基于能量守恒定律对涡轮流量计的脉动误差上限的估算  

Estimation of pulsation error limit of turbine flowmeterbased on energy conservation law

作　　者：刘可薇[1] 胡银春 张禾[1] Liu Kewei;Hu Yinchun;Zhang He(School of mechanical engineering,Southwest Petroleum University,Chengdu 610500,China)

机构地区：[1]西南石油大学机电工程学院,成都610500

出　　处：《电子测量与仪器学报》2024年第2期85-91,共7页Journal of Electronic Measurement and Instrumentation

基　　金：国家自然科学基金(52274230)项目资助。

摘　　要：在管道输运当中,非稳态流会使涡轮流量计的计量结果产生偏差。为了指导脉动流工况下的涡轮流量计选型和修正,需估算脉动工况对涡轮流量计产生的最大脉动误差。忽略流体压力和温度变化影响,基于涡轮流量计的动态特性和能量守恒定律,在一个脉动周期内计算脉动流和定常流对叶轮的做功比值,推导得出正弦脉动流误差上限公式。基于6DOF模型和UDF建立了涡轮流量计CFD仿真模型,搭建了空气流实验平台,以工作级流量标准装置作为标准表,被校表和标准表间采用内置整流器的管段相连。对比定常流下的流量值,计算各脉动工况下的误差限值。综合各脉动工况点,上限公式与CFD仿真所得脉动误差上限的最大差值为0.281%,与空气流实验所得脉动误差上限的最大差值为0.224%。经CFD仿真和空气流实验结果对比验证,脉动误差上限公式较为准确,可以直接用于脉动频率大于10 Hz的工况下误差值的估计和修正。In pipeline transportation,the measurement results of turbine flowmeter are easily deviated by unsteady flow.In order to guide the selection and correction of turbine flowmeter under pulsating flow condition,it is necessary to estimate the maximum pulsation error of turbine flowmeter under pulsation conditions.Ignoring the change of fluid pressure and temperature,based on dynamic characteristics of turbine flowmeter and conservation of energy,the upper limit formula of sinusoidal pulsating flow error is derived by calculating the work ratio of pulsating flow and steady flow to the impeller in one pulsating period.A CFD simulation model of turbine flowmeter was established based on 6DOF model and UDF.The air flow test platform is built,the working grade standard device is used as the reference,and two flowmeters are connected by a tube section with built-in rectifiers.Compared with the flow value under constant flow,the error limit under each pulsating condition is calculated.The maximum pulsation difference between the results of the formula and CFD simulation is 0.281%,and 0.224% between the results of the formula and the air flow experiments.The upper limit formula for pulsation error is proved its accuracy when compared to the results of CFD simulation and air flow experiment.The pulsation error upper limit formula is proved to be accurate,and can be directly used to estimate and correct the value under the condition that the pulsation frequency is greater than 10 Hz.

关 键 词：涡轮流量计 数学模型 CFD 正弦波脉动流 实流实验 

分 类 号：TH814[机械工程—仪器科学与技术] TB937[机械工程—精密仪器及机械]