Development of an advanced large-aperture parabolic trough collector

Abstract

The SpaceTube® is a new cost-optimized parabolic trough collector with an aperture width greater than 8m. This paper summarizes the development and testing of first-round SpaceTube® SCE prototypes and their related componentry. These tests showed good agreement with the modeled performance, confirming the commercial potential of the design. The optical accuracy of the SpaceTube® is higher than previous designs, due to improvements in the mirror quality and frame stiffness. To take advantage of these improvements, the concentrator geometry was analytically optimized for maximum performance under two different heat transfer fluid scenarios; current (oil-based) fluid in the range of 400°C and next-generation (molten salt or direct steam) at temperatures above 500°C. This led to an increase in the nominal heat collection element (HCE) diameter. Compared to the benchmark EuroTrough II, the SpaceTube® uses a 65% larger mirror module (SCE) and a more efficient frame structure, reducing the cost per unit aperture of the installed collector by approximately 40% [1]. A full-scale solar collector array (SCA) is now being constructed for on-sun thermal qualification with both oil and molten salt HTF mediums. Startup of the test loop is scheduled to occur in late 2013. © 2013 P. Marcotte.