齿轮流量计的理论与实验研究

发布时间：2018-03-26 05:37

本文选题：齿轮流量计　切入点：动态特性　出处：《安徽理工大学》2016年硕士论文

【摘要】：齿轮流量计,作为一种测量精度较高的容积式流量计,正被广泛地应用于重油、树脂、聚乙烯醇等较高粘度介质的流量测量中。虽然稳态流量的测量技术已经成熟,但是在测量动态流量,尤其在测量液压系统高压侧的动态流量方面一直不尽如人意,存在较大的误差。流量计的动态特性不仅会受到一次仪表的影响,二次仪表对其也存在一定的影响,本文所研究的主要内容即齿轮流量计的二次仪表。现将本文所做工作归纳如下：(1)设计了一种基于Modbus总线协议支持远程实时监控的标准化表头。调试阶段以高性价比1T单片机12C5A60S2作为控制芯片,利用单片机自带PCA模块精准测频,利用单片机自带10位AD采集流量传感器送来的电压信号,PWM模块(脉宽调制)配合接口电路模拟DA稳定输出模拟电压信号。按照IEEE754单精度浮点数标准由RS485负逻辑电平差分信号组成半双工通信网络,数据链路层基于Modbus标准协议将流量计表头所测数据传输至上位机。上位机监控系统采用亚控组态王软件编写,支持远程访问、数据超限报警、参数设定等功能。表头的制作使得后面的实验结果能够直观的显示出来。(2)改进了原有的实验台。该试验台通过PLC来控制变频器以进一步控制电机,由电机来带动齿轮旋转,最终实现模拟动态流量信号的结果。通过实验,流量计响应动态的频率被再次提高,最终可以达到16.67Hz。(3)搭建了伺服阀、流量计综合试验台。该试验台用于对齿轮流量计的动态性能进行研究,该试验台不仅能对流量计的测量精度进行标定,而且还能在有压力存在的环境下对流量计的动态特性进行测试。试验台表头显示的压力信号值与采集卡采集的信号绘制的图表数值是一致的。这说明压力信号采集系统工作稳定可靠,而且通过该试验台采集了大量宝贵的有用数据,为下一步的分析和研究提供了依据。(4)通过FLUENT软件对由三维建模软件所建立的双齿轮流量计中的齿轮进行了仿真,做出压力云图、压力矢量图以及速度云图和速度矢量图,仿真结果与实验结果一致,验证了实验的正确性。
[Abstract]:Gear Flowmeter, as a kind of volumetric Flowmeter with high measuring precision, is widely used in flow measurement of heavy oil, resin, polyvinyl alcohol and other high viscosity media. However, the measurement of the dynamic flow rate, especially the dynamic flow rate of the high pressure side of the hydraulic system, is always unsatisfactory, and there are large errors. The dynamic characteristics of the Flowmeter are not only affected by the primary meter, Secondary instruments also have a certain impact on them. The main content of this paper is the secondary instrument of gear Flowmeter. In this paper, the work done in this paper is summarized as follows: 1) A standardized head based on Modbus bus protocol to support remote real-time monitoring is designed. In the debugging stage, the price is high. Compared to 1T single chip microcomputer 12C5A60S2 as the control chip, Using single-chip microcomputer with its own PCA module accurate frequency measurement, The voltage signal and PWM module (pulse width modulation) from 10 bits AD flow sensor are collected by single chip microcomputer, and the interface circuit simulates DA to output the analog voltage signal stably. According to the IEEE754 single precision floating-point standard, the negative logic electricity is produced by RS485. The half-duplex communication network is composed of flat differential signals. The data link layer transfers the data measured by the Flowmeter head to the upper computer based on the Modbus standard protocol. Parameter setting and other functions. The manufacture of the watch head makes the experimental results of the back can be displayed intuitively. The original experimental bench is improved. The test bed controls the frequency converter through PLC to further control the motor, and the motor drives the gear rotation. Finally, the result of simulating the dynamic flow signal is realized. Through the experiment, the frequency of the Flowmeter's response dynamic is raised again, and finally the servo valve is built up, which can reach 16.67 Hz. The test bench is used to study the dynamic performance of gear Flowmeter, which can not only calibrate the measuring accuracy of Flowmeter, The dynamic characteristics of the Flowmeter can also be tested in the presence of pressure. The pressure signal displayed by the tester head is in agreement with the chart drawn by the acquisition card. This shows that the pressure signal is collected. The set system works stably and reliably. Moreover, a large number of valuable and useful data are collected through the test bed, which provides the basis for further analysis and research. The gear in the double gear Flowmeter built by the three-dimensional modeling software is simulated by FLUENT software, and the pressure cloud diagram is made. The simulation results of pressure vector, velocity cloud and velocity vector are in agreement with the experimental results, and the correctness of the experiment is verified.
【学位授予单位】：安徽理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TH814.8

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