No abstract

No abstract

No abstract

No abstract

Current technologies of concentrated solar power plants (CSP) are under extensive industrial development hut still suffer from lack of adapted thermal energy storage (TES) materials and systems. In the case of e.xtended storage (some hours), thousands of tonnes of materials are concerned leading to high investment cost, high energy and GHG contents and major conflicts of use. In this paper, recycled industrial ceramics made by vitrification of asbestos containing wastes (ACW) are studied as candidates to be used as sensible TES material. The material presents no hazard, no environmental impact, good thermophysicalproperties (/.= 1.4 W m~' K~': Cp = 1025 J kg'' K'': p= 3100 kg m~^) and at very low investment cost. Thanks to the vitrification process of the wastes, the obtained ceramics is very stable up to 1200 °C and can be directly manufactured with the desired shape. The vitrified ACW can be used as TES material for all kinds of the CSP processes (from medium up to high concentration levels) with properties in the same tange than other available materials but with lower cost and without conflict of use. The proposed approach leads also to sustainable TES allowing a pay back of the energy needed for the initial waste treatment. Eurthermore, this new use of the matter can enhance the waste treatment industry instead of landfill disposal.

No abstract

New thermal storage composites made of graphite and PCM (NaNO3∕KNO3 eutectic) have been developed for solar thermal power plants using direct solar steam generation. Those materials, obtained using different elaboration routes (compounding, infiltration, cold compression) and graphite types, are presented with their respective properties (enhanced thermal conductivities, thermal storage capacities, stability) and compared together. Both the laboratory and industrial scales and grades are considered and compared. The infiltration route has been found to be inefficient before the two other ones. Compound composites present isotropic properties and thermal conductivity intensification in the medium range (a factor of 10 for 7wt% in graphite). Cold compressed composites present highly anisotropic properties and strong intensification in thermal conductivity (a factor of 31 at 200°C for 20wt% in graphite). Their melting and solidification temperatures as well as their intrinsic storage capacity are close to the pure salt ones.

No abstract