【作者】 刘燕；

【导师】 马一太；

【作者基本信息】 天津大学 ， 工程热物理， 2004， 博士

【摘要】 本文研究目的是解决目前燃气管网水力计算中存在的诸如输入数据繁琐、计算精度不高、缺乏符合实际燃气管网工况的稳定流及不稳定流管网水力计算方法等问题,试图根据热力学基本理论建立燃气在管道中传热过程数学模型,给出较为精确的长输管线及城市高压管网储气量的计算方法,并将研究成果应用于实际管网运行中。其主要研究内容与成果可归纳如下:1. 对燃气管网拓扑结构的关联矩阵 A 和环路矩阵 B 的计算机形成方法进行了详细分析,提出了关联矩阵 A 和环路矩阵 B 的最优组合方法,从而有效地解决管网计算初始数据输入繁琐、容易出错等问题。2. 对多种实际气体物性参数状态方程的计算方法进行了研究,运用这些方程计算了某些典型物质的热力学性质,并与实验数据进行比较,得出 SHBWR 方程在计算天然气等烃类物质物性时具有很高精度,可满足计算高压天然气热力状态的结论。并首次用于北京外环管网计算中,结果表明采用本文的方法使管道压降特征值的计算精度提高约 10%。3. 用图论与数学分析的方法,建立了稳定流燃气管网水力计算的数学模型,提出了用插值法解决燃气管网计算中不收敛问题。增加了开环能量方程从而避免了定压多气源管网存在虚平衡现象。在管网计算时考虑压缩机运行的压力流量特性曲线,并已将此方法用于了现北京煤气管网实际调度中。4. 根据热力学原理研究了输气管线因压降存在产生的焦耳-汤姆逊效应造成的天然气温度变化,提出了焦耳-汤姆逊系数的近似计算方法,对输气管路天然气与土壤的换热问题进行了全面的分析,并推导出了相关计算模型。5. 建立了天然气不稳定流动的数学模型,并利用傅立叶积分变换和有限差分法对数学模型求解。找出了储气量与供气负荷函数吻合的动态不稳定流计算模型,并分别用解析法和数值法进行了求解。更多还原

【Abstract】 To solve the problems in present hydraulic calculations of gas pipe networksuch as numerous data-inputting, unprecise output and a lack of hydraulic calculationmethods to keep consistent with steady flow and non-steady flow in real workingconditions of gas pipe network, in the paper the author has set up a mathematicalmodel of heat transfer process of gas in pipes on the basis of thermodynamic basictheories and obtained more accurate calculation methods of gas storage quantity inlong conveying pipes and urban pipe network of high pressure. This research achievement has been applied to real pipe network. Maincontents and results of the study are generalized as following:1. A computerized method of associated matrix A and loop matrix B in topologicalstructure of gas pipe network is fully analyzed, furthermore, the optimal combinationmethod of associated matrix A and loop matrix B is proposed. All these help to solvethe problem of numerous and fallible data inputting and the like efficiently.2. The calculation method of physical property parameter state equations of manyreal gases has been studied for its application in some typical substances. Thetheoretical results are compared with experimental data to reach a conclusion thatSHBWR equations can get higher precision in physical property calculations ofhydrocarbon compound and meet the needs of thermodynamic state calculations ofnatural gas of high pressure. The method in this paper has been applied in pipenetwork calculations of Beijing outer hoop. The results indicate that the calculatedprecision of characteristic number in pipe pressure drop has been increased by about10%.3. With graph theory and mathematical analysis used, a mathematical model ofsteady flow hydraulic calculation of gas pipe network is set up and the solution that aninterpolation method is used in the divergence problem of gas pipe networkcalculation is put forward. More open loop energy equations help to avoid virtualbalance phenomena in polygenetic gas pipe network of certain pressure. In calculation,performance curves of working pressure and flux in the compressor has beenconsidered. This approach has been put into practice in dispatching of Beijing coalgas pipe network4. On the basis of thermodynamic theory, variation of natural gas temperaturecaused by Joule-Tomson effect following the pressure drop in conveying pipelines hasbeen explored to find out an approximate calculation method of Joule-Tomsoncoefficient. Heat transfer between natural gas in pipes and soil has been fully analyzedwith derivation of concerning calculation models.5. A mathematical model of non-steady flow of natural gas is set up and solved withthe help of Flourier integral transformation and finite difference. The dynamicnon-steady flow calculation model of gas storage quantity which tallies with the gassupply load function has been found out and settled with analysis and numericalmethods respectively. The theoretical calculation results of Beijing outer hoop areconsistent with its real performance.更多还原