摘要
密相颗粒流动过程中的传热行为研究还不充分.在综合考虑颗粒接触传热的多个过程的基础上提出了颗粒接触传热模型,并与DEM模型结合模拟了移动床中颗粒与加热面间的传热过程.比较各传热过程的关系,可知通过接触面传递的热量对整体有效传热量的影响最大;有效传热系数主要受与加热面接触的颗粒数目、接触时间、颗粒加热面间接触面的大小等因素的影响;当颗粒的平均粒径相同时,不同的颗粒粒径分布对颗粒系统的传热影响不是很大;当颗粒的粒径增大,有效传热系数降低;颗粒与加热面间的传热量在空间上的分布是不均匀的.
The heat transfer in granular materials can be found in many industrial processes, but such phenomenon is not well understood. A particle contact heat transfer model （PCHM） was developed by taking independent mechanisms into account. The model combined with discrete element methods （DEM） was used to simulate heat transfer between particles and inserted heating surface. Comparing the mechanisms with each other showed that, the heat conduction through contact area had the greatest contribution to apparent effective quantity of heat transfer Qeff. The key factors effecting Qeff include the number of particles contacting with heating wall, contact time, and contact area. When the average diameter was the same, the diameter distribution had little effect on heat transfer. When the average diameter was different, the effective heat transfer coefficient decreased with increasing particle diameter. The quantity of heat transfer was spatially non-uniform.
出处
《化工学报》
EI
CAS
CSCD
北大核心
2006年第4期719-725,共7页
CIESC Journal
基金
国家自然科学基金重大项目(20490200).~~
关键词
接触传热
移动床
颗粒
数值模拟
contact heat transfer
moving bed
granular
simulation
