流化床中射流机制和双射流相互作用

在文献的基础上, 通过实验和模拟的方法研究了射流机制和双射流的相互作用. 采用一个300 mm′51 mm的两维气固流化床，内置两个垂直射流, 使用多路毕托管系统测量射流穿透深度. 使用描述气固流态化的双流体模型进行模拟，用改进的IPSA求解模型方程，通过数值模拟, 讨论了射流产生的机理, 再现了双射流, 并发现双射流的相互作用可分为三类：孤立射流、过渡射流和互作用射流，提出了相应的射流间距判据. 发现影响双射流穿透深度最主要的因素是射流动量、两相间曳力、射流间距和床层表观气速, 建议使用Froude数、Reynolds数、床层表观气速、射流间距和喷口直径来关联不同区域的射流穿透深度. 得到了一个关联式并与文献中的关联式或实验数据做了比较.

Jet Regime and Double Jet Interaction in Gas-Solid Fluidized Beds

Experimental investigation and numerical simulation were conducted for a gassolid fluidized bed with a single jet or double jets. The jet penetration heights in a 300 mm51 mm two-dimensional fluidized bed were measured with pressure transducers. Numerical modeling and simulation was based on a two-fluid model with K(\226)52.6(\345)] model for gas turbulence. Jet formation and detachment above jet nozzle, bubble ascending and coalescence in bed, and bubble burst on bed surface were visualized by computer simulation. It was found that the behavior of the double jet system could be classified into three categories: isolated jets, transitional jets, and interacting jets. The criterions of jet separation for those categories were proposed. Jet penetration correlations were also recommended for those categories