钢铁企业蒸汽动力系统经济环境多目标优化

Economic-Environmental Multi-Objective Optimization of Steam Power System in Iron and Steel Enterprises

为缓解钢铁企业面临的经济环境矛盾,针对钢铁企业蒸汽动力系统(SPS),提出了涵盖上游过程污染物排放的多目标多周期混合整数非线性规划模型。考虑动态供需、分时电价、燃料结构等因素,采用运行成本的经济指标并结合生命周期评价(LCA)方法构建了环境目标函数,对钢铁企业SPS进行了全流程多能源的优化调度研究,通过GAMS和Matlab软件交互完成模型的求解和数据处理。仿真结果表明:该优化模型和多目标优化方法不仅可以为钢铁企业SPS建立合理的负荷分配方案和生产调度及电网交易计划,也能提供一种环境影响与经济成本之间的权衡运行策略。相较优化前,经济优化可使系统运行成本降低3.75%,环境优化可使系统环境影响降低12.21%。双目标权衡点可使环境影响降低11.91%,运行成本降低3.46%,经济环境效益良好。在一定范围内煤价升高能缓解经济和环境优化的矛盾,而高炉煤气的使用可以显著降低全系统运行成本,一定程度降低全系统环境影响,但将增加系统内部CO_(2)、NO_(x)的排放量。所得结论可为企业改善经济环境效益、深化节能减排提供一定的理论参考。

In order to alleviate the economic-environmental contradiction faced by iron and steel enterprises,a multi-objective and multi-period mixed integer nonlinear programming model is proposed for the steam power system(SPS)of iron and steel enterprises,which covers the pollutant emission in the upstream process.On the basis of considering dynamic supply and demand,time-of-use electricity price,and fuel structure,the whole process multi-energy optimal dispatching of SPS in iron and steel enterprises is realized through using the economic index of operating cost and the environmental index established by life cycle assessment method(LCA).The solution and data processing of the model are completed through the interaction between GAMS platform and MATLAB.The simulation results show that the optimization model and method can establish a reasonable load distribution scheme,production scheduling and power grid transaction plan for SPS of iron and steel enterprise,and provide a trade-off between environmental impact and economic cost.Compared with the results without optimization,economic optimization can reduce the operating cost of the system by 3.75%,environmental optimization can reduce the environmental impact of the system by 12.21%.The double-objective trade-off point can reduce the environmental impact by 11.91%,the operating cost by 3.46%,and more economic and environmental benefits are achieved.In a certain range,the increase of coal price can reduce the contradiction between economic and environmental optimization,while the use of blast furnace gas can significantly reduce the operating cost of the whole system,cut down the environmental impact of the whole system to a certain extent,but will increase the emissions of CO_(2) and NO_(x) from the system.These results may serve as a theoretical basis for reducing economic cost and environmental impact of enterprises,and improving energy conservation and emission reduction.