The Application of a Non-Intrusive Particle Temperature Measurement Methodology for an On-sun Falling Particle Receiver*

Falling particle receivers (FPR) such as the one at Sandia National Labs, represent the state-of-the-art Concentrating Solar Power (CSP) technology for energy harvesting. FPR operate by creating a gravity-driven particle curtain which is directly used a transport and storage media for concentrated light. A system paired with an appropriate Brayton power loop is capable of achieving thermal-to-electric conversion efficiencies when operating at temperatures greater than 700 C. However, the FPR presents a unique challenge to the CSP field as the complex coupling of multiple variables, such as particle temperature, wind speed and direction, etc., can impact its thermal performance as advective losses can be strongly present on the system. This work presents the continuation of a series of improvement to a non-intrusive methodology using a high-speed IR camera and a visible-light camera (Nikon D3500) to accomplish this indirect particle temperature measurement, which in turn is used to estimate the heat losses of the receiver. Six variables were considered to study their relative impact towards the receiver efficiency by means of an ANOVA analysis to further understand the importance of mitigating these variable to increase the receiver efficiency.