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 re-circulation patterns is presented. Using smart recirculation schemes, high receiver efficiencies can be main-tained also at part load operation (100%-load ~90%; 50%-load ~86%; 20%-load ~67%). In terms of total annual solar-to-electric efficiencies the face-down geometry yields excellent 24%, although implicating a surround heliostat 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-efficient turbine processes.