Experimental and Numerical Analyses of a Pressurized Air Receiver for Solar-Driven Gas Turbines

A high-temperature pressurized air-based receiver for power generation via solar-driven gas turbines is experimentally examined and numerically modeled. It consists of an annular reticulate porous ceramic (RPC) foam concentric with an inner cylindrical cavity-receiver exposed to concentrated solar radiation. Absorbed heat is transferred by combined conduction, radiation, and convection to the pressurized air flowing across the RPC. The governing steady-state mass, momentum, and energy conservation equations are formulated and solved numerically by coupled finite volume and Monte Carlo techniques. Validation is accomplished with experimental results using a 3 kW solar receiver prototype subjected to average solar radiative fluxes at the CPC outlet in the range 1870–4360 kW m−2. Experimentation was carried out with air and helium as working fluids, heated from ambient temperature up to 1335 K at an absolute operating pressure of 5 bars. The validated model is then applied to optimize the receiver design for maximum solar energy conversion efficiency and to analyze the thermal performance of 100 kW and 1 MW scaled-up versions of the solar receiver.