Mathematical modelling and analysis of variation in surface of solar Scheffler concentrator for seasonal variations

摘要

Solar concentrators are extensively tested as an alternative for conventional thermal sources. Scheffler concentrators is proving to be very effective in medium temperature applications as it has advantage of easy manufacturing and tracking. Though manufacturing is easy, it is complex to design for any required area of the reflector. The work here is an attempt to make the design process simpler. The seasonal tracking variation in the parabola curvature was calculated. It shows that variation in vertical curvature from the equinox position to summer solstice is 22.4% while that for winter solstice is -18.2% and that in horizontal curvature for summer solstice is -22.6% and for winter solstice is 13.2%. Also, variation in the curvatures of the crossbars were studied and it is found that the variation during equinox and seasonal extremes vary from 7.6% to 16.6%. The maximum depth of the 7m2 concentrator for equinox, summer and winter solstice is 0.227m, 0.223m and 0.229m respectively.