Performance enhancement of a solar-assisted pulverized coal power system by integrating a supercritical CO2 cycle

Abstract

Current solar-assisted pulverized coal power (SPCP) systems lack the efficient cascading utilization of solar energy, resulting in its wastage. Therefore, there is a need to optimize the integration scheme between solar energy and pulverized coal power systems. In this study, the integration of two different supercritical CO2 cycles with SPCP systems is proposed to enable the cascaded utilization of solar energy. The thermal performances of the two proposed power systems are presented. Then, a sensitivity analysis is performed to examine the effects of supercritical CO2 cycle variables on the system. Finally, an economic evaluation is conducted to examine and compare the economic performance. The results demonstrate significant reductions in the extraction steam superheat and the exergy loss in feedwater heaters. Compared to SPCP systems, both proposed systems exhibit a decrease in the standard coal consumption rate by approximately 4.7 g/kWh. Sensitivity analysis shows that the CO2 mass flow rate has the most important effect on the system performance. The economic evaluation reveals that the cost of electricity for the two suggested systems increases by only about 0.04 cents/kWh. In summary, the findings suggest that the proposed power systems exhibit superior thermal performance and confirm its economic feasibility in the future.