The Influence of Evacuated-tube Collector Assembly on Heat Loss in Tracking Solar System with Parabolic Mirror Reflectors

The heat transfer between the absorber and the heat pipe in evacuated-tube collector is done by a fin, typically made of an aluminum. During the assembly of solar installation, the position of the asymmetric fin in relation to the direction of the incident solar radiation is unknown. The aim of this research was to study the influence of solar vacuum tube assembly on heat loss. A pipe with the aluminium fin and parabolic glass mirror reflectors were selected to the analysis. The amplification factor of solar irradiance caused by concentrator mirror elements was determined experimentally. The impact of the fin position in relation to the direction of solar radiation on heat loss was assessed by numerical methods. Analyses were performed in a steady state for various external conditions (ambient temperature) and a variety of density solar radiation. It was discovered that the maximum difference between the preferred and the least advantageous variant does not exceed 2.5% of absorbed energy.