基于信息熵分析的喷动流化床流动特性

建立了300 mm×30 mm×2000 mm的喷动流化床煤气化炉冷态实验装置和多通道压力信号采集系统，引入压力波动时间序列的Shannon信息熵分析，讨论了不同喷动气速度和流化气流率下各床层区域的Shannon 信息熵，并结合高分辨率数码CCD相机所记录的流动状态，建立了Shannon信息熵与流型之间的联系.床层不同区域的Shannon 信息熵具有较大的差异，不同流型的Shannon 信息熵区分度较好.在较高的喷动气速度或流化气流率下，喷动流化床气固运动周期特性消失，呈现出明显的混沌特性，表现为床层各区域Shannon信息熵的急剧增长和床内不稳定的流动状态的发生.结果表明，Shannon信息熵分析有助于认识喷动流化床复杂的流型及其转变和床内气固两相流动的混沌动力学特性.

Flow characteristics in spout-fluid bed by Shannon entropy analysis

Shannon entropy(SE) analysis of pressure fluctuation time series was developed to characterize the flow characteristics in a spout-fluid bed coal gasifier cold model with cross section of 300 mm×30 mm and height of 2000 mm.A multi-channel pressure signal acquisition system was established to obtain the pressure fluctuation time series at various bed locations, and a high-resolution digital CCD camera used to record the flow patterns in various operating conditions.The effects of spouting gas velocity and fluidizing gas flow rate on SE were examined. The characteristics of dynamic behavior were discussed according to the operating parameters and SE. SE was found different for different flow patterns, and was used to identify the flow patterns. SE was also found significantly different at various bed locations. It indicated that a spout-fluid bed at a high spouting gas velocity or a high fluidizing gas flow rate showed no periodic nature but chaotic nature since the SE at all bed locations increased sharply and flow instabilities existed.Research results showed that SE analysis could help to understand the complex flow characteristics of spout-fluid beds, providing reference to the engineering of spout-fluid bed coal gasifiers.