Jiangxi Provincial Natural Gas Pipeline AC Interference Detection And Prevention

Many gas pipelines, belong to Jiangxi Provincial Natural Gas Company Limited, are currently located at high voltage power lines or electrified railways. A large number of domestic and international project cases and research results show that HVAC transmission lines or electrified railways, nearby buried gas pipelines, are able to induce alternating voltage and current on pipelines by way of electromagnetic induction or resistive coupling, and the AC interference is a major threat to the security operation of gas pipelines.In order to evaluate the risk of AC interference on pipelines and eliminate potential safety problems, the paper has tested the AC interference parameters of Jiangxi provincial natural gas limited company’s pipelines in short time (<5min), on which AC interference risk exists, and in accordance with the relevant standard to rank AC interference risk levels; based on the preliminary testing results, exerted24hours or48hours’continuous monitoring on those high risk locations. According to the monitoring datas, analysed the rule of AC interference parameters with time change, and picked out those serious parts of pipe:then carried out the remission-test on spot, worked out the AC interference calculation, and combined with spot test and calculation results to work out the AC interference protection scheme; according to the scheme, adopted the technique of horizon zinc belt combined with isolator to reduce AC interference on three serious parts of pipe; detected AC interference voltage and current density of pipelines where AC interference protection measures had been taken, analysed the detection results, and evaluated the effect.After practicing the AC interference protection scheme, detection results of relevant pipelines indicate that it has achieved the desired protective effect.The program can be a reference for other similar projects.