{"title":"Numerical study of parametric effects on heat transfer deterioration of supercritical CO2/DME mixture flowing in a horizontal tube","authors":"Xiaojuan Niu, Ziyang Yin, Wenpeng Hong","doi":"10.1016/j.csite.2025.106567","DOIUrl":null,"url":null,"abstract":"Compared to using pure CO<ce:inf loc=\"post\">2</ce:inf> as a working fluid, mixing CO<ce:inf loc=\"post\">2</ce:inf> with dimethyl ether (DME) in specific ratios can enhance heat transfer efficiency and reduce system operating pressure. However, the issue of heat transfer deterioration (HTD) in supercritical CO<ce:inf loc=\"post\">2</ce:inf>/DME mixtures has received limited attention. This study conducts a numerical analysis of the heat transfer characteristics of these mixtures in horizontal tubes. We conducted a systematic study for the first time on how various operating parameters influence the HTD mechanism and establish multiscale correlations between mixture thermophysical nonlinearities and thermal transport instabilities.The findings offer valuable insights for the safe operation of next-generation energy systems. Results show that DME addition delays HTD, while increasing system pressure and mass flux helps mitigate its severity. Moreover, gravitational acceleration introduces asymmetry in the local heat transfer coefficient (HTC) distribution. Under normal gravity conditions (gy = -9.8 m/s<ce:sup loc=\"post\">2</ce:sup>), HTC suppression is observed compared to the zero-gravity condition (gy = 0 m/s<ce:sup loc=\"post\">2</ce:sup>).","PeriodicalId":9658,"journal":{"name":"Case Studies in Thermal Engineering","volume":"2 1","pages":""},"PeriodicalIF":6.4000,"publicationDate":"2025-06-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Case Studies in Thermal Engineering","FirstCategoryId":"5","ListUrlMain":"https://doi.org/10.1016/j.csite.2025.106567","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"THERMODYNAMICS","Score":null,"Total":0}
引用次数: 0
Abstract
Compared to using pure CO2 as a working fluid, mixing CO2 with dimethyl ether (DME) in specific ratios can enhance heat transfer efficiency and reduce system operating pressure. However, the issue of heat transfer deterioration (HTD) in supercritical CO2/DME mixtures has received limited attention. This study conducts a numerical analysis of the heat transfer characteristics of these mixtures in horizontal tubes. We conducted a systematic study for the first time on how various operating parameters influence the HTD mechanism and establish multiscale correlations between mixture thermophysical nonlinearities and thermal transport instabilities.The findings offer valuable insights for the safe operation of next-generation energy systems. Results show that DME addition delays HTD, while increasing system pressure and mass flux helps mitigate its severity. Moreover, gravitational acceleration introduces asymmetry in the local heat transfer coefficient (HTC) distribution. Under normal gravity conditions (gy = -9.8 m/s2), HTC suppression is observed compared to the zero-gravity condition (gy = 0 m/s2).
期刊介绍:
Case Studies in Thermal Engineering provides a forum for the rapid publication of short, structured Case Studies in Thermal Engineering and related Short Communications. It provides an essential compendium of case studies for researchers and practitioners in the field of thermal engineering and others who are interested in aspects of thermal engineering cases that could affect other engineering processes. The journal not only publishes new and novel case studies, but also provides a forum for the publication of high quality descriptions of classic thermal engineering problems. The scope of the journal includes case studies of thermal engineering problems in components, devices and systems using existing experimental and numerical techniques in the areas of mechanical, aerospace, chemical, medical, thermal management for electronics, heat exchangers, regeneration, solar thermal energy, thermal storage, building energy conservation, and power generation. Case studies of thermal problems in other areas will also be considered.