Article
Thermodynamics
Dongnan Cai, Xiaoxiao Xu, Shijie Zhang, Chao Liu, Chaobin Dang
Summary: The study focuses on the heat transfer deterioration and flow instability of supercritical CO2 in a tube, where experiments show that flow instability occurs in upward flow tubes due to buoyancy effects and changes in heat transfer modes.
APPLIED THERMAL ENGINEERING
(2021)
Article
Thermodynamics
Zhengming Yi, Yong Xu, Xiaolin Chen
Summary: This study investigates the effects of mass flux and heat flux on heat transfer in a vertical serpentine micro-tube, as well as the different influences of buoyancy and centrifugal force in the liquid-like and gas-like regions. The results show that the heat transfer coefficient decreases with increasing heat flux and increases with increasing mass flux. The liquid-like region is more affected by buoyancy, resulting in significant differences between upward and downward flow heat transfer coefficients, while the gas-like region is less affected, with smaller differences between the coefficients. At the turning point of the micro-tube, centrifugal force weakens heat transfer, with a larger effect in the liquid-like region. These findings provide important insights into the effects of buoyancy and centrifugal force on flow and heat transfer in different regions.
APPLIED THERMAL ENGINEERING
(2022)
Article
Thermodynamics
Hang Pu, Ni Li, Ming Dong, Yan Shang, Honglong Du, Changxu Hou, Junjie Zhang
Summary: This study investigates the mixed convective heat transfer behaviors of turbulent supercritical CO2 flowing in a horizontal miniature tube. The results show that natural convection has a significant influence on the heat transfer, even in a small diameter and high turbulence intensity scenario. The mechanism of mixed convection heat transfer was studied by analyzing the thermal properties, eddy diffusivity of heat, and secondary flow vectors. The effect of wall heat flux on the non-uniformity in heat transfer was also investigated.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2023)
Article
Thermodynamics
Jiangfeng Guo, Jian Song, Zengxiao Han, Konstantin S. Pervunin, Christos N. Markides
Summary: The thermohydraulic characteristics of supercritical CO2 flows in a vertical tube at cooling conditions are numerically investigated. The influence of the heat-flux condition and flow direction are evaluated. The study shows that the heat-flux condition has little effect on the peak value of the heat transfer coefficient, and the heat transfer characteristics are affected by the buoyancy effect in upward and downward flows.
Article
Thermodynamics
Zhongyang Yu, Leren Tao, Lihao Huang, Dong Wang, Suhan Zhang, Qing Yu, Meng Li
Summary: This study investigates the convective flow and heat transfer characteristics of supercritical carbon dioxide in various inclined spirally fluted tubes using numerical simulation. The results show that buoyancy forces have different effects on flow behavior at different inclination angles and fluid regions. The optimal inclination angle for maximum heat transfer coefficient varies as the helix angle increases.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2021)
Review
Thermodynamics
Mei Yang, Guangrong Li, Fan Liao, Jingde Li, Xiang Zhou
Summary: The study investigated the influence of supercritical CO2 on cooling heat transfer and pressure drop in horizontal helically coiled tube with non-circular cross section. It was found that with the increase of polygon edge number, heat transfer and pressure drop increase, but the range of increase gradually decreases; when the polygon edge number reaches a certain extent, pressure drop decreases. Additionally, the increase in pitch P, diameter d, and radius R leads to a decrease in heat transfer, with different effects on pressure drop.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2021)
Article
Chemistry, Physical
Shang Mao, Tao Zhou, Dong Wei, Wenbin Liu, Chunhui Xue
Summary: The thermal performance of supercritical carbon dioxide in horizontal ribbed tubes has been investigated through numerical simulation. Three types of ribs were studied to understand their effects on heat transfer. The results show that the triangular ribbed tubes can significantly enhance the heat transfer coefficient and reduce wall temperature. However, circular ribbed tubes demonstrate the best performance from the viewpoint of performance evaluation criteria. Moreover, the rib configuration promotes the transition of the flow field, leading to improved heat transfer. Finally, small rib size and medium pitch further enhance the turbulent heat transfer of supercritical CO2.
JOURNAL OF SUPERCRITICAL FLUIDS
(2022)
Article
Thermodynamics
Chenshuai Yan, Jinliang Xu, Shuxiang Wang, Guanglin Liu
Summary: The study investigates the heat transfer characteristics in a supercritical system under non-uniform heating conditions. Numerical simulations and experimental data reveal that the gas-like film layer dominates the wall temperature and heat transfer deterioration in both uniform and non-uniform heating.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2022)
Article
Chemistry, Physical
Shang Mao, Tao Zhou, Dong Wei, Huaichang Lu, Wenbin Liu
Summary: This paper investigates the cooling heat transfer characteristics of supercritical water in horizontal tubes using numerical simulation. The effects of heat flux, mass flux, tube diameter, and buoyancy on heat transfer performance are revealed, and two models are validated against experiments.
JOURNAL OF SUPERCRITICAL FLUIDS
(2022)
Article
Thermodynamics
Jiangfeng Guo, Jian Song, Yao Zhao, Konstantin S. Pervunin, Christos N. Markides
Summary: The thermo-hydraulic characteristics of heated supercritical CO2 flows were numerically investigated in a vertical pipe. The results showed that heat transfer was enhanced in downward flows but deteriorated in upward flows. The heat flux distribution had a significant effect on the heat transfer performance, and the turbulence production in the core region of the flow was suppressed in upward flows.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Thermodynamics
Yi-Gao Lv, Zhe-Xi Wen, Qing Li, Yu Qiu
Summary: This study analyzes the heat transfer characteristics of different channel structures in supercritical CO2 Brayton cycles and proposes the idea of thermophysical property-matching partitioned heat transfer enhancement. Three types of hybrid channels are designed to examine the effectiveness of the partitioned heat transfer enhancement concept, showing significant advantages in reducing total pressure drop. The overall thermal hydraulic performance is best in the type-C channel, indicating potential practical guidance for the development of highly efficient heat exchangers with highly variable thermophysical properties.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2021)
Article
Thermodynamics
Jian Wang, Xin-ping Yan, Bendiks J. Boersma, Ming-jian Lu, Xiaohua Liu
Summary: Printed circuit heat exchangers (PCHE) are proposed to improve heat recovery and energy saving in supercritical CO2 (S-CO2) power cycles. A modified channel PCHE is investigated to enhance the thermal-hydraulic performance. The results show that the inserted straight section reduces pressure loss and improves flow uniformity, leading to a significant improvement in performance.
APPLIED THERMAL ENGINEERING
(2023)
Article
Thermodynamics
X. L. Li, X. Y. Yu, P. T. Liu, Y. H. Fan, D. L. Yang, G. H. Tang
Summary: In this study, large tubes (24 mm) were experimentally investigated under supercritical carbon dioxide flow, confirming the severity of heat transfer deterioration in large tubes and exploring the mechanism through a comprehensive comparison between numerical simulations and experimental tests. The analysis of vapor-like film development inspired the use of structured-inner-surface to mitigate the problem, and numerical evaluations of five types of enhancement structures were conducted. The proposed methods were found to fully prevent heat transfer deterioration, with conical strips achieving a high heat transfer performance and recommended for prevention in vertical large-diameter tubes under near-critical conditions.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2023)
Article
Physics, Multidisciplinary
Zhuang Xiao-Ru, Xu Xin-Hai, Yang Zhi, Zhao Yan-Xing, Yu Peng
Summary: A three-dimensional steady-state numerical simulation was conducted to study the flow and heat transfer of supercritical CO2 in a heated circular tube with specific parameters. The results showed an increase in convection heat transfer coefficient and a decrease in Nusselt number with increasing fluid temperature. Mass flux increase and heat flux decrease greatly enhanced the convective heat transfer coefficient and Nusselt number, especially at higher heat flux levels.
ACTA PHYSICA SINICA
(2021)
Article
Thermodynamics
Yong Cao, Xiaoxiao Xu, Dan Li, Chao Liu, Chaobin Dang
Summary: This study investigates the heat transfer characteristics of supercritical CO2 (S-CO2) in a smooth tube and a smooth tube with Helmholtz oscillators. The results show that the heat transfer deterioration of S-CO2 can be significantly inhibited by the Helmholtz oscillator. The pulsating flow generated by the oscillator enhances the disturbance between near-wall fluid and core fluid, resulting in more uniform thermophysical properties of S-CO2 and weaker buoyancy effect.
APPLIED THERMAL ENGINEERING
(2023)
Article
Thermodynamics
Xiaojun Xiong, Wensheng Lin, Anzhong Gu
Article
Thermodynamics
Xiaojun Xiong, Wensheng Lin, Rong Jia, Yang Song, Anzhong Gu
JOURNAL OF CHEMICAL AND ENGINEERING DATA
(2015)
Article
Energy & Fuels
Xiaojun Xiong, Wensheng Lin, Anzhong Gu
JOURNAL OF NATURAL GAS SCIENCE AND ENGINEERING
(2016)
Article
Chemistry, Physical
Jingxuan Xu, Wensheng Lin
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2017)
Article
Chemistry, Physical
Wensheng Lin, Meibin Huang, Anzhong Gu
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2017)
Article
Chemistry, Physical
Wensheng Lin, Jingxuan Xu, Lin Zhang, Anzhong Gu
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2017)
Article
Thermodynamics
Wensheng Lin, Xiaojun Xiong, Anzhong Gu
Article
Engineering, Chemical
Wensheng Lin, Xiaojun Xiong, Marco Spitoni, Anzhong Gu
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2018)
Article
Engineering, Chemical
Wensheng Lin, Jingxuan Xu, Ting Gao, Anzhong Gu
INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH
(2018)
Article
Chemistry, Physical
Wensheng Lin, Minfei Hu, Anzhong Gu
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2018)
Article
Chemistry, Physical
Jingxuan Xu, Wensheng Lin, Shilong Xu
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2018)
Article
Thermodynamics
Wensheng Lin, Lin Zhang, Anzhong Gu
Article
Thermodynamics
Minfei Hu, Wensheng Lin, Anzhong Gu, Jinlai Li
FLUID PHASE EQUILIBRIA
(2014)
Proceedings Paper
Thermodynamics
W. Lin, R. Jia, A. Gu, X. Lu
11TH IIR GUSTAV LORENTZEN CONFERENCE ON NATURAL REFRIGERANTS (2014): NATURAL REFRIGERANTS AND ENVIRONMENTAL PROTECTION
(2014)
Proceedings Paper
Thermodynamics
R. Jia, Y. Song, W. Lin
11TH IIR GUSTAV LORENTZEN CONFERENCE ON NATURAL REFRIGERANTS (2014): NATURAL REFRIGERANTS AND ENVIRONMENTAL PROTECTION
(2014)