基于有限体积法的城市燃气管网运行分析

在大力发展燃气用户的同时，要确保燃气输配管网运行的可靠性，就需要对燃气输配管网进行工程计算。目前对燃气管网工程计算的研究多集中在天然气长输管线，而与之相比，城市燃气管网结构更复杂、计算数据量更庞大。为此，建立了采用有限体积法对管网模拟方程组进行求解的燃气管网分析系统，并据此对某次高压管线进行了动态工程计算，各站点压力的计算结果与实际监控信息平均相对误差为0.02%～4.13%（与采用美国SPS软件验证计算结果基本一致）；采用燃气管网分析系统还对某城市中压管网进行了稳态工程计算，得到管网压力最低点及“瓶颈”管段，这将有助于管网改造与运行方案的制订；同时结合运营经验、监控信息对计算结果进行了综合分析。结论认为：①如果对城市燃气输配管网进行动态模拟，必须研究各燃气用户的用气规律，找出不同工况下燃气用户的小时流量估算方法；②监控点信息值选取城市全年最大小时流量发生日对应的时段值，并结合日常运营工作的经验判断计算结果的合理性。

Operation analysis of city gas pipelines by the finite volume method

Engineering calculation is extremely necessary for urban gas operators to guarantee the reliability of transmission and distribution networks meanwhile attracting more and more gas users. However, such related studies at present mostly focus on the long distance gas pipelines; but by comparison, the urban gas pipelines are much more complicated and huger data will have to be involved in the engineering calculation. In view of this, an analytical system was established, in which the finite volume method was adopted to obtain the solutions of pipeline network simulation equations. Then, this analytical system was applied to the dynamic engineering calculation of a high pressure pipeline; as a result, the average relative deviation between the calculated results and actual monitoring data was 0.02%~ 4.13%, which shows a good coincidence with those validated by use of the Stoner Pipeline Simulator(SPS) software. In another case study of medium pressure urban gas pipe network in a city, the static engineering calculation was made to obtain the lowest pressure points and bottlenecking pipes, which will help engineers to scheme on modification and operation of the whole line network. But on the other hand, if dynamic engineering calculation is really done for a city's gas pipeline network, the gas consuming regularity should be further investigated of different types of gas users, and the estimating method should be found out for the instantaneous hourly flow rate of gas users under different working conditions. Whether the calculated results from this analytical system are rational or not will also rely on operators' working experience and refer to the monitored data, i.e. the corresponding time interval at the maximum hourly flow rate yearly in this city.