Article
Engineering, Chemical
Xu Ma, Yindong Song, Yang Wang, Yuni Zhang, Jingya Xu, Shouguang Yao, Kambiz Vafai
Summary: This study focuses on functionalizing graphene nanoplatelets to improve hydrophobicity while maintaining good thermal properties, and preparing hybrid nanofluids for enhanced heat transfer. Novel GNP-Fe3O4 hybrid nanoparticles with high purity and hydrophilic functional groups were prepared. The addition of metal or non-metal nanoparticles improved the heat transfer characteristics of nanofluids. Experimental results showed significant enhancement in heat transfer properties compared to deionized water, with GNP-Fe3O4 + Al2O3 and GNP-Fe3O4 + SiO2 hybrid nanofluids exhibiting the best heat transfer effects.
Article
Nanoscience & Nanotechnology
Youngsup Song, Shuai Gong, Geoffrey Vaartstra, Evelyn N. Wang
Summary: Boiling is a fundamental process in many applications where surfaces with microcavities or biphilic wettability can enhance heat transfer efficiency. This study investigated microtube structures to simultaneously enhance heat transfer coefficient and critical heat flux, achieving significant improvements compared to smooth surfaces. The combination of micropillars and microtubes further increased critical heat flux by separating nucleating bubbles and rewetting liquids.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Review
Thermodynamics
M. M. Mahmoud, T. G. Karayiannis
Summary: The study focuses on assessing the discrepancies in performance of enhanced surfaces for pool boiling heat transfer, providing insights into understanding the impact of fluid-surface combinations. Challenges in evaluating performance, effects of fluid type, and heat transfer enhancement mechanisms are discussed, with future recommendations for researchers. The paper aims to guide researchers in concluding on the best surface structure and manufacturing technique for specific fluids.
THERMAL SCIENCE AND ENGINEERING PROGRESS
(2021)
Review
Thermodynamics
Munonyedi Egbo, Mohammad Borumand, Yahya Nasersharifi, Gisuk Hwang
Summary: This paper reviews the effects of surface orientation on pool boiling, including experimental and theoretical approaches to understand the changes in heat transfer coefficient and critical heat flux. The results show that tailored two-phase flow can enhance the performance of pool boiling. This review also discusses future research directions for engineered surfaces under different surface orientations.
APPLIED THERMAL ENGINEERING
(2022)
Article
Nanoscience & Nanotechnology
Youngsup Song, Chi Wang, Daniel J. Preston, Guanyu Su, Md Mahamudur Rahman, Hyeongyun Cha, Jee Hyun Seong, Bren Philips, Matteo Bucci, Evelyn N. Wang
Summary: This study investigates sandblasting as a scalable surface engineering technique for enhancing pool boiling heat transfer. The results show that surface roughness and volumetric wicking rate increase with the abrasive size, resulting in significant improvements in the critical heat flux and heat transfer coefficient.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Mechanics
Gangtao Liang, Yang Chen, Jiajun Wang, Zhao Wang, Shengqiang Shen
Summary: This study investigates pool boiling heat transfer on hybrid-wettability surfaces, showing that the nucleate boiling heat transfer coefficient is improved on these surfaces compared to the substrate and plain copper reference. However, the critical heat flux (CHF) behavior is complex on the enhanced surface. The difference in contact angles between the pattern and substrate plays a significant role in the CHF enhancement on the hybrid surface, although it affects the nucleate boiling heat transfer coefficient negatively.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2021)
Article
Mechanics
Hasan Alimoradi, Mehrzad Shams, Nasser Ashgriz
Summary: The boiling characteristics of a copper surface coated with graphene oxide (GO) using the electro-phoretic deposition (EPD) method are presented. Three different concentrations of GO solutions (1, 3, and 5 mg/ml) were tested. The coated surfaces exhibited improved surface properties, resulting in rapid cooling and rewetting of hot and dry points. Different electrolyte concentrations and coatings were tested to optimize the heat transfer coefficient (HTC) and critical heat flux (CHF). The HTC and CHF were improved by 60.3% and 90.5%, respectively, for the 1 mg/ml GO coating compared to the uncoated surface.
INTERNATIONAL JOURNAL OF MULTIPHASE FLOW
(2023)
Article
Thermodynamics
Kai Zhang, Lizhan Bai, Haichuan Jin, Guiping Lin, Guice Yao, Dongsheng Wen
Summary: Experimental validation shows that the novel porous artery structure can significantly enhance the pool boiling heat transfer performance, with increased nucleation site density, improved liquid replenishment by capillarity, and effective liquid/vapor phase separation being the main reasons.
APPLIED THERMAL ENGINEERING
(2022)
Review
Thermodynamics
Sudhir Kumar Singh, Deepak Sharma
Summary: This paper provides a comprehensive review of the importance of enhancing boiling heat transfer performance and the impact of various surface modification methods on heat transfer effects, proposing key technologies for reducing energy dissipation and improving heat transfer efficiency.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2021)
Article
Thermodynamics
Pulak Sen, Sanjib Kalita, Dipak Sen, Ajoy Kumar Das, Bidyut Baran Saha
Summary: In this study, hydrophobic copper micro-structured surfaces were prepared through chemical etching and heat treatment, resulting in different micro-structural features. The experimental results showed that the prepared hydrophobic surfaces have a higher heat transfer coefficient, although the critical heat flux is slightly smaller compared to the bare copper surface. Additionally, the micro-porous surface prepared by a combination of two conventional processes significantly improves heat transfer.
INTERNATIONAL COMMUNICATIONS IN HEAT AND MASS TRANSFER
(2022)
Article
Thermodynamics
Lin Lin, Yanxin Hu, Zipei Su, Minghan Zhu, Jin Huang, Changxiang Fan
Summary: The preparation of micro-nano hybrid structured copper surfaces through sandblasting and ultrasonic wet etching techniques has been investigated for its impact on nucleate pool boiling. The study found that the hybrid structure exhibits improved critical heat flux and heat transfer coefficient compared to smooth and individual micro or nano structured surfaces. The enhancement mechanisms are attributed to the combined effects of roughness, surface area ratio, and wettability.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Thermodynamics
Shangzhen Xie, Mengnan Jiang, Haojie Kong, Qing Tong, Jiyun Zhao
Summary: This study decouples the contributions of surface wettability and hierarchical structure on boiling enhancement, revealing that surface orientation influences boiling performance and proposing new correlations for downward-facing critical heat flux prediction, which could be useful for future multi-oriented surface designs.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2021)
Article
Thermodynamics
Atul Ranjan, Israr Ahmad, Rinku Kumar Gouda, Manabendra Pathak, Mohd Kaleem Khan
Summary: This study reports the creation of Cu(OH)2 nanoneedles on a copper surface using an anodization process, which can enhance critical heat flux (CHF) limit in pool boiling applications by improving surface wettability and wickability. Results show that the anodized surface requires higher wall superheat for nucleation and exhibits a higher CHF value compared to the plain surface.
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
(2022)
Article
Energy & Fuels
Hak Rae Cho, Su Cheong Park, Doyeon Kim, Hyeong-min Joo, Dong In Yu
Summary: This study developed hydrophilic micro/nanotextured surfaces with hydrophobic patterns to enhance both boiling heat transfer and critical heat flux simultaneously. Experimental data supported the hypothesis that capillary-induced flow between microtextures and superhydrophilic nanotextures contribute to increasing critical heat flux, while the hydrophobicity at the top of the micropillars leads to higher nucleate site density and boiling heat transfer.
Review
Thermodynamics
Huaqiang Chu, Nian Xu, Xinyu Yu, Hantao Jiang, Weigang Ma, Fen Qiao
Summary: This paper focuses on the surface modification technology in boiling heat transfer, including physical and chemical methods. It also summarizes the common boiling strengthening mechanisms and provides CHF prediction models for nanostructured coatings.
APPLIED THERMAL ENGINEERING
(2022)
Article
Engineering, Chemical
Xu Ma, Yindong Song, Yang Wang, Yuni Zhang, Jingya Xu, Shouguang Yao, Kambiz Vafai
Summary: This study focuses on functionalizing graphene nanoplatelets to improve hydrophobicity while maintaining good thermal properties, and preparing hybrid nanofluids for enhanced heat transfer. Novel GNP-Fe3O4 hybrid nanoparticles with high purity and hydrophilic functional groups were prepared. The addition of metal or non-metal nanoparticles improved the heat transfer characteristics of nanofluids. Experimental results showed significant enhancement in heat transfer properties compared to deionized water, with GNP-Fe3O4 + Al2O3 and GNP-Fe3O4 + SiO2 hybrid nanofluids exhibiting the best heat transfer effects.
Article
Chemistry, Physical
Tong Zhang, Xin-Yuan Tang, Wei-Wei Yang, Xu Ma
Summary: This paper proposes a reflux solar methanol steam reforming reactor (SMSRR) system for efficient solar thermal hydrogen production. A two-dimensional (2D) axisymmetric model is used to compare the comprehensive performance of three different SMSRRs: no reflux tube (SMSRR0), flow from the inside of the reflux tube to the outside (SMSRR1), and flow from the outside of the reflux tube to the inside (SMSRR2). The results show that the reflux SMSRR utilizes the heat of the fluid at the outlet to further provide reaction heat, greatly reducing the outlet temperature and improving the overall performance of the SMORE. By optimizing the diameter of the reflux tube and the operating conditions, the energy conversion rate can be increased by 19.5%, and the temperature distribution coefficients can be increased by 1.89%, while the methanol conversion is increased by 6.43% and the hydrogen yield is increased by 5.96%.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Energy & Fuels
Miao Ye, Long Rong, Xu Ma, Weiwei Yang
Summary: This study investigates the impacts of triple-phase contents on cell performance in an ordered cathode catalyst layer. The results show that the overall cell power density can be maximized when the triple-phase contents ratio is optimized, with a Pt loading of 0.15 mg cm(-2), carbon loading of 1.0 mg cm(-2), and ionomer volume fraction of 0.2.
Article
Thermodynamics
Xin-Yuan Tang, Wei-Wei Yang, Xu Ma, Xiangkun Elvis Cao
Summary: This study proposes an integrated membrane reactor modeling method based on thermodynamic equilibrium to investigate the enhancement potential of membrane reactors. The modeling method applies MATLAB codes to calculate local reaction equilibrium and determine product separation. Through parametric analysis and optimization by GA and NSGA-II, it is found that pressure-driven hydrogen recovery enhancement is the key to improving membrane reactor performance. The results provide reference conditions for theoretical reactor design.
Article
Thermodynamics
Wei-Wei Yang, Xin-Yuan Tang, Xu Ma, Yong-Jian Yang, Pei-Yuan Dou, Ya-Ling He
Summary: This study proposes a helical insert-enhanced solar membrane reactor to eliminate the adverse impact of concentration polarization. It is shown that enhancing radial mass transfer effectively alleviates concentration polarization and improves methane conversion. By optimizing the number of helical inserts, the reactor performance is further enhanced under different operating conditions.
ENERGY CONVERSION AND MANAGEMENT
(2023)
Article
Chemistry, Physical
Yong-Jian Yang, Wei-Wei Yang, Xu Ma, Xin-Yuan Tang, Xiangkun Elvis Cao
Summary: In order to counteract the effects of solar radiation fluctuation, phase change material (PCM) was employed in the solar volumetric reactor. A new design, SVR2, was proposed to address issues of high temperature, slow charging-discharging rate, and fluctuating methane conversion. Simulation results showed that SVR2 achieved a lower maximum temperature and higher methane conversion rate compared to the conventional SVR1 under natural solar radiation fluctuation.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2023)
Article
Engineering, Chemical
Pei-Yuan Dou, Wei-Wei Yang, Xin-Yuan Tang, Xu Ma, Jia-Chen Li
Summary: In this study, the distribution of catalysts in a solar steam methane reforming reactor was optimized using topology optimization. By adjusting the porosity distribution of the catalysts, the reactor performance was improved in terms of hydrogen production and methane conversion.
CHEMICAL ENGINEERING SCIENCE
(2023)
Review
Energy & Fuels
Wei -Wei Yang, Xu Ma, Xin-Yuan Tang, Pei-Yuan Dou, Yong-Jian Yang, Ya-Ling He
Summary: This article systematically reviews the research progress on improving the durability, carbon deposition resistance, and sintering resistance of methanol steam reforming (MSR) catalyst through material modification, additives utilization, and structure optimization. It also discusses the studies on revealing the MSR reaction path under different catalytic conditions and the heat/mass transport and distribution behaviors in MSR reactor under different catalyst structures. This review provides a detailed summary of the methodologies to optimize the catalytic system for reducing the energy barrier of MSR, improving methanol conversion efficiency and rate, which lays the foundation for the engineering application of MSR technology.
Article
Engineering, Chemical
Ri Zhang, Shasha Zhang, Mengyan Ding
Summary: A thin liquid film method is proposed to evaluate sand erosion in annular flow. This method considers the direct interaction between the liquid film and gas core, as well as the entrainment and deposition of droplets. The erosion rate is calculated by considering the effects of liquid entrainment and particle velocity decay. The method is fully verified by comparing with experimental data.
Article
Engineering, Chemical
Yu Suo, Xianheng Su, Wenyuan He, Xiaofei Fu, Zhejun Pan
Summary: This research investigates the mechanical properties of sandstone-shale composite through orthogonal experimental method and discrete element simulation. The results show that different lithologies and thickness ratios can affect the strength and fracture mode of the composite rock samples.
Article
Engineering, Chemical
Maurizio Troiano, Andrea El Hassanin, Roberto Solimene, Alessia Teresa Silvestri, Fabrizio Scala, Antonino Squillace, Piero Salatino
Summary: This study investigates the potential of Fluidized Bed Finishing (FBF) for square flat AlSi10Mg specimens manufactured via Laser-Powder Bed Fusion (L-PBF) additive manufacturing technology. The results show that good finishing can be achieved using rotation-assisted tests, with a maximum reduction of surface roughness by 67%. Steel particles are found to be the most effective bed material.
Review
Engineering, Chemical
Ningbo Song, Wanzhong Yin, Jin Yao
Summary: Seawater's dissolved salts and minerals have various effects on the flotation process, including influencing the characteristics and behavior of flotation factors, as well as affecting the surface of sulfide minerals. In most cases, seawater has adverse effects on the flotation of sulfide minerals, but these effects can be mitigated by adjusting the reagents.
Article
Engineering, Chemical
Kaiqiao Wu, Shuxian Jiang, Victor Francia, Marc-Olivier Coppens
Summary: In rectangular and cylindrical annular fluidized beds, pulsating gas flow can create regular bubble patterns, overcoming challenges seen in conventional units. This study provides new opportunities for modularization of fluidized bed operations.
Article
Engineering, Chemical
Shuo Li, Huili Zhang, Jan Baeyens, Miao Yang, Zehao Li, Yimin Deng
Summary: The paper assesses the behavior of cohesive Geldart C-type particles when fluidized by air with the aid of vibration. It determines that mechanical vibration is a simple and effective method to improve the fluidity of cohesive particles during fluidization.
Article
Engineering, Chemical
Zhenfei Feng, Qingyuan Zhang, Shanpan Liang, Zhenzhou Li, Fangwen Guo, Jinxin Zhang, Ding Yuan
Summary: A new micro/mini-channel heat sink (MCHS) with a combined structure of longitudinal and transverse vortex generators is designed, using Al2O3 nanofluid as the working medium. The study explores the effects of transverse vortex generator shape and longitudinal vortex generator angle on the hydraulic and thermal characteristics, comprehensive performance, entropy generation, and exergy efficiency. The results show that the triangular transverse vortex generator improves the comprehensive performance and exergy efficiency. Combined with the longitudinal vortex generator, the MCHS achieves the best comprehensive performance, entropy generation, and exergy efficiency when the Reynolds number is 742.
Article
Engineering, Chemical
Kostas Giannis, Christoph Thon, Guoqing Yang, Arno Kwade, Carsten Schilde
Summary: This study presents a 3D convolutional neural network (3D-CNN) methodology for generating realistic 3D models of particles. The method trains on 2D projections of particle images to predict their 3D shapes, and evaluates the accuracy of the predictions using Fourier shape descriptors (FSDs). This methodology has wide applications in particle shape analysis.
Article
Engineering, Chemical
Zheng-qing Zhou, Lu-jia Chai, Yu-long Zhang, Ya-bin Wang, Ze-chen Du, Tian-yi Wang, Yu-zhe Liu
Summary: The dynamic oxidation and shell-breaking processes of aluminum nanoparticles (ANPs) during heating were studied using in situ transmission electron microscopy. The results revealed that the changes in shell thickness can be divided into three stages, and the active aluminum content of ANP decreased before shell-breaking.
Article
Engineering, Chemical
Fulei Chen, Huaqing Ma, Zihan Liu, Lianyong Zhou, Yongzhi Zhao
Summary: A particle breakage model based on the particle replacement scheme, using the polyhedral model to describe particles, is proposed in this work to accurately describe the breakage of a large number of particles. Additionally, a fast-cutting algorithm is proposed to reproduce the size distribution of progeny particles determined by the breakage model. The validation and simulation results show satisfactory accuracy, efficiency, and stability of the algorithm.
Review
Engineering, Chemical
Matteo Errigo, Christopher Windows-Yule, Massimiliano Materazzi, Dominik Werner, Paola Lettieri
Summary: Gas-solid fluidized-bed systems have advantages in terms of chemical reaction efficiency and temperature control, making them widely used in industrial applications. However, the design, scale-up, and optimization of these complex units are limited by the lack of deep physical understanding. Non-invasive and non-intrusive diagnostic techniques provide a way for researchers to study these systems without affecting the flow field or directly contacting the medium under study.
Article
Engineering, Chemical
Saeed Fateh, Mohammad Behshad Shafii, Mohammad Najafi, Cyrus Aghanajafi
Summary: Applying a magnetic field to ferrofluids alters their flow characteristics and enhances heat transfer. Through visualization and quantitative investigation, it is found that the magnetic field influences the flow patterns and velocity profiles, improving fluid mixing and vorticity magnitude.
Article
Engineering, Chemical
Lei Gao, Bingbing Wei, Xiaochuan Hu, Zaifeng Yao, Yiwen Fang, Xuejian Gao
Summary: In this study, a numerical model of sand triaxial test was established using discrete element software PFC3D, and an indoor triaxial test was conducted to calibrate the numerical model. The influence of microscopic parameters on the macroscopic mechanical response of sand was analyzed. The results showed that the friction coefficient had the greatest impact on the peak strength and residual strength of the sand's stress-strain curve, and it was positively correlated. The normal tangential stiffness ratio was negatively correlated, while the porosity and boundary flexibility stiffness had minimal influence on it.
Article
Engineering, Chemical
Xuan Liu, Jie Gong, Kai Jiang, Xiaojuan Lai, Yu Tian, Kang Zhang
Summary: This study aimed to improve the performance of lignite coal water slurries (CWSs) by synthesizing a series of three-arm amphiphilic block copolymers. By controlling the relative molecular weight, hydrophilic/hydrophobic ratio, and ionic group content, the apparent viscosity of CWSs was significantly reduced and the static stability was improved. Thermogravimetric testing and XPS analysis were conducted to reveal the mechanism behind the improved performance.
Article
Engineering, Chemical
Lanka Dinushke Weerasiri, Daniel Fabijanic, Subrat Das
Summary: Fluidization at low pressure offers significant benefits for the fine chemical industry. This study investigates the behavior of bubbles and bed expansion under low pressure conditions. It is found that lower pressure leads to larger bubbles, increased bubble quantity, and higher aspect ratio. The predictability is affected by the inhomogeneous fluidization, but low pressure fluidization can generate similar bubble sizes with lower fluidizing mass compared to atmospheric pressure.
