Optical design of a high flux solar simulator configurable to achieve either a line or a point focus

Abstract

High flux solar simulators, comprising an array of high-intensity-discharge lamps coupled with elliptical reflectors, have been widely employed to study concentrated solar thermal energy in a controlled manner. However, the procedures for the optical designs of such systems are rarely reported. This paper presents designs, and a design methodology, of an optical configuration consisting of an array of lamps, using a commercial Monte Carlo ray-tracing code, Tracepro®. The design employs an array of 23 × 6 kW metal halide lamps introduced through two sizes of elliptical reflectors, 17 have a diameter of 950 mm and are in the inner section, while the other 6 reflectors have a diameter of 715 mm and are in an outer ring. An average heat flux of 1.447 MW/m2 through a target aperture of 50 mm was calculated to be achieved with this array. These reflectors were configured with a maximum cone angle of 42°, relative to the axis of the aperture. Using an additional 7 lamps, the array is reconfigurable to achieve a line focus with an array of 30 × 6 kW metal halide lamps, calculated to achieve an average heat flux of 0.32 MW/m2 through a cylindrical focal surface with dimensions of 120 mm diameter and 1 m length.