多气源混输管道在线气相色谱仪安装位置的确定方法

发布时间：2018-06-23 22:20

本文选题：普光气田 + 普光首站　；参考：《天然气工业》2017年10期

【摘要】：采用在线气相色谱仪实时监测管道中天然气组分的变化是目前大型输气场站保证天然气计量准确性的关键工艺,而在线气相色谱仪抽取样品的代表性则是保证分析检测结果准确可靠的关键因素,对于多气源汇合的输气场站,不同气源天然气的混合程度直接关系到在线气相色谱仪所取样品的代表性。为此,以中石化川气东送工程的普光首站为例,按照该站的工况条件,采用FLUENT软件对多气源天然气的混合规律进行了仿真模拟,探讨了多气源天然气混合距离与温度、压力、流速等因素的关系,以及多气源天然气混合均匀的最近位置。试验结果表明:(1)含两种不同摩尔分数值组分的天然气在汇管不同位置处混合的均匀程度不同——距汇管50 m处天然气各组分混合不均匀,具明显分层现象,距汇管150 m处天然气各组分的混合开始呈现均匀状态,但仍存在分层现象,距汇管280 m处天然气各组分混合完全呈现出均匀状态,其CH_4摩尔分数为98.30%,CO_2摩尔分数为0.95%;(2)在普光首站距混合点280 m以远处的位置安装在线气相色谱仪取样较为合适;(3)对于气源体积流量或气源的体积流量差别较大、压力较高或温度较低的工况条件,在线气相色谱仪的取样点可适当靠近混合点。
[Abstract]:On-line gas chromatograph is the key process to ensure the accuracy of natural gas measurement in large gas transmission stations. On the other hand, the representativeness of sampling samples by on-line gas chromatograph is the key factor to ensure the accuracy and reliability of the analysis and detection results. The mixing degree of natural gas from different gas sources is directly related to the representativeness of the samples taken by on-line gas chromatograph. Therefore, taking Puguang first station of Sinopec Chuan Gas East Transmission Project as an example, according to the working conditions of the station, the mixing law of multi-gas source natural gas is simulated by fluent software, and the mixing distance, temperature and pressure of multi-gas source natural gas are discussed. The relationship between flow rate and other factors, as well as the nearest position of multiple gas source natural gas mixing uniformity. The experimental results show that: (1) the mixing uniformity of natural gas containing two different molar numerical components is different at different locations of the sink pipe, and the mixture of natural gas components is not uniform at 50 m away from the sink tube, and there is obvious stratification phenomenon. The mixture of each component of natural gas begins to show uniform state at 150 m from sink tube, but there still exists stratification phenomenon, and the mixture of each component of natural gas shows uniform state completely at 280 m from sink pipe. Its Ch _ 4 mole fraction is 98.30 and the CO _ 2 molar fraction is 0.95; (2) it is more appropriate to install an on-line gas chromatograph to sample at a distance of 280 m from the mixing point at Puguang first station; (3) for gas source volume flow or gas source volume flow, When the pressure is high or the temperature is low, the sampling point of on-line gas chromatograph can be close to the mixing point.
【作者单位】：中国石化天然气分公司计量研究中心;
【基金】：中国石油化工股份有限公司科研项目“中国石化天然气能量计量先导试验研究”(编号:714024)
【分类号】：O657.71;TE832.2

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