Thermodynamic Performance and CO₂Emission Characteristics of Solar-Aided Coal-Fired Power Plant under Off-design Conditions

Solar-aided coal-fired power plant (SACFPP) is cost-effective to ensure energy security with less CO2 emission than coal-fired power plant. Its efficient and low-carbon operation is important but difficult because of the time-varying solar energy. This paper evaluates the thermodynamic performance and CO₂emission characteristics of SACFPP under off-design conditions. Three SACFPP configurations (marked as HP123, HP23 and HP3) were analyzed and the optimized operation strategy is proposed to achieve highest solar-to-power efficiency and lowest CO₂emission rate through adjusting feedwater ratio to trough collector system. The best achievable solar-to-power efficiency and CO₂emission rate depend on the power load, DNI, system safety limitation and system configuration. The annual CO₂emission reductions of the 600 MW SACFPP are about 61352.2, 54009.9 and 51769.8 tonnes under configurations of HP123, HP23 and HP3, respectively. The results can guide the SACFPP operation optimization.