Experimental and numerical analysis of multi-layer micro channel applied to parabolic solar concentrator

Abstract

There are numerous applications for micro-channel technology, but it has just a few applications in solar collectors. Therefore this research makes a clear contribution in this field by using a new design absorber in the concentrator, and the reflector was designed to focus the solar radiation on two sides. The solar concentrator system was attached to the tracking system to maintain the parabolic collector's perpendicularity to sun rays. This study investigates the experimental and numerical effects of the micro-channel technique on solar concentrator performance for different velocity values to meet the need for temperature differences, which gives Reynolds numbers varying from 1011 to 3273. The absorber plate was made from aluminum metal with 44 rectangular microchannels (0.3 m in length, 0.02 m in width, and 0.0009 m in height). The result indicated that the two-axis tracking system would increase output temperature by roughly 18 %. Outlet air temperature decreased significantly by 13.9 °C with changing flow rate from 0.009339 to 0.030235 kg/s. The highest efficiency was 91 % in March, 89 % in November, 80 % in February, 69.8 % in December and 65.5 % in January. A good agreement was obtained between numerical and experimental with a maximum deviation of 1.4, 1.7, 9.4 and 8.88 % for the glass cover, absorber plate, upper channel and lower channel, respectively.