Study on effect of glazing on performance and heat dynamics of asphalt solar collectors: An experimental study

Abstract

Exposure to solar irradiation for an extended period during a day causes asphalt pavements can reach to a considerable temperature. Consequently, they can be converted into an affordable solar collector by harvesting thermal energy. In recent years much effort and time have been devoted to improving the thermal performance of solar collectors. To this aim, the glazing strategy is a promising technique. The glass covers results in the reduction of heat loss and protecting the asphalt surface (absorber surface) from the outside environment. Little attention has been given to the glazing strategy in improving the performance of ASCs. The chief aim of the current investigation is a comparative assessment of the performance and heat dynamics of unglazed asphalt solar collectors with glazed asphalt solar collectors under field conditions. The evaluation was carried out using an experimental test-setup composed of an asphalt solar collector with a surface area of 1.2 m2 and a pipe network length of 12 m. Various sensors were utilized to monitor and measure the key parameters such as ambient conditions and working fluid temperature during the experimental runs. The experimental results prove that the glazing strategy is an effective method to improve the performance of ASCs. The constructed glazed ASC increases hot water temperature, meanly around 5 °C, and pavement temperature, meanly around 20 °C, while represents an improvement in the performance, near 10%, compared with the unglazed one.