基于文丘里管的湿天然气在线计量技术研究与应用  

Research and application of on-line measurement technology of wet natural gas based on venturi tube

作　　者：施昊彤 SHI Haotong(Construction Project and Management Company,PipeChina)

机构地区：[1]国家石油天然气管网集团有限公司建设项目管理分公司

出　　处：《石油石化节能与计量》2024年第6期76-81,共6页Energy Conservation and Measurement in Petroleum & Petrochemical Industry

摘　　要：为实现湿天然气的在线不分离计量,取代现有分离器的单独计量方式,在梳理湿天然气计量模型的基础上,通过CFD技术模拟单一气相、单一液相和等量气液两相流经文丘里管压差流量计时的压力分布和速度分布,考察不同气相流量和液相流量下的静压参数,以此计算虚高系数,并通过非线性拟合得到虚高系数与气相流量、液相流量和管道内压的关系,最后通过湿气流量计现场对比测试撬完成效果验证。结果表明:单一液相的轴向压降较小,气液两相在收缩段和喉道处的压降最大,单一气相流量计的计量结果存在虚高现象;气相和液相流量越大,虚高现象越明显,虚高流量值与实际值的差异越大;在线湿气流量计的气相计量误差范围为-0.8%~6.3%,液相计量误差范围为-22.1%~-0.3%,准确度基本满足现场计量需求,具有较高的实用价值。In order to realize the online non-separation measurement of wet natural gas and replace the separate measurement method of the existing separator,on the basis of sorting out the measurement model of wet natural gas,the CFD technology is used to simulate the pressure distribution and velocity distribution of the differential pressure flowmeter flowing through the venturi tube in a single gas phase,a single liquid phase and an equal amount of gas-liquid two phases,and the static pressure parameters under different gas phase flow and liquid phase flow are investigated to calculate the virtual high coefficient.The relationship between the virtual high coefficient and gas phase flow,liquid phase flow and pipeline internal pressure is obtained by nonlinear fitting.Finally,the effect is verified by onsite comparison test of wet gas flowmeter.The results show that the axial pressure drop of single liquid phase is small,the pressure drop of gas-liquid phase at the contraction section and throat is the largest,and the measurement results of single gas phase flowmeter have the phenomenon of virtual high.The higher the flow of gas phase and liquid phase are,the more obvious the phenomenon of virtual high makes,leading to the greater the difference between the virtual high flow value and the actual value.The gas phase error range of online wet gas flowmeter is-0.8%~6.3%,and the liquid phase error range is-22.1%~-0.3%.The accuracy basically meets the needs of on-site measurement,and has high practical value.

关 键 词：湿天然气在线计量 虚高系数 CFD 文丘里管 气相流量 液相流量 

分 类 号：TE863.1[石油与天然气工程—油气储运工程]