Optimal Failure-Finding Intervals for Heat Shields in a Gas Turbine Combustion Chamber Using a Multi-Criteria Approach

Abstract

When a component, as heat shields, degrade, two stages can be distinguished. First, a potential failure appears, which could evolve to the second stage and become a functional failure. The time between these two stages is called delay-time, which has been widely studied in literature to determine when to inspect to avoid breakdown. These studies have shown only single analysis criteria to find failure finding interval (FFI). In order to overcome this limitation, we developed a novel strategy to apply multicriteria methodology to optimize FFI. Our approach considers availability, system breakdown risk and reliability analysis from a systemic perspective, studying heat shields as groups, according to their location in the combustion chamber, regardless of age defect. Hence, it is not necessary to check every one of the shields. Our results show an optimal FFI policy subject to a determined breakdown risk level. This analysis may be adaptable to other components that can be grouped together.