Multi-energy Cooperative Optimization of Integrated Energy System in Plant Considering Stepped Utilization of Energy

The industrial park is a typical complex energy system. Multi-energy complementation can be achieved by making use of the coupling mechanism of multiple energy sources, which can significantly enhance the economic efficiency and energy utilization of plant. Thus, this paper proposes a multi-energy cooperative optimization model of integrated energy system in the plant considering stepped utilization of energy. Firstly, the structure of the integrated energy system in a plant is described. Then, the energy production equipment, energy conversion devices, and energy storage devices in the integrated energy system are independently modeled. Taking the lowest daily operation cost as the optimization objective, the mixed integer linear programming method is used to solve the model under the constraints of cooling and thermal power balance and the physical constraints of equipment. The proposed model follows the idea of scientific energy use of "grade counterparts, stepped utilization", which achieves the stepped utilization of energy according to the grade of heat. Thus the optimization of industrial production process and equipment operating parameters is realized. Finally, the example analysis shows that the proposed optimal dispatch strategy is more suitable for the actual demand of engineering, and can reduce the operation costs of industrial users. © 2018 Automation of Electric Power Systems Press.