面向分时电价的大极板锌电解过程建模与优化控制方法

Large-plate and long-period are inevitable trends in the development of zinc electro-winning technology. However, there exists distortion of electric field, flow field and concentration field, which brings the difficulty of process modeling. Furthermore, the time-of-use (TOU) electricity price will cause large adjustment of electric load in different peak-valley period. This will result in large variation of working-condition and influence the optimal operation of zinc electro-winning process (ZEWP), even make it a bottleneck restricting energy-saving for large-plate and long-period ZEWP. At first, the reaction mechanism and the relationship between different reactions in ZEWP will be investigated and the kinetics model of the competitive-opposite parallel reactions system will be established. Then the mass transfer mechanism and the influence of multi-fields to mass transfer process are analyzed, and the prediction model for concentration of zinc ion and acid is established. Considering the energy consumption, TOU of electricity price and constraint conditions, the optimization method for process parameters to minimize the energy consumption and power rate is proposed. Considering the problems such as working-condition variation and high energy consumption caused by the adjustment of electric load, the optimal control method for working-condition migration is proposed. At last, the proposed methods will be applied to the practical process to validate the effectiveness, and lay theoretical foundation and offer technical support for large-plate and long-period ZEWP. The achievement has important significance for energy saving in ZEWP. More importantly, it will promote the development of control science and nonferrous metallurgy. Therefore, it is of great significance for both scientific research and industrial application.

大极板长周期是锌电解工艺发展的必然趋势，但也带来了电解槽中电场、流场及浓度场的畸变，过程建模困难；分时电价引起不同峰谷用电时段负荷的大幅调整，造成工况波动大，严重影响锌电解生产的优化运行，成为制约大极板长周期电解工艺节能降耗的瓶颈。本项目研究锌电解过程反应机理及各反应之间的关系，建立竞争-对峙并行反应体系动力学模型；分析锌电解过程的传质机理及多物理场对传质过程的影响，建立多场耦合作用下的酸/锌离子浓度预测模型；综合考虑能耗、分时电价及生产约束，提出面向能耗及电费最低的工艺参数优化方法；针对电解负荷调整引起工况波动、能耗高的问题，提出工况迁移轨迹优化控制方法，实现工况快速、平稳、低耗地过渡，并在实际锌电解过程控制中验证方法的有效性，为大极板长周期锌电解优化运行提供理论与方法支持。研究成果对锌电解生产的节能降耗具有重要意义，也将推动控制科学与有色冶金学的交叉研究，具有重要的科学意义和应用价值。

锌电解是在直流电作用下，将硫酸锌溶液中的锌离子在阴极上析出，以获得高纯度金属锌。大极板长周期锌电解工艺带来了电场、流场、浓度场的畸变新问题，导致锌电解过程建模困难；同时，电的分时计价引起不同用电时段锌电解负荷的大幅调整，造成电解过程工况波动大，严重影响锌电解生产的优化运行，成为制约大极板长周期电解工艺节能降耗的瓶颈。本项目深入锌电解实际生产现场，获取了大量工业运行数据，深入分析了锌电解电极反应中的传质与电化学反应机理，研究了锌电解过程析出锌反溶的原理，基于有限元方法构建了电解过程多物理场仿真模型，对锌电解过程进行了准确描述；基于过程数据与机理模型，研究了锌电解全流程离子浓度预测模型，实现了对锌电解过程运行状况的实时预测；结合分时电价引起的工况波动以及机理模型复杂难解的问题，提出了基于Kriging代理模型的锌电解过程工艺参数优化方法；针对锌电解过程中工况参数波动大、波动过程电能消耗代价高问题，提出了基于偏差预测控制的锌电解过程酸锌比优化控制策略，实现了工况频繁波动下的锌电解过程稳定控制；提出了面向电价与能耗最小的锌电解工况迁移方法，缩短了人工调整下的迁移时间并减低了工况迁移过程中的直流电耗；针对电解工况复杂、多变导致的控制器无法及时更新问题，提出了基于强化学习的锌电解优化控制方法，实现了控制器自主学习工况状态，提升了长周期下的电解过程控制稳定性与节能降耗表现。利用现场实际运行数据进行了仿真研究，验证了所提方法的有效性，为锌电解过程的优化控制提供了理论指导。