Cascade Utilization of Waste Heat and Low-Carbon Optimization for Integrated Energy System Accounting for Time-Varying Characteristics of Temperature

To enhance the wind-solar accommodation rate and the low-carbon operation of integrated energy system (IES), the utilization potential of waste heat is explored for participation in heterogeneous energy flow interaction. Firstly, a waste heat cascade utilization system is proposed. The relationship between waste heat temperature and carbon emissions of the system is investigated. Building on this, the time-varying characteristics of waste heat temperature are analyzed in accordance with carbon emission variation. And an intraday waste heat cascade utilization strategy is formulated. Then, a comprehensive benefit evaluation model is constructed with economic costs, wind-solar accommodation rate, and carbon emissions as evaluation indicators. Finally, an actual region in Northeast China is simulated. Results show that the cascade utilization of waste heat plays an important role in promoting low-carbon operation. The carbon emissions are reduced by 6.02%~25.69% compared with the scenario without waste heat utilization. Thus, the effectiveness and feasibility of the proposed strategy can be verified.