基于图像法喷动床内空隙率研究

发布时间：2018-05-04 19:49

本文选题：空隙率 + 喷动床　；参考：《化学反应工程与工艺》2017年04期

【摘要】：利用图像二值化方法处理图片,并采用Matlab编程实现空隙率的测量,从微观层次分析空隙率对喷动流化床内流动状态的影响。研究了颗粒粒径、喷口数量和表观气速对空隙率分布的影响。结果表明,增大表观气速使床层底部的稀相区增大,床层膨胀高度增加,空隙率也随之增加。增大颗粒粒径会增大最小临界流化速率,所以在其达到流化状态后流化床内颗粒粒径增大,床内喷动区空隙率减小比较明显。在相同条件下,与单喷口相比双喷口在床层底部附近存在合并射流,同时颗粒能到达的高度显著增加,底部两侧停滞区面积减小。结合对空隙率的分析,提出一种新的表征流化床内流化状态的参数(流化指数),可以直观地表示流化床内颗粒的流化状态。
[Abstract]:The image binarization method is used to process the images and the Matlab programming is used to measure the voidage. The influence of the voidage on the flow state in spouted fluidized bed is analyzed from the micro level. The effects of particle size, nozzle number and apparent gas velocity on the distribution of porosity were studied. The results show that the dilute phase region at the bottom of the bed increases with the increase of the apparent gas velocity, the expansion height of the bed increases, and the void ratio increases. Increasing particle size increases the minimum critical fluidization rate, so the particle size in the fluidized bed increases and the voidage in the spouted zone decreases obviously when the particle size reaches the fluidized state. Under the same conditions, compared with single nozzle, there is a combined jet near the bottom of the bed, while the height of the particle energy reaches a significant increase, and the area of the stagnant area on both sides of the bottom decreases. Based on the analysis of voidage, a new parameter (fluidization index), which can represent the fluidization state of particles in fluidized bed, is proposed.
【作者单位】：华北电力大学;
【分类号】：TQ021.1

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