基于Laplace-Borel变换的过程周期性操作的分析

Analysis of Forced Periodic Operations Using Laplace-Borel Transform

鉴于化工过程非线性动态分析的复杂性,本工作提出使用Laplace-Borel(LB)变换分析化工单元周期操作、实现过程强化的方法。将原非线性动态方程组LB变换成无穷泛函形式,通过Shuffle运算,可以获得原系统的近似解析解,进而实现周期性操作的分析。通过乙醇发酵-膜分离及串联-平行反应案例,探讨了单扰动和多扰动问题,发现蒸汽吹扫流量的周期性变化可以强化乙醇传质,但周期性改变反应物浓度不能强化串联-平行反应中间产品的产量。基于LB变换分析,可以为定性或定量分析化工单元周期性操作提供理论和方法依据。

In view of the complexity of nonlinear dynamic analysis of chemical process,a method of analyzing the periodic operation of chemical unit by Laplace Borel(LB)transformationwas proposed to realize process intensification.The original nonlinear dynamic equations were transformed into infinite functional form by the LB transformation,and the approximate analytical solution of the original system was obtained by Shuffle operation,so as to realize the analysis of periodic operation.Through the cases of ethanol fermentation membrane separation and series-parallel reaction,the problems of single disturbance and multi disturbance were discussed.It was found that the periodic change of steam purge flow rate could enhance ethanol mass transfer,but the periodic change of reactant concentration could not enhance the production of intermediate products in the series-parallel reaction.It can provide theoretical and methodological basis for qualitative or quantitative analysis of chemical unit periodic operationbased on LB transformation analysis.