Study On Energy Flow Modeling And Simulation Of Steel Manufacturing Process Based On Hybrid Petri Net

The energy efficiency level of steel industry has significantly improved in China,but it has still not fundamentally overcome the constraints of resources,energy,and environment.With the progress of energy-saving work,the difficulty of energy-saving is increasing,and the potential is decreasing under traditional technological systems in steel manufacturing processes.In the new period of high-quality development on the constraint of the "dual control" of energy consumption and carbon emissions,the steel industry is entering a new stage with efficient energy conversion,intelligent energy-flow dispatching,and integrated matching optimization.The energy flow network for the steel manufacturing process is described as a "directed net",and the "unit models" based on hybrid Petri Net are constructed,as well as a modular,hierarchical modeling structure and its integration method are presented respectively in this dissertation.Firstly,based on metallurgical process engineering theory and engineering dynamics methods,the engineering characteristics of steel manufacturing processes are analyzed deeply from the perspective of the directed net.As a "directed net",the system structure and dynamic operating characteristics of energy flow network are extracted.The energy flow network is abstracted as a "directed net",which creates conditions for modeling formal directed net systems.Secondly,by analyzing the common characteristics of the directed net system of the processes in the energy flow network,various processes are abstracted into "production units" and "storage units".Through formal mapping of the elements between real system and model system,a production unit model with Transition as the core and a storage unit model with Place as the core are developed based on hybrid Petri Net.These two unit models and their combinations can describe the net-system characteristics of all processes in the energy flow network.Thirdly,following the modeling principle of "Top-down decomposing,bottom-up integrating",a modular and hierarchical structure of the Petri Net model for steel manufacturing processes is proposed.By synthesizing/decomposing and abstract/extended methods,operational rules and computational methods for gradually integrating unit models into multi-dimensional and multi-scale open system models are provided.The differential and integral algorithms of continuous variables and the definition and rules of adjoint Place are also given.A large-scale complex energy flow network system can be constructed by integrating the unit models.Finally,a simulation example about a Petri Net model for energy conversion process of a typical steel plant is developed to verify the methods provided in this dissertation.