改进的微生物连续发酵动力系统及参数辨识

Improved Dynamic System of Microbial Continuous Fermentation and Its Parameter Identification

以微生物连续发酵生产1,3-丙二醇为背景,研究了非线性动力系统及其参数辨识问题.首先根据发酵过程的特征和动态行为,在底物甘油过量的条件下,考虑了细胞内甘油与1,3-丙二醇的浓度变化,改进了描述微生物连续发酵过程的非线性动力系统,分析并论述了该非线性动力系统的主要性质;其次以平均相对误差为性能指标,建立了参数辨识最优化模型,并用粒子群算法求解.计算结果表明,该模型适合描述主要产物1,3-丙二醇的动态行为,但用来描述副产物的浓度变化率不够精确.

Based on the producing 1,3-propanediol from continuous fermentation of glycerol , a dynamic system model and its parameter identification were investigated .Firstly, under substrate-excess conditions , according to the dynamic behaviors and characteristics , the corresponding nonlinear dynamic system was improved by considering intra-cellular substances and 1,3-propanediol.Then the major properties of the system were discussed .Secondly, optimiza-tion model of parameter identification was proposed with average relative error as objective function , and it was solved by Particle Swarm Optimization algorithm .The results showed that the system fits for the dynamic behaviors of 1,3-propanediol but not for other by-products .