Detection Of Partial Blockages In Long Distance Natural Gas Pipelines

With the rapid development of China's economy,energy demand is more and more bigger,in order to meet the country's demand for energy,China has built the west-east gas pipeline system,Shanxi-Beijing system,Seninglan system,Southwest gas pipeline system.Pipeline transportation has become the main way of natural gas.But with the operation of gas pipeline corrosion,material aging or man-made damage and other factors,it is inevitably lead to pipeline accidents.Especially for the natural gas pipeline,because of a long time in the field and the lack of daily check and maintenance,it is prone to blockage accident.In addition,due to the pipeline deformation,pigging operation often causes blockage.Blockage will lead to reduced efficiency of the system of the natural gas pipeline,and increase the risk of potential accident.If the blockage occurs at the early stage,it will be able to take measures to clear the pipe,and avoid cause serious blockage accident.Therefore,it is very important to find a practical and reliable method to detect the incomplete blockage of natural gas pipeline,which can ensure the safe operation of natural gas pipelineIn this paper,the problem of incomplete blockage of long distance natural gas pipeline is studied.Based on the continuity equation and motion equation of gas flow in pipeline,the transient flow model of natural gas pipeline is established by the method of fluid mechanics.The transient characteristics of long distance natural gas pipeline are studied,and the propagation law of pressure disturbance is obtained.We study the incomplete blockage of long distance natural gas pipeline,and get the characteristic parameters of incomplete blockage,the location,length and strength of incomplete blockage.This paper analyzes the relationship between the transient pressure fluctuation in pipeline and the characteristic parameters of incomplete blockage of pipeline,and obtains the method of calibrating the location,length and strength of the incomplete blockage of the pipeline.Based on the transient pressure analysis,the clogging detection experiment is designed.The blockage detection of the incomplete plugging module is designed,and the experimental analysis is carried out.The location of incomplete blockage was measured.It is found that the length of incomplete blockage that can be measured is longger than the 1/2 of the propagation distance of the mass pulse.