Numerical Study of the Performance Effect of Varying Vaneless Space in He Turboexpander Nozzles

26th International Cryogenic Engineering Conference & International Cryogenic Materials Conference 2016

材料科学;物理学

Meng, Y.R.^1,2,3 ; Xiong, L.Y.^1,2 ; Liu, L.Q.^1,2 ; Peng, N.^1,2 ; Ke, C.L.^1,2,3 ; Li, K.R.^1,2,3 ; Wang, H.R.^1,2,3

Key Laboratory of Cryogenics, Technical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing

100190, China^1

State Key Laboratory of Technologies in Space Cryogenic Propellants, Beijing

100190, China^2

University of Chinese Academy of Sciences, Beijing

100190, China^3

关键词: CFD simulations;    Cryogenic turboexpanders;    Design iteration;    Liquefaction systems;    Performance characteristics;    Performance effect;    Radial clearance;    Reference nozzles;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/171/1/012025/pdf
DOI  :  10.1088/1757-899X/171/1/012025

学科分类：材料科学（综合）

来源: IOP

【 摘 要 】

A numerical analysis has been carried out on a 16 mm tip diameter radial-axial flow cryogenic turboexpander using He, in order to directly compare performance characteristics by varying the vaneless space. A reference nozzle with radial clearance 0.1 mm was used in the helium liquefaction system, and six other nozzles were designed with radial clearance of 0.3 mm, 0.5 mm, 0.8 mm, 1.0 mm, 1.2 mm and 1.5 mm. As part of the design process a series of CFD simulations were carried out in order to guide design iterations towards achieving a matched flow capacity for each design. In this way the variations in the stage efficiency could be attributed to the different vaneless space only, thus allowing direct comparisons to be made. The variation in computed efficiency was used to recommend optimum value of the ratio of the nozzle vane trailing edge radius to the rotor leading edge radius (Rte/rle).