Structural Design and Analysis of Heliostat of Solar-Thermal Plant

Abstract

A 2MWe solar plant is proposed to be set-up. A 40.8 m diameter hyperboloid supported on three towers (60 m height), 118 heliostats of dimension 10 m × 10 m, 228 heliostats of dimension 5 m × 5 m and an 8 m diameter receiver are the major components of the proposed plant. Heliostat is one of the key components of the concentrated solar power plants based on central receiver concept. Large number of reflector assemblies (heliostats) that are capable of tracking the movement of sun, are installed in the field and are manipulated by computer programme to constantly focus the reflected rays of sun on to a centrally fixed receiver. The objective of heliostat is to accurately focus the reflected rays on to a calibrated target point. The positioning accuracy of heliostat is achieved through servo control drive system using gear drives. A 10 m × 10 m heliostat, made of carbon steel box and circular sections, is designed against wind load of 39 m/s basic wind speed. Finite element analyses have been performed to optimize the design and estimate the deflections and stresses due to dead weight, imposed loads, seismic loads and wind loads. Stresses due to various loads and their combinations have been checked against the allowable stresses as per IS 800. Buckling checks have been performed as per IS 800.