1 On-Sun Experiments on a Particle Heating Receiver with Red Sand as the Working Medium Prof. Hany Al-Ansary Mechanical Engineering Department King Saud University SolarPACES 2017, Santiago, Chile, September 27, 2017 Outline 2  What is a particle heating receiver (PHR)?  Motivation and Objective  Description of KSU PHR facility  Experimental Methodology  Sample Results  Conclusion What is a Particle Heating Receiver (PHR)? 3  A receiver in which particles (rather than molten salt or steam) are heated directly or indirectly  Types of PHR  Free-falling curtain  Free-falling curtain with novel release patterns  Obstructed flow  Rotary kiln  Centrifugal particle flow  Tubular receiver with shell-side particle flow  Particle-laden gas flow  … Obstructed Flow PHR 4  Design developed by KSU and GIT  Particle flow is impeded by chevron obstructions  Increases particle residence time and efficiency Previous Tests of Obstructed Flow PHR 5  Tests conducted at Sandia National Labs  Particulate material was Accucast ID50K (alumina-based)  Results are encouraging (efficiency approaching 90%) Challenges With Obstructed Flow PHR 6  Durability  Suitability for high mass flow rate  Cost of particulate material  General concern with all PHR designs  Current cost of engineered particles is $1-$2/kg Motivation 7  Engineered particles are relatively expensive despite their superior optical properties  When the material is also used for storage, the initial cost becomes considerable  A “true” cavity receiver is less sensitive to the optical properties of the particulate material Motivation 8  It is desirable to work with less expensive particulate materials that can achieve reasonable thermal efficiency  Small efficiency penalty may be mitigated by the significantly lower cost  Candidate materials:  Red sand  Spent catalysts  Fly ash Candidate Particulate Materials 9  Red sand is particularly promising  Abundant and very inexpensive ($0.01-$0.02/kg)  No sintering at temperatures as high as 1000°C  Depending on source, it can be relatively dark and round Stock Photo SENER Objective 10 To assess the thermal efficiency of an obstructed flow PHR using red sand as the particulate material