Author(s): Ariane Immarigeon; Martin Gagnon

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Keywords: No Keywords

Abstract: The ranking of turbine runners, based on their cracking probabilities, can be useful for planning and decision-making. However, the analyst doing so needs to choose the level of complexity used. In this study, we propose to use the conditional probability of an event on an interval, given that it did not occur at the start of the interval. This enables one to estimate the probability of the event on a specified inspection interval and obtain a ranking given the time of the last inspection or based on the current inspection interval. This approach will be evaluated on data from Francis runners to look at the impact of operation, fatigue damage parameters and inspection data on cracking probability. A high-risk runner may be at risk because of inspection interval length, lack of knowledge leading to high parameter uncertainties or simply because it is at the end of its remaining useful life. These results will enable us to have a discussion on how one may be able to lower the probability on a given time interval at the cost of either additional inspections, change of operating conditions or a better quantification of parameter uncertainties.

DOI: https://doi.org/10.1088/1755-1315/1561/1/012019

Year: 2025