中国电机工程学报2025，Vol.45Issue(14)：5402-5412,中插6,12.DOI:10.13334/j.0258-8013.pcsee.240347
U型弯管对超临界CO2跨类临界换热的影响分析
Analysis on the Influence of U-bend on Heat Transfer of Supercritical CO2 Crossing Pseudo-critical Point
摘要
Abstract
U-bend tubes remain one of the most commonly heat exchange channels used in heat exchangers,but the characteristics and mechanisms of supercritical CO2(S-CO2)in U-bend tubes have not been adequately investigated.In the present study,comparing with a vertical circular tube,the characteristics of S-CO2 flow and heat transfer in a vertical inverted U-bend tube are numerically investigated.Based on the assumption of supercritical phase transition when S-CO2 crossing pseudo-critical temperature,the mechanism of S-CO2 heat transfer behavior in the U-bend tube and the reason why difference of S-CO2 heat transfer between U-bend tube and vertical tube appears are explained.The results show that CO2 has better heat transfer capacity in the U-bend section than in the vertical tube,but wall temperature of U-bend section shows an uneven distribution along the circumference.In addition,the supercritical liquid-like phase in the cross-section of the U-bend tube deviates significantly from the center region and converges to the top region due to the centrifugal force.While the supercritical gas-like phase converges at the bottom,and the flow parameters show obvious differences from the vertical tube.Above factors determine the characteristics of S-CO2 heat transfer and wall temperature distribution in the U-bend tube.The present work provides valuable insights for the design of S-CO2 heat exchanger utilizing the U-bend tube.关键词
超临界CO2/跨类临界/传热/U型管/数值模拟Key words
supercritical CO2/cross pseudo-critical point/heat transfer/U-bend/numerical simulation分类
能源科技引用本文复制引用
闫晨帅,张炎,张鑫奕,王维雪,陈奇成,赵亚莹..U型弯管对超临界CO2跨类临界换热的影响分析[J].中国电机工程学报,2025,45(14):5402-5412,中插6,12.基金项目
国家自然科学基金项目(52206132) （52206132）
吉林省教育厅科学研究项目(JJKH20230116KJ) （JJKH20230116KJ）
吉林省自然科学基金项目(20230101341JC). Project Supported by National Natural Science Foundation of China(52206132) （20230101341JC）
Jilin Provincial Department of Education Scientific Research Project(JJKH20230116KJ) （JJKH20230116KJ）
Jilin Provincial Natural Science Foundation(20230101341JC). （20230101341JC）
