In the Project Si-CO a novel parabolic trough collector for concentrating solar power (CSP) plants was designed, manufactured, and tested. It features a large 8 m aperture and was designed for operation with the silicone-based fluid HELISOL® XLP (HXLP), which increases the possible operating temperature to above 430 °C. The techno-economic benefits of CSP plants using HXLP and the new collector compared with the state of the art were also demonstrated. Furthermore, the exchange of the state-of-the-art fluid against HXLP in an existing CSP plant was simulated at a small-scale test facility. Laboratory studies were conducted on fluid samples to check the effect of leftovers of state-of-the-art fluid in HXLP after such exchange. The following results were reached:
Designing, manufacturing, and qualifying a parabolic trough collector with an aperture 8 m length and 18 m of each SCE, against a standard of 5.56 m aperture and a 12 m SCE length in the industry, for use with HXLP. This is the first parabolic trough in the world with these dimensions, constructed with a torsion tube and without a central union flange. This design allows for reduced foundations and fewer elements, thereby decreasing the overall cost of the solar field. Additionally, we aim to develop and demonstrate new components adapted to the larger aperture, as well as the new operating temperature of 430 °C, including HCEs and REPA.
Techno-economically validate a new optimized, large-scale parabolic trough design and demonstrate its viability. Studies demonstrate an overall performance increase from 36.74% to 39.71% and a reduction in costs of 8.5 % of CAPEX in large scale plants.
RIOGLASS has designed and manufactured a new receiver of innovative dimensions to operate with HELISOL® XLP at 430ºC. Validation of the performance and durability of the developed product for commercial plants has been performed.
A fluid change-over simulation was conducted at the KONTAS test facility at PSA. The vacuum insulation of receiver tubes was doped with hydrogen to emulate the condition of used receiver tubes in an already existing CSP plant. A long-term experiment on hydrogen back-permeation from these receivers to recover their performance was started. It was found that low concentrations of leftover fluid should be achieved. After the change-over process the hydrogen concentration in the system must be kept sufficiently low, e.g. by blanket gas ventilation, in order to allow for H2 back-permeation.