Analysis of thermal performance of parabolic dish collectors having different reflective surfaces

Thermal performance of parabolic dish collectors having different reflective surfaces(white paint, Al foil and mirror) is investigated at a site in Faisalabad, Pakistan. The experimental data were collected in Oct/ 2016 and in Feb, Mar, and May 2017.Water is used as working fluid, circulating through a helical tube copper coil. The annual average of solar energy available for this site is approximately 5.14 kWh/m2 per day. The results indicated that mirror type PDC was most efficient in terms of thermal performance (heated water temperature) followed by Al foil and white paint PDC. Mirror type PDC showed the highest exergetic efficiency of 43%, followed by 31.9% and 20.9% for Al foil and white painted PDCs respectively. A similar trend was observed for water and receivers temperatures.