【作者】 罗成；

【导师】 廖平；

【作者基本信息】 中南大学 ， 机械电子工程， 2025， 硕士

【摘要】 目前市面上常见的管道流体流速检测装置大部分采用管段式安装方式,在测量过程中会干扰流体原有的流体状态,同时安装、检修不便,无法适应快速测量的应用场景。通过采用超声波方法测量管道流体流速,采用外夹式安装,可简单便捷地实现管道内流体流速检测。本文针对超声波管道流体流速检测方法进行研究,选择时差法作为流体流速测量方法,设计小型的、可实时显示数据的超声波流体流速检测装置。经过实验验证,该超声波管道流体流速检测装置能够精准的测量出管道内流体流速大小。本文的主要研究内容有以下几个方面:(1)分析比较了几种常见流量检测装置测量原理,初步决定本文测量方法和设计参数大小;对超声波时差法原理进行具体分析,结合流体流动状态分析得到修正后的流速计算公式;通过对超声波传播特性与换能器原理进行分析,选取合适的超声波基本参数,完成换能器的型号选择。(2)使用COMSOL软件对超声波管道流体流速检测装置进行仿真分析,分别对三维模型下超声波顺逆流传播声压图、二维模型下各种参数变化对超声波传播的影响进行分析,通过比较声压分布图和超声波信号接收图,对超声波传播过程中发生的声压、波形变化进行分析,验证时差法基本原理以及为超声波参数选择提供参考。(3)针对超声波管道流体流速检测的设计难点与实际设计要求,完成了超声波流体流速检测的软硬件设计,实现了对超声波回波信号的调理、传播时间的准确测量和上位机通信等功能。通过采用阈值法结合高精度时间测量芯片完成超声波传播时间的测量;采用可调运放放大与峰值检测控制经调理后接收信号的最高幅值范围,并结合卡尔曼滤波方法处理测量数据,减少时间测量过程中跳波现象的误差,提升测量精度;采用物联网通信实现对流速数据的实时测量,为后续可能的智能控制提供方案设计。(4)在实验室条件下,搭建实验平台,对硬件设计中主要功能模块进行实验测试,对整体系统进行流速测量实验,采用市面上标准流量计进行测量结果比较,验证设计整体系统的可行性和测量结果的准确性。图72幅,表10个,参考文献84篇更多还原

【Abstract】 At present,most of the common pipeline fluid velocity detection devices in the market are installed in the form of pipe sections,which will interfere with the original fluid state of the fluid during the measurement process,and at the same time,it is inconvenient to install and repair,which can not adapt to the application scene of rapid measurement.By using ultrasonic method to measure the fluid velocity in the pipeline and adopting external clamp installation,the fluid velocity detection in the pipeline can be realized simply and conveniently.In this thesis,the detection method of ultrasonic pipeline fluid velocity is studied,and the time difference method is selected as the measurement method of fluid velocity,and a small ultrasonic fluid velocity detection device which can display data in real time is designed.The experimental results show that the ultrasonic pipeline fluid velocity detection device can accurately measure the fluid velocity in the pipeline.The main research contents of this thesis are as follows:(1)The measurement principles of several common flow detection devices are analyzed and compared,and the measurement methods and design parameters of this thesis are preliminarily determined;The principle of ultrasonic time difference method is analyzed in detail,and the modified velocity calculation formula is obtained by combining with the analysis of fluid flow state.By analyzing the propagation characteristics of ultrasonic wave and the principle of transducer,the appropriate basic parameters of ultrasonic wave are selected to complete the model selection of transducer.(2)Using COMSOL software to simulate and analyze the ultrasonic pipeline fluid velocity detection device,respectively analyzing the sound pressure diagram of ultrasonic wave propagation in three-dimensional model and the influence of various parameter changes in two-dimensional model on ultrasonic wave propagation.By comparing the sound pressure distribution diagram with the ultrasonic signal receiving diagram,analyzing the sound pressure and waveform changes during ultrasonic wave propagation,verifying the basic principle of time difference method and providing reference for ultrasonic parameter selection.(3)According to the design difficulties and actual design requirements of ultrasonic pipeline fluid velocity detection,the software and hardware design of ultrasonic fluid velocity detection are completed,and the functions of ultrasonic echo signal conditioning,accurate measurement of propagation time and communication with upper computer are realized.The measurement of ultrasonic propagation time is completed by using threshold method combined with high-precision time measuring chip;Adjustable operational amplifier amplification and peak detection are used to control the highest amplitude range of the conditioned received signal,and Kalman filtering method is combined to process the measured data,so as to reduce the error of wave skipping in the time measurement process and improve the measurement accuracy.Real-time measurement of flow velocity data is realized by using Internet of Things communication,which provides scheme design for possible intelligent control in the future.(4)Under the laboratory conditions,an experimental platform is built to test the main functional modules in hardware design,and the whole system is tested for velocity measurement.The measurement results are compared with the standard flowmeter in the market to verify the feasibility of designing the whole system and the accuracy of the measurement results.更多还原