基于维纳退化过程的海底腐蚀管道可靠性分析

目的研究海底腐蚀管道的寿命可靠性,提出基于维纳过程(Wiener Process)和贝叶斯方法估参的可靠性分析模型。方法首先以管道内壁腐蚀退化数据和维纳过程为基础,建立针对海底管道的腐蚀退化模型,并针对不同时段的腐蚀退化数据,以正态-逆伽马分布作为模型未知参数的先验分布。然后采用一种优化的贝叶斯方法递推计算,得到未知参数值,最终实现腐蚀管道的可靠性分析,并以某海底腐蚀管道为例进行验证。结果可靠性分析得到腐蚀管道在运营前期的12年几乎完全可靠,可靠性达99.22%;13年之后,腐蚀进程开始加快,当可靠度为90%时,该段管道的可运营时间为13.6年;运行15年时,可靠度为68.97%;运行20年时,可靠度为2.4%;而到设计寿命25年时,管道可靠度几乎为0,求得管道的平均剩余寿命为15.99年。结论以海底管道的腐蚀退化数据为切入点,为长寿命、小子样的海底管道可靠性提供了一种较直观的分析方法。分析模型可以处理不同时间段测量的管道腐蚀数据,并且随着管道运营时间的增加,能够不断更新可靠性分析结果,而不需要反复处理历史数据,进而可以用于海底腐蚀管道的实时可靠性分析。

Reliability Analysis of Corroded Submarine Pipeline Based on Wiener Process

The work aims to propose a reliability analysis model based on Wiener process and Bayesian method to study the life reliability of corroded submarine pipelines. The corrosion deterioration model of submarine pipelines was established based on the corrosion data of inner wall and wiener process. For different periods of corrosion data, the normal-inverse gamma distribution function was used as the prior distribution for the unknown parameters of the model. The unknown parameters were calculated by an optimized Bayesian method recursively to finally analyze the reliability of corroded submarine pipelines. A corroded submarine pipeline was taken as an example to verify the model. The reliability analysis showed that the corroded pipeline was almost completely reliable the in the first 12 years and the reliability was 99.22%. And 13 years later, the corrosion rate began to accelerate. When the reliability was 90%, the pipeline could be operated for 13.6 years. When the pipeline operated for 15 years, the reliability was 68.97%, and for 20 years, the reliability was 2.4%. When the pipeline operation time reached to the design life of 25 years, the pipeline reliability was almost 0%. The average residual life of the pipeline was 15.99 years. Based on the corrosion data of submarine pipelines, an intuitive analysis model is provided for the reliability of long-life and small-sample submarine pipelines. The analysis model can calculate the corrosion data measured in different times, and with the increase of pipeline operation time, the reliability analysis results can be updated continuously. It does not need to calculate the historical data repeatedly and can be used for real-time reliability analysis of corroded submarine pipelines.