非接触式超声波流量计收发电路的设计与性能分析  

Design and performance analysis of transceiver circuit of non-contact ultrasonic flowmeter

作　　者：贾惠芹[1] 王成 云张铁煜 白永鑫 Jia Huiqin;Wang Chengyun;Zhang Tieyu;Bai Yongxin(School of Electronic Engineering,Xi’an Shiyou University,Xi’an 710076,China)

机构地区：[1]西安石油大学电子工程学院,西安710076

出　　处：《电子测量与仪器学报》2020年第9期123-132,共10页Journal of Electronic Measurement and Instrumentation

基　　金：陕西省自然科学基础研究计划项目(2019JZ-37)资助。

摘　　要：增大信噪比是提高非接触式超声波流量计测量精度的有效措施。但通过提高发射电压来增大信噪比,会损坏超声波传感器与接收电路,也会加剧收发电路的相互干扰。设计了一种针对复合管道流量测量用的超声波收发电路:在发射电路中以中轴变压器替代阻尼电阻,在接收电路中采用限幅桥电路来保护接收电路,并基于匹配电阻法来平衡收发电路。实验结果表明,设计的发射电路能够提高发射电压、减小放电时间,空载时对输出电压可放大13.85倍,带载时对输出电压可放大4.5倍,同时,接收电路能够有效抑制收发电路的相互干扰,并提高接收支路功率,接收电路对5 V以下信号的传输效率超过了90%。把该电路应该到非接触式超声波流量计中,对难于穿透的复合管道中的流体进行多次重复测量,测试结果表明,该流量计的线性度和重复性都满足实际流量测量要求。The increase of signal-to-noise ratio(SNR)is an effective measure to improve the measurement accuracy of an ultrasonic flowmeter.However,the increase of transmission voltage for higher SNR could damage the ultrasonic sensor and the receiving circuit;it also introduces higher mutual interference between the transmitting and receiving circuits.Proposing an ultrasonic transceiver design for flow measurement of composite pipes:In the transmission circuit,a central-axis transformer instead of a damping resistor is used.In the receiving circuits,a limiting bridge circuit is employed for protection.The experimental results showed that the optimized transmission circuit proposed in this paper could increase the transmission voltage and reduce the discharge time.The output voltage is amplified by 13.85 and 4.5 times without and with loads,respectively.At the same time,the receiving circuit can effectively suppress the mutual interference and improves the power of the receiving branch.The transmission efficiency of the receiving circuits for signals below 5 V exceeds 90%.The circuit design was applied to a non-contact ultrasonic flowmeter,and the fluid in the composite pipeline was measured.The test results showed that the linearity and repeatability of the flowmeter had met the actual requirements of the flow measurement.

关 键 词：超声波流量计 大管径 发射电路 接收电路 中轴变压器 限幅桥 干扰 

分 类 号：TH814[机械工程—仪器科学与技术]