Dynamic Thermoelastic Analysis of Thermocline-like Storage Tanks

Thermocline storage system is considered as a cheaper alternative to the common two-tank molten salt approach.However, its configuration and performance might lead to a catastrophic structural failure known as thermal ratcheting. It may occur when a tank filled with particulate solids is cyclically heated and cooled. This paper aims at studying the transient evolution of thermocline tank wall stresses, taking into account both thermal and mechanical loads. A complete numerical methodology to deal with the fluid-structure interaction problem, based on a thermoelastic model for the shell, is used.For validation purposes and getting better understanding of the stress-strain response of the structure, Solar One Pilot Plant thermocline case is reproduced. Although some experimental data obtained from the literature suffers of large uncertainty, the numerical results show consistent good agreement.