Multi-objective optimization based optimal setting control for industrial double-stream alumina digestion process  

基于多目标优化的双流法氧化铝溶出过程最优控制

作　　者：WANG Xiao-li LU Mei-yu WEI Si-mi XIE Yong-fang 王晓丽;陆美钰;尉思谜;谢永芳(School of Automation,Central South University,Changsha 410083,China)

机构地区：[1]School of Automation,Central South University,Changsha 410083,China

出　　处：《Journal of Central South University》2022年第1期173-185,共13页中南大学学报（英文版）

基　　金：Project(62073342)supported by the National Natural Science Foundation of China;Project(2014 AA 041803)supported by the Hi-tech Research and Development Program of China。

摘　　要：The operation variables,including feed rate of ore slurry,caustic solution and live steams in the double-stream alumina digestion process,determine the product quality,process costs and the environment pollution.Previously,they were set by the technical workers according to the offline analysis results and an empirical formula,which leads to unstable process indices and high consumption frequently.So,a multi-objective optimization model is built to maintain the balance between resource consumptions and process indices by taking technical indices and energy efficiency as objectives,where the key technical indices are predicted based on the digestion kinetics of diaspore.A multi-objective state transition algorithm(MOSTA)is improved to solve the problem,in which a self-adaptive strategy is applied to dynamically adjust the operator factors of the MOSTA and dynamic infeasible threshold is used to handle constraints to enhance searching efficiency and ability of the algorithm.Then a rule based strategy is designed to make the final decision from the Pareto frontiers.The method is integrated into an optimal control system for the industrial digestion process and tested in the actual production.Results show that the proposed method can achieve the technical target while reducing the energy consumption.双流法氧化铝溶出过程中的操作变量包括矿浆、苛性钠溶液和生蒸汽的进料速率,这些变量决定了产品质量和生产成本,并与环境污染密切相关。在实际生产中,这些变量是根据离线分析结果和经验公式由人工计算设置的,会导致工艺指标不稳定、消耗高。为此,本文首先以一水硬铝石溶出动力学为基础建立过程模型,以工艺指标和能效最优为目标,建立多目标优化模型。然后,通过改进一种多目标状态转移算法(MOSTA),采用自适应策略动态调整MOSTA的算子,并采用动态不可行阈值处理约束,以提高算法的搜索效率和搜索能力。最后,设计一种基于规则的策略,从帕累托前沿做出最终决策。该方法已集成到工业溶出过程的最优控制系统中。工业数据仿真和在实际生产中的测试结果表明,该方法能在保证工艺指标满足要求的同时降低能耗。

关 键 词：double-stream digestion process optimal setting control multi-objective optimization state transition algorithm rule based decision making 

分 类 号：TQ133.1[化学工程—无机化工]