Concentrated Solar Power: A comparison and evaluation of innovative parabolic trough collector concepts for large scale application

Kurzfassung

The present thesis aims to define the state of the art of parabolic trough collectors and to identify the concepts in the framework of innovation´s requirements. These are the increase of operating temperatures and of the plant´s overall efficiency, as well as the cost reductions of the solar field by eliminating components and also the reduction of the parasitic power consumption [1]. The study is based on the investigation of 34 concepts. The collectors were classified according to their main structural features depending on their mechanisms or materials. The categories include conventional collectors (Category A), alternative structures and sheet reflectors collectors (Category B), non-metallic materials (i.e. sandwich composite structures and concrete), enclosed aperture collectors (Category D) and fix focus collectors (Category E). In order to identify the potential among the collectors, an analysis is made of their optical and thermal properties, as well as of their structures and performance. For this comparative analysis, two conventional collectors are taken as the reference baseline, namely of both the EuroTrough and the UltimateTrough, to compare them against the innovations. This analysis also separates those collectors that operate with thermo-oils as heat transfer fluid and those that can operate with molten salts. A total of 16 collectors were included in the analysis for later evaluation. The design Engineering method of the guideline VDI2225 is used, which suggests the implementation of an evaluation matrix, where the analysed criteria can be integrated. For the assessment, a metric table of These criteria is additionally defined. Results show that the collectors operating with molten salts, instead of thermo-oils, have a significant techno-economic potential, for instance, the MS-Trough, the UltimateTrough and the SkyFuelDSP. They also show that the inflatable Heliovis collector has an economic superiority once operating with thermo-oils. The detailed description of the collectors, which correspond to the basis of this work, is included in Annex B or supplement of the thesis. In addition, Annex A includes the results of a previous survey carried out to estimate the scope of the current most known collectors.