流化床内粉煤气固流动特性的实验研究  

Experimental study on flow characteristics of gas-solid of powdered coal in a fluidized-bed

作　　者：屠功毅 宗弘元[1] 钟思青[1] 徐俊[1] 周靖[1] 辛忠[2] 

机构地区：[1]中国石油化工股份有限公司上海石油化工研究院,上海201208 [2]华东理工大学化工学院,上海200237

出　　处：《化工进展》2017年第B11期180-186,共7页Chemical Industry and Engineering Progress

摘　　要：采用5种不同粒径分布的粉煤对流化床内粉煤气固两相流动形态和压力波动进行了实验研究。确定了不同操作参数下的流动形态,考察了不同操作条件对压力分布和压力波动的影响,采用了一种新方法——通过流化床底部相邻两点压差关于流态化气速的曲线来分析临界流态化速度,通过压力标准偏差最大值对应的流态化速度来确定起始湍动流态化速度,提出了临界流态化和起始湍动流态化雷诺数关于粉煤粒径的关系式,揭示了压力变化与流态演变的内在联系。结果表明,粉煤颗粒粒径越小,各流动形态的临界速度越小;当床内出现节涌流态化或湍动流态化时,细颗粒粉煤的压力波动较小,而粗颗粒粉煤的压力波动比较剧烈;流化床底部相邻两点压差和压力标准偏差均随着流态化速度的增大先增加后减小。The flow regimes and pressure fluctuations of powdered coal gas-solid two-phase flowin a fluidized-bed are experimentally studied by using five different particle size distributions ofpowdered coal. The flow patterns under different operating parameters are determined. Theeffects of different operating conditions on the pressure distribution and the pressure fluctuationare investigated. The critical fluidization velocity was analyzed by a new method, which is basedon the curve of the pressure difference between two adjacent points at the bottom of the fluidized-bed. The initial turbulent fluidization velocity is determined by the fluidization velocity of themaximum value of the pressure standard deviation. The relation formulas between the Reynoldsnumbers of the critical fluidization and the initial turbulent fluidization on the particle size ofpowdered coal are proposed. The internal relation between the pressure variations and theevolution of the flow regimes is revealed. The results show that the smaller particle size ofpowdered coal is, the smaller critical velocity of each flow regime is. When slugging fluidizationor turbulent fluidization occurs in fluidized-bed, the pressure fluctuation of fine powdered coal isslight, while the pressure fluctuation of coarse powdered coal is severe. The pressure differencebetween two adjacent points and pressure standard deviation at the bottom of the fluidized-bedincrease first and then decrease with the increase of fluidization velocity.

关 键 词：流化床 流态化 流域 粉体 流体动力学 

分 类 号：TQ051[化学工程]