废液中和处理系统pH控制仿真  

Simulation of pH control of a wastewater treatment system in MATLAB/Simulink

作　　者：谭超[1,2] 王超[1] 吴同[1] 任根宽[1] 朱登磊[1] 

机构地区：[1]宜宾学院化学与化工学院,四川宜宾644007 [2]计算物理四川省高校重点实验室,四川宜宾644007

出　　处：《计算机与应用化学》2013年第4期395-398,共4页Computers and Applied Chemistry

基　　金：宜宾学院科研与教学创新团队项目(Cx201104);四川省应用基础研究项目(2013JY0101);四川省教育厅重点项目(2012A201)

摘　　要：pH值控制广泛存在于石油化工、生物制药、污水处理、发电等诸多工业过程,其控制品质好坏直接影响整个系统能否长期、安全、稳定运行,因而十分重要。由于强非线性和大滞后等特性,致使其控制难度大,pH值控制系统的设计一直是过程控制界的难点和研究热点。弄清pH中和控制过程的原理,并在计算机上模拟其控制过程及参数扰动的影响,对控制系统的分析与设计具有重要的指导作用。本文以废液中和处理系统为例,分析了溶液系统pH值和流量之间的非线性问题,讨论了在控制系统中将pH值变化转化为中和反应酸碱的流量变化的基本规律,给出了滴定特性曲线转化为酸碱流量变化规律的3种主要方法。最后在MATLAB/Simulink平台进行了pH控制系统设计及仿真,并对滞后时间参数进行了鲁棒性分析。结果显示,只要控制器参数整定合理,时间延迟不超过一定界限,PID控制的控制效果能够满足实际要求。Nowadays, pH control finds application in a wide range of industries including petrochemical, pharmaceutical, wastewater-treatment, power generation and many other industrial processes. The performance of a pH control system directly decides whether the entire system can work on safe and stable status in the long-term and therefore is very important. However, in practice, to design a satisfactory pH control system is difficult because of built-in strong nonlinearity and relatively big lag time. In recent years, there are more and more researches associated with the pH control problem because of its industrial importance. Obviously, Understanding the principle of pH process control, realizing the corresponding simulation in a computer, and checking the effect of variable parameters on the quality of control are very important for the analysis and design of a pH control system. Taking wastewater treatment for example, the nonlinear problem between the pH of a solution system and flow is first analyzed. The change of pH in the control system can be transformed into a flow change based on the titration law. Three main methods of transforming acid-base titration characteristic curve into the flow variation into are then given. Last, the pH control scheme is designed and simulated in MATLAB/simulink platform. Its robustness to lag time is also analyzed. This results reveal that such a scheme achieve an acceptable performance when the parameters of a controller is adjusted on reasonable levels and the lag time does not exceed the upper limits.

关 键 词：废水处理 PH控制 仿真 MATLAB 

分 类 号：TP273[自动化与计算机技术—检测技术与自动化装置]