Virtual Solar Field - Validation of a detailed transient simulation tool for line focus STE fields with single phase heat transfer fluid

Abstract

Simulation models enable designers and operators to test different settings of the real systems while avoiding the large costs associated with experimental or practical systems. However, creating models that resemble the real physical system with acceptable accuracy and computational time remains a challenge for developers of such tools. With this motivation, a new simulation tool, the Virtual Solar Field (VSF), has been developed for line-focus power plants with single-phase heat transfer fluid (HTF) to assist in plant control during transient processes. VSF is a whole-field model based on an efficient coupling of hydraulic and thermal solvers that take into account the flow distribution in the parallel loops, as well as the transient conditions in the field. In this paper, some validation cases for VSF using data from Andasol-3 power plant are shown. Five test cases are examined, which include normal operation, start-up and evening operation during clear-sky and strong transients. The results show very good agreement with the real plant and some discrepancies are discussed and studied. The main sources of discrepancies are associated with difficulties in modelling all fine details of reality using the current technologies in some commercial power plants. For example, small cloud passage are not detected by the few weather stations in the power plant, as well as knowing the exact loop valve settings is not possible in Andasol-3. In addition, an overview of the potential applications of VSF are mentioned and briefly discussed. VSF offers a suitable platform for testing novel control strategies and assessing the performance of the solar fields