doi:10.3969/j.issn.16715152.2016.11.005
周策·埋地燃气管道的极性排流实验研究
埋地燃气管道的极性排流实验研究
同济大学机械与能源工程学院（201804）周策
摘要：轨道交通(以下简称轨交)与天然气管道是两个重要的城市基础设施，近年来均在快速扩
张中，轨交杂散电流对邻近理地天然气管道所导致的腐蚀问题日益凸显，已有天然气管道被腐蚀、接近穿孔的报导。现有的管道设计均采用外加电流结合牲阳极的阴极保护方案，但无法有效降低轨交行驶造成的动态杂散电流的千扰。有关国家标准规定可采用极性排流方法来降低杂散电流对已施加朗极保护管道的干扰，但国内并无公开报导的研。本文对上海某轨交站附近的燃气管道进行了管地电位、地电位梯度等系统测试，通过管轨电压与管地电位的时间同步性确定了轨交系统对管道的影响。之后进行了管道与轨交负母排直接搭接的极性排流实验，排流点测试桩处的管地电位满足相关标准对排流效采的要求，但相距150m的另一个测试桩因绝缘接头的作用仍处于剧烈的管地电位波动中。极性排流可作为外加电流与辆牲阳极保护措施的有效补充，用于城市燃气管网的扇蚀防护。实验发现，对于处于复杂干扰情况下的管道，排流改善的作用范图尚有待深入研究。
关键词：轨道交通杂散电流燃气管道极性排流管道保护
Experimental Research of One-wayDrainageforBuried Gas Pipelines
ZhouCeSchool ofMechanical Engineering,Tongji University,Shanghai
Abstract:As two indispensable parts of city infrastructures, both rail transits and gas networks are
developing rapidly. Corrosion risk of buried gas pipelines suffering from direct current (d.c.) interference of transit systems becomes increasingly serious in big cities, It was reported that gas pipelines were corroded by stray current from d.c. traction system. In existing cathodic protection design, impressed current in combination with sacrificed anodes were mainly adopted, which turned out to be unable to mitigate d.c interference. Although it has been specified in some standards that one-way drainage can be effective, research based upon field test has not been reported publicly. In this paper a field test was performed for a gas pipeline in the neighborhood of a rail transit station in Shanghai. The pipe-to-soil potential, d.c. potential gradient and pipe-to-rail potential were measured, and then synchronism were analyzed to determine relationship between interference suffered by pipeline and transit system operation. Drainage effect was evaluated from both on-potential and off-potential in light of d.c. interference mitigation. The improvement result of drainage point was observed to be perfect if
城市燃气2016/11总第501期|21
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