Smith预估-模糊控制在硝酸氧化炉自设定氨空比控制中的应用

Application of Smith-Fuzzy Predictive Control in Auto-setting Ammonia-Air Ratio in Nitric Acid Oxidation Furnace

硝酸生产氧化炉温度控制系统具有大惯性、非线性及时变等特点,采用常规控制方法对温度进行控制难以获得满意的效果。因此,提出一种新的基于模糊控制的氨空比自动设定方案,通过模糊控制器输出氨空比修正值,实现了氨空比的自动设定;同时,将Smith预估控制应用于主回路进行温度补偿,减小了时滞的不利影响。仿真结果显示:该方案自动设定的氨空比能够很好地调节氧化炉温度,较常规控制方法超调量小、调节时间短。

Considering the large inertia, nonlinearity and time variation of the oxidation furnace＇ s temperature control system in the nitric acid production, and the conventional control methods＇ difficulty in obtaining saris- factory control effect there, a fuzzy control-based auto-setting scheme for the ammonia-air ratio was proposed, which adopts fuzzy controller to output the ammonia-air ratio modified so as to realize the auto-setting of ammo- nia-air ratio ; in addition, it has Smith predictive control applied to the main circuit for temperature compensa- tion to reduce the delay of the adverse effects. The simulation results show that, the auto-setting ammonia-air ratio in this scheme can adjust the oxidation furnace temperature better than the conventional control method in controlling both overshoot and time.