Experimental Study on Inducement and Development of Flow Instabilities in a Centrifugal Compressor with Different Diffuser Types

作     者：XUE Xiang WANG Tong XUE Xiang;WANG Tong

作者机构：Gas Turbine Research InstituteShanghai Jiao Tong UniversityShanghai 200240China 

出 版 物：《Journal of Thermal Science》 (热科学学报（英文版）)

年 卷 期：2020年第29卷第2期

页      面：435-444页

核心收录：

学科分类：080704[工学-流体机械及工程] 08[工学] 0807[工学-动力工程及工程热物理] 0805[工学-材料科学与工程（可授工学、理学学位）] 0702[理学-物理学] 

基　　金：This research was funded by the National Natural Science Foundation of China(Grant No.51276108) the Defense Industrial Technology Development Program(B1420110136). 

主　　题：compressed air energy storage centrifugal compressor flow instability stall 

摘      要：A centrifugal compressor is a typical compressed air energy storage device. In order to ensure the safety of the compressed energy storage process in the compressor, the internal unsteady flow phenomena need to be closely monitored, especially some serious ones like stall and surge. It is necessary to explore the mechanism of flow instabilities under different conditions. A centrifugal air compressor was tested with a vaneless diffuser and a variable vaned diffuser with five different vane setting angles, respectively. Various diffuser types resulted in various modes of flow instabilities prior to surge. The vaneless region between the impeller and the diffuser was focused on. Multiple high-speed sensors were arranged along the circumferential direction. The pressure signals at all these positions were being measured and collected in real time as the compressor was slowly throttled into surge. This paper emphasizes on the influence of matching between the impeller and the diffuser on the flow instability. The experimental results showed that the diffuser vane setting angle affected the stall characteristics. Due to the asymmetry of the volute, the circumferential pressure distribution was always severely distorted prior to surge. A high-pressure region appeared near the volute tongue, and a low-pressure region was formed away from the volute tongue. In the case of the vaned diffuser with non-design installation angle and the vaneless diffuser, the rotating stall signal was originated in the low-pressure region and propagated circumferentially. However, in the case of the vaned diffuser with the design installation angle, the circumferential high-pressure region became the most sensitive region for the generation of stall, and another form of instability occurred there. Both the inducement and development of these flow instabilities have been studied. The dynamic experimental research on the compressor matching different types of diffusers could be a good case supplement.