基于运行仿真的多气源环状管网能量计量方法研究

目的 天然气能量计量的对象是其完全燃烧后产生的总热量，通常采用体积计量值与体积发热量相乘的方法确定天然气的能量值，而体积发热量取决于天然气的组成，即天然气中各组分的摩尔分数。多气源管网中天然气的组成通常随空间位置和时间变化，故管网的每个计量站都需要确定不同时刻输入或输出本站的天然气的体积发热量。国内长输管道的A级计量站均配置了在线气相色谱仪，可以分析天然气发热量，B级和C级计量站可使用仿真方法为天然气发热量赋值，从而降低配置气相色谱仪的投资与运行维护费用。方法 依据面向能量计量的管网仿真理论基础，针对某多气源环状管网，分别使用TGNET和SPS仿真软件建立了具有天然气组分跟踪与发热量计算功能的运行仿真模型。为提高仿真结果准确性，基于历史运行数据校准了仿真模型的管段输气效率这一关键参数。结果 分别应用TGNET和SPS模型对该管网持续48 h的历史运行过程进行了动态仿真，TGNET模型的发热量仿真结果与历史记录值的偏差在0.3%以内。结论 基于运行仿真的多气源环状管网能量计量是一种可行的方法，研究成果为国内天然气能量计量的实施和推广提供了一种可操作的方法。

Energy measurement method of annular pipeline network with multi-gas sources based on operation simulation

ObjectiveThe object of natural gas energy measurement is the total heat quantity generated after complete combustion. The energy value of natural gas is usually determined by multiplying the measured value of volume by the volume calorific value, and the volume calorific value depends on the composition of natural gas, that is, the mole fraction of each component in natural gas. The composition of natural gas in multi-gas source pipeline network usually changes with space position and time, thus each metering station of the pipeline network needs to determine the volume calorific value of natural gas input or output from the station at different times. Class A metering stations of long-distance pipelines in China are equipped with on-line gas chromatograph to analysis the calorific value of natural gas, while class B and class C metering stations can use simulation method to assign value to the calorific value of natural gas, so as to reduce the investment, operation and maintenance cost of configuring gas chromatograph. Methods Based on the theoretical basis of pipeline network simulation for energy measurement, aiming at a multi-gas source annular pipeline network, this paper establishes the operation simulation model with the functions of natural gas component tracking and calorific value calculation by using TGNET and SPS simulation software. In order to improve the accuracy of simulation results, the gas transmission efficiency of pipe section,a key parameter in the simulation model, is calibrated based on historical operation data. ResultsTGNET and SPS models are respectively used to dynamically simulate the historical operation process of the pipeline network for 48 hours. The deviation between the calorific value simulation result of TGNET model and the historical value is within 0.3%. ConclusionsThe energy measurement of multi-gas source annular pipeline network based on operation simulation is a feasible method. The research results provide an operable method for the implementation and popularization of natural gas energy measurement in China.