Study On Transportation Production Model And Algorithms For Producing Methane Based On Microbial Water Treatment

By utilizing the life activity characteristics of microorganisms for degradation of organic pollutants in wastewater and production of methane,this paper researched on the issue that macro scheduling of each link in large-scale methanogenic production system based on microbial water treatment.Methanogenic production system based on microbial water treatment is a hybrid dynamic system,which consists of three links: microbial culture,microbial transportation and methane production.It has the characteristics that the microbial culture and methane production processes not only change continuously with time but are driven by the discrete event of transportation.The interval between two transportation events is called a cycle,and the income of methane,cost of transportation and cultivation constitute the comprehensive income of the system.In order to maximize the comprehensive income of the production system in the future,this paper established a transport production model of microbial water treatment for methane production,and designed an adaptive genetic algorithm to solve the optimal microbial transport and distribution cycle scheme of the system under the target.The main research contents of this paper are as follows:(1)Considering the perishable nature of microorganisms and the effect of microbial growth function on inventory,the change of microbial transportation cost caused by the difference in cycle,optimal allocation of microorganisms in the case of real-time changes in methane yield,this paper analyzed the single-cycle and multi-cycle perspectives in detail,and pointed out that the system optimization is a transportation problem in the single-cycle situation but has no effect on the optimization effect,and optimization under multi-cycle meets the control needs of the system.Combined the system's periodic and dynamic characteristics to unify the system's single-cycle and multi-cycle characteristics,in this paper using hybrid dynamic systems,inventory models,transportation issues,optimization,a transportation production model for producing methane based on microbial water treatment was established,and determined the objective function and variable constraints of the model(2)The solution of the transportation production model for producing methane based on microbial water treatment belongs to the constrained nonlinear optimization problem.By analyzing the solution of the model,it was pointed out that the system has the characteristics of strong interaction between variables and interaction between variables and constraints under periodic and hybrid dynamic characteristics.In addition,the scale of the decision variables of this model is the product of the number of microbial culture devices,the number of methane production devices,and the number of cycles.The traditional gradient algorithms will face the problem of disaster recovery and the inability to find a global optimal solution.In this paper,an adaptive genetic algorithm was designed to solve the problem.The algorithm used Gray code coding and corrected the variables in a step-by-step correction to solve the problem that constraints were complex and difficult to handle.And a penalty function method was used to correct the fitness of individuals which violate the parameter constraints to make the algorithm converge faster and the solution quality higher.This paper designed and implemented the algorithm.The three control strategies of single-cycle fixed allocation time,multi-period fixed allocation time and multi-cycle unfixed distribution time were compared by simulation.The operation results showed that control strategy of transportation production model for producing methane based on microbial water treatment was superior to the single-cycle and fixed-time allocation strategies,which verified the effectiveness and advancement of the algorithm.