Study on Friction and Wear Performance of Flow-Blocking Packing for High-Temperature Gas-Cooled Reactor

Abstract To mitigate the bypass helium flow within the core structure of a high-temperature gas-cooled reactor and enhance the efficiency and power output, this study explores the use of braided packing as flow-blocking components in the core support structure. Structural design and optimization were carried out, considering various technical factors associated with the application of braided packing as fillers in the high-temperature gas-cooled reactor core support structure. Four distinct models of braided packing were compared for their friction and wear performance under diverse environmental conditions, including high temperatures and a helium atmosphere. Possible friction and wear mechanisms, along with influencing factors, were investigated. Through the evaluation of data such as loss in mass after wear, coefficient of friction, and post-wear surface morphology, preliminary conclusions suggest that braided packing may meet the operational requirements for a 60-year lifespan of a high-temperature gas-cooled reactor. The test results indicate that the selected braided packing exhibits favorable friction and wear performance in the high-temperature gas-cooled reactor core environment. The loss in mass after wear, under frictional distances equivalent to a 60-year lifespan of a high-temperature gas-cooled reactor, is deemed acceptable. Furthermore, friction and wear performance testing was conducted on braided packing subjected to 450°C thermal aging for 2000 hours. The experimental outcomes reveal that the braided packing, after undergoing 450°C thermal aging for 2000 hours, still demonstrates satisfactory performance. Based on the aforementioned research findings, it can be concluded that disk materials, when employed as flow-restricting components, do not experience functional failure due to friction and wear mechanisms in a high-temperature gas-cooled reactor.