【作者】 李勇；

【导师】 焦圣喜；

【作者基本信息】 东北电力大学 ， 控制科学与工程， 2017， 硕士

【摘要】 流量检测在工业生产、科学实验以及经济核算中占有重要地位,是能源计量的重要组成部分。目前,大管径管道流量检测非常广泛,然而大多数流量计的安装需要截断管道,很多时候对工业生产造成不便。传统的插入式光纤流量计不仅可以实现不断管拆装,方便大管径管道的流量检测,还具有适用性强、抗干扰能力强等优点。但是,传统的设计将光纤探头置于管道内部,光纤检测对被测流体的清洁度要求较高,存在被测流体性质影响流量检测精度的问题。本文设计了一种插入式垂直轴涡轮光纤流量传感检测系统,改进了涡轮机构和反射式强度调制型光纤传感器(RIM-FOS),将光信号检测单元设计在管道上方,避免了光信号与流体的直接接触,解决了传统的插入式光纤流量计检测精度受流体清洁程度影响的问题。首先,本文通过UG软件建立管道及涡轮机构的三维模型,并设计了两种垂直轴涡轮。将两种模型导入ANSYS进行流体仿真,对比两种涡轮的仿真结果,根据仿真结果确定了一种更优化的涡轮机构,同时得到涡轮仿真系数k。通过CAXA软件绘制涡轮机构的工程图纸并进行实体加工。其次,通过MATLAB对RIM-FOS的光强调制函数仿真,得到光纤的实际参数参考值。采用光纤放大器作为RIM-FOS的光源装置及探测器,同轴光纤作为光纤探头。光信号由光纤放大器的光源装置发出经轮轴端面反射后由光纤放大器中的探测器接收,接收的光信号经光电转换后由ARM的A/D转换模块采集电压信号。再次,电压信号经处理后由RS232串口发往上位机PC,由上位机监控平台显示电压与转速、流速与流量等曲线或参数。最后,搭建实验台,验证流量检测系统的可行性。实验结果证明,本系统涡轮机构设计合理,涡轮旋转均匀稳定,可测量0.122~1.203m/s流速的流体流量。反射光纤检测转速精度较高,最高可识别336.13r/min的转速。同时能够在上位机实时显示结果曲线,有良好的稳定性。结论部分对本系统的优势、缺点以及未来的改进方向做了分析说明。更多还原

【Abstract】 Flow detection plays an important role in industrial production,scientific experiment and economic accounting and it is an important part of energy measurement.At present,large diameter pipe flow detection is very extensive but most of the flow meter installation need to cut off the pipeline,which often cause inconvenience to industrial production.The traditional plug-in fiber flowmeter can not only realize the disassemblywithout cutting off the pipeline and facilitate the detection of large diameter flow but also has the advantages of good applicability and strong anti-interference ability.However of the fiber optic probe is placed inside the pipeline in the traditional design,the measured fluid cleanliness requirements are higherbased on fiber detection,which brings about a problem that the flow detection accuracyis affectedby properties of measured fluid.In this paper a plug-in vertical axis turbine fiber flow sensing detection system is designed,which improves the turbo mechanism and the reflective intensity modulation fiber optic sensor(RIM-FOS).The optical signal detection unit is designed above the pipeline to avoid the optical signal coming into contact with the direct fluid and solve theproblems thatthe detection accuracy of traditional plug-in fiber flow meter is influenced by the degree of fluid cleaning.Firstly the three-dimensional model of pipeline and turbine mechanism is established by UG software and two kinds of vertical axis turbines are designed.The two models are imported into ANSYS for fluid simulation and the simulation results of the two turbines are compared.A more optimized turbine mechanism is elected according to the simulation results,the turbine simulation coefficient k is obtained at the same time.Then the engineering drawings of the turbine are drawn by CAXA software to manufactureentities.Secondly the optical intensity modulation function of RIM-FOS is simulated by MATLAB and the actual parameter reference value of the fiber is obtained.Fiber amplifier is used as light source equipment and detectorof RIM-FOS and coaxial fiber as the probe.The optical signal is transmitted by the optical fiber amplifier and then received by the detector after reflected by the head face of the axle.The received optical signal is converted by the A/D converter module of ARM to collect the voltage signal.Thirdly the voltage signal is sent to the host computer program through the RS232 serial port and voltage and speed flow rate and flow curves or parameters are displayed by the host computer monitoring platform.Finally an experiment is built to verify the feasibility of the flow detection system.The experimental results show that the design of the turbine is reasonable and turbine has a uniform and stable rotation,which can measure the flow rate from 0.122m/s to 1.203m/s.The detection accuracy of rotate speed through reflected optical fiber is high,which can detect the maximum rotate speed of 336.13r/min.At the same time the results of real-time curve can be displayedin the host computer with good stability.In the end,the advantages disadvantages and future improvement of the system are analyzedin the conclusion part.更多还原