Study On Reliability Analysis And Standby Scheme Optimization For Gas Pipeline Compressor System

With the development of natural gas pipeline,the study of its reliability is deeper and deeper.But most of the studies focus on the reliability of pipeline itself and equipment in station.Compressor is the source of power and most important part in pipeline system.What's more,it is different from other equipment.All compressors relate to each other and form a system which affects pipeline's running status.So the study of compressor system reliability offers great significance to the study of pipeline system reliability.Setting up standby units is an effective method to enhance the reliability of compressor system.But at present,most standby schemes are designed based on qualitative analysis and experience.A quantitative method is very necessary to guide standby scheme designing.The characteristic of natural gas pipeline compressor system is that the number of units is large and the running status is complicated.So Monte Carlo simulation is a suitable method to analyze its reliability.Assessment model is established based on single machine shut down probability.Random numbers on the interval of [0,1] are used to represent the units' operation conditions.Sampling method is used to select status.Improved importance sampling method is used to sample which improves sampling efficiency and calculation precision of Monte Carlo simulation effectively.The reliability index is flow loss.Steady-state model is established to calculate flow rate.In order to improve the computational efficiency,effective compressor combination and redundancy compressor combination are used.So the schemes which can't meet the requirement can be removed timely.Standby scheme optimization method for gas pipeline compressor system based on reliability is proposed.Standby scheme is designed by means of compressor system reliability analysis.With this method the reliability of pipeline can be promoted while the number of standby units can be reduced.What's more,the standby scheme has quantitative evaluation basis.A computer program is compiled.It is easy to get a standby scheme with this program by inputting basic parameters of pipeline and reliability index only.Take xinyuezhe pipeline as an example to validate the feasibility of the method.The number of standby units in new scheme is 7 less than it is in the original scheme.Pipeline reliability reaches as high as 96.86%.The feasibility of new scheme is validated using SPS software.The results show that new standby scheme can ensure the reliability of flow rate and stationarity of pressure under fault conditions.Therefore it is proved that compressor system reliability analysis method is correct and standby scheme optimization program is feasible.