Influence of Seasonal Heat Load Variation on Daily Optimal Scheduling of CHP System With Renewable Energy and Heat Storage

Due to fluctuation and intermittence, renewable energy sources (RESs) require high adjustability of power system. However, the existing combined heat and power (CHP) system has limited adjustability because of being controlled in the “heat-led” mode, which, consequently, hinders the development of the RESs. A solution of the problem is to introduce the heat storage (HS), which decouples heat supply from heat load. Although a number of researchers have studied in the design and the planning optimization of such CHP systems with RESs and HS, few people have paid attention to the seasonal variation of the heat load, which may vary the daily optimal planning of the systems. In this dissertation, we set up the model and optimize the planning of a CHP system with RESs and HS, with the consideration of the seasonal variation of the heat load. We find that in the beginning/ending of the heating season, the HS should store heat when the wind power is being abandoned and release heat in the rest of the days, while in the middle of the heating season, the HS should release heat when the wind power is being abandoned and store heat in the rest of the days.