直流接地极入地电流对附近埋地管道电位的影响

Potential Influence of Ground Return Current from HVDC Grounding Electrode on Buried Pipeline

随着我国对能源需求的快速增长,直流输电工程和输送油气管道的建设也在迅速增加。在直流接地极与管道均十分密集的地区,为了减少土地的占用,直流输电工程和输油气管道甚至共用走廊,使得直流输电工程对附近埋地金属管道的影响日益突出。目前,已有研究成果关于直流接地极入地电流对长距离油气管道的影响研究不深入,土壤电阻率横向分区和管道极化效应的研究工作未有效开展,尚不能系统、全面地分析直流接地极入地电流对长距离油气管道的影响机理。提出考虑土壤电阻率的横向分区的计算方法,基于矩量法建立复杂地质条件下考虑管道措施的长距离管道受地中电流影响的仿真模型,并利用实际管道测量数据和小模型管道长期测量数据优化模型参数,从而利用仿真计算模型准确评估入地电流对油气管道的影响程度,提出有效的缓解措施,为管道防护措施的设计和实施提供理论依据。

With the rapid growth of energy demand, the construction of HVDC transmission projects and gas transmission pipelines is also increasing rapidly. In developed area, there is not only dense electric power grid, but also dense gas pipelines. In this situation, the DC current injected into the earth through the HVDC grounding electrodes would aggravate the corrosion of the pipelines and even destroy the protection devices of the pipelines. The influence of the ground return current from HVDC grounding electrode on buried metal pipeline is not studied in depth. The research on the horizontal partition soil model and the polarization effect of the buried pipeline has never been carried out effectively. The influence of ground return current on buried metal pipeline could not be analyzed systematically and comprehensively. In the project, the calculation method of the horizontal partition soil model was presented. On this basis, the simulation model of the influence of ground return current on buried metal pipeline considered the main cathodic protection methods was built in multi-region layered soil structure. The results from actual pipeline measurement test and small-scale model test were used to optimize the simulation mode. Then, the simulation model was used to study the influence of the ground return current on the buried pipelines. The comprehensive protection measures were presented, which provided theoretical basis for the design and implementation of the pipeline.