Design and Optimization of a Single Stage Centrifugal Compressor for a Solar Dish-Brayton System

• Published in: Journal of thermal science 2013-10, Vol.22 (5), p.404-412
• Main Authors: Wang, Yongsheng, Wang, Kai, Tong, Zhiting, Lin, Feng, Nie, Chaoqun, Engeda, Abraham
• Format: Article
• Language: English
• Subjects: Classical and Continuum Physics; Engineering Fluid Dynamics; Engineering Thermodynamics; Heat and Mass Transfer; Physics; Physics and Astronomy; 优化; 单级; 叶片扩压器; 叶轮设计; 太阳能; 布雷顿; 离心式压缩机; 绝热效率
• ISSN: 1003-2169; 1993-033X
• DOI: 10.1007/s11630-013-0642-x

According to the requirements of a solar dish-Brayton system, a centrifugal compressor stage with a minimum total pressure ratio of 5, an adiabatic efficiency above 75% and a surge margin more than 12% needs to be de- signed. A single stage, which consists of impeller, radial vaned diffuser, 90° crossover and two rows of axial sta- tors, was chosen to satisfy this system. To achieve the stage performance, an impeller with a 6：1 total pressure ra- tio and an adiabatic efficiency of 90% was designed and its preliminary geometry came from an in-house one-dimensional program. Radial vaned diffuser was applied downstream of the impeller. Two rows of axial sta- tors after 90~ crossover were added to guide the flow into axial direction. Since jet-wake flow, shockwave and boundary layer separation coexisted in the impeller-diffuser region, optimization on the radius ratio of radial dif- fuser vane inlet to impeller exit, diffuser vane inlet blade angle and number of diffuser vanes was carried out at design point. Finally, an optimized centrifugal compressor stage fulfilled the high expectations and presented proper performance. Numerical simulation showed that at design point the stage adiabatic efficiency was 79.93% and the total pressure ratio was 5.6. The surge margin was 15%. The performance map including 80%, 90% and 100% design speed was also presented.