Research On Optimization Method Of Heat Integrated System Considering Waste Heat Recovery

With the rapid development of social economy,the continuous growth of energy consumption and the increasingly tight energy supply have become a great challenge facing the world today.It has become a consensus to improve energy efficiency and develop low-carbon economy.As an important part of the petroleum,chemical and other process industries,the heat integrated system is of great significance to guide enterprises to increase production,save energy and reduce consumption,and reduce capital costs.Therefore,the optimization and retrofit of heat integrated system is receiving more and more attention and has become one of the research hotspots of scholars at home and abroad.Research on waste heat recovery(WHR)that can further improve the efficiency of basic energy utilization,reduce corporate costs and enhance corporate competitiveness is also one of the focus of attention.However,at present,there is no research on the optimization of high-dimensional many-objective heat integrated system integrating various waste heat recovery systems.Therefore,this paper proposes a high-dimensional many-objective optimization method for heat integrated systems considering waste heat recovery.Based on this method,the following work has been carried out in this paper.1.Based on Aspen simulation,a waste heat recovery model is established with the waste heat recovery amount and heat source temperature as independent variables,and the cold,heat or electricity output of the waste heat system as the dependent variable.This model eliminates the influence of various variables in the waste heat recovery system on the system and simplifies the solution model.2.The MINLP model of the stage-wise superstructure with non-isothermal mixed is set up with the objective functions of energy consumption,waste heat recovery system output,annual retrofit capitalt costs and annual retrofit profit.3.Based on the NSGA-? algorithm,an optimization method for a heat integrated system considering waste heat recovery is proposed for solving high-dimensional many-objective.Through the optimization of industrial examples of crude oil preheating system,the optimization results verify the effectiveness and practicability of the proposed method.4.Two large-scale cases are optimized by applying the established model and solving strategy.The case study shows that integrated WHR systems can further improve energy efficiency,reduce total annual costs,and provide different solutions for different user groups.The practicability and superiority of the proposed method are verified.