考虑非线性极化的接地极对管道泄漏电流计算及验证

直流接地极对邻近埋地油气管道的腐蚀影响和危险影响问题日益突出,迫切需要更为准确的计算方法。文中在前续研究的基础上,将管道和接地装置使用矩量法建立等效电路模型,将管道表面破损处的极化效应考虑为非线性受控电压源,由此给出了考虑金属表面非线性极化的直流接地极对埋地金属管道影响计算方法。并通过搭建高压直流接地极和油气管道的缩比试验模型进行实验研究,得出了管道表面的断电电位和泄漏电流密度。基于实验结果对计算方法进行了有效性验证,结果表明该计算方法与测试结果在工程应用范围内吻合较好,可为工程应用提供估算参考。

Calculation and verification of pipeline leakage current considering the influence of DC earth electrode on the non-linear polarization

The corrosion and hazard effects of DC earth electrode on adjacent buried oil and gas pipelines are becoming increasingly prominent, and more accurate calculation methods are urgently needed. On the basis of previous research, the equivalent circuit model of pipeline and grounding device is established by moment method, and the polarization effect at the damaged surface of pipeline is considered as a non-linear controlled voltage source. A calculation method considering the non-linear polarization effect of DC earth electrode on the surface of buried metal pipeline is proposed. In the rectangular tank of grounding Laboratory of UHV AC test base, the scaling test model of HVDC earth electrode and oil and gas pipeline is built to carry out experimental research. The validity of the calculation method proposed in this paper is verified. The results show that the calculation method is in good agreement with the test results, and it can provide an estimation reference for engineering application.