Article
Thermodynamics
Hainan Zhang, Yaling Tian, Changqing Tian, Zhiqiang Zhai
Summary: In this paper, a compact flat-evaporator loop heat pipe is designed and the effects of key structural parameters and working conditions on its dynamic and steady-state performance are studied. The results show that increasing heat load or the filling ratio, arranging vapor channels in the middle of the wick (rather than at the bottom) or lengthening the condenser can all reduce the temperature fluctuation; A small inclination angle of 5° and 10° can reduce the temperature fluctuation and the stable temperature, while large inclination angle of 15° will instead bring higher stable temperature; When the heat load increases step by step, the stable temperature (average temperature for fluctuation conditions) decreases and then increases for all filling ratios and structures; Minimized thermal resistance is achieved by optimizing wick and condenser structure under low and high heat load, respectively.
Article
Thermodynamics
Shwin-Chung Wong, Mao-Shen Deng
Summary: Two types of novel triple composite mesh-groove-powder wicks were proposed and tested in a flat-plate heat pipe. The results showed that the powders in the mesh-groove evaporator increased flow resistance and caused partial dry-out in some grooves at high heat loads, but the powder-only evaporator improved the heat load.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2024)
Article
Thermodynamics
Shwin-Chung Wong, Mao-Shen Deng, Min-Chieh Liu
Summary: This study investigates the capillary properties of a flat-plate heat pipe with a sintered composite copper mesh-groove wick and proposes a new formula for calculating its permeability. The experimental results show that the composite mesh-groove wick has a higher maximum heat load compared to another commonly used wick.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Thermodynamics
Jigneshsinh Rathod, Vikas Lakhera, Atindra Shukla
Summary: This study investigates the effect of different working fluids on the thermal performance and start-up performance of a miniature flat heat pipe (FHP). The results show that methanol and acetone heat pipes have higher effective thermal conductivity values at low heat loads and under natural convection. Ethanol heat pipe performs better at higher heat loads for the same condenser cooling method. Methanol heat pipe has enhanced thermal performance under forced convection cooling mode. Water is not suitable as a working fluid in most experimental trials due to its higher boiling point.
JOURNAL OF THERMAL SCIENCE AND ENGINEERING APPLICATIONS
(2023)
Article
Thermodynamics
Nguyen Phan, Hosei Nagano
Summary: Two miniature loop heat pipes with novel hybrid evaporator structures were developed for cooling electronic devices. These structures ensure good heat conduction and low heat leak, improving the thermal performance of the heat pipes.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2022)
Article
Thermodynamics
Zikang Zhang, Runze Zhao, Zhichun Liu, Wei Liu
Summary: Loop heat pipe, utilizing a biporous wick, exhibits improved performance compared to traditional monoporous wicks. The driving forces for loop circulation include capillary force, phase-change driving force, and gravity force. Experimental results show that under horizontal conditions, the loop can transfer a maximum heat load of 110 W with a minimum thermal resistance of 0.382 degrees C/W.
APPLIED THERMAL ENGINEERING
(2021)
Article
Thermodynamics
Zhengang Zhao, Guohong Peng, Yanhui Zhang, Dacheng Zhang
Summary: In this paper, a novel sintered multi-size copper powder wick is designed and experimentally investigated for heat flux management. The results show that the new wick has shorter liquid transfer time, faster dynamic response time, and lower overall thermal resistance compared to single-size copper powder wicks.
CASE STUDIES IN THERMAL ENGINEERING
(2023)
Article
Thermodynamics
Zhuo Cui, Li Jia, Zhou Wang, Chao Dang, Liaofei Yin
Summary: This paper presents an ultra-thin flat heat pipe (UTFHP) with small thickness and high thermal performance for the thermal management of high-performance electronic devices. The effects of fill ratio, mesh number, and passage width on the thermal resistance and temperature distribution of UTFHPs are analyzed, and the optimal thermal performance is achieved under specific conditions.
APPLIED THERMAL ENGINEERING
(2022)
Article
Thermodynamics
Ji Li, Guohui Zhou, Tong Tian, Xingping Li
Summary: This paper introduces a new compact loop heat pipe module, which achieves high reliability operation and high thermal performance through improved structure, suitable for cooling edge-computing server CPUs.
APPLIED THERMAL ENGINEERING
(2021)
Article
Construction & Building Technology
Yifan Wu, Hongli Sun, Mengfan Duan, Borong Lin, Hengxin Zhao
Summary: This study developed a novel radiant cooling terminal integrated with a heat exchanger and a flat heat pipe, achieving fast thermal response speed and excellent surface temperature uniformity. By separating sensible and latent heat transfer, a dehumidification-adjustable cooling method was proposed, effectively decoupling condensation prevention and cooling capacity issues, with forced convection further enhancing cooling performance.
BUILDING AND ENVIRONMENT
(2021)
Article
Thermodynamics
Prem Kumar, Mayur Gachake, Sameer Khandekar
Summary: The study focuses on reducing heat leak in loop heat pipes (LHP) by manipulating the properties of the copper wick, leading to improved thermal performance. It was found that the oxidized copper wick performs better thermally than the pure copper wick, attributed to the lower thermal conductivity of the oxidized porous wick reducing heat leak.
APPLIED THERMAL ENGINEERING
(2022)
Article
Engineering, Chemical
Bing Cai, Weizhong Deng, Tong Wu, Tingting Wang, Zhengyuan Ma, Wei Liu, Lei Ma, Zhichun Liu
Summary: This study explores the influence of using a pouring silicate wick on the production and performance of loop heat pipes. The results show that the system can operate stably, adapt well to changes in heat load, and have good heat load matching capabilities.
Article
Thermodynamics
Suttida Maneemuang, Niti Kammuang-Lue, Pradit Terdtoon, Phrut Sakulchangsatjatai
Summary: The study investigated the effect of pipe flattening on pressure drop and heat transfer characteristics of heat pipes. It was found that flattening the heat pipe resulted in increased pressure drop and reduced vapor core space, hindering heat transfer. Flattening the heat pipe caused the vapor core area to approach zero, leading to a high value of thermal resistance.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2021)
Article
Thermodynamics
Qiang Zhang, Ganglin Cao, Xiongwen Zhang
Summary: A battery thermal management system combining wet cooling and flat heat pipe is proposed in this study for electrical vehicles. The system is optimized for compactness, and a numerical model is built to study its efficiency. Compared to traditional air cooling, the proposed design has an advantage in maximum temperature control but compromises temperature uniformity. Increasing inlet humidity improves temperature uniformity but raises the maximum temperature.
APPLIED THERMAL ENGINEERING
(2023)
Article
Chemistry, Multidisciplinary
Yanhui Zhang, Zhengang Zhao, Chuan Luo, Dacheng Zhang
Summary: The study focused on improving the thermal efficiency of Flat-plate Micro Heat Pipe (FMHP) by studying the impact of wick structure and wettability, resulting in the development of Composite Wick FMHP (CW-FMHP) and Oxidized Composite Wick FMHP (OCW-FMHP). Experimental results showed that CW-FMHP achieved optimal thermal transfer performance at a liquid filling rate of 150%, while OCW-FMHP had higher maximum thermal power and lower thermal resistance compared to CW-FMHP.
Article
Optics
Zhang Xinyuan, Jining Wang, Yao Li, Ronggui Yang, Yaohui Zhan
Summary: In this study, a 3D full-wave model was developed to investigate the emission characteristics and light-matter interactions in silica-polymer metamaterials. The results revealed strong coupling between the silica and polymer components and quantitatively evaluated the geometry-dependent light-matter interactions. This research is of great importance for designing similar thermal-control materials.
Article
Chemistry, Multidisciplinary
Zhenmin Ding, Lorenzo Pattelli, Hongbo Xu, Wenhai Sun, Xin Li, Lei Pan, Jiupeng Zhao, Chengyu Wang, Xiang Zhang, Ying Song, Jun Qiu, Yao Li, Ronggui Yang
Summary: This work presents a colorful daytime radiative cooling surface based on structural coloration, achieved by manufacturing a radiative cooler with a bioinspired array of SiO2 microcones via self-assembly method. The radiative cooler exhibits broadband iridescent coloration while maintaining high reflectance and thermal emissivity in the solar spectrum, resulting in strong cooling performance.
Article
Chemistry, Physical
Yujie Ke, Yanbin Li, Lichen Wu, Shancheng Wang, Ronggui Yang, Jie Yin, Gang Tan, Yi Long
Summary: On-demand and selective regulation of radiative cooling and solar heat gain in buildings is crucial for energy efficiency. Researchers have developed a reconfigurable interwoven surface that can dynamically switch sequences to achieve spectral selectivity and broadband modulation, enabling effective modulation of windows, walls, and roofs for energy savings.
ACS ENERGY LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Dezhao Huang, Qiangsheng Sun, Zeyu Liu, Shen Xu, Ronggui Yang, Yanan Yue
Summary: The authors developed a tip-enhanced Raman thermometry approach to study thermal transport at nanoscale hotspots and predicted the phonon mean free path through a combination of experiments and simulations.
Article
Chemistry, Multidisciplinary
Lu Chen, Te-Huan Liu, Xiangze Wang, Yandong Wang, Xiwei Cui, Qingwei Yan, Le Lv, Junfeng Ying, Jingyao Gao, Meng Han, Jinhong Yu, Chengyi Song, Jinwei Gao, Rong Sun, Chen Xue, Nan Jiang, Tao Deng, Kazuhito Nishimura, Ronggui Yang, Cheng-Te Lin, Wen Dai
Summary: The rapid development of highly integrated microelectronic devices leads to a demand for advanced thermally conductive adhesives (TCAs) to solve the issue of heat transfer. Metal nanoflakes with a natural 2D structure and isotropic thermal conductivity are promising fillers for high-performance TCAs. However, achieving TCAs with thermal conductivity over 10 W m(-1) K-1 at filler content below 30 vol% remains challenging. This study introduces a top-down strategy to prepare 2D Ag nanoflakes with an intrinsic thermal conductivity of 398.2 W m(-1) K-1, reaching 93% of the theoretical value, and demonstrates their superior heat transfer efficiency in microelectronic cooling performance evaluations.
ADVANCED MATERIALS
(2023)
Article
Physics, Applied
Zeyu Xiang, Yu Pang, Xin Qian, Ronggui Yang
Summary: Characterizing spatially varying thermal conductivities is crucial for understanding the structure-property relation in various thermal functional materials. This study presents a machine-learning-based method for directly extracting depth-dependent thermal conductivity profiles from pump-probe phase signals. The proposed method demonstrates excellent performance in accurately reproducing different types of thermal conductivity profiles and shows potential for depth-dependent thermal property mapping.
APPLIED PHYSICS LETTERS
(2023)
Review
Chemistry, Physical
Changkang Du, Xinpeng Zhao, Xin Qian, Congliang Huang, Ronggui Yang
Summary: Solar evaporation technology, which is free of fossil fuel consumption and carbon dioxide emission, has attracted significant research interest in recent years. Although many systems have achieved high evaporation efficiency, the upper limit of this efficiency is not bounded by 100%. In this article, the thermodynamic limit of solar evaporation efficiency is analyzed, and the challenges and potential improvements for heat-localized solar evaporation and their hybrid systems are discussed.
Article
Chemistry, Physical
Zesheng Yang, Muzhang Huang, Ronggui Yang, Jingbo Sun, Xuefei Zhang, Wei Pan, Chunlei Wan
Summary: The high operation temperature of next generation gas turbines poses a challenge for the durability of metallic turbine blades due to near-infrared (NIR) thermal radiation. Although thermal barrier coatings (TBCs) are used for thermal insulation, they are transparent to NIR radiation. This study introduces an NIR metamaterial consisting of Gd2Zr2O7 ceramic matrix with dispersed Pt nanoparticles, which achieves a broadband NIR extinction and effectively shields radiative heat transfer.
Article
Materials Science, Multidisciplinary
Tianbo Lu, Boyi Wang, Guodong Li, Jiawei Yang, Xiaofan Zhang, Nan Chen, Te-Huan Liu, Ronggui Yang, Pingjuan Niu, Zongxiang Kan, Hangtian Zhu, Huaizhou Zhao
Summary: In order to meet the increasing demand for thermoelectric cooling in high heat flux systems, it is necessary to construct high-performance thermoelectric devices with materials that have both high thermoelectric properties and mechanical strength. However, improving the thermoelectric and mechanical properties simultaneously is challenging due to the anisotropic thermal and electrical transports in the layered structure of Bi2Te3. In this study, a hot extrusion (HE) technique was developed to manipulate the texture ordering in Bi2Te3 material, resulting in significant improvements in thermoelectric and mechanical properties.
MATERIALS TODAY PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Yiteng Tu, Xinyu Tan, Guiguang Qi, Xiongbo Yang, Xiqiao Ouyang, Wensheng Yan, Weiwei Hu, Jialin Geng, Ronggui Yang
Summary: Daytime radiative cooling, a passive cooling technology, has attracted significant interest due to its zero energy consumption and zero greenhouse gas emissions. We propose a spectrally selective coating based on tri-cyclodecane dimethanol diacrylate (DCPDA) monomer, which can be fabricated with simple and scalable methods. The coated glass exhibits high transmissivity in the visible wavelengths and high thermal emissivity in the atmospheric window. Outdoor cooling tests demonstrate the sub-ambient cooling capability of the coating applied to aluminum sheets, making it a promising solution for transparent radiative cooling applications.
MATERIALS TODAY PHYSICS
(2023)
Article
Chemistry, Physical
Yuchi Chen, Qiangqiang Huang, Te-Huan Liu, Xin Qian, Ronggui Yang
Summary: This study used molecular dynamics simulations to predict the thermopower of the redox pairs Fe(CN)6(3-)/Fe(CN)6(4-) and Fe3+/Fe2+, and found excellent agreement with experimental values. It was discovered that the thermopower of Fe3+/Fe2+ can be increased from 1.7+/-0.4 mV/K to 3.8+/-0.5 mV/K by increasing the acetone to water fraction. This increase was attributed to the intercalation of acetone molecules into the first solvation shell of Fe2+ at high acetone fractions.
Article
Thermodynamics
Qiangqiang Huang, Yuchi Chen, Xin Qian, Ronggui Yang
Summary: The utilization of low-grade heat sources has been a long-standing challenge due to the limited temperature difference. This study shows that coupling a thermally regenerative electrochemically cycled flow battery with radiative coolers can enhance the energy density and generate additional operating temperature difference. The model also captures the effects of mass transfer and electrochemical kinetics on power density and efficiency.
ENERGY CONVERSION AND MANAGEMENT
(2023)
Article
Thermodynamics
Jing Wu, Hao Zhang, Tianyu Wang, Xin Qian, Bai Song, Te-Huan Liu, Ronggui Yang
Summary: In this study, the pressure-dependent thermal conductivity of isotope-engineered cubic boron nitride (c-BN) was investigated using ab initio calculations and the Boltzmann transport equation. It was found that the thermal conductivity of isotopically mixed c-BN is less sensitive to pressure variations compared to isotope-enriched c-BN. The results provide a fundamental understanding of pressure-dependent phonon transport in c-BN from a microscopic perspective.
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
(2023)
Article
Chemistry, Multidisciplinary
Hao Zhang, Yongsheng Ji, Yonggang Yao, Long Qie, Zhiheng Cheng, Zhihao Ma, Xin Qian, Ronggui Yang, Chenghang Li, Yaqing Guo, Yifei Yuan, Haoyu Xiao, Haiping Yang, Jing Ma, Jun Lu, Yunhui Huang
Summary: Battery recycling is becoming increasingly important due to the widespread use of Li-ion batteries. Direct recycling methods have advantages of high-purity material recovery and lower environmental impact, but most methods are complex and have low yield. This study presents a transient recycling approach with high efficiency for battery materials, achieving a recovery ratio of over 97% and intact metal foil of nearly 100% through shock-type or rolled-over heating.
ENERGY & ENVIRONMENTAL SCIENCE
(2023)
Article
Green & Sustainable Science & Technology
Weiping Xu, Sihong Gong, Ningsheng Wang, Wenbo Zhao, Hongle Yin, Ronggui Yang, Xiaobo Yin, Gang Tan
Summary: Radiative cooling technology, using a membrane with spectrum-selective optical properties, has been shown to effectively reduce temperatures in grain storage warehouses. Field testing in Hangzhou, China demonstrated temperature reductions of up to 9.8°C and 4°C in headspace and grain respectively. By creating a building model, it was found that significant electricity savings and temperature reductions can be achieved without the use of air conditioning.
