Design and Construction of Molten Salt Parabolic Trough HPS Project in Évora, Portugal

In the Portuguese city of Évora a parabolic salt loop is being constructed in order to demonstrate the viability of this system. Different partners have teamed-up for this task. Siemens takes the project lead in the German HPS consortium. The solar demonstration plant will be capable to produce high live steam parameters in an once-through steam generation system (SGS). The SGS is designed for 580 °C and 140 bar. The live steam parameters and the design of the SGS and the overall plant provide a highly flexible steam production. Since the solar field needs to provide heat at higher temperatures than typical solar field set-ups and uses molten salt as heat transfer fluid, different adoptions have had to be made. Several of these adoptions are described in the paper. Furthermore the layout of the flexible connections consisting of hose and rotary must be re-designed. Targets of the developments are: both thermal expansion of the absorber pipe and rotation of SCA must be compensated for reasonable number of lifetime cylcles and the complete system must be designed in order to prevent any freezing of the salt within the component