INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
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2022
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IF 5.431
Zhen Yang,Yuanpeng Yao,Huiying Wu
Surfactants are often used as additives to stabilize the dispersed phase of the water-based multicomponent fluids (such as non-azeotropic emulsion) for enhancing the boiling process, but their effects on the boiling heat transfer of water are still not clear. In this paper, a pool boiling experiment is designed to investigate the specific effects of surfactants (Tween20 (Polysorbate 20), Span20 (Arlasel 20), and Tween20-Span20 mixture) on the subcooled boiling heat transfer characteristics of pure water. The experimental results are analyzed by considering the influences of addition type and concentration of surfactant as well as the applied heat loads. It is found that: (1) Tween20 can achieve excellent boiling enhancing performance (decreasing the wall superheat by up to 10.4 °C and raising the boiling heat transfer coefficient by up to 13.4%) by increasing the number of nucleation sites. And the enhancement is improved with the increase of concentration when the heat flux is below a certain level, while it is weakened at high heat flux for Tween20 with a high concentration (1 mL L -1 ). The reason is that high concentration Tween20 results in an excessive increase of nucleation sites which prevents the return of working fluid and weakens the enhancement of heat transfer. (2) Span20 shows a boiling enhancement only when its concentration is 0.05 mL L -1 (lower than the CMC) among the test ones. Further increment in Span20 concentration (exceeding the CMC) leads to a large increase of wall superheat because it increases the viscosity of working fluid and deteriorates the heat transfer performance. (3) Tween20-Span20 mixture significantly aggravates the aforementioned boiling deterioration effect of Span20 (due to the reduced CMC for the mixture of Tween20 and Span20, weakening the heat transfer), and thus is not suitable for preparing boiling-heat-transfer-enhancing fluids. These results can provide a better understanding of surfactants and guide the practical preparation of multicomponent fluids for boiling heat transfer enhancement.
研究领域:
热力学
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传热学
✓ 已验证
产品关联
DOI
高影响因子
Sustainable Cities and Society
·
2018
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IF 3.073
Nan Zhang,Yanxia Du
In this work, ultrasonic is firstly used to enhance the heat transfer rate of palmitic acid-stearic acid eutectic mixture (PA-SA) in a cylindrical stainless-steel unit. The heating boundary condition of the phase change material (PCM) is constant wall temperature condition in this work. The effects of ultrasonic parameters including ultrasonic power and operation time on heat transfer enhancement of PA-SA are experimentally studied. The results show that the heat transfer rate in melting process of PA-SA increases with the increasing of ultrasonic power, Specifically, heat transfer rate is increased by 10.64%, 23.40% and 31.91% at the ultrasonic power of 60 W, 105 W and 150 W respectively. The heat transfer rate of PA-SA is also increased with the increasing of ultrasonic action time. Effect of ultrasonic on heat transfer enhancement varies in terms of different ultrasonic action stage of the charging process. Therefore, the optimal effect of ultrasonic on heat transfer enhancement can be obtained by using intermittence ultrasonic. In conclusion, it is an effective way to enhance the heat transfer of PCM used in the latent heat storage system by intruding ultrasonic.
研究领域:
能源工程
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传热学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
·
2021
·
IF 5.584
Yongping Huang,Dongcheng Cao,Dongke Sun,Xiangdong Liu
To improve the thermal performance of horizontal latent heat storage (LHS) units, this study investigates two innovative LHS units using uniform and gradient tree-shaped fins. By coupling visualization experiments and three-dimensional numerical simulations, the melting/solidification behavior and thermal properties of innovative LHS units are comprehensively analyzed and compared with traditional LHS units. The results show that tree-shaped fins facilitate heat diffusion from point to area, breaking the heat transport hysteresis in traditional LHS units, thus accelerating the melting/solidification rate. During the melting process, the gradient tree-shaped fins strengthen the heat transfer in lower parts of the LHS unit and extend the convective heat transfer duration in upper regions, promoting the synergistic strengthening of natural convection and heat conduction in the late melting stage. Compared to the uniform fin layout, the gradient tree-shaped fins effectively increase the melting rate, shortens the melting duration by 9%, and further improve the overall temperature uniformity of LHS units. However, the non-uniform transport path of gradient tree-shaped fins is not conducive to solidification heat transfer with conduction as the primary thermal regime, which increases the temperature gradient of LHS units and prolongs the solidification duration by 57.4% compared to the uniform tree-shaped fins.
研究领域:
热能工程
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传热学
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2025
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IF 19
Liangyuan Qi,Wei Cai,Tianyang Cui,Junwei Li,Lei Song,Zhou Gui,Bin Fei,Jixin Zhu,Yuan Hu,Weiyi Xing
Radiative cooling coatings demonstrate broad applicability on equipment surfaces, spanning spacecraft to precision instruments, for sub-ambient cooling. However, unlike conventional equipment relies on solar reflection and infrared emission for cooling, the heat-generating equipment relies on coupled thermal conduction and radiative cooling, representing a distinct heat transfer paradigm. This study introduces an innovative fire-safe radiative cooling-enhanced anisotropic thermal rectification coating (TRC) by leveraging the thermal rectification effect. The rectification mechanism stems from engineered thermal conductivity gradients with temperature-dependent anisotropy, where asymmetric phonon transport in multilayer architectures enables unidirectional heat flux control. Through the rational coupling of radiative cooling emitters at the cold terminal with thermal diodes, the TRC achieves unidirectional heat transfer enhancement through conduction-radiation coupling, demonstrating a thermal rectification coefficient of 1.78 and 3.1–3.4 °C daytime temperature reduction below ambient. Crucially, under concurrent solar irradiation and simulated heat-generating equipment (50 °C), TRC attains 6.8 °C maximum cooling enhancement. Notably, the TRC integrates gas-phase and condensed-phase flame retardant mechanisms to effectively mitigate the risk of thermal runaway in heat-generating devices. This multifunctional integration advances radiative cooling technology toward practical implementation in thermal-critical infrastructure, including power electronics thermal management and smart building systems.
研究领域:
热工程
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材料科学
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传热学
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纳米技术
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消防安全工程
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应用物理学
✓ 已验证
产品关联
DOI
高影响因子
Thermal Science and Engineering Progress
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2025
·
IF 5.4
HaoMing Huang,Shan Qing,XiaoHui Zhang,ChengHang Li,Jing Zhang,Ying Zhang,Xi Wang
Nanofluids (NFs) are considered advanced heat transfer fluids due to their enhanced thermal conductivity, improved heat transfer efficiency, energy-saving potential, and prospects for system miniaturization. However, the development of NFs faces challenges, as traditional single-component NFs often suffer from poor stability, limited thermal conductivity improvement, and high viscosity, which hinder their practical application. Herein, we prepared multi-walled carbon nanotubes (MWCNTs)-TiO 2 /H 2 O NFs via a two-step method and investigated the regulatory effects of temperature (20 °C-80 °C) and mass ratio (10:1-1:10) on their dispersion stability, thermal conductivity, and viscosity characteristics. It turned out that MWCNTs and TiO 2 nanoparticles formed an interfacial coupling structure through physical adsorption. This structure was mediated by the preferential anchoring of TiO 2 nanoparticles onto the surface-active sites of MWCNTs, which effectively suppressed particle agglomeration and ensured dispersion stability of the MWCNTs-TiO 2 /H 2 O NFs. The MWCNTs-TiO 2 /H 2 O NFs with a mass ratio of 1:2 demonstrated optimal performance enhancement ratios (PER) by reducing viscosity loss and significantly improving thermal conductivity within the temperature range. Comparative studies with single-component NFs revealed that this hybrid NFs exhibited significant advantages in both thermal conductivity and viscosity performance, further confirming the synergistic optimization effect between the MWCNTs and TiO 2 nanoparticles. Our work reveals the core role of the interface coupling mechanism between MWCNTs and TiO 2 nanoparticles in optimizing the thermal transport performance of NFs, providing a theoretical basis for the development of efficient heat transfer systems based on synergistic effects.
研究领域:
纳米流体技术
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传热学
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材料科学
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热工学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
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2025
·
IF 2.8
Ying Lei,Jianyang Zhang,Haoquan Zhuang,Tao Yin,Pengcheng Lin
High-power consumption causes excessive heat of 5G devices, compromising performance and lifespan. Phase change materials (PCMs) enable passive, constant-temperature thermal management but suffer from leakage and low thermal conductivity, limiting their application. In this work, a strategy of heat transfer enhancement in thermal energy storage gels by size engineering of boron nitride (BN) towards 5G thermal management is proposed. Specifically, tetradecanol (TD), whose thermal storage temperature is close to the thermal management temperature of electronic devices, is selected as the working medium. Based on the van der Waals force and hydrogen bond between TD and styrene-ethylene-butylene-styrene (SEBS), TD@SEBS@BN gels (TSBGs) with suppressed leakage are formed. The enthalpy of the TSBG is as high as 128.12 J g −1 , stably storing heat at around 35.84°C. The synergistic enhancement of heat transfer of TSBGs by large/small-sized BN is studied. An efficient heat transfer network has been established by coupling large-sized BN (average 30 μm) and small-sized BN (average 1 μm). The thermal conductivity of TSBG is increased from 0.304 W m −1 K −1 to a high value of 0.966 W m −1 K −1 (an increase of 317.76%). The efficient thermal management of 5G electronic components is finally realized using TSBGs.
研究领域:
热管理
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材料科学
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电子器件
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纳米技术
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传热
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）