Dynamic Performance Evaluation of Line-Concentrating Steam Collectors

This publication presents a newly developed procedure for performance evaluation of direct steam generating collectors. Performance testing and evaluation of solar collectors operating with direct steam are not yet standardized, since accredited testing standard procedures do not foresee testing with compressible heat transfer media. Due to the existence of two-phase flow, the measurement concept as well as the collector simulation model needs to be adjusted. Two approaches of steady-state and dynamic performance evaluation are introduced. The corresponding methodology is applicable to small- and large-scale parabolic trough as well as linear Fresnel collectors. The application of the newly developed simulation model and evaluation procedure to measurement data proves the practicability and reliability of the introduced approach. On the basis of exemplary results, the benefits and remaining drawbacks of the procedure are thoroughly discussed. They particularly demonstrate the adapted testing method to be a valuable tool for fast and simple performance checks of steam generating systems. Meaningful performance testing is considered highly beneficial for a further dissemination and global acceptance of steam collectors and solar process heat in general.