Corrosion in Thermal Storage Applications

Research Project, 2018 – 2023

Energy storage is one of the most pressing topics during the transition to “green” electricity. Thermal storage and heat transfer fluids have attracted attention since they can bridge novel and existing technologies. The general concept of deploying heat storage media is simply by thermally running gas turbines or conveying heat to households independent of the energy sources. Among the applications that utilize thermal storage could be concentrated solar power (CSP) or excess electricity to heat conversion from wind- or solar power. Water or gasses do not possess sufficiently high heat capacities for efficient thermal storage. On the other hand, Eutectic salt melts offer a large liquidus window, several hundred degrees.

Here, we work with eutectic molten salts for current and future thermal storage applications operating in a temperature window of 250 – 1000 °C. Our focus is on the compatibility between the thermal storage medium and the alloys used to contain it.

Specifically designed experimental setups that mimic conditions in thermal storage tanks and push stage-of-the-art alloys to their limits. These include stainless steels, Ni-based alloys and Fe(Ni)CrAls.

Alkali nitrates, including the so-called “Solar Salt”, alkali carbonates, and eutectic chlorides, have already been used in our setups for systematic performance analysis.