常减压装置减压塔的链控制系统研究

Research of chain-control-system to vacuum tower in distillation and vacuum unit

为了提高减压塔的质量控制水平,研究了链系统方法在减压塔上的应用。通过对减压塔工艺流程的分析,以减压塔顶温度和真空度为受控变量,分析了影响塔顶温度和真空度的主要因素,建立了由4个单元模型、2条控制链和3支链间关联的链系统模型。设计了减压塔工艺中塔顶温度和真空度的链预估算法和链控制系统,通过对过程未来动向的预估和系统链之间的控制联系确定出最优的控制律。仿真结果表明,设计的链系统模型稳定性和抗干扰能力强,容错性好,控制效果良好。

In order to improve the quality control level of vacuum tower, the chain-system method on vacuum tower is studied. With the analysis of industrial arts of the vacuum tower the top tower temperature and vacuum rate are taken as the control objects and control arithmetic based on chain-system is brought forward. The two major factors that affected the tower top temperature and vacuum rate are found out, and the chain system model is built which is consisted of four unit models, two causality chains and three inter - chain associations. Based on this model, predicative arithmetic and control system are designed. The optimization of system control law by prediction of the further trend in the process and the causal connections between the system chains are found out. The simulation demonstrated that the chain system model have strongly stability, anti-interference ability, fault-tolerant and control easily.