Attenuation of absorber end loss in parabolic trough collectors

An adjustment to the conventional design of parabolic trough collectors aimed at reducing absorber end losses is suggested. The adjustment is quite simple and consists of deliberately misaligning the parabolic trough collector from its absorber in the axial direction by a predetermined amount. The structure of the parabolic trough collector remains essentially the same in the new design; however, the exposed part of the absorber will no longer be perfectly aligned with the collector due to a deliberate but calculated axial move. The cost of the new collector is expected to be equal to that of the conventional collector since the only difference between the two designs is a small misalignment. The extent of the misalignment was optimized to minimize end losses based on typical meteorological year weather data for eight locations. An Operations Research tool was employed to find the ideal level of misalignment at each location that will result in maximum incident solar radiation. A performance model of a concentrating solar power plant was then used to evaluate gains realized by the suggested misalignment at each location. The gains were modest; however, they will most likely be accomplished at almost no extra cost.