Research On Dynamic Load Distribution Of Three Parallel Compressors In The Zhongwei-Guiyang Natural Gas Transportation Project

As human beings continue to explore the fourth generation of new energy sources,natural gas,a kind of clean and high-quality fuel,catches people's eyes,and its demand rises year by year.With the exploitation of a large number of gas fields in west China,the natural gas pipelines network is becoming increasingly large and complex,and long-distance pipeline technologies develop with a fast pace.The difficult part of a pipeline transportation project is the design,validation and control of load distribution of compressor units,the core equipments in a compressor station.Since normal operation of the compressor units exert all-round influence on production,supply,and marketing of natural gas,there is an urgent need to develop a low-efficient,safe and reliable load distribution control system according to characteristics of the process routes of gas pipeline network,and keep it operating stably under perfect planning.In the context of the Zhongwei-Guiyang natural gas transportation project,the structure and working principle of natural gas compressor units are analyzed,and the control system for the units are set up in Triconex TS3000 PLC programming environment.On the basis of relevant domestic and foreign research on the unit load distribution,dynamic programming methods are employed to carry on research and optimization of load distribution among three parallel units according to process characteristics and load distribution demand of these three units.Among differentdynamic programming method,in consideration of safety margin and mechanical efficiency of the units,equal margin load distribution is selected to realize parallel control of the three units.During control of load distribution,the coupling factor of the units'speed control and anti-surge control is considered,and a safe and reliable decoupling process and control program are put forward.Taking the advantage of TS30001131 and Intouch' s convenience in simulation,the feasibility and effectiveness of equal margin load distribution is validated in an offline simulation.In view of problems found in the simulation,the control program of the units is optimized.In the study,decoupling of dynamic load planning and and speed adjusting and anti-surge control for the units' control system is elaborated,and parallel control of units is improved in a rational and efficient manner,thus providing a new idea for further study on load distribution control for multiple units.