摘要制作了一种用于测量多相流气泡参数的双探针电导探头，探索了0.1mm、0.5mm、3mm三种探针前端距离对气泡信号的影响；编写了Mp426采集卡数据采集源程序，使其能够连续采集并储存数据；将气相色谱热导池出口气体在液相中产生的气泡作为评价标准，利用排水法测量气泡的直径，并用该数据来确定探针测量系统的误差。研究结果表明：前端距离太小,产生的时间延迟太短, 难以分辨，读取时间差时容易产生误差；距离太大,2个电极得到的两段时间序列信号难以判别是否对应于同一气泡, 信号脱落率增大。3mm的前短距离测得的信号质量最好，将气泡假定为球形，探针测定的气泡直径误差为30 %，按照椭球形校正后，系统误差仅为2.25%；电导探针测试系统在气液搅拌釜搅拌时的信号噪音很大，对气泡的测量产生较大影响，主要原因为：反应釜内气泡在搅拌下的运动方式的不确定性、液体为混合物、采集卡自身的存在信号噪声。61478

毕业论文关键词：电导探针  气含率  Labview  气泡尺寸

毕业设计说明书（论文）外文摘要

Title    Dual conductivity probe fabrication and measurement     of the bubble in the agitator          

Abstract Made a double probe conductance probes which used for measuring the parameters of the multiphase flow of bubbles, and chose different probe front distance, respectively is 0.1 mm, 0.5 mm and 3 mm; And improved the source program of Beijing Shuang Nuo Mp426 acquisition card, to make the program can continuous collection and storage the data which the acquisition card collected; Drainage method is used to measure the bubble diameter making by hose of 3mm diameter, and use the data to calculate the Deviation of the probe measurement system. The research results show that a small front end distance lead to a short time delay, it can make reading time difference become difficult. Distance is too big, two time series signal of two electrodes is difficult to tell if corresponds come from the same bubble, that’s why the signal loss rate increased. When the distance is 3mm the signal quality is the best , when the bubble was treated as ball, the system error of the average diameter of bubbles which was measured by the probe was determined to be 30%, but if the diameters was corrected as these bubbles were ellipsoids, the final system error is only 2.25%, conductivity probe test systems in gas-liquid stirred tank stir the signal noise is very big, it will largely influence on bubble measurement, that’s because: bubble’s motive can be uncertainty while the reaction kettle is under stirring, liquid not pure, the signal noise coming from the acquisition card itself 

Keywords  Conductivity Probe  gas holdup  Labview  Bubble Size

目录

1  引言 1

1.1 发展现状 1

1.2  Labview简介 2

1.3  数据采集卡 3

1.3.1  数据采集卡的组成 3

1.3.2  MP426数据采集卡 3

2  实验设计 4

2.1  双电导探针的制作 5

2.2  数据采集软件编写 6

2.2.1  调用库函数 7

2.2.2  主要函数介绍 8

2.2.3  LabView中的节点与结构简单介绍 11

2.3  实验电路 16