管输天然气气质的相特性  

Investigation on phase behavior of the pipelining natural gas

作　　者：王玮[1,2] 张晓萍 李明[2] 张文伟 宫敬[2] 

机构地区：[1]中国石油天然气管道局博士后科研工作站,河北廊坊065000 [2]中国石油大学(北京)城市油气输配技术北京市重点实验室,北京102249 [3]总装备部工程设计研究总院,北京100028 [4]中国石油天然气管道局管道工程有限公司,河北廊坊065000

出　　处：《油气储运》2011年第6期423-426,392,共4页Oil & Gas Storage and Transportation

摘　　要：天然气气质对其管输相特性影响显著,相关研究可为解决管道析烃等问题提供依据。基于气-液相平衡理论,结合PR状态方程和Van der Waals混合规则,通过气-液闪蒸计算,分析了天然气中CH4～C7组分变化对其相特性的影响规律。研究表明:CH4～C3组分对天然气相特性影响不大,C4以上组分的影响相对较大;随着管输天然气中高碳数组分含量的增加,其相特性曲线明显偏移;重组分含量的少量增加,即可显著提高管输天然气的临界凝析压力和温度,影响天然气的相特性,其中C7、C8组分的影响程度明显超过C6组分,C8组分的影响程度又明显超过C6、C7组分。工程设计中仅根据C6+总量分析天然气相特性不够准确,有必要对天然气重组分特征化和拆分方法进行研究。Components of natural gas have significant influence on its phase behavior during pipeline transmission,while thorough investigation on its phase behavior will help to avoid condensation and related hazards. Based on the gas-liquid equilibrium theory and combined with PR state equation and Van der Waals mixing rules,the influence of C4-C7 components on the phase behavior is analyzed by means of gas-liquid flashing calculation. Results show that the heavier components like butane,pentane,hexane,etc. can significantly influence the phase behavior of natural gas,while the light components has less influence on it. With the increase of the heavier components,the phase behavior curve has an obvious shift. The tiny raise of heavier components will obviously enhance the critical condensation pressure and temperature of pipelined gas and influence the phase behavior of gas. Among heavier components,the influence level of C7 and C8 is higher than C6,and C8 is higher than C7 and C6,remarkably. In project design,It will be incomplete if C6+ total content is used to analyze the phase behavior of natural gas,and it is necessary to study the characterigation of heavier components for natural gas and split method.

关 键 词：输气管道 天然气 气质 相平衡 相特性 重组分 

分 类 号：TE832[石油与天然气工程—油气储运工程]