论文信息 - Yearly-averaged daily usefulness efficiency of heliostat surfaces

Yearly-averaged daily usefulness efficiency of heliostat surfaces

Abstract An analytical expression for estimating the instantaneous usefulness efficiency of a heliostat surface is obtained. A systematic procedure is then introduced to calculate the usefulness efficiency even when overlapping of blocking and shadowing on a heliostat surface exist. For possible estimation of the reflected energy from a given field, the local yearly-averaged daily usefulness efficiency is calculated. This efficiency is found to depend on site latitude angle, radial distance from the tower measured in tower heights, heliostat position azimuth angle and the radial spacing between heliostats. Charts for the local yearly-averaged daily usefulness efficiency are presented for Φ = 0, 15, 30, and 45°N. These charts can be used in calculating the reflected radiation from a given cell. Utilization of these charts is demonstrated.

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