Coupled abrasion Erosion-Oxidation wear from particles in Concentrating solar thermal power facilities

Abstract

Solid particles represent an attractive heat transfer and energy storage media for next generation solar thermal power facilities for their ability to operate at high temperatures without concerns for freezing or corrosion. A potential outstanding issue that still remains for particles as heat transfer media is the wear on components operating with particles flowing (sliding) in, along, or over them. Prior work has shown that even at the low velocities (∼1 cm/s to ∼ 1 m/s) expected in solar thermal facilities, material wear will still occur, and the lifetime and performance of components undergoing wear needs to be well understood. Abrasion erosion occurs when particles come into contact with containment materials at extremely shallow angles, and is likely to be seen in heat exchangers, storage bins, and flow control mechanisms. Additionally, because of the open nature of most of these systems to air, oxidation of metals is also of concern. Here, we show how critical the coupled erosion-oxidation mechanism is to understanding particle/material durability and therefore need for greater in-depth analysis. Abrasive wear experiments are conducted on metals such as SS316 (L and H grades), Inconel 740H, Haynes 230 with different particles (HSP 40/70, Wedload 430, and CarboMax HD) for different operating conditions. Results clearly indicate that oxide spallation and removal is critical to the overall wear seen at high temperatures.