面向机械密封试验装置的网络化测控系统

发布时间：2018-06-15 20:02

本文选题：虚拟仪器 + 远程测试　；参考：《南京林业大学》2012年硕士论文

【摘要】：机械密封广泛应用于化工、水利以及船舶等领域，其性能直接影响相关设备的安全性与可靠性。机械密封技术的发展，要求有高性能的机械密封试验装置与之相适应。本课题将虚拟仪器技术及其网络通信技术引入到机械密封性能试验装置设计中，开发了基于虚拟仪器技术的网络化机械密封性能试验装置测控系统。此系统不仅完成了对机械密封性能参数信号的采集、显示、存储与处理，还实现了远程监控与测试数据的网络共享。主要研究工作与结果如下：（1）基于机械密封性能试验的基本原理，结合虚拟仪器网络化技术及测控系统的一般组成结构，，提出了网络化机械密封性能试验测控系统的设计流程；（2）依据LabVIEW2009的开发环境特点，讨论了网络化机械密封性能测控系统的构建方案。B/S模式非常灵活，是一种“瘦客户”模式，但是在开发深层次的功能时受限于浏览器通信方式；C/S模式可以充分利用服务器与客户端的硬件资源，但是存在升级困难等缺点；（3）探讨了机械密封性能参数的测量方法与传感器输出信号的种类，完成了测控系统的硬件组装调试。选择了输出浮地信号的传感器和USB总线型采集卡，构建了一个具有强抗干扰能力的差分式测量系统；（4）完成了机械密封性能试验测控软件的开发。基于模块化设计理念，将满足用户功能要求的控制系统划分成多个子程序来实现，在完成各个子VI的编写调试工作后，再由主程序动态调用各子VI，最终实现了系统所需的信号采集、分析、显示和存储等功能；（5）对运转中的机械密封端面温度进行了探索式试验研究。采用指数拟合和多项式拟合两种方法对由热电偶测得的4路温度信号进行曲线拟合，选取误差值小的拟合函数计算出密封端面的温度。试验结果表明：一般工况下，机械密封端面温度与被密封介质的温度基本持平，同时测得的温度信号沿轴向服从多项式函数分布；而在特殊工况下，如干摩擦等工况下端面温度会骤然升高，同时测得的温度信号沿轴向服从指数函数分布；（6）通过对Web、TCP/IP和DataSocket三种技术优缺点的试验比较，最终以DataSocket技术实现了系统的网络化。Web技术无法实现测试数据的进一步处理，TCP/IP技术编程复杂，DataSocket技术不但编程简便，而且易于将读取到的数据进行深入处理。在由DataSocket技术编写的系统中，服务器程序不需直接和客户机通信，只需单独加载一个独立的DataSocket服务器，将数据发送至此服务器上，客户端就可从该服务器读取数据，从而达到远程测试的目标。
[Abstract]:Mechanical seal is widely used in chemical engineering, water conservancy and ship, and its performance directly affects the safety and reliability of related equipment. With the development of mechanical seal technology, high performance mechanical seal test device is required. In this paper, the virtual instrument technology and its network communication technology are introduced into the design of mechanical seal performance test device, and the networked mechanical seal performance test device measurement and control system based on virtual instrument technology is developed. The system not only collects, displays, stores and processes the signals of mechanical seal performance parameters, but also realizes the network sharing of remote monitoring and testing data. The main research work and results are as follows: 1) based on the basic principle of mechanical seal performance test, combined with the network technology of virtual instrument and the general structure of measurement and control system, According to the characteristics of LabVIEW2009 development environment, this paper discusses the construction scheme of networked mechanical seal performance measurement and control system. It is a "thin client" mode, but it is limited by the browser communication mode C / S mode when developing deep functions, but it has some shortcomings such as the difficulty of upgrading. The measurement method of mechanical seal performance parameters and the type of sensor output signal are discussed. The hardware assembly and debugging of the measurement and control system are completed. A differential measurement system with strong anti-interference capability is constructed by selecting the sensor and USB bus data acquisition card, and the testing and controlling software of mechanical seal performance is developed. Based on the modular design concept, the control system that meets the user's functional requirements is divided into several subprograms. After the completion of each sub-VI programming and debugging work, Finally, the functions of signal acquisition, analysis, display and storage are realized. Finally, the temperature of the end surface of the mechanical seal in operation is studied experimentally. The four channel temperature signals measured by thermocouple were fitted by exponential fitting and polynomial fitting, and the temperature of seal face was calculated by selecting the fitting function with small error. The test results show that the temperature of the mechanical seal face is basically equal to that of the sealed medium under general working conditions, and the measured temperature signals are distributed along the axial direction according to the polynomial function. For example, under dry friction and other conditions, the end surface temperature will rise suddenly, and the measured temperature signals will be distributed along the axial orientation of the exponential function. (6) by comparing the advantages and disadvantages of the three technologies, WebTCPP / IP and DataSocket, Finally, the network. Web technology of the system can not realize the further processing of test data by DataSocket technology. It is not only simple to program, but also easy to deal with the read data deeply. In the system written by DataSocket technology, the server program does not need to communicate directly with the client, only need to load a separate DataSocket server separately, send the data to the server, the client can read the data from the server. In order to achieve the goal of remote testing.
【学位授予单位】：南京林业大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TP273;TH136

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