多级离心压缩机械的系统稳定性分析

STUDY ON FLOW StABILITY IN MULTI-STAGECENTRIFUGAL COMPRESSORS

本文对多级离心压缩机的喘振动态特征进行了分析。采用稳态与动态参数相结合的方式，对诱导机组出现非稳定性的因素进行了研究；从压缩机内部流动的惯性和阻尼特征上，解释了该类机组的动态响应特征；发现了该类机组低压缸首先出现非稳定性，高压缸出现压力崩溃的现象．

In the present paper, the dynamic characteristics of surge in the set of four--stage centrifugal compressors are investigated experimentally. By combining static parameters anddynamic parameters, the decisive factors, which induce the systems into unstable flow, areanalyzed in detail. On the other hand, the unsteady features of the pressure disturbancesat the exit of every stage are also made use of explaining the mechanism, which the firstsurge onset occurs at the exit of the second stage. In fact, the variable nature of both staticpressure and flow rate is corresponded with unsteady flow nature while operating pointsapproaches to surge boundary line. Further, in virtue of behavior of the flow inertia anddamped oscillation in the compressors, the distinction between multi-stage centrifugal compressors and single centrifugal compressor is analyzed qualitatively. Finally it is found thatthe early onset of surge manifests at the last low-pressure stage, but the first flow collapseappears at the last high-pressure stage.