复杂土壤条件高压直流接地极与埋地油气管道防护距离研究

Study on Protection Distance Between HVDC Grounding Electrode and Buried Oil and Gas Pipeline Under Complex Soil Conditions

为保障埋地管道附近人员的安全,对高压直流接地极对埋地管道的电流干扰及人身安全距离进行了研究。首先,利用CDEGS仿真软件建立了埋地管道受高压直流接地极的干扰模型,筛选了影响安全距离的主要因素;其次,研究了埋地管道在不同均匀土壤和多层复杂土壤的安全距离;最后,建立了均匀土壤与复杂土壤的安全距离折算关系,提出了采用最大管地电位并利用系数修正得到复杂土壤安全距离的方法。研究结果表明,土壤电阻率对安全距离的影响最大;若均匀土壤的安全距离小于8km,修正系数采用0.85,可以得到复杂土壤的安全距离;若均匀土壤安全距离为8~12 km,修正系数与安全距离符合幂函数的关系;若均匀土壤安全距离大于12 km,建议修正系数取0.53。所提方法可供高压直流接地极及管线设计提供参考,并且可为未来拟建高压直流接地极选址提供借鉴。

In order to ensure the safety of the persons near the buried pipelines,the current interference of HVDC grounding electrode to buried pipelines and its personal safety distance are investigated.Firstly,CDEGS simulation software is used to establish the interference model of buried pipeline by HVDC grounding electrode,and the main factors affecting the safety distance are screened.Secondly,the safe distances of buried pipeline in different uniform soil and multilayer complex soil are studied.Finally,the safety distance conversion relationship between uniform soil and complex soil is established.A method is proposed to obtain complex soil safety distance by using maximum pipelines ground potential and utilization coefficient correction.The research results show that soil resistivity has the greatest influence on the safety distance.If the safety distance of uniform soil is less than 8 km,the safety distance of complex soil can be obtained by using a correction coefficient of 0.85.If the uniform soil safe distance is between 8 km and 12 km,the relationship between the correction coefficient and the safety distance of uniform soil satisfies power function.If the safety distance of uniform soil is greater than 12 km,a correction coefficient of 0.53 is recommended.This proposed method can provide reference for the design of HVDC grounding electrode and pipeline,and also for the site selection of HVDC grounding electrode in future.