S mith预估-模糊控制在硝酸氧化炉自设定氨空比控制中的应用

摘要

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.%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.