基于模糊控制的离心压缩机防喘振控制方案的研究与仿真

发布时间：2018-02-06 04:14

本文关键词： 离心压缩机防喘振模糊控制 MATLAB仿真　出处：《哈尔滨工业大学》2012年硕士论文　论文类型：学位论文

【摘要】：离心压缩机是在石油、化工、冶金等行业中被广泛采用的流体升压输送机械，在工业生产中有着重要的地位。喘振是离心压缩机工作在小流量状态时的一种不稳定流动特性，一旦喘振现象发生，轻则压缩机会被迫停机，重则就会损坏叶片导致整台压缩机报废。因此，防喘振控制的研究对离心压缩机运行的效率及安全性有着重要的意义。目前最常使用的防喘振措施是采用固定极限流量法或可变极限流量法，对压缩机进行PI或PID防喘振控制。但是，固定极限流量法会降低压缩机的效率，造成能量的损失；可变极限流量法比较复杂，稳定性较差；而且PID控制参数的整定十分复杂麻烦，存在不确定性。所以目前的防喘振控制还存在着很大的问题需要改进。本文针对离心压缩机防喘振控制存在的问题，主要做了以下的工作。首先，通过对喘振特性的分析，利用相似换算原理得到了离心压缩机的喘振线，为防喘振方案设计做好准备；其次，提出了“分段”控制的方案，该方案的防喘振控制线为一条折线，只需要对若干个转速的喘振点进行计算，，而且算法简单，易于实现，适用范围大，能够有效的避免固定极限流量法和可变极限流量法的缺陷，平衡了离心压缩机的运行效率和稳定性之间的矛盾。然后，采用模糊控制，设计了离心压缩机防喘振模糊控制系统，并利用MATLAB对其进行了仿真，结果表明，该系统能够根据压缩机不同的入口流量及转速及时的调节防喘振控制阀的开度，有效地避免了压缩机喘振工况的发生，并且在取得了良好的控制品质的同时具有一定的节能效果。
[Abstract]:Centrifugal compressor is widely used in petroleum, chemical, metallurgy and other industries. Surge is an unstable flow characteristic of centrifugal compressor working in small flow state. Once surge occurs, the compressor will be forced to stop. Therefore, the study of anti-surge control is of great significance to the efficiency and safety of centrifugal compressor. At present, the most commonly used anti-surge measures are to use the fixed limit flow method or variable limit flow method to control the compressor by Pi or PID. However, the fixed limit flow method will reduce the efficiency of the compressor. Loss of energy; Variable limit flow method is more complex and less stable. Moreover, the tuning of PID control parameters is very complicated and uncertain, so there are still many problems in anti-surge control. Aiming at the problem of anti-surge control of centrifugal compressor, the following work has been done in this paper. Firstly, by analyzing the characteristics of surge, the surge line of centrifugal compressor is obtained by using the principle of similarity conversion, so as to prepare for the design of anti-surge scheme. Secondly, a "piecewise" control scheme is proposed. The anti-surge control line of the scheme is a broken line, which only needs to calculate the surge points of several rotational speeds. Moreover, the algorithm is simple, easy to realize and has a wide range of application. It can effectively avoid the defects of fixed limit flow method and variable limit flow method, and balance the contradiction between operation efficiency and stability of centrifugal compressor. Then, using fuzzy control, the anti-surge fuzzy control system of centrifugal compressor is designed and simulated by MATLAB, the results show that. The system can adjust the opening of anti-surge control valve timely according to different inlet flow and speed of compressor, and effectively avoid the occurrence of compressor surge condition. And has obtained the good control quality at the same time has the certain energy-saving effect.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH452

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