Modular Design and Experimental Testing of a 50 kWth Pressurized-Air Solar Receiver for Gas Turbines

A high-temperature high-concentration pressurized-air solar receiver is considered for driving a power generation Brayton cycle. The modular design consists of a cylindrical SiC cavity surrounded by a concentric annular reticulated porous ceramic (RPC) foam contained in a stainless steel pressure vessel, with a secondary concentrator attached to its windowless aperture. Experimentation was carried out in a solar tower for up to 47 kW of concentrated solar radiative power input in the absolute pressure range of 2-6 bar. Peak outlet air temperatures exceeding 1200 °C were reached for an average solar concentration ratio of 2500 suns. A notable thermal efficiency—defined as the ratio of the enthalpy change of the air flow divided by the solar radiative power input through the aperture—of 91% was achieved at 700 °C and 4 bar.