Temperature and thermal stress field analyses of tube receiver under intermittent concentrated solar irradiation

Temperature and thermal stress analyses of receiver can provide theoretical guidance to the suppressing of thermal stress. Coupled-field element method is adopted to conduct temperature and thermal stress field analyses of tube receiver under non-uniform and intermittent concentrated solar irradiation. During the temperature analyses of tube receiver, angle relationships between incident direction of solar rays and surface elements of tube receiver are calculated, and the relationships multiplied by magnitude of concentrated solar irradiation are used as the secondary boundary condition of temperature analyses. The secondary derivative of temperature field along length direction of tube receiver is also investigated to clarify the thermal stress distribution along length direction. The numerical results indicate that axial stress and tangential stress have much higher influence on thermal stress field than radial stress, and the inflexion of secondary derivative of temperature distribution will induce an inflexion of thermal stress distribution.