强制循环蒸发器的非线性解耦控制

Nonlinear decoupling control of forced-circulation evaporator

强制循环蒸发器是一个多输入多输出的且回路间存在着较强耦合的强非线性的复杂化工过程。针对单纯的采用常规控制方法很难满足实际的工业要求的问题,在深入研究上述过程的动态特性的基础上,根据模型的结构特点,采用全局输入输出反馈线性化的方法实现了其解耦控制,并证明了系统的零动态稳定性。通过仿真表明采用全局输入输出反馈线性化解耦方法能够有效地解决系统的强非线性对系统带来的影响,而且还能消除密度回路与液位回路间的耦合作用,该方法对提高产品质量和提高系统的蒸发效率具有重要意义。

The forced-circulation evaporator is a multi-input and multi-output process with complex dynamics, such as strong nonlinearity, strong coupling. Therefore, the existing conventional control strategy can not satisfy production demand. The dynamic characteristics of forced-circulation were studied. According to the structure characteristics of the evaporator model, decoupling control was achieved by using the global input and output feedback linearization control technology and zero-dynamic stability of system was proved subsequently. Simulation results showed that the global input and output feedback linearization control technology could not only reduce the effect of nonlinearity on the system, but also eliminate the coupling between density loop and level loop. At the same time, the method could improve production quality and evaporation efficiency simultaneously.