Using Tip Gaps on Tandem Diffuser to Broaden the Operation Range of a Centrifugal Compressor  

作　　者：FANG Junyi JI Chunjun LI Chunyang SUN Qi 

机构地区：[1]School of Power Engineering,Dalian University of Technology,Dalian 116024,China [2]Institute of Engineering Thermophysics,Chinese Academy of Sciences,Beijing 100190,China

出　　处：《Journal of Thermal Science》2021年第3期999-1009,共11页热科学学报（英文版）

摘　　要：Gaps in compressors are generally unfavorable because they lead to energy loss.However,gaps on diffuser blades can broaden the operation range of a compressor.To broaden the operation range of a centrifugal compressor with a tandem diffuser,gaps with different sections and widths on the diffuser blades were examined to determine their influence on the compressor performance.The results show that the compressor’s surge margin increased from 33.28% to 49.2% for a 2.5%tip gap ratio,while its stability margin increased from 44% to 60.5%.However,pressure ratio and efficiency losses of 1.16% and 1.14%,respectively,were incurred.Gap widths less than 5%of the height of the diffuser blade are adequate for broadening the operation range,whereas gap ratios greater than 5%cause more energy loss without broadening the operation range further.Gaps can also reduce the Mach number in the diffuser blade channels and can be influenced by the impeller-tip gap.Moreover,diffuser gaps on the shroud side yield better performance than those on the hub side.An experiment was conducted to investigate the reliability of the calculation and conclusions in this study,and the results proved that the conclusions are valid for different types of centrifugal compressors.

关 键 词：centrifugal compressor tandem diffuser tip gap flow operation range SURGE CHOKE 

分 类 号：TH452[机械工程—机械制造及自动化]