基于LabVIEW的轴封泵动态性能试验控制系统设计

发布时间：2018-04-08 20:39

本文选题：轴封泵　切入点：动态性能　出处：《沈阳工业大学》2017年硕士论文

【摘要】：泵动态性能测试技术对于泵基础理论的研究和发展、性能的改进与其设计方法的完善都显得尤为重要,泵性能试验系统的设计研究已经成为工业泵类行业的焦点之一。目前,我国自主研发的泵性能试验系统还存在精度低、实时性差和可靠性低的问题,很多还是传统的半自动化形式,与国外相比,技术水平相对落后。本文首先介绍了核电行业轴封泵动态特性系统的需求问题,以及泵动态性能参数检测技术的现有科研成果。轴封泵原理及试验部分着重分析了泵性能试验、汽蚀实验的原理,总结了扬程、流量、轴功率等的测试原理与方法。系统采用将PID控制和模糊控制相结合的方法,构建一种模糊PID算法,应用在流量控制系统中。泵性能参数检测系统的整体结构基于虚拟仪器平台,构建了能够满足实际试验需求的轴封泵动态性能试验系统。其中硬件结构方面使用NI 9188XT系列数据微处理系统,其内置信号调理电路,由传感器输出的信号经过信号调理电路,进入NI 9000系列数据采集卡,最终导入工控机,进行数据的采集和处理。试验系统的软件部分设计了LabVIEW程序主面板程序、数据采集、试验数据统计等子程序。采用数字滤波法来提高泵性能参数的检测精度、采集稳定性和可靠性。因系统采集的信号离散化较高,故采用基于最小二乘法的分段三次曲线拟合方法实现,得到动态特性图。针对流量控制环节具有的非线性、时变性与不定性等控制难点,轴封泵试验系统采用模糊PID流量控制子程序,针对轴封泵变工况条件下的流量进行实时监测与控制。试验系统整体能够完成实时在线监测与显示轴封泵回路参数、变工况条件下的参数设定和流量控制、试验动态曲线生成和试验数据存储与调用等功能。系统采样速率初值设定为1000次每秒,测试精度达到0.1%的技术需求。经Matlab仿真试验结果表明,轴封泵试验系统的流量控制具有超调量小、稳定性好、响应速度快的特点。
[Abstract]:The testing technology of pump dynamic performance is very important for the research and development of pump basic theory, the improvement of performance and the perfection of design method. The design and research of pump performance test system has become one of the focuses of industrial pump industry.At present, the self-developed pump performance test system in China still has the problems of low precision, poor real-time and low reliability. Many of them are still traditional semi-automation, compared with foreign countries, the technical level is relatively backward.This paper first introduces the demand of shaft seal pump dynamic characteristic system in nuclear power industry, and the existing scientific research results of pump dynamic performance parameter detection technology.The principle and test part of shaft seal pump mainly analyzes the principle of pump performance test and cavitation test, and summarizes the measuring principle and method of head, flow rate and shaft power etc.By combining PID control with fuzzy control, a fuzzy PID algorithm is constructed and applied to the flow control system.Based on the virtual instrument platform, the whole structure of the pump performance testing system is constructed, which can meet the needs of the actual testing of the dynamic performance of the shaft seal pump test system.In the aspect of hardware structure, NI 9188XT series data microprocessing system is used, which has built-in signal conditioning circuit. The signal output by sensor goes through signal conditioning circuit, enters NI 9000 series data acquisition card, and finally imports into industrial control computer.Collect and process data.In the software part of the test system, the main panel program of LabVIEW program, data acquisition, test data statistics and other subprograms are designed.The digital filtering method is used to improve the measuring accuracy, sampling stability and reliability of pump performance parameters.Because of the high discretization of the signals collected by the system, the piecewise cubic curve fitting method based on the least square method is used to obtain the dynamic characteristic map.In view of the nonlinear, time-varying and uncertain control difficulties in flow control, fuzzy PID flow control subroutine is used in the shaft seal pump test system, and the flow rate is monitored and controlled in real time under the condition of variable working conditions of the axial seal pump.The whole system can monitor and display the parameters of shaft seal pump loop in real time, set parameters and flow control under variable working conditions, generate test dynamic curves, store and transfer test data, and so on.The initial sampling rate of the system is set at 1000 times per second, and the testing accuracy is 0.1%.The Matlab simulation results show that the flow control system of the shaft seal pump test system has the characteristics of small overshoot, good stability and fast response speed.
【学位授予单位】：沈阳工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TP273;TM623.4

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