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 cyc

le 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.