汇管对气体超声流量计计量性能的影响  

Influence of header on measurement performance of ultrasonic gas flowmeter

作　　者：陈文琳 丁昭 王海同 CHEN Wenlin;DING Zhao;WANG Haitong(Xinjiang Institute of Measurement&Testing Technology,Urumqi 830011,China;School of Quality and Technical Supervision,Hebei University,Baoding 071002,China)

机构地区：[1]新疆维吾尔自治区计量测试研究院,新疆乌鲁木齐830011 [2]河北大学质量技术监督学院,河北保定071002

出　　处：《中国测试》2021年第10期161-168,共8页China Measurement & Test

基　　金：国家重点基础研究发展计划(2017YFF0205305)。

摘　　要：为研究汇管对气体超声流量计计量性能的影响,该文基于高压音速喷嘴法空气流量标准装置,分别在安装流动调整器和无流动调整器两种条件下进行对照实验。结果显示,无流动调整器时超声流量计的测量结果为1.5%,超过其最大允许误差1.0%;而安装流动调整器后测量结果为0.5%,超声流量计在不同安装条件下测量结果相差1%。为直观呈现速度分布对超声流量计计量性能的影响,将标准装置结构简化为上下游均带有汇管的实验管路。在验证计算流体动力学方法可靠性后,分别模拟不同安装条件下实验管道内的流场,对比不同入口流速下的速度分布情况,研究汇管对速度廓线产生的影响及流量计安装位置对测量结果的影响。结果表明,相同安装位置处,入口流速越大流态畸变越严重;汇管下游管道内的速度分布随着直管段长度的增加渐趋稳定,而流动调整器对汇管引起的流态畸变有显著的调节作用。In order to study the influence of the header on the measurement performance of the ultrasonic gas flowmeter,experiments were carried out on a set of high-pressure sonic nozzles air flow standard device with and without flow conditioner.It showed that the measurement result of ultrasonic flowmeter was about 1.5%when there was no flow conditioner was installed,which exceeded its maximum permissible error 1.0%.And the measurement result was about 0.5%after the installation of the flow conditioner.The measurement results differed by 1%under different installation conditions.This paper simplified the structure of the standard device into experimental pipelines with inlet and outlet headers,in order to visually observe the velocity distribution under different conditions.After verifying the reliability,the computational fluid dynamics(CFD)method was used to simulate the flow field in the experimental pipeline.The velocity distribution was observed under different inlet flow rates with or without flow conditioner.The influence of header on velocity profile and the influence of installation position on the ultrasonic flowmeter measurement results were also studied.The results showed that the flow field distortion became more serious as the inlet velocity increased at the same location.And as the length of the straight pipe downstream the header increased,the flow field was gradually stabilized.The flow conditioner had a good adjustment effect on the flow field distortion caused by the header.

关 键 词：气体超声流量计 速度分布 流动调整器 汇管 流量标准装置 

分 类 号：TB126[理学—工程力学] TB9[理学—力学]