Extended Resource Task Network For Collaborative Scheduling Of Material And Energy Flows In Iron And Steel Enterprises

China's iron and steel industry is of great significance to achieve industrial energy saving and green production,during the steel and iron manufacturing,material and energy flows have an interactive relationship,thus collaboratively scheduling steel production and energy can improve economical revenues and achieve energy saving as well as emission reduction.In this paper,an extended resource task network(ERTN)is proposed to realize the coordination between material and various energy flows of the iron and steel enterprises.The method is applied to collaboratively scheduling of material and energy flows in some critical production processes to discuss synergetic mechanism of material and energy flows.The main contents and novelty are as follows:(1)According to the characteristics of material and energy flows in the steel and iron production,based on traditional RTN method,a graphical and systematic modelling method ERTN is proposed to realize collaboratively scheduling of steel production and energy flows.This method extends the traditional RTN to a graphical and general modeling method which can systematically model the material and energy flows in the steel and iron enterprises.(2)Taking the relationship between the production of molten iron and byproduct gases,gas-electricity transfer and emissions into consideration,an ERTN model is proposed to maximize profit,minimize production cost and emissions.The model discusses the laws of production and consumption of blast furnace gas and coke oven gas,and explores the possibility of reducing the emissions from industrial point of view.The variable electricity price is used to optimize the profit generated by gas-electricity generation,which proves that the total profit increases 19.386%by moving the production from low price area to the high one,compared to the result of traditional schedule method which only considers materials flows.Numerical experiments discuss synergetic mechanism between materials and energy flows from economic and environmental aspects through exploring the influences of various parameters on the profit and costs.(3)Considering gas-electricity transfer and variable electricity prices,an ERTN model is established to collaboratively schedule material and energy flows in the steelmaking and continuous casting.Compared to traditional scheduling models about the steelmaking and continuous casting,this model firstly discusses the influences of various energy flows on the production.Based on the features of the problem,a new two-stage optimization method is proposed based on different scheduling units,which can be applied to solve industrial size problem.The numeric experiment verifies that the total profit obtained from proposed model increases 65.61%by considering all energy constraints,comparing to the result of traditional method which optimizing minimum makespan.Finally,the impacts of variable prices and production load on the profit and costs are explored.(4)An ERTN model is proposed to achieve co-scheduling steel production and various energy flows in the ironmaking,steelmaking and continuous casting.Compared with traditional process scheduling models,the integrated model firstly combines an ironmaking system with a steelmaking system,and considers the interactive relationship between byproduct gases and the production.Numerical experiments are used to explore synergetic mechanism between the material and energy flows through discussing the impact of proposed model on gas consumption of process users,equipment maintenance and initial values.In this paper,taking account of the characteristics of logistics and energy flows in the iron and steel enterprises,a new graphical representation and modeling method,extended resource task network(ERTN),is proposed basing on traditional resource task network.This method is applied to solve collaborative scheduling problems of steel production and energy flows in some critical processes(ironmaking and steelmaking).Numerical experiments are employed to explore synergetic mechanisms between material and energy flows in iron and steel production from the perspectives of economic,cost and environment,which provides theoretical guidance for production management and energy balance optimization of steel production and energy flows in some critical processes(ironmaking and steelmaking).To verify the feasibility and efficiency of the proposed model,numerical experiments are employed to explore synergetic mechanisms between logistics and energy flows in iron and steel production from the perspectives of economic,cost and environment,which provides theoretical guidance for production management and energy balance optimization in the steel and iron enterprises.