Research On Optimization And Control Of Carbonation Process In Soda Manufacture

Carbonation process is the core process in soda unit. It is a process with high coupling, time-variant, nonlinear and long-time delay behaviors. There are chemical reaction and physical processes such as heat transfer, mass transfer, crystallization process, etc in carbonation columns. And there is a co-existence of gas, liquid and solid in the columns as well. So it is very hard to apply optimal control strategies to carbonation process. To solve these problems, some research on carbonation process control are given in this thesis. The main works of this thesis are as follows:1. The situation of soda manufacture at home and abroad is briefly introduced. Then the principle-characteristic and process control requirement of soda manufacture carbonation process are analyzed. The research and application of carbonation process control are retrospect systemically.2. The basic process control problems including optimization objective and control strategy for soda manufacture.carbonation process are presented. The mechanism. characteristic and function of traditional control strategies in ammonia-soda process are analyzed systemically, also which deficiencies are associated in application. The necessity of applying carbonation process advanced control and optimization technology is proposed.3. In view of the dynamic model and optimization objective of single column carbonation process, a 2-layer optimization control strategy with objective of maximize soda manufacture is proposed. The simulation results demonstrate that the proposed 2-layered control strategy can fulfill the optimization objective of maximize soda manufacture effectively and possess a preferable robust characteristic on the premise of guaranteeing product quality control requirements.4. In view of the control and optimization problem of single group of carbonation columns, on the basis of 2-layer optimization model predictive control strategy, a carbonation load coordinated optimization strategy on single group of carbonation columns is proposed. The simulation results demonstrate that the proposed control strategy can automatically adjust the loads of columns as the working condition change, and optimize the total soda manufacture of columns on the premise of guaranteeing product quality control requirements.The last part is summary and perspective.