| As an important energy source,natural gas has the characteristics of cleanliness,convenience,and high efficiency,making people’s demand for it increase day by day.Only by properly planning the natural gas pipeline network system can the safe transportation of natural gas be ensured as much as possible.In order to optimize the natural gas pipeline network transmission and distribution system in Centeral Qiqihar,this paper established natural gas source capacity calculation,natural gas demand and storage balance equations based on the planning and supply status of natural gas in the central city.Combining the gasification rate to predict the future natural gas demand,and optimize the transmission and distribution pipeline network system,determine the gas storage peak-regulation capacity in different time periods to ensure a reasonable and effective supply of natural gas.In order to cope with the increasing demand and supply of natural gas,it is particularly important to precisely calculate the pressure loss of natural gas pipelines.Therefore,the revised calculation formula of the pressure loss of the contraction-expanding pipe and the elbow is given by the numerical simulation method.Finally,based on the predicted natural gas demand and the revised calculation method for the pressure loss of natural gas pipelines(contraction-expanding pipes,elbows),the natural gas pipeline network in the central urban area of Qiqihar is optimized for the transmission and distribution system.The research results show that,the total natural gas required in the downtown area of Qiqihar is 23974×10~4m~3 in2022,which is much smaller than the gas supply of Xushen Gas Field,which is 35×10~8m~3.There is no need to plan new gas sources in the short term.Natural gas demand will gradually increase from 2021 to 2026,and the total natural gas demand in 2026 will increase by 14.2%year-on-year compared to 2021.The revised calculation method of pressure loss of contraction-expanding pipe,expanding-contraction pipe and elbow is proposed to lay the foundation for the optimization analysis of natural gas pipeline network.When L_d<2D、L_D<3.75D and R_b≥15.5+13Q,the traditional pressure loss calculation formula is no longer applicable,so a modified formula is given.The optimization analysis of the natural gas pipeline network shows that the volume of gas storage equipment required from 2021 to 2026has also increased from 8.87×10~4 m~3 to 10.14×10~4 m~3.In order to meet the long-term gas storage demand,it is necessary to add three 5000 m~3 storage balloon tanks before 2025.The total pressure loss of the optimized natural gas pipeline network is 0.197 Mpa,which meets the design requirements. |
