OPTICAL PERFORMANCE OF BOOSTER MIRROR IN A BOX TYPE SOLAR COOKER: A RAY TRACE EVALUATION

摘要

A mirror is commonly used to increase the solar radiation input onto the glazing of a box type solar cooker. Overall contribution of a booster mirror to the total solar energy incident upon the aperture of a box type solar cooker would depend upon its tilt with the horizontal and its orientation. Due to the apparent movement of the sun in the sky, its tilt (with the horizontal) and the orientation (surface azimuth) need periodic adjustment. Users normally adjust the same as per their experience and/or convenience. The required frequency of these adjustments (tilt and azimuth) would depend upon the location and the season. The effect of tilt and orientation of the booster mirror on the contribution made by it to the energy incident on the aperture of the box type solar cooker has been studied using an optical ray trace program. Effect of the optical quality of the booster mirror and the glazing of the box type solar cooker has also been studied. Results of some preliminary calculations are presented and briefly discussed.