The Reliability Of Shanjing Pipelines' Gas Supply For Beijing Market

As a kind of clean and efficient fossil energy,natural gas plays a more and more important role in the society.Piping is the major way to transport mass of it,however,its reliability decreases and malfunctions always take place with the influence of the environment and the degradation of the pipeline.Once malfunctions happen,not only the safety of people's lives and properties is threatened but also the capability of transportation is impacted,which means that customers will be in shortage of gas.Doing research on the reliability of pipelines can help decrease the occurrence of malfunctions and guarantee that pipelines can finish their jobs successfully.There are two aspects about the reliability.One is safety reliability which refers to how malfunctions influence the safety of people's lives and properties,the other one is reliability of gas supply for markets which refers to whether pipelines' capability can meet customers' demand.This dissertation is to assess the reliability of Shanjing pipelines' gas supply for Beijing market,guaranteeing that Shanjing pipelines can provide Beijing market with enough gas.Firstly,the specific indicator needs to be built to evaluate Shanjing pipelines' gas supply for Beijing market,based on the information of Shanjing pipelines and the basic knowledge of reliability.Secondly,factors that influence the indicator need to be figured out.After analyses,the uncertainty of elements'(compressor stations' and pipes')states and the uncertainty of the demand of Beijing market are the main factors.By using data and Markov Chain method,the probability distributions of elements' states and the demand of Beijing market are obtained.Lastly,calculate the value of the indicator,combining the probability distributions and hydraulic calculation by Monte-Carlo simulations.Reliability is used as the specific indicator.After calculations,the reliability of Shanjing pipelines' gas supply for Beijing market is between 0.99 and 0.9999,and it decreases with the demand of Beijing market increasing.When the demand of Beijing market is 6.26×107m3/d,the reliability of gas supply for Beijing market is 0.99923153;When the demand of Beijing market is 8.74×107m3/d,the reliability of gas supply for Beijing market is 0.99806369.Pipes and compressor stations have different influence on the indicator.Among elements of pipelines,the first Shanjing pipeline,part of the second Shanjing pipeline(from Yulin station to Yangqu station)and part of the third Shanjing pipeline(from Yulin station to Yangqu station)have the most influence on the indicator.Among compressor stations,Shijiazhuang and Yulin compressor stations have the most influence on the indicator.Keeping these important pipes and stations in good performance can enhance the indicator.