶片结构提炼为叶片长度、叶片个数和叶片倾角三个变量,通过Box-Behnken原理设计了响应面试验组,分别进行了变量分析、主效果分析、Pareto图分析和独立变量效果分析,进一步通过期望函数多目标优化方法获得的最优叶片结构能同时满足较高的分离效率和较低的装置压降。最后根据最优结构重新进行建模计算,模拟结果与预测结果之间的偏差在3%以内,证明了响应面分析和期望函数多目标优化方法能够较好的优化装置结构,具有一定的工业应用价值。文章的最后对数值模拟与试验研究中获得的关于切向速度场、装置压降、分离效率,以及装置结构尺寸优化等方面的相关结论进行了总结,分析了研究中存在的部分问题,并对课题的发展方向提出了展望。
[Abstract]:Since the cyclone separator has the advantages of simple structure, low installation cost, easy operation and maintenance, and stable performance, it has been used since its inception in thermal power plants, incinerators, ore smelters, sand plants, cement plants, etc. Powder processing plants and other fields play a pivotal role. The further development of conventional cyclone separators has been limited by increasingly stringent performance requirements. In the past few decades, a large number of scholars have been engaged in basic research on improving the performance of cyclone separators, which can be basically divided into two parts: on the one hand, Some scholars focus on improving the configuration and geometry of cyclone separators; on the other hand, some scholars have begun to add additional components to cyclone separators. In this paper, the idea of adding extra parts is continued, the rotating blade is added to the ordinary cyclone separator, and an efficient dynamic cyclone separator is designed. The separation performance of the cyclone separator is obviously improved compared with that of the ordinary cyclone separator. In chapter 2, the dynamic cyclone separator is modeled and meshed with Gambit software. The basic conservation equation, turbulence model, particle phase model, rotation model and boundary conditions are set up by Fluent software. Furthermore, the effects of inlet gas velocity, blade speed and blade structure on tangential velocity field, pressure drop distribution and separation efficiency of dynamic cyclone separator were studied. The simulation results show that the separation performance of the dynamic cyclone separator is much better than that of the ordinary cyclone separator under some test conditions, but the pressure drop of the dynamic cyclone separator is also improved to some extent compared with the ordinary cyclone separator. In chapter 3, the accuracy of the numerical simulation model in chapter 2 is verified by experimental method. A test stand was set up in the laboratory. The inlet gas velocity was controlled by the flow guide valve and measured by ZRQF series F30J hot ball anemometer. The total pressure of import and export is measured by SYT2000 digital microbarometer and AS-T-1 type skin tube to measure the feed quantity of particles controlled by SAG410 aerosol generator. The mass distribution of different particle sizes in the inlet and outlet gas of the dynamic cyclone separator is measured separately by ELPI / Electrical Low Pressure Impactor). Thus, the fractionation efficiency of the single particle size was obtained. There is a slight difference between the experimental results and the simulation results. The possible causes of the deviation are analyzed in this paper, but in general, there is the same trend of variation between the experimental and simulated results. In Chapter 4, based on the principle of multi-objective optimization of response surface analysis and expected function, the blade structure of dynamic cyclone separator is optimized by using Design-Expert software. In this paper, the blade structure of the device is abstracted into three variables: blade length, number of blades and blade inclination. Response surface test group is designed by Box-Behnken principle, and variable analysis, main effect analysis and independent variable effect analysis are carried out respectively. Furthermore, the optimal blade structure obtained by the expected function multi-objective optimization method can satisfy both higher separation efficiency and lower device pressure drop. Finally, according to the optimal structure, the deviation between the simulation results and the prediction results is less than 3%. It is proved that the response surface analysis and the multi-objective optimization method of expected function can better optimize the device structure. It has certain industrial application value. At the end of the paper, the conclusions about tangential velocity field, device pressure drop, separation efficiency and structure size optimization obtained from numerical simulation and experimental study are summarized, and some problems existing in the research are analyzed. The prospect of the development of the project is also put forward.
【学位授予单位】：山东大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ051.8

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