Integration strategy optimization of solar-aided combined heat and power (CHP) system

Solar-aided combined heat and power (CHP) system is a practical way for green electricity generation and heating supply. This paper proposed a novel integration strategy (i.e., integration strategy IV), in which solar heat was designed to preheat the reheated steam via an oil/steam heat exchanger and then to replace the 1st -stage extraction steam via an oil/water heat exchanger. This integration strategy could integrate more solar heat with higher temperature without the temperature drop of reheated steam. To demonstrate its advantages in thermodynamic and economic, this integration strategy and three others were modeled and compared by analyzing solar energy conversion, annual performance and levelized cost of energy. Through case study, inte-gration strategy IV achieved the highest solar heat-to-electricity efficiency (i.e., 37.1%) with the corresponding integrated solar heat being 54.45 MW. And this integration strategy also achieved the highest annual solar-to -electricity efficiency (i.e., 21.5%) and the lowest levelized cost of energy (i.e., 0.129 $/kWh) with the optimal aperture area being 103620 m2. Under this condition, the corresponding annual solar-generated electricity would be 33.28 GWh.