Research On Optimization And Control Of Calcination Process In Soda Manufacture

Soda calcination processes invariably emerge complicated characteristics such as time-varying, large time-delay and strong-coupling, etc. In this thesis, a MPC optimization strategy is studied for the single-calciner MPC system. Furthermore, an intelligent MPC optimization strategy for the real parallel multi-calciner MPC system is proposed.The main contributions of the research work are summarized as follows:1. The basic principles and equipments of soda calcination process are briefly introduced, followed which the principles and characteristics of the process are mainly analyzed. In addition, the state of art of soda calcination process is summarized.2. According to the investigation of practical industrial application and theoretical analysis, the main control objects of soda calcinations are presented. The shortage of conventional control strategies is analyzed based on the study of the process's principals and characteristics. Consequently, the necessity of implementation of advanced process control (APC) strategy is demonstrated.3. A multivariate DMC optimization control strategy is designed for a single-calciner process based on its dynamic model and optimization objects. This strategy is further validated through MATLAB simulation examples, which illustrates the effectiveness and superior performance of the proposed approach. According to the simulation results, the key indicators such as the temperature of outlet soda and outlet air can be successfully controlled in the normal range. Afterwards, a multivariate MPC optimization control strategy is proposed on the basis of the above mentioned one. Simulation results indicate that the new strategy can not only keep the key variables in the normal range but also realize the bonder control. This advantage can reduce the energy consumption and finally bring benefit for the company.4. In practical applications, the soda calcinations process is parallel of multi-calciner. Besides, of the varying production states in real cases should be considered. Hence, a new intelligent MPC optimization control strategy is proposed combined with fuzzy control and expert control technologies. A mechanism of dynamic distribution of the feed of wet soda according to different conditions is invented in the new strategy. Simulation results state that this strategy can optimize the whole feed of soda on condition of good products quality. The good performance is also validated by the implementation to the light soda calcination process in a soda plant.