频率对燃煤飞灰声波团聚影响的模型及实验验证  

A Theoretical Model and Experimental Verification on the Influence of Frequency on Acoustic Agglomeration of Coal-fired Fly Ash

作　　者：张光学[1] 刘建忠[1] 周俊虎[1] 王洁[1] 岑可法[1] 

机构地区：[1]能源清洁利用国家重点实验室(浙江大学),浙江省杭州市310027

出　　处：《中国电机工程学报》2009年第17期97-102,共6页Proceedings of the CSEE

基　　金：国家自然科学基金项目(50576083);新世纪优秀人才支持计划项目(NCET-04-0533)~~

摘　　要：为研究声波团聚过程中频率的影响,基于碰撞效率修正的同向作用机理,提出一种声波团聚的新模型。通过实验对模型的计算结果进行了验证,发现该模型能很好地描述声波团聚过程。计算所得的声波团聚中的粒径分布和浓度变化与实验值基本吻合。数值模拟再现了气溶胶在声波团聚中粒径分布的变化,细颗粒逐渐团聚产生大颗粒,气溶胶总浓度降低、平均粒径增大。计算结果和实验值均表明,频率对团聚效果影响很大,声波团聚中存在最佳频率,高于或低于该最佳频率均使团聚效果迅速降低。计算结果还表明,在声波作用下,燃煤飞灰气溶胶总浓度随时间呈指数衰减规律降低。This paper presented model and experimental studies on the influence of frequency on acoustic agglomeration of coal-ftred fly ash. Orthokinetic interaction mechanism corrected by collision efficiency was used in the numerical simulation, and the results agree with the experimental results well. Simulation results show that acoustic agglomeration process shifts the particle size distribution towards larger size and reduces the number of fine particles. Both experimental and numerical simulation results confirm that the effectiveness of agglomeration is sensitive to the frequency change and there exists an optimum frequency for a given particle size distribution of an aerosol. A considerable effectiveness of agglomeration could only be obtained in a narrow frequency range and it decreases significantly beyond the range. In addition, the simulation results show that with sound application the concentration of fly ash decreases exponentially with respect to time.

关 键 词：声波团聚 同向碰撞机理 碰撞效率 燃煤飞灰 PM2.5 

分 类 号：X513[环境科学与工程—环境工程]