A protective method for preventing direct current into the ground from corroding metal pipelines

Abstract

The invention discloses a protection method for preventing influences on a metal pipeline from the electric system earth current. The method comprises the following steps that modeling is conducted according to actual project parameters, and the simulated analysis is conducted on the value of leakage current density of the pipeline when a high-resistance protection layer is not added; the multipleneeded for limiting the corrosion current is determined according to the pipeline corrosion current; the current needing to be limited is determined after the high-resistance layer is added; the value to which the leakage current density needs to be reduced is calculated after pavement of the high-resistance protection layer; the value of the pipeline leakage current density is subjected to simulating calculation after the high-resistance protection layer is added; whether the value, obtained through calculation after the high-resistance protection layer is added, of the pipeline leakage current density and the calculated value to which the leakage current density needs to be reduced are close or not is judged through comparison, and the resistance value and thickness of the high-resistance protection layer are adjusted according to the comparison result. The method has high adaptability, influences on most of pipelines from the electric system earth current can be avoided, and meanwhile the beneficial effects of simple later maintaining and the like are achieved.

Description

technical field [0001] The invention relates to the field of the influence of a high-voltage direct current transmission system on an underground metal pipeline system, in particular to a protection method for preventing the influence of direct current into the ground on metal pipeline corrosion. Background technique [0002] With the continuous development of my country's power grid, HVDC transmission has been more and more widely used because of its advantages in long-distance large-capacity transmission. Almost all DC transmission projects that have been built so far adopt the method of grounding the neutral point at both ends of the bipolar pole, which allows the operation of a single pole ground return line. In the operation mode of the single pole ground circuit, the DC system will have a large DC current flowing into the ground, which will cause serious corrosion to the metal oil and gas pipelines in the nearby ground, threatening the normal operation of the pipelines...

AI Technical Summary

Problems solved by technology

Each measure needs to be selected according to different conditions due to its different applicability, which is relatively complicated. A more general method is proposed to protect the pipeline

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