Analyses for energy consumption of domestic natural gas pipelines by using energy-consumption indexes

By using relevant parameters of a large-scale domestic natural gas pipeline network, data model and structural model of the pipeline network have been established to calculate volume of the circular flow, energy consumption rate, unit fuel and power cost and other indexes for performance assessment of the four natural gas pipelines within the pipeline network and to analyze changes in energy consumption within the pipeline network. Assessment results show the rational energy consumption rate of various pipelines and the major pipeline network shall be maintained below 2.5%, whereas the cost shall be lower than RMB 31×10⁸, and the unit fuel and power cost shall be RMB 200/(10⁷ m³·km). Accordingly, practical proposals for optimization have been highlighted: new hub stations shall be constructed downstream of the pipeline network to reduce energy consumption and to achieve maximum economic efficiency by using the large-diameter pipelines; natural gas pipelines can be classified into different systems with their actual physical properties. In addition, corresponding optimization programs shall be prepared individually to reduce overall energy consumption of the pipeline network; during preliminary planning of the pipeline network, general conditions and future trends of the pipeline network shall be considered jointly to preserve necessary spaces for expansion of designed transportation capacity, station location and pipeline routing. In this way, overall costs can be reduced.