A simple solution to the conflicting constraints of providing uniformity and collimation of irradiance in multiple-lamp solar simulators is proposed. As proof of concept, irradiance measurements obtained in a simulator comprised of 28 1-kW mercury-iodide gas discharge lamps and capable of irradiating a 1.22 m-by-2.44 m collector plane are given. The design is based on preventing a portion of the light from each bulb from reaching the collector plane. Light blockage is achieved by placing a “shadow board” 1.02 m from and parallel to the plane of the lamps. Lamps are arranged in an hexagonal pattern with 4 columns of 7 lamps at a lampto- lamp spacing and column-to-column spacing of 0.45 m. Lamp-to-collector plane distance is 3.05 m. The design is determined from measurements of the spatial distribution of radiant energy from a single lamp. Irradiance from an array of lamps is then simulated. Measurements of irradiance in the full-scale simulator confirm that uniformity and collimation conform to the American Society of Heating, Refrigerating and Air Conditioning Engineers’ standard. Average irradiance is 1080 W/m2. Maximum irradiance is 1190 W/m2 and minimum irradiance is 980 W/m2. Every point on the plane of the collector receives 100 percent of radiant energy from an area on the lamp array contained within a subtended angle of 20 deg.
|Original language||English (US)|
|Number of pages||6|
|Journal||Journal of Solar Energy Engineering, Transactions of the ASME|
|State||Published - Nov 1994|