Análisis del comportamiento medioambiental de aceros y fluidos de transferencia de calor implicados en centrales termosolares con tecnología cilindro-parabólica y almacenamiento térmico

Abstract

This research is based on renewable energy and particularly focused on parabolic trough concentrating solar power technology.Concentrating Solar Power (CSP) enjoys a considerable advantage over other renewables in that it is manageable through the use of Thermal Energy Storage (TES) systems. The storage is done in steel tanks filled by molten salts. The contact between steel and salt produces material corrosion phenomenon then that must be resolved with advances in technology. Historically, the parabolic trough solar plants have been composed by a primary circuit made of steel absorber tubes in where circulates through them Heat Transfer Fluid (HTF). It is called indirect system.HTF is technologically limited by their maximum operating temperature which affecting decreasing the power cycle efficiencies. While the molten salts have a higher maximum operating temperature. If molten salt is used both as HTF and TES then the system is called direct. Currently, there are many studies which consider the benefits of direct systems.Therefore, this thesis is a material assessment. However, there is not a material assessment from the conventional point of view, in which mechanical, chemical, thermal properties are studied. It is an environmental analysis. In fact, this is the main contribution of this research.Steels selected are: P92 and 316 for high temperature applications such as absorber tubes, pipes and hot storage tanks. Steels 516 and T22 applied in lower temperatures parts of the plant, such as cold storage tank, are also assessed. Therminol is studied as HTF and binary solar salt and solar salt Hitec as HTF and TES...