精细化工过程控制技术的发展动向

Overview on the development trends of fine chemical process control

精细化工产品的市场需求快速多变,产品更新换代快,使得精细化工生产过程一般采取小批量、多品种生产,生产过程多为间歇或半连续过程,时变性、非线性强,生产过程的工艺流程复杂,操作步骤繁杂,劳动强度大;精细化工生产过程的工艺介质多为有一定毒性、腐蚀性和易燃易爆性的化学品,过程运行危险性大:这些特点使得精细化工生产过程更难以控制,综合自动化水平普遍较低。为了提高精细化工生产过程的综合自动化水平,需根据精细化工生产过程的特点及其控制需求,进行精细化工生产过程控制技术的研究和应用。目前,精细化工过程控制技术的主要发展动向为:从常规仪表控制向计算机控制、集散式控制系统(Distributed Control System,DCS)控制发展;从简单的顺序控制、程序控制向基于ISA SP88间歇过程控制标准的自动批量生产控制发展;从人工控制、常规PID控制向先进的批次-批次迭代学习优化控制发展:从简单工艺参数的控制向生产工况和生产质量的综合性统计过程控制发展:从简单的工艺参数越限连锁报警向综合性安全保护控制和在线实时非正常工况管理发展。

The market demands and product varieties of fine chemicals are changing rapidly nowadays, and this leads to the small-scale, multi-variety production of fine chemicals. Most fine chemical production processes are batch or semi-batch processes with strong nonlinear and time-varying properties, and their process flow-sheets and operation procedures are quite complex. Furthermore, the operation of fine chemical process usually is dangerous, as most substances in the fine chemical processes are toxic, corrosive, flammable and explosive chemicals. These characteristics of fine chemical production processes make them hard to control, and their automatic control and operation level is not satisfactory. In order to improve the automatic control and operation level of fine chemical processes, the development and application of fine chemical process control technology should be carried out according to their unique process characteristics and control requirements. At present, the main development trends of fine chemical process control technology are as follows. The hardware of fine chemical process control system is developing from analogy or digital instrumentation system to computer control system and distributed control system （DCS）. The software of fine chemical process control system is developing from simple sequential control, program control to total automatic batch recipe control based on ISA SP88 batch control standard. The control strategy of fine chemical process is developing from manual control, PID control to Run-to-Run iterative learning optimized control. The process monitoring and quality control of fine chemical process is developing from ordinary parameters control to comprehensive statistical process control. And the safety control of fine chemical process is developing from alarm and interlock of ordinary process parameters to comprehensive safety protection and real-time on-line abnormal situation management.