Multi-objective optimization of energy distribution in steel enterprises considering both exergy efficiency and energy cost

In integrated steel works, the core objective of system energy conservation techniques is to improve energy utilization and reduce energy costs. Currently, the research on energy distribution optimization of steel enterprises considers only the energy cost of the system and ignores the energy utilization efficiency. However, energy utilization efficiency and energy cost are equally important indicators. Therefore, in this study, a multi-objective optimization model for energy systems was established, which considered minimizing energy cost of the system and maximizing exergy efficiency as the objective functions. The case results indicate that after the optimization aiming at the minimum energy cost (Scheme A) and the maximum exergy efficiency (Scheme B), the energy cost of the two schemes reduced by 24.96% and 9.60%, respectively, and the exergy efficiency increased by 1.67% and 8.65%, respectively. Although Scheme A can significantly reduce the system energy cost, the increase of exergy efficiency is limited. Scheme B is opposite to Scheme A. However, after adopting multi-objective optimization, compared with previous optimization strategies, the energy cost reduced by 22.81%, the exergy efficiency increased by 7.71%, and the energy cost and exergy efficiency of the system were found to be in a better state. •A model considering the energy cost and utilization efficiency is established.•Equivalent electrical efficiency is taken as an index of energy quantity and quality.•Pareto optimality is used to balance the energy cost and efficiency.•The impact of changes in energy price on optimization results is considered.