The first reporting period covered activities in tasks related to design of the ASTEP concept.
To design the SunDial (solar collector), some simulation models were developed and different choices were analysed (type of receivers and the solar fields). A set of calculations completed the analysis of the SunDial's performance at daily and yearly basis. Some activities on the thermal-hydraulic and thermo mechanical assessment have been also carried out (heat losses in the receiver, and mirrors deflection after the bending moment actuation).
For the design of the TES, a number of methodologies were developed. The PCM material was selected, the inserts and the manufacturing method were defined, and the design of the accumulator was accomplished. Application of anticorrosive coating of inserts was considered.
Regarding the design of the ASTEP concept, series and parallel layouts were analysed. Steady and dynamic simulation models were developed to define the solution for the two case-studies, Mandrekas (MAN) in Greece and ArcelorMittal (AMTP) in Romania. Finally, the control strategy was analysed and optimised, checking the suitability to manage the transients as well as the energy supply to the different demands (boiler and chiller in MAN and two heat exchangers in AMTP).
These design activities finished at the begining of the second reporting period. After that, the work focused on three spects: the construction of the demo pilots, the preparation of the end-user sites, and the LCA, LCC and Social LCA analyses.
All the equipment has been already bought and the demo is being built in Madrid (SunDials) and Cartagena (TES). Some components of the SunDial have been re-designed to improve the design/construcion. Similarly, the design of the TES system and the accumulators has evolved. Finally, due to the small power rate of the demo plant, it was not possible the purchase of a suitable absorption chiller. Instead, the system will demonstrate that is able to reach the operating conditions required by commercial ones.
Some travels to the end user sites were done to analyse the industries and select the best placement for the system. After the visits, the plans for integration also evolved although maintaining the objective of testing on-site at real operational conditions. In AMTP, the SunDial will be housed outside at ground level close to the main production building, and the TES in-house. The demo plant for preheating the tubes will be constructed adjacent to the location of the SunDial. It will use tubes typical of those produced in the plant. In MAN, the SunDial will be placed at roof height, on a platform. Due to the small contribution of the demo plant and the lack of an absorption chiller, the objetive will be to demonstrate the pilot-scale ASTEP system without steam generation.
Finally, the LCA, LCC, Social LCA and exergy analysis is ongoing. The two first stages of the LCA have been completed. The first one includes a literature review, while the second focuses on the assessment of the environmental impacts. Similarly, the first phase of the LCC has been completed, including a literature review on the economic impact of solar thermal plants; and the second one, on the Capital and Operational Expenditures, has started. Within the Social LCA analyses, the two first phases have been completed. The first one focuses on defining the goal and scope of the analysis, and the second on the social impact assessment of the ASTEP system throughout its life cycle.
