An Approach for Optimising Inspection Plan of Tubes Operated at Elevated Temperature with Markov Chain Model

摘要

In order to assess the creep lives for welded joints of tubes operated at elevated temperatures in a probabilistic way, Markov chain model (MCM) is used to represent the process of creep damage in this study. Creep rupture lives are estimated based on L.M.P. in popular use, and the calculation of MCM is based on L.M.P. While conventionally the damage states in future have been estimated only with inspection results. In this study, future operating creep damage is estimated from the combination of the estimated damage state from MCM and the inspection results. Bayesian analysis is applied to update the expected distribution of creep damage with inspection results. With Bayesian analysis, more appropriate estimation of creep rupture can be achieved. The results can be used for the risk analysis in the future operation and the optimisation of inspection and maintenance plan.