基于声学法测量气体分子量的初步研究

超声流量计可以实现当地声速的直接测量,声速与气体分子量存在定量关系,而分子量大小取决于气体组分。因此,可利用超声流量计实时测量得到的声速实现对天然气组分的间接核查,这对完善天然气能源计量体系具有至关重要的作用。该文分析声学法测量气体分子量的理论基础;以超声流量计为主体搭建声学法测量气体分子量的实验装置;并以氮气为实验介质,对实验装置声速测量的不确定度进行初步分析。研究结果可为声学法测量气体分子量在天然气能量计量中的应用提供理论依据和数据支撑。

Preliminary study on measurement of gas molecular mass based on acoustic method

The local sound speed can be directly measured by the ultrasonic flowmeter.There is certain relationship between sound speed and the gas molecular mass determined by its components.So,the sound speed measured by the ultrasonic meter can be used to indirectly verify natural gas components,which takes an important role in energy determination of natural gas.In this paper,the theoretical analyses were conducted on the measurement of the molecular mass with acoustic method.The experimental equipment for measuring the molecular mass with an ultrasonic flowmeter as the main body was built.The uncertainty of sound speed measurement in the experimental equipment was analyzed on the basis of the measuring results of nitrogen.The results of this paper provide theoretical basis and data support for the application of acoustic measurement of molecular mass in the natural gas energy metrology system.