WIND TUNNEL STUDY OF WIND EFFECTS ON HELIOSTAT

Large-area, glass-metal heliostats have collection areas in the range of 100 to 200 m(2); they are the culmination of more than 10 years of development of commercial heliostats for solar thermal central receiver technology. The heliostats of Solar Tower power station locates at open terrain or suburban terrain, with high accuracy requirements during working. However, it is sensitive to gust, so wind load and wind-induced response should be an important factor in design. Realistic heliostats design requirements must be set to allow efficient, non-conservative, and thereby low-cost structures which still result in good heliostat performance. Monitoring of wind effects on heliostats such as the SPECO heliostat and the ATS heliostat can give important validation of design procedures and assurance of acceptable behavior. In fact, measurements of wind effects on prototype heliostats are very useful to further the understanding of wind-resistant structural design. Some studies have addressed the wind loads on the prototype heliostat in previous work. Wind tunnel testing is also an effective method for investigating wind effects on heliostats. The full-scale measurements can provide reliable but limited information. The wind tunnel test can generate detailed and additional results that are not available from the field measurements. Therefore, the full-scale measurements and the wind tunnel study are complementary so that the understanding of wind effects on heliostats can be improved. It was found from the previous wind tunnel testing that the wind effects of heliostats need to be studied comprehensively, which will be conducted in this paper. Taking a heliostat as example, this paper provides some useful results for the heliostat wind-resistance design by wind tunnel testing, including force coefficients and pressure contour.