著者

岡島 智史 泉 聡志 酒井 信介

出版者

公益社団法人 日本材料学会

雑誌

材料 (ISSN:05145163)

巻号頁・発行日

vol.57, no.4, pp.401-407, 2008 (Released:2008-04-18)

参考文献数

6

被引用文献数

1 1

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Because of the lessening number of maintenance experts, a method to rationalize pipe inspection interval is desired. For this purpose, the evaluation method for the pipe integrity in the form of failure probability has been developed based on the Bayesian inference method in the previous paper. In this paper, the previous method is called the linear-Bayes method. The linear-Bayes method assumes wall thinning due to Flow Accelerated Corrosion (FAC) as the principal damage mechanism, and it can define the safety margin of a pipe's residual life depending on the number of inspections. However, the linear-Bayes method ignores the corrosion rate fluctuation against time, which may be caused by the change of environment such as water chemistry and flow velocity. Therefore, the linear-Bayes method may underestimate the failure probability of the pipe segments if the online monitoring of the environments is not used. In this paper, the linear-Bayes method is extended for the wall-thinning model with the corrosion rate fluctuation. The extension is carried out through following two approaches : correction-term and error-term approaches. In this paper, the formulation and the procedure for each approach are shown at first. And then, the accuracy and the merit of the extended method are examined through the evaluation using the artificial and the actual inspection records. Through the examination, it is confirmed that the extended method makes the evaluation of the pipe integrity available in view of safety margin for the corrosion rate fluctuation, keeping the merits of the linear-Bayes method.

著者

岡島 智史 岩崎 篤 泉 聡志 酒井 信介

出版者

一般社団法人 日本高圧力技術協会

雑誌

圧力技術 (ISSN:03870154)

巻号頁・発行日

vol.43, no.6, pp.335-340, 2005 (Released:2005-12-26)

参考文献数

6

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The verification test of machine diagnosis techniques was carried out by Japan Power Engineering and inspection Corporation, and a system called as the RET (Residual Life Evaluation of Thermal Power Plants) system was developed as the result of this activity. The RET system can evaluate the primary damage of equipments in boiler or turbine using several residual life evaluation methods. The RET system provides valuable function for the residual life evaluation. However, this system is not necessarily utilized widely. In this study, online version of the RET system is developed for the purpose of populization of the RET system. The online RET system can evaluate the primary damage of the equipments in boiler or turbine without any extra application, and is easy to reflect new information.