pilot case 2 – Computational protocol for understanding thermal energy storage in molten salts and nanofluids

(Key person: P. Ordejón, ICN2, in collaboration with Abengoa Research)

Improving the efficiencies and lowering the cost of energy generation is essential for the economic viability of novel, renewable and clean energy sources. Solar thermal energy is one of the most competitive alternatives: The heat generated can be stored in a heat storage medium by means of an intermediate heat transfer fluid, for further transportation and use.

Due to their high heat capacity molten salts are one of the preferred options used by this industry. Optimising the thermal storage and transport properties of molten salts is therefore key for the global efficiency of these technologies. Introducing nanoparticles in the molten salts improves both the thermal storage and the transport properties. In particular, the heat capacity of these nanofluids has been reported to increase up to 100%, with respect of the original molten salts. Accurate computer simulations play a crucial role in this innovation process, as producing reliable experimental data for these systems is difficult and expensive, thus reduc
ing innovation costs and uncertainty, and significantly speeding up the whole innovation cycle.

Within this Pilot Case we developed protocols (see figure) to compute both specific heat and thermal conductivity. The protocols have been tested so far using classical potentials. Their adaptation to be used in conjunction with quantum engines as the MaX flagship codes (SIESTA, QUANTUM ESPRESSO, and FLEUR) is currently under way.







Snapshot of a simulation run for a graphene nanoflake in solution of Dimethylformamide (DMF), used to compute the specific heat of the nanofluid.