Effect of Eccentricity on the Thermal Stresses in a Bayonet Tube for Solar Power Tower Receivers

摘要

The receivers of thermosolar tower plants are subjected to elevated thermal gradients as a consequence of the highly concentrated sun radiation that is reflected by the heliostat field. These thermal gradients can easily rupture the receiver tubes, which limits the operation of the plant. One way of solving this problem is the use of new receiver designs. The present work characterizes, by means of combined CFD-FEM simulations, the thermal stresses in a new bayonet tube receiver. The results are compared with those of a simple tube receiver. The influence of the tube fastening (i.e. clips) in the tube stresses is also analyzed. The simulations carried out show that the asymmetry created by the eccentricity in the bayonet tube reduces the temperatures on the most thermally demanded surface of the tube, which translates into a decrease in the thermal stresses, independently of the kind of tube fastening.