Lifetime optimization of solar central receivers via linear actuators

Abstract

The receiver is a key component of concentrated solar power plants, whose operation can be interrupted by its early failure. In this research, a novel approach to the enhancement of solar receiver lifetime is presented, studying the use of linear actuators in the longitudinal supports of the tubes to induce forced displacements, reducing thermal stresses. Existing analytical models have been improved and joined together, in order to be implemented in a genetic algorithm to optimize the solar receiver lifetime. In a first approach, the maximum equivalent elastic stress, produced by the thermal gradients over the receiver, has been minimized. This approach reduces the maximum thermoelastic stress up to a 9.5%, and increases the lifetime of the receiver to an 8% when a forced displacement of 100 mm (1% of the tube length) is considered. When the rupture time due to creep is optimized, with the same forced displacement of 100 mm, the tube lifetime is enhanced up to a 25%. Small forced displacements (0.1% of the tube length) may lead to a lifetime improvement up to 6%. The small amount of force necessary to carry out the forced displacement of the supports makes feasible the implementation of linear actuators in future solar power plants.