Optimal Design Of Cogeneration System Based On Multi-Objective Teaching-Learning-Based Optimal Algorithm

As a kind of popular energy production mode with high efficiency and low emission,cogeneration has been widely applied and promoted all over the world.The modeling,optimization and design is always a research focus,which would improve the comprehensive performance and the cost of the whole system.The design of a benchmark cogeneration system is a multiobjective optimal problem.It needs a simultaneous consideration of thermodynamic efficiency and economic objective.As a classical one,CGAM cogeneration model includes economic model and thermodynamic model.This work is mainly focused on the research of CGAM cogeneration multi-objective optimal problem.According to the thermodynamics theory,thermal economics method and life cycle cost analysis.This work builds the CGAM model from two aspects which are thermal performance and thermal economics.Moreover,the in order to satisfied the requirement of design and real operation environment,decision variables and constrain condition are determined here.To make some improvement,the concept of life cycle analysis and the method of equal pay conversion are brought into the thermal economic model.After establishing the CGAM multi-objective optimization problem,a method named Multi-Objective Teaching-learning based optimal algorithm(MOTLBO)is applied to solve this problem,and the optimal results of MOTLBO show its superiority by comparing with traditional nondominated sort genetic algorithm(NSGA-II).For the complex nonlinear constrain condition,we improve some step of MOTLBO to speed up the runtime of optimal process.Since MOTLBO has better astringency and distribution,according to the analysis of the result,it may loss some elite solution.In order to get the optimal solution set with more widely distribution,a kind of modified MOTLBO is proposed in this work.Finally a fitted function is given to relationship between the two objectives,which means the designer can make a decision of optimal parameter configuration according to weight factor.Further analysis on the relationship between main parameters and the objective functions are also put forward through make some diagrams,this diagrams can indicate the trend of cogeneration development and give some useful suggestions on the design of cogeneration system.The work in this thesis combine engineering economic and thermodynamics,simplify the process of thermal system design.and improve the thermal performance,as well as minimize the total cost.