Abstract:

Parameter estimation of chemical processes can be presented as a tough optimization problem which can be solved with optimization methods.As a robust global searching method, genetic algorithm (GA) has been frequently applied in this area.However, the genetic algorithm has some shortcomings, such as weak local search ability and tends to premature.Furthermore, the encoding of GA cannot reflect the genetic information of biological organism.To overcome the deficiencies of GA, a new DNA genetic algorithm is proposed for the parameter estimation of chemical engineering processes.The proposed method uses nucleotide bases to present the individual. The novel crossover and mutation operators inspired by DNA molecular are designed.The novel crossover operators include permutation crossover operator and translocation crossover operator, and the novel mutation consists of anticodon mutation and maximum-minimum mutation.The solutions with two typical test functions show that the proposed method outperforms the other two methods in the searching speed, searching precision and the success rate.Finally, this method is applied to estimate the parameters of heavy oil thermal cracking model.The results of eight cross validation shows that the proposed algorithm possesses small self-check relative error, prediction relative error, and the standard deviation of relative error.Compared with the other two models, the model established by the proposed DNA genetic algorithm has smaller modeling error.