BEST

Otros

• TFM – Ingeniería Industrial (UPNA)
  Daniel Aristu Ojer: Estudio de la corrosión por sales fundidas de carbonatos en recubrimientos por proyección térmica sobre acero inoxidable (junio, 2023)

The main goal when the project started was to use coating development techniques to produce two coatings for two specific components of CSP plants in order to increase their efficiency and eliminate or reduce to a minimum some of the main problems that kind of power plant has and make the technology more competitive. Three specific goals that were necessary to complete it were defined to achieve that main goal:
 Develop a highly absorbent, cheap and easy to apply coating that could withstand the demanding working conditions of a solar collector with temperatures above 600º C and solar flows 800 times greater than solar radiation on the surface

 Develop a coating for melted salt storage tanks that eliminates the corrosion problems that frequently arise with that technology. The coating had to be able to withstand the highly corrosive environment inside the tanks that store a mixture of nitrate salts at 565º C that can reduce the useful life of high-quality stainless steel to a third of what is expected.

 An evaluation of the effect of those improvements on the operation and energy cost of a conventional tower CSP plant using a plant model based on two commercial power plants

The results obtained were promising, especially in one of the two areas studied in the project (high-absorbency coatings and anti-corrosion coatings), and they have let us make progress in developing the technology and foresee potential reductions in the energy costs (LCOE) created by those plants by more than 10%.

Insofar as high-absorbency coatings, after an iterative development phase in which eight different solutions were tested, absorption rates greater than the current state of the art were achieved, and values above 96% were measured, which is a promising value with potential. Furthermore, coating development was done for a simple application method that can be repainted with just one spray. Nevertheless, none of the solutions could withstand the tough durability tests the coatings were submitted to. They could not withstand solar radiation concentrated 800 times for enough time to make the solution viable.

On the other hand, the results in terms of the high-corrosion coating were much more promising. Solutions that were highly resistant to more corrosive environments than the current state of the art were achieved (chloride salt corrosion at 700º C) with very little degradation of the coating and that were practically inert to nitrate salt corrosion at 565º C. The results of this branch of the project opened up a line of research whose development should be continued, because of the high potential for using it in this kind of power plant and its promising results.

In conclusion, despite not achieving 100% of the goals set at the beginning of the project, very promising results were achieved that have opened up new lines of work and have shown the high economic impact of the solutions developed in the plants, where energy costs can be lowered more than 20%. In addition, this project made it possible for the members to collaborate and become acquainted with other entities in the Navarre research space, which will surely turn into future joint developments and collaborative projects, reinforcing the R&D fabric of Navarre.