基于声发射信号递归分析的气固流化床流型转变

发布时间：2018-03-25 19:57

本文选题：流化床　切入点：过渡　出处：《化工学报》2017年02期

【摘要】：利用声发射技术采集不同流化气速下流化床内颗粒与壁面碰撞的声信号,结合声能量及递归分析法研究不同流型下颗粒运动特征,得到鼓泡流态化到湍动流态化的临界转变速度及流型转变规律。特别是针对声能量分析无法准确区分不同床层高度处流型转变的不足,利用递归分析可有效预测系统周期性的特点,将声信号进行递归分析,研究了流化床不同位置的流型转变性质。结果表明,鼓泡流态化下颗粒运动的周期性较湍动流态化强,并能够清晰地检测到由鼓泡流态化向湍动流态化的流型转变速度,而且床层较低处的流型转变速度比床层较高处大。由此获得了一种便捷灵敏、安全环保的非侵入式流化床流型转变速度的测量技术,可用于对整个流化床内不同位置流型转变过程的实时在线监控。
[Abstract]:Acoustic emission technique is used to collect acoustic signals of particles colliding with wall in fluidized bed under different fluidized gas velocities. The characteristics of particle motion under different flow patterns are studied by combining acoustic energy and recursive analysis. The critical velocity of bubbling fluidization to turbulent fluidization and the rule of flow pattern transition are obtained, especially in view of the deficiency that acoustic energy analysis can not accurately distinguish the flow pattern transition at different bed heights. By using recursive analysis to predict the periodicity of the system effectively, the acoustic signal is analyzed recursively, and the characteristics of flow pattern transformation in different positions of fluidized bed are studied. The results show that the periodicity of particle motion in bubbling fluidization is stronger than that in turbulent fluidization. The velocity of flow pattern transition from bubbling fluidization to turbulent fluidization can be clearly detected, and the velocity of flow pattern transition at the lower part of the bed is larger than that of the bed higher. Thus, a convenient and sensitive flow pattern is obtained. A safe and environmentally friendly non-invasive fluidized bed flow rate measurement technique can be used to monitor the flow pattern transition process in different positions in the whole fluidized bed in real time and online.
【作者单位】：化学工程联合国家重点实验室浙江大学化学工程与生物工程学院;中国石油化工股份有限公司天津分公司烯烃部;
【基金】：国家自然科学基金项目(21406194,91434205) 国家杰出青年科学基金项目(21525627) 浙江省杰出青年科学基金项目(LR14B060001) 高等学校博士学科点专项科研基金项目(20130101110063) 化学工程联合国家重点实验室基金项目(SKL-ChE-13T03)~~
【分类号】：TQ051.13

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