基于气固两相流流动特性风帽式布风板结构参数优化  

Optimization of Structural Parameters of Nozzle Distributor Based on Gas-Solid Two-Phase Flow Characteristics

作　　者：张健平 赵彦宾 邓尧 ZHANG Jianping;ZHAO Yanbin;DENG Yao(School of Manufacturing Science and Engineering,Key Laboratory of Testing Technology for Manufacturing Process,Ministry of Education,Southwest University of Science and Technology,Mianyang 621010,China)

机构地区：[1]西南科技大学制造科学与工程学院制造过程测试技术教育部重点实验室,四川绵阳621010

出　　处：《大学物理实验》2022年第6期1-11,共11页Physical Experiment of College

基　　金：国家自然科学基金(51308480);教育部在线教育研究基金(2016YB163);博士研究基金项目(17ZX7125)。

摘　　要：布风板结构参数显著地影响着床层内部气固两相流流动特性,为了探究流化床干燥装置内油菜籽颗粒流化性能和空气流速脉动规律,明晰不同面板凸度、风帽开孔夹角和开口瓣数对风帽布风板布风性能的影响,提出布风板结构数的优化方案。以15.84%开孔率圆形非均匀布孔布风板为基础,根据Euler/Euler双流体模型和Standardk-ε湍流模型,采用ANSYS19.1中流体动力学分析模块Fluent软件对面板凸度(2 mm、5 mm和10 mm)、风帽开孔夹角(0°、5°和10°)和开口瓣数(四瓣、六瓣和八瓣)进行优化设计,并通过实验进行验证。结果表明:5 mm凸度球面板、四瓣风帽、5°开孔夹角布风板是油菜籽流化床干燥的最佳布风板。与平面布风板相比,凸形球面布风板的油菜籽分布均匀性好,其中凸度为5 mm球面板油菜籽平均体积分数方差(0.0073)最小,促使其与热空气接触均匀充分。5°风帽开孔夹角有利于颗粒运动呈现脉动流动,是油菜籽干燥布风板的最佳开孔夹角。风帽开口瓣数对油菜籽流化床干燥的布风性能影响不大,相对来说四瓣风帽开口瓣数能更好地均布空气流。通过实验对模拟结果进行验证,结果发现数值模拟与实验结果相吻合,验证了所优化的最佳布风板是合理可行的,该研究结果可为干燥设备设计提供理论依据,同时也为油菜籽流化床干燥效率提供理论支撑。There are extremely significance effects of structural parameters of nozzle distributor on gas-solid two-phase flow characteristics of fluidized bed.And this study aims to explore fluidization characteristics of the rapeseed(Brassica rapus)and pulsation law of air velocity in the fluidized-bed dryer.Thereby to clarify influence of the plate convexity,opening angle,and opening petal number on the airflow distribution performance of nozzle distributor.Then the optimization scheme of structural parameters was proposed.Based on the distributor of the open porosity ratio of 15.84%and uneven circular holes arrangement.The plate convexity(2 mm,5 mm,and 10 mm),opening angle(0°,5°,and 10°),and opening petal number(four petals,six petals,and eight petals)was optimally designed through numerical simulation software of Fluent based on Euler/Euler two-fluid model and standard k-εturbulence model.Then verify it by experiment.The results showed that plate convexity of 5 mm,opening angle of 5°,and four opening petals were the optimized structure parameters of nozzle distribution for the rapeseed fluidized bed drying.The nozzle distributor of convex plate made the rapeseed(Brassica rapus)evenly distribute compared with the parallel plane.And the variance of average volume fraction of rapeseed(Brassica rapus)is 0.0073(minimum)for the nozzle distribution of plate convexity of 5 mm,with the result that the rapeseed(Brassica rapus)fully mixed with hot air and evenly distributed.The opening angle of 5°was optimum value for the rapeseed fluidized bed drying,which was favorable to the pulsating flow of the rapeseed(Brassica rapus).Nevertheless,the opening petal number had no significant effect on the airflow distribution performance of nozzle distributor.The four opening petals can cause that the hot air and the rapeseed(Brassica rapus)would be redistributed equably in whole region of fluidized bed compared with the other opening petals.The drying kinetics curves of nozzle distributor of variable plate convexity,opening angle,and

关 键 词：风帽式布风板 结构参数 面板凸度 开孔夹角 开口瓣数 数值模拟 

分 类 号：TQ021.3[化学工程] TQ026.7