Simulation And Operation Optimization Research On Central Asian Natural Gas A/B Pipelines

The first station of central Asian natural gas A/B pipelines is located in border of Turkmenistan and Uzbekistan.Along the way through Uzbekistan,Kazakhstan,reached Horgos port connected to the second line of West-East gas pipeline.All adopts double pipelines parallel laying method,which diameter of 1067 mm,design pressure of 9.81 MPa and 8 stations along the pipelines.A line and B line are completed in 2009 and 2010.It reached design of gas transmission capacity of 300×10~8Nm~3/a in december 2012.Central Asia natural gas pipelines are long distance and double pipelines,which operation and dynamic management is relatively complex.Management personnel have many factors to consider when making scheduling and establishing operation scheme.With the help of simulation,management personnel develop a safe and reliable operation plan or emergency measures on the basis of simulation analysis and operation optimization for all kinds of accidents that may occur in transmission.In this paper,based on the actual situation of central Asia natural gas pipeline,simulation model is built by SPS and SCADA system operation interface is exploited by VB,which make management personnel using simulation system more convenient according to the mode of operation on the interface of SCADA.It can be also used to training scheduling personnel to improve their ability to find the risk and handle emergency events.By means of the established simulation system,simulation model of A/B double lines are built based on the basic data and analysis of operation condition of central Asia natural gas pipelines.According to this simulation model,flowing rate and pressure variation characteristics of A/B double lines is analyzed when working condition of pipeline leakage,block valves shutting off and compressor start-stop.The results show that characteristics of transient conditions between central Asia natural gas pipelines and single pipe are different.A/B double lines are interacted mainly through sharing working station.When there is a leakage point in line A,the pressure of leakage point A decreases rapidly after the spill.Comparing with pipe A,the pressure and flow rate variation ranges of pipe B are smaller.When one block valve of pipe A is shut off abruptly,in pipe B,flow rate and pressure of pipe segment begin to change nearby the junction of both pipes.Based on working condition characteristics of accidents occurred in central Asia natural gas pipelines,corresponding emergency measures are put forward.In order to improve the efficiency of the pipe,according to the exit temperature’s influence on the flow rate and pressure,the location and quantity of air cooler is optimized.The results show that the outlet temperature reduced through air cooler which is conducive to improve flowing rate.The more front station added air cooler,the greater influence flow rate variation.Increasing the number of air cooler appropriately is helpful to increase the flow rate.The research has an important guiding significance for dual pipelines’accident diagnosis and urgent repair.