Solar Disc Concentrator: Material Selection for the Receiver

Solar concentration is the ability to harness solar radiation in order to increase the temperature of a receiver. The receiver is a component into which a heat transfer fluid can flow in an ORC system, which produces electricity, or it can be used for high-temperature thermal storage or even to implement thermochemical cycles. The choice of material is critical to ensure optimal performance and long-lasting operation. It is also essential that such material can operate at high temperatures and high thermal gradients. In short, material identification involves high thermal stresses that result in structural deformation. Different metal alloys were used to verify that the yield strength limit was not exceeded due to thermal stress induced by concentrated solar radiation. Starting with the general heat equation, the problem was implemented in Matlab. The purpose was to test whether thermal stress exceeds the yield strength, which is the condition in which elastic bonds in the material are changed, causing deformation. This condition, if exceeded, is sufficient to discard the material; otherwise, it is a necessary but not sufficient condition to resist over time. The best material identified was Inconel 740H, which had a high yield strength value and the lowest temperature difference. Under extreme working conditions, it withstood induced thermal shocks.