天然气水露点与含水量的换算  

The conversion calculation method between water content and water dew point of natural gas

作　　者：李大全[1,2] 艾慕阳[2] 张鹏[1] 王玉彬[2] 苗青[2] 刘凯 

机构地区：[1]西南石油大学,四川成都610500 [2]油气管道输送安全国家工程实验室中国石油管道科技研究中心,河北廊坊065000 [3]中国石油兰州输气分公司,甘肃兰州730070

出　　处：《油气储运》2012年第3期225-227,246,共3页Oil & Gas Storage and Transportation

摘　　要：在天然气水露点与含水量的换算过程中,涉及天然气状态方程、气液相平衡、气体混合规则等多步计算,参数多且需要迭代求解,整个计算过程相当复杂。为此,提出了一种快速、准确的天然气水露点与含水量的换算方法:选用PR状态方程,并基于GB/T22634-2008提供的关联关系曲线,通过相平衡理论导出计算气、液相的逸度系数公式,最后迭代求解。给出了整个换算过程的详细计算步骤,该计算方法的适用范围可扩展至0.1MPa≤p≤30MPa,-50℃≤t≤40℃。实际算例结果表明:该换算方法在压力范围为0.1～5MPa内计算结果准确性较高,当压力超过8MPa时,计算不确定度有待进一步分析。In the conversion calculation process between the water dew point and water content of natural gas,several calculations are involved in the state equations of natural gas,gas-liquid phase equilibrium and gas mixing rules.In addition,there are many parameters are concerned and an iterative solution is required.So,the calculation is a very complex process.For these reasons,a quick and accurate calculation method for their conversion is put forward.The basic conversion process is that the PR Equation of State is used based on the incidence relation specified in GB/T 22634-2008 to calculate the fugacity coefficient about gas-liquid phase in line with the theory of phase equilibrium,and in the final,an iterative solution is used to finish the conversion calculation.Detail steps in the conversion calculation process are provided.This method is suitable for the pressure range from 0.1 MPa to 30 MPa,at-50～40 ℃.Actual calculation case shows that calculation results will be accurate if the pressure is at 0.1～5 MPa,and when the pressure is higher than 8 MPa,the uncertainty of calculation should be further analyzed.

关 键 词：天然气 水露点 含水量 换算 PR状态方程 逸度系数 相平衡 

分 类 号：TE832[石油与天然气工程—油气储运工程]