The design of metal halide-based high flux solar simulators: Optical model development and empirical validation

• Published in: Solar energy 2017-11, Vol.157 (C), p.818-826
• Main Authors: Roba, Jeffrey P., Siegel, Nathan P.
• Format: Article
• Language: English
• Subjects: Arc lamps; Calorimetry; Computer simulation; Design; Electric power distribution; Electric power generation; Electricity generation; Empirical analysis; Fluctuations; Flux; Hardware; High temperature; Mathematical models; Metal halide lamps; Metal halides; Metals; Optics; Performance prediction; Ray tracing; Simulator; Simulators; Solar; Solar energy; Solar generators; Solar power; Solar simulators; Spatial distribution; Surface properties; Thermochemistry
• ISSN: 0038-092X; 1471-1257
• DOI: 10.1016/j.solener.2017.08.072

•Volumetric emission from a metal halide lamp is empirically characterized.•Arc emission is simulated with nested, ellipsoidal surface emitters.•Generalized arc model inputs are limited to lamp power and lamp dimensions.•Simulated peak flux and power are accurate to within ±20% and ±9%, respectively. In this paper we present an experimentally validated process for the design of high flux solar simulators based on metal halide arc lamps, which are suitable for research applications including high temperature materials evaluation, concentrating solar power generation, and solar thermochemistry. The objective of our work is to facilitate the design of solar simulator hardware from commercially available components, with an emphasis on accurately predicting hardware performance in the design stage. The inputs to the design process include reflector geometry and surface properties, rated lamp power, and lamp dimensions. These inputs are incorporated in a ray tracing analysis along with a semi-empirical model of a metal halide arc source that accounts for arc shape and the spatial variation of emitted power within the arc volume. This lamp-specific optical model is then further generalized to be applicable to a range of commercially available metal halide lamps. The experimental validation of the design process is accomplished using a single simulator module, and a combination of optical flux mapping and calorimetry to compare the distribution of radiant power delivered by the module to design predictions. Our validation process includes data from four different metal halide lamps, spanning a power range from 1.5 kWe to 4.0kWe. Design predictions for the generalized optical model agree with experimental data to within ±20% for peak flux and ±9% for total power delivered to a 6cm diameter target.