离心式压缩机出口动态压力的单重分形特征研究  

Exploring Monofractal Characteristics of Dynamic Pressure at Exit of Centrifugal Compressor

作　　者：刘雁[1,2] 陈党民 柳黎光 王航 程凯 

机构地区：[1]西北工业大学机电学院,陕西西安710072 [2]西安陕鼓动力股份有限公司,陕西西安710072

出　　处：《西北工业大学学报》2013年第1期60-66,共7页Journal of Northwestern Polytechnical University

基　　金：国家"973"计划(2012CB026002);国家"863"计划(SS2012AA052303)资助

摘　　要：以800 kW离心压缩机系统在不同工况下的出口动态压力特征为分析对象,通过分析其单重分形特征,研究了系统在小流量工作状态下,从稳定工作状态进入失稳状态的复杂特性。首先,详细分析了在不同工况下的动态压力波形状态,并研究出了其自相关函数及曲线。进一步,分析了其Hurst参数及方差的变化,并捕获到一些重要的特征。研究结果表明:当压缩机正常运行时,其自相关函数曲线表现出明显的随机特征,并且方差较小。然而,当系统进入失稳状态时,其自相关函数曲线表现出明显的重尾分布特征,而且方差较高。另外,研究显示Hurst参数可以明显表示系统由稳态进入失稳的过程。所得到的分析结果将为实现离心压缩机的初始喘振预测及防喘振控制器的设计带来新的思路。We study the complexity of a centrifugal compressor with 800 kw when its flow changes from stable to unstable state under the low flux condition. First, we change its dynamic pressure by controlling the opening of the surge prevention valve at the exit and analyze its dynamic pressure wave properties under various working conditions and obtain its autocorrelation functions and curves. Second, we analyze the Hurst parameters, autocorrelation func- tions and variances to obtain the monofractal characteristics of the centrifugal compressor. Finally , we tested the dy- namic pressure at the exit of a certain large-type centrifugal compressor. The test results, given in Figs. 2 through 7 and Table 1, and their analysis show preliminarily that： （ 1 ） when the centrifugal normal condition, its autocorrelation function curve demonstrates apparent stochastic compressor is working under characteristics, and its vari- ance is lower; however, when it is working in an unstable condition, its autocorrelation function curve demonstrates an apparent heavy tail distribution, and its variance is higher; （2） the Hurst parameter can effectively show the change from stable to unstable state. Our exploration results can be used to predict the incipient surge of a centrifu- gal compressor and design its surge controller.

关 键 词：离心压缩机 流动失稳 单重分形 自相关函数 HURST参数 

分 类 号：TK312[动力工程及工程热物理—热能工程]