Oscillating Arc as an Improvement Strategy for Welds in Thermal Storage Systems in CSP Plants
Abstract
The molten salt two-tank thermal storage system, based on a mixture of sodium nitrate and potassium, is widely used in concentrating solar power plants, operating between 290 °C and 565 °C. However, failures associated with the welded joints have been reported. This study evaluates the effect of oscillated arc versus non oscillation arc on welds exposed to molten salts. Techniques such as electron microscopy, metallography, microhardness and dilution analysis were applied to characterize the microstructure after different exposure times. The results indicate that arc oscillation improves the distribution of protective elements, reduces residual stresses and decreases mass loss under severe conditions.
Keywords
Renewable electricity, Capacity installed, Storage, Thermal Energy Storage (TES)