Thermal and hydrodynamic performance of a novel volumetric solar receiver

Concentrated solar power (CSP) technology is a promising alternative to the traditional coal-fired power plant due to the abundance and non-pollution of solar radiation. As the key component of a CSP plant, solar receiver thus attracts much attention recently. Nevertheless, existing receivers suffer from low efficiencies when attaining high outlet temperatures. This paper proposes a highly efficient solar receiver equipped with metal coated mirrors. It is theoretically demonstrated to possess a high thermal efficiency of 88.6% at a high outlet temperature of 1352 K. This extraordinary performance is attributed to that the recycle of radiative heat loss via the metal-coated mirrors. These mirrors could reflect the radiation emitted from porous media, and the numerical results indicate that 64.27% of the reflected radiation then returns to porous media. Therefore, the amount of the radiation released to atmosphere decreases dramatically, thereby significantly improving the thermal efficiency of the proposed receiver. In addition, the recycle of radiation loss could contribute to reducing light pollution of the solar receiver. The application of highly reflective reflectors to the solar receiver provides a novel approach to improve the thermal efficiency of the high-temperature solar receiver.