Cylindrical near-field solar thermophotovoltaic system with multilayer absorber/emitter structures: Integrated solar radiation absorption and cooling energy consumption

Near-field radiative heat transfer enhances the intensity of the thermal radiation significantly through evanescent waves, while the combination of selective emitters can effectively improve the output power and system efficiency of solar thermophotovoltaic systems. By calculating the polariton dispersion relation between different layers and combining the energy transmission coefficient of the emitter at different layers, the mechanism by which the emitter enhances near-field radiative heat transfer was analyzed. Concurrently, a comprehensive consideration was given to the conversion of solar radiation to thermal energy, the transformation of thermal radiation into electrical energy, and the impact of the circulating water-cooling system on performance. The analysis indicates that with concentration ratio of > 70 and operating temperatures ranging from 900 K to 1200 K, the output power of near-field solar thermophotovoltaic system can achieve a range of 8905 W/m2 to 52875 W/m2, and the system efficiency can be stably maintained above 20 %.