Heat Transfer Fluid (HTF) Expansion vessels are component parts of a solar power plant and are designed to hold the HTF, which transfers energy from solar collector arrays (SCA’s) to steam generators.
These vessels undergo extreme thermal cycling in their daily operation. The vessels begin to warm up at sunrise as energy becomes available and quickly reach maximum operating temperatures and remain there until the solar energy starts to fade and the vessels cool off. Shorter, less severe, thermal cycles also occur during the day when passing clouds partially obscure the sun and reduce the amount of solar radiation available. This thermal cycling results in stresses being induced, then reduced, on a frequent basis.
Sterling, applying its vast deaerator experience, kept this fact in mind when designing the features of the Sterling Expansion vessels. Past vessel designs have suffered serious failures when the nature of this thermal cycling was not adequately considered. Sterling applies Finite Element Analysis techniques to both the vessel and accompanying saddle designs in order to reduce thermally-induced stresses and the subsequent failures that result.