Longitudinal supports shape influence on deflection and stresses in solar receiver tubes

Abstract

Longitudinal supports have a key role in solar central receivers, preventing tubes from excessive deflection. In this work, its influence on tube deflection and thermo-mechanical stresses has been studied. In exiting literature, the longitudinal supports are not modelled when the behaviour of solar receiver tubes is studied. In this research, they have been considered developing numerical models using a finite element analysis software. To carry out the analysis, a new geometry of the metal sheet attached to the receiver tubes has been proposed. With this new shape, different cases have been studied, varying the separation between supports and their size to study its impact on stress and deflection in the tubes. Results have shown that extremely rigid supports may induce additional stress in the receiver tube. With the geometry considered in this research, supports do not cause additional mechanical stress in tubes. Small supports are preferred to bigger ones due to the stresses arisen in the own support.