弯管对超声波流量计测量精度的影响及改善措施  

Effect of elbow on measurement accuracy of ultrasonic flowmeter and the improvement measures

作　　者：刘亚男 杨鸣[1] LIU Yanan;YANG Ming(Faculty of Electrical Engineering and Computer Science,Ningbo University,Ningbo 315211,China)

机构地区：[1]宁波大学信息科学与工程学院,浙江宁波315211

出　　处：《宁波大学学报（理工版）》2022年第3期98-105,共8页Journal of Ningbo University：Natural Science and Engineering Edition

摘　　要：流体经过弯管易产生二次流、涡流等扰流情况,使流道内流速分布不均匀,会对流量计的测量精度产生影响.为研究扰流对流量计的影响,利用建模与模拟仿真方式,对G16型号单流道流量计在入口管道为双弯管及半月双弯管情况下的计量效果展开研究,计算两种情况下相对于入口管道为直管时的流量误差度,以此表明单流道流量计在安装弯管时,扰流给测量结果带来的误差.为减小此类误差,建立G16型号双流道流量计模型,并对其进行完全相同条件下的仿真实验,最后将所得数据与单流道流量计对应数据进行对比分析.结果表明,双流道流量计相对于单流道流量计在各流量下的测量精度均有所提高.当流量为2.5 m^(3)·h^(-1)及10 m^(3)·h^(-1),入口管道为半月双弯管时,测量精度分别提高了1.0940%和1.2058%;入口管道为双弯管时,测量精度分别提高了2.1120%和2.2930%.双流道流量计相比于单流道流量计,较大程度地改善了弯管带来的扰流影响,且计量精度有效提高.When the fluid passes through the elbow of a channel,it is easy to produce secondary flow,eddy current and other complications,resulting in uneven velocity distribution in the channel.These complexities will affect the measurement accuracy of the flowmeter.In order to study the effect of turbulence on flowmeter,the measurement effect of G16 single channel flowmeter is investigated when the inlet pipe bears either double elbow or half moon double elbow by modeling and simulation.The flow error is calculated when the inlet pipe is straight pipe,so as to show the error was caused by the turbulence to the measurement result when the single channel flowmeter is installed with elbow.In order to reduce this kind of error,the model of G16 double channel flowmeter is established,and the simulation experiment is conducted under the same conditions.Finally,the obtained data are compared with the corresponding data of single channel flowmeter.The results show that the measurement accuracy of double channel flowmeter is higher than that of single channel flowmeter at each flow point.When the flow points are 2.5 m^(3)·h^(-1)and 10 m^(3)·h^(-1)and the inlet pipe is half moon double elbow,the measurement accuracy is improved by 1.0940%and 1.2058%respectively.When the inlet pipe is double elbow,the measurement accuracy is improved by 2.1120%and 2.2930%respectively.Compared with the single channel flowmeter,the double channel flowmeter greatly inhibits the disturbance caused by the elbow,and the measurement accuracy is thus significantly improved.

关 键 词：超声波流量计 弯管 单流道 双流道 模拟仿真 

分 类 号：TH814[机械工程—仪器科学与技术]