Abstract: The accuracy of a flowmeter is influenced greatly by the flow field structure in the natural gas pipeline. The numerical simulation was introduced to study the flows in a natural gas pipeline. The flow fields in a diffusive pipeline with different rectifiers were computed as examples. The result show that the length of the irregular flow induced by the diffuser is abut 17 times of the pipe diameter. The effect of a rectifier is obvious. The length of the irregular flows with a plate rectifier is about 12 times of the pipe diameter. The length of the irregular flows induced by the diffuser with a tube rectifier is about 6 times of the pipe diameter. The conclusions will be very useful for the flowmeter selection and installation. It provides a new method for the study of improving the natural gas measurement accuracy.

Key words: Natural gas flow metering   ,    , fluid dynamics(CFD)    ,  ,  Rectifier  ,  , Numerical simulation

摘要： 天然气计量准确度受管内流场影响大。首次采用数值模拟方法,以加带扩散管的管路为例,对其在
加装不同整流器时的管内流场进行计算。计算结果表明,扩散段引起的流动不均匀区域延伸至下游17倍管径左右,
整流器作用明显,加板式整流器和管式整流器后,管内主流速度在整流器下游恢复均匀稳定的距离依次为12倍直径
和6倍直径左右。研究结论对于流量计的选择、现场安装具有指导作用,为提高天然气计量准确度的研究提供了一
种新的方法。

关键词: 天然气计量   ,   , CFD   ,   , 整流器  ,   , 数值模拟