埋地钢制燃气管道受杂散电流腐蚀寿命的预测模型研究

Study on Prediction Model of Corrosion Life of Buried Steel Gas Pipeline Subjected to Stray Current

为缩短传统实测试验耗时长、误差大的缺点,构建杂散电流干扰下的管道寿命预测模型,基于非线性Wiener过程,结合逆幂律模型、步进加速退化模型和两步极大似然估计法,推导剩余寿命概率密度函数近似表达式;采用贝叶斯方法实现预测结果的动态更新;通过实例验证并在MATLAB中仿真,将仿真拟合值与实际值对比。结果表明:与未受电流干扰管道相比,杂散电流干扰下管道腐蚀速率明显加快;且所建模型仿真的寿命预测精度有所提高,验证了所建模型的正确性和优势。

In order to shorten the shortcomings of traditional measurement test,such as long time consuming and large error,a pipeline life prediction model under the interference of stray current was established.The method was based on the nonlinear Wiener process,combined with inverse power law model,stepwise accelerated degradation model and two-step maximum likelihood estimation method,the approximate expression of residual life probability density function was derived.The dynamic update of prediction results is realized by Bayesian method.By the example verification and simulation in MATLAB,the simulation fitting value was compared with the actual value.The results show that the corrosion rate of the pipeline under the interference of stray current is obviously faster than that without the interference of current.Moreover,the accuracy of life prediction of the model improves,which can verify the correctness and advantages of the model.