Festigkeit keramischer sauerstoffionenleitender Membranen und deren reaktivgelöteter Verbunde
| Autor: | Herzog, Simone |
|---|---|
| Jazyk: | němčina |
| Rok vydání: | 2022 |
| Předmět: | |
| DOI: | 10.18154/rwth-2023-00770 |
| Popis: | Dissertation, Rheinisch-Westfälische Technische Hochschule Aachen, 2022; Aachen : RWTH Aachen University 1 Online-Ressource : Illustrationen, Diagramme (2023). = Dissertation, Rheinisch-Westfälische Technische Hochschule Aachen, 2022 Oxygen separation from air by means of ceramic membrane tubes requires gas-tight components that enable failure-free permeation operation in the oxygen partial pressure gradient at 850 °C. However, the test operation and observed membrane failure in a pilot module raised questions, the answers to which are of crucial importance for future module developments and their operation. In this work, firstly, the understanding of separate damage mechanisms of the membrane material Ba0.5Sr0.5Co0.8Fe0.2O3-δ in long-term operation is elaborated and then the associated strength degradation is quantified. This is followed by the simulation of the position- and time-dependent stress distribution during operation and emergency shutdown. The results lead to a re-evaluation of the cause of the damage, which allows the derivation of constructive and process-side measures to prevent membrane failure. The second part of the work focuses current challenges of reactive brazing in air, which have to be overcome in order to use membrane tubes reliably and effectively without water cooling. This requires optimal braze distribution, high joint strength and absence of damage to the membrane in the as-brazed condition, as well as little change in this condition during isothermal ageing. The investigations carried out provide answers to the fundamental question of which process parameters and material combinations can be used to meet these requirements. Published by RWTH Aachen University, Aachen |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|