流场扰动对超声波燃气表计量性能的影响  

Flow field disturbance impactultrasonic gas meter measurement

作　　者：王德群[1] 林强 黄象欢 华威 陈书强 WANG Dequn;LIN Qiang;HUANG Xianghuan;HUA Wei;CHEN Shuqiang(Institute of Metrology of Hai Nan Province,Haikou 570102,China;Tancy Instrument Group Co.,Ltd,Wenzhou 325800,China)

机构地区：[1]海南省计量测试所,海南海口570102 [2]天信仪表集团有限公司,浙江温州325800

出　　处：《工业计量》2024年第6期113-117,共5页Industrial Metrology

摘　　要：测试某厂家G16超声波燃气表计量性能,大流量误差与出厂平均差异达1.62%。分析导致不合格原因,根据超声波燃气表计量原理,采用线平均流速与面平均流速两个参数进行计算,文中对管道中水平运动稳定的层流流体进行受力分析,推算出速度分布以及两者关系。同时对弯曲运动的层流流体进行分析,其速度分布不同于直管,如未考虑流场扰动优化设计,按照水平直管流场进行计算,将产生较大误差。通过将燃气表进口及出口分别加装5倍管径的直管段后再测试,大流量误差与出厂平均差异仅为0.07%,验证以上分析结论。流场扰动作为影响其计量性能的重要因素,在产品研发设计验证中需要重点关注。The measurement performance of a G16 ultrasonic gas meter from a certain manufacturer was tested,and the difference between the large flow error and the factory average was 1.62%.Analyze the reasons for the disqualification,and based on the measurement principle of ultrasonic gas meters,calculate using two parameters:line average flow rate and surface average flow rate.In this paper,the force analysis of laminar fluid with stable horizontal motion in the pipeline is carried out,and the velocity distribution and their relationship are calculated.At the same time,the analysis of laminar fluid in bending motion shows that its velocity distribution is different from that of straight pipes.If the flow field disturbance is not considered for optimization design,calculating according to the horizontal straight pipe flow field will result in significant errors.By installing straight pipe sections with a diameter of 5 times the inlet and outlet of the gas meter,and then testing,the difference between the large flow error and the factory average is only 0.07%,which verifies the above analysis conclusion.Flow field disturbance,as an important factor affecting its metrological performance,requires special attention in product development and design verification.

关 键 词：燃气表 计量性能 流场扰动 平均流速 直管流场 弯管流场 

分 类 号：TH814[机械工程—仪器科学与技术]