基于换热器动态模型的PID模拟控制研究

Research on PID Simulation Control Based on Dynamic Model of Heat Exchanger Dynamic Model

换热器是重要的化工单元操作设备,广泛用于化工、轻工、制药、能源等工业中。对换热器的建模和模拟对于研究单元操作及单元过程控制有重要的作用。之前的研究中使用基于流动微元的方式及单元传热模型对换热器内的流动和传热建立了数学模型,能够对换热器进行动态模拟。在此模型的基础上,结合单元操作的自动控制过程,对换热器的动态控制进行了模拟。模拟结合了PID控制算法及换热器的动态模型,可以对控制过程中的温度变化及换热器的响应进行模拟。将出口流体温度作为控制变量,以控制变量的稳定时间为指标,分别研究了P、I、D参数对于自动控制过程的影响。并通过模拟计算得到了当前条件下较优的控制参数组合。上述方法可应用于化工流程的模拟分析,通过基于机理的模拟及分析及换热器控制算法的研究及参数优化。

Heat exchanger is an important chemical unit operating equipment,which is widely used in chemical industry,light industry,pharmaceutical industry,energy and other industries.Modeling and simulation of heat exchangers play an important role in the study on unit operation and unit process control.In previous studies,the flow and heat transfer model based on flow element and unit heat transfer model were used to establish a mathematical model for the flow and heat transfer in heat exchanger,which can simulate the heat exchanger dynamically.Based on this model,combined with the automatic control process of unit operation,the dynamic control of heat exchanger was simulated.The simulation conbined the PID control algorithm and the dynamic model of the heat exchanger,which can simulate the temperature change and the response of the heat exchanger in the control process.Taking the temperature of the outlet fluid as the control variable and the stability time of the control variable as the target,the effects of P,I and D parameters on the automatic control process were studied respectively.The optimal combination of control parameters under current conditions was obtained by simulation calculation.This method can be applied to the simulation and analysis of chemical process,through the mechanism-based simulation and analysis,and the research of heat exchanger control algorithm and parameter optimization.