Research On Dynamic Energy Allocation Of Rolling Area In Iron And Steel Industry

The development of iron and steel industry has close relationship with that of the national economy.Reducing energy cost is not only an important means to improve the competitiveness of enterprises,but also one of the measures to realize green steel.An effective way to reduce the energy consumption of iron and steel industry is to optimize the allocation of energy.The production of steel rolling lines,including hot rolling and cold rolling processes,is an intensive area for the final product of the enterprise.Energy optimization in the production process plays an important role in reducing the unit consumption of products and the total energy consumption of the whole plant.In this thesis,7 typical production lines in the rolling area of iron and steel industry are taken as the research background,and the dynamic energy allocation problem in rolling area is studied,where the energy consumption objective,energy supply and demand constraints and stochastic information in energy management process are considered.The temporal difference based approximate dynamic programming algorithm is researched.The decision support system for optimal energy allocation in rolling area of iron and steel enterprise is designed and developed.The main works of this thesis are as follows:1)Based on the analysis of the characteristics of energy consumption in the rolling area of iron and steel enterprises,and the energy allocation problem is extracted,which aims at minimizing the total energy cost,considering the constraints of energy supply capacity,secondary energy production capacity and energy outsourcing requirements.The static model of the problem is established and solved by CPLEX solver for different problem sizes.The results verified the model’s effectiveness and show the deficiency for large-scale problems.2)Considering the dynamic characteristics of energy price,energy supply and demand in the energy allocation process of rolling area,the dynamic energy allocation problem is extracted and the approximate dynamic programming solution algorithm is designed.Based on the analysis of the dynamics of the energy problems during the production process of the rolling area,an ADP modeling framework is established.According the ADP modeling components,the state variables,the decision variables,external random variables and state transition functions are defined.Finally the value function approximation strategy for ADP algorithm is designed.3)As the most important part of approximate dynamic programming algorithm,the value function approximate method is studied.The expression of the value function based on linear approximation of parameters is designed.An iterative updating method of the value function based on temporal difference is proposed.The real data of 8 production lines are used to verify the performance of the algorithm,also analysis of the relationship of the parameters of temporal difference method with the algorithm convergence is presented.4)According to the practical needs of the iron and steel production,the decision support system for energy optimization of rolling area is designed and developed.The goal of the system is to generate a reasonable and effective allocation plan for rolling lines in iron and steel production.Considering the actual characteristic of production process,two functional modules-deterministic and stochastic multi-energy allocation are designed,which aims at providing effective decision support for energy optimization.