Alternative designs of a high efficiency, north-facing, solid particle receiver

Falling solid particle receivers can enable increased working-fluid temperatures for central receiver power plants, but will need to have high thermal efficiencies. This can increase power-cycle efficiencies and reduce thermal storage costs. A previous north-facing solid particle receiver (SPR) design was estimated to have a thermal efficiency of 72.3%. This design included a large aperture (17 m x 17 m), a slight downward facing nod (20 degrees), a high-sloping ceiling to accommodate the beam angles from the closest heliostats, and particles released near the back wall of the receiver. Receiver design modifications have been introduced to achieve a thermal efficiency of >90% as stated in the SunShot initiative. Design changes including a reduced aperture size, bottom lip on aperture, increased nod angle, deeper cavity, reduced ceiling slope angles, and more specular walls resulted in higher thermal efficiency designs. DELSOL was used to determine viable receiver dimensions, aperture sizes, and nod angles for a desired power output. The optimum receiver parameters were 10.63 m x 10.63 m aperture size, 50 degrees nod angle, and a tower height of 194.7 m. The new aperture size had a higher concentration ratio and provided maximum incident power on the particles with minimum radiative loss. An aperture with a lip, nod angle of 50 degrees, and extended back wall prevented buoyant hot air from leaving the receiver. A ceiling with higher reflectivity allowed more incident radiation to be reflected onto the particles rather than absorbed and thermally re-emitted. (C) 2013 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license