非均匀降膜式气液交叉流除尘系统运行能耗数值分析  

Numerical Analysis of Operating Energy Consumption in Non-uniform Falling Film Gas-Liquid Cross-flow Array System

作　　者：余徽[1] 刘泽坤 熊国栋 杨雅琪[1] 郑一玮 魏文韫[1] YU Hui;LIU Zekun;XIONG Guodong;YANG Yaqi;ZHENG Yiwei;WEI Wenyun(School of Chemical Eng.,Sichuan Univ.,Chengdu 610065,China)

机构地区：[1]四川大学化学工程学院,四川成都610065

出　　处：《工程科学与技术》2021年第1期188-194,共7页Advanced Engineering Sciences

摘　　要：气液交叉流(GLCA)除尘系统通过分布板形成阵列液柱群以捕获工业尾气中的颗粒物,尾气颗粒脱除率随液柱群阵列单元排数的增加而增大,但系统运行能耗较高且主要集中于循环水耗。为降低循环液量及运行能耗,提出仅在对颗粒捕获起主要作用的迎风面布膜的非均匀降膜阵列以代替原液柱阵列。采用大涡模拟(LES)和离散相模型(DPM)分别对不同布膜角度的非均匀降膜式GLCA系统除尘过程的流场和颗粒运动进行数值模拟,将360°布膜角度条件视为液柱式GLCA系统模型并将其与相同操作条件下的实验数据进行对比验证,所得模拟结果与实验吻合。不同布膜角度的数值模拟结果表明:随布膜角度的减小,虽然系统单元排脱除效率逐渐降低,但系统水耗量亦随之降低,故对于特定的除尘任务,存在一个最优的布膜角度使得系统水耗量最低;对于大颗粒而言脱除效率变化相对较小,表明惯性碰撞是其主要脱除机理。结合某氨酸法复合肥生产线尾气数据,以比电耗为评价标准,利用所得模型对降膜槽的迎风面布膜角度进行寻优。结果表明,当尾气颗粒物质量脱除效率达到80%时,非均匀降膜式GLCA系统达到最低运行能耗对应的最佳布膜角度为70°,此时系统所需单元排数为634,对应的比电耗可低至1.83×10^-4(kW·h)/m^3,与燃煤电厂电除尘器能效等级的1级能效相当。The gas-liquid cross-flow array(GLCA)system captures particles from industrial tail gas by forming arrays of liquid columns through distribution plates and the particle removal efficiency can be improved by increasing the number of unit rows of liquid columns arrays.However,the system has high operation energy consumption which mainly composed of water recycle.To reduce the energy consumption of GLCA system,non-uniform falling film at windward side which plays a major role in particle capture was utilized to supersede previous liquid columns technology.Large eddy simulation(LES)and discrete phase model(DPM)were employed in the numerical simulation of flow field and particle motion respectively for non-uniform falling film GLCA system with different liquid film angles.The model of liquid falling film angle of 360°was regarded as that of liquid-columns GLCA system and compared with the experiment under the same conditions for verification,which proves a good agreement between simulation result and experiment data.The numerical simulation results of different liquid film angles indicated that particle removal efficiency of one unit row decreases gradually with the reduction of the angles,but the water consumption also decreases.There is an optimal angle of film to minimize water consumption in the system for a specific particle removal task.The removal efficiency of large particles is relatively small,indicating that inertial impact is the main removal mechanism.Using the evaluation criteria of specific power consumption as a baseline,the windward film angle of falling film channel was optimized with the numerical simulation model based on the ex-hausted gas data of a certain compound fertilizer production by ammonia-acid process.The results showed that the optimal angle with the lowest operation energy consumption of the non-uniform falling film GLCA system is 70°,634 rows of units required in the system and the corresponding specific power consumption could be as low as 1.83×10-4 kW·h·m-3 when the quality dus

关 键 词：气液交叉流 降膜流动 数值模拟 比电耗 运行能耗 

分 类 号：X513[环境科学与工程—环境工程]