6、lueCostmethodcanalsoestimatetheeconomicsofdifferentplans.Thisthesishasaguidingeffectonconstructionofprojectoflonggastransmissionpipelines.Keywords:Longgastransmissionlines;trialcalculationmethod;Present value cost中国石油大学(华东)本科毕业设计目录第1章引言1第2章设计概述22.1设计依据22.1.1设计原则22