Face-Down Solid Particle Receiver Using Recirculation

Abstract

Solar thermal energy generation needs receiver technologies which can drive highly efficient turbines and decouple the collection of energy from its use by an economic storage technology. High-temperature solid particle receivers for solar tower systems with particle storage are one option. Important issues regarding high-temperature particle receivers are minimization of convective losses, no particle loss due to susceptibility to wind, and high efficiency also in part-load operation. A design approach facing these challenges is the face-down receiver using recirculation of particles. A screening performance analysis studying different recirculation patterns is presented. Using smart recirculation schemes, high receiver efficiencies can be maintained also at part-load operation (100% load ~90%; 50% load ~86%; 20% load ~67%). Simulations of the face-down geometry yield total annual solar-to-electric efficiencies of 24% using a surround field. From the analyses, it can be concluded that solid particle receivers using smart recirculation patterns are a viable receiver option for storage and high-temperature high-efficiency turbine processes.