Influence of Real Gas Properties on Aerodynamic Losses in a Supercritical CO_(2) Centrifugal Compressor  

作　　者：YANG Mingyang CAI Ruikai ZHUGE Weilin YANG Bijie ZHANG Yangjun 

机构地区：[1]School of Mechanical Engineering,Shanghai Jiao Tong University,Shanghai 200240,China [2]School of Vehicle and Mobility,State Key Laboratory of Intelligent Green Vehicle and Mobility,Tsinghua University,Beijing 100084,China [3]Department of Mechanical Engineering,Imperial College London,London SW72AZ,UK

出　　处：《Journal of Thermal Science》2024年第6期2032-2046,共15页热科学学报（英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant No.52076130)。

摘　　要：Supercritical carbon dioxide(SCO_(2))centrifugal compressor is a key component of a closed Brayton cycle system based on SCO_(2).A comprehensive understanding of the loss mechanism within the compressor is vital for its optimized design.However,the physical properties of SCO_(2) are highly nonlinear near the critical point,and the internal flow of the compressor is closely related to its properties,which inevitably influences the generation of aerodynamic losses within the compressor.This paper presents a comprehensive investigation of the compressor's loss mechanism with an experimentally validated numerical method.The real gas model of CO_(2) embodied in the Reynolds-Averaged Navier-Stokes(RANS)model was used for the study.Firstly,the numerical simulation method was validated against the experimental results of Sandia SCO_(2) compressor.Secondly,performance and loss distribution of the compressor were compared among three fluids including SCO_(2),ideal CO_(2)(ICO_(2))and ideal air(IAir).The results showed that the performance of SCO_(2) was comparable to IAir under low flow coefficient,however markedly inferior to the other two fluids at near choke condition.Loss distribution among the three fluids was distinctive.In the impeller,SCO_(2) was the most inefficient,followed by ICO_(2) and IAir.The discrepancies were magnified as the flow coefficient increased.This is due to a stronger Blade-to-Blade pressure gradient that intensifies boundary layer accumulation on walls of the shroud/hub.Furthermore,owing to the reduced sonic speed of SCO_(2),a shock wave appears earlier at the throat region and SCO_(2) encounters more intenseboundarylayerseparation.

关 键 词：SCO_(2) centrifugal compressor loss mechanism real gas properties 

分 类 号：TK05[动力工程及工程热物理]