The Development And Application Of In-service Medium-pressure Gas Network Simulation Softwares

With the rapid development of the applications of natural gas,the scale of the construction of natural gas pipe network in China is growing more and more huge and complex.Only when the gas pipe network simulation technology is used,can the planning and design requirements of the modern gas pipe network be more efficient and the operation management requirements be more flexible.The study objective of this paper is the city medium-pressure gas distribution system.And the aim is establishing the gas pipe network model which starts with urban gas source station such as urban gate station and gas regulator station,and ends up with industrial gas regulator facilities and community gas regulator facilities such as regulator cabinet and building regulator box,and then developing a medium-pressure gas network simulation software.The simulation of the medium-pressure gas network in-service is carried out by applying the monitoring data of SCADA system as the gas supply outlet point pressure,and together with asymmetrical coefficient and at the base of the business data and meter reading data to get the node flow of gas consumption node.The gas network of Nanning city is taken as the example.In this paper,the automatic data to node flow converting processing program of customer service system which can easily convert one hundred and thirty-five thousand gas meter reading data of mechanical membrane type gas meter and five hundred and fifty-six thousand IC card charge data of Nanning City Gas Development Co.,Ltd.to three thousand,five hundred and fifty gas consumption data was developed by VBA language.Based on node equation method,the medium-pressure gas network simulation software named Gasnet was developed by C# language.With Object ARX for development tools,the automatic processing of CAD gas network diagram which is used to extract the initial hydraulic calculation data from CAD gas network diagram automatically and draw the simulation results in gas network automatically was developed.With the use of the automatic data to node flow converting processing program of customer service system and the automatic processing of CAD gas network diagram,the Gasnet can not only be used to simulate medium-pressure gas network during planning and design phase,but also to simulate the in-service medium-pressure gas network during the operation process.In this paper,the main medium-pressure gas network of Nanning city in 2013 was simulated by Gasnet.Compared with the foreign famous commercial gas network simulation software WinFlow,the relative error of simulation results were within ±5%.It shows that the simulation accuracy of Gasnet can meet the engineering requirements.However,when the Gasnet was used to simulate the total in-service medium-pressure gas network of Nanning city which includes 6,302 nodes and 6,347 gas pipes,perhaps because of the large amount of calculation,the Gasnet failed to obtain the simulation results even it runs 168 hours.Finally,according to the monitoring gas supply data of SCADA system,the month,day and hour asymmetrical coefficients of Nanning city was calculated.Combined with the asymmetrical coefficient and the use of the automatic data to node flow converting processing program of customer service system,the operation situation of the total in-service medium-pressure gas network of Nanning city at 19:00 on December 18 th,2015 was simulated by WinFlow.The simulation results obtained in five seconds showed that the pressure of 7-1 canteen in acacia lake campus of Guangxi University Of Finance and Economics was 0.182 MPa.Although it was the lowest pressure node of the total in-service medium-pressure gas network of Nanning city,itwas still in the normal range of medium-pressure.Therefore,the current gas supply demand of Nanning city can be satisfied by the in-service medium-pressure gas network.