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

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。

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

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 satis-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.