POWDER TECHNOLOGY
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2017
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IF 2.942
Yanwei Hu,Ziyu Liu,Yurong He
Boiling heat transfer is widely used in energy power equipment, while the poor thermal property conventional fluids cannot meet the increase of heat transfer demand. The addition of nanoparticles into base fluids can modify the properties of base fluids and is a potential way to improve heat transfer characteristics. In present work, amorphous SiO 2 nanoparticles with an average size of 98 nm were synthesized via Stober process. And they were added into water with different mass fractions to investigate the pool boiling heat transfer characteristics. The heat transfer coefficient and critical heat flux were analyzed. Results show that the heat transfer coefficient of all fluids increases rapidly in the natural convective region but then rises gradually in the nucleate boiling region. Moreover, owing to the deposition of SiO 2 nanoparticles, the heat transfer coefficients of SiO 2 -H 2 O nanofluids are lower than that of the base fluid and reduce as the concentration increase. On the other hand, because of the wettability improvement of the heating wire surface caused by the deposition of SiO 2 nanoparticles, the critical heat fluxes of nanofluids are higher than that of the base fluid. When the concentration is 0.081%, the critical heat flux achieves a peak improvement of approximately 68.8%.
研究领域:
热力学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF THERMAL SCIENCES
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2022
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IF 4.779
Tao Wen,Jielin Luo,Kai Jiao,Lin Lu
Enhancing heat transfer performance of pool boiling is attractive in practical applications, while the utilization of nanofluid is regarded as an effective approach. However, existing knowledge of boiling enhancement with nanofluid is still limited in terms of the influences of its type, concentration, deposition and boiling time. In this paper, the pool boiling performance of a highly self-dispersion TiO 2 nanofluid with mass concentration from 0.0001% to 0.1% was experimentally investigated and compared with Al 2 O 3 and ZnO nanofluid. The effect of boiling-induced deposition layer was studied by means of repeatability test, wettability test and macro/micro morphology test. Results indicated that a super-hydrophilic micro-porous deposition layer formed on nanofluid boiling surface and led to nearly twice higher CHF than distilled water, and nanofluid itself had negligible influence on CHF enhancement. Increasing concentration of nanofluid led to occasional falling off of the deposition on surface and resulted in complicated and unpredictable boiling performance. Nanofluid type and concentration had limited influence on CHF, whose value kept around 1800 kW/m 2 . 0.0001% TiO 2 and Al 2 O 3 nanofluids had similar boiling curves, but ZnO nanofluid exhibited lower heat transfer coefficient . Finally, a novel criterion to predict the occurrence of film boiling in advance was proposed based on wall superheat change rate threshold. The present study will contribute to design guidance and security control of nanofluid-based pool boiling device.
研究领域:
工程热物理
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
·
2022
·
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
·
传热学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2025
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IF 8.2
Zhiming Xu,Hongpeng Jiang,Xiaoliang Wang,Zhirong Zhang,Yunfeng Qiu,Jie Xu,Debin Shan,Bin Guo
Pool boiling offers exceptional heat transfer performance, making it crucial for advanced thermal management. However, simultaneously optimizing both critical heat flux (CHF) and heat transfer coefficient (HTC) is challenging due to the inherent trade-off between promoting bubble nucleation and mitigating detrimental bubble coalescence. This study presents a micro/nano-hierarchical surface architecture designed to overcome this limitation. Fabricated via laser machining and chemical vapor deposition, the architecture comprises an array of micro pits (MPs) decorated with Co-catalyzed carbon nanotubes (CoCNTs). Computational fluid dynamics (CFD) simulations demonstrate that the MP array enhances HTC by increasing the density of nucleation sites and reducing the bubble departure diameter. Simultaneously, the CoCNTs within the MPs enhance interfacial heat transfer and promote capillary-driven liquid replenishment to the heating surface, effectively mitigating dry-out and significantly improving CHF. The synergistic effects of these micro/nanofeatures yield remarkable performance enhancements on Cu substrates, with the HTC and CHF increasing by 211.5% and 125.2%, respectively, compared to a bare Cu surface. This hierarchical surface design offers a promising strategy for developing high-performance boiling heat transfer surfaces for next-generation thermal management applications.
研究领域:
热能工程
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED THERMAL ENGINEERING
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2025
·
IF 6.9
Xue-Ying Hao,Yan Wang,Jian-Shu Liu,Xiao-Bin Li,Hong-Na Zhang,Feng-Chen Li
Effective boiling control is crucial for the thermal management in high-power electronics. Conventional passive methods lack adaptability while active electric field approaches often require high voltages or engineered surfaces. This study presents a low-voltage (<5 V) electrostatic strategy based on the electro-de-wetting (EDW) effect, using a low-concentration cationic surfactant solution and a common conductive surface. Without specialized substrates, by leveraging electric-field-driven surfactant migration and adsorption, the dynamic regulation of nucleation site density and surface temperature was achieved, reducing the heat flux required for the onset of nucleate boiling by approximately 50 % via enhanced surface hydrophobicity. The discovery of unique bubble clustering behavior multiplies nucleation at a single site by up to 5 times, while identification of a “main effective region” enhances the heat transfer coefficient by 12.0 %. The EDW effect enables reversible temporal boiling modulation, reducing copper surface temperature by 4.6 °C. This work establishes a low-voltage approach for intelligent boiling regulation, offering new paradigm for real-time, adaptive heat transfer enhancement
研究领域:
传热学
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界面科学
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电润湿
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热管理
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微尺度流体力学
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER
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2018
·
IF 3.891
Lingnan Lin,Zheng Chang,Guoliang Ding
The resuspension of deposited nanoparticles within a boiling fluid is a nanoparticle behavior that may mitigate or even avoid the degradation of nanofluids, which is of great significance to the long-lasting heat transfer enhancement of nanofluids. In this study, the nanoparticle resuspension behavior during pool boiling was investigated experimentally and theoretically. Visualized pool boiling experiments were conducted for the nanoparticle-deposited surfaces which were prepared by boiling nanofluids. Various methods were employed to capture the resuspension phenomenon and characterize the morphology of nanoparticle deposition layer. The nanoparticle resuspension ratio was measured for various boiling durations, deposition area densities, and heat fluxes to elucidate the effects of these factors on the resuspension behavior. It was found that a part of deposited nanoparticles were resuspended to the bulk of the boiling liquid and then migrated with the internal flow during pool boiling, and the porous structure of nanoparticle deposition layer played a key role in the occurrence of resuspension. The measurement showed that heat flux was a main influential factor, and increasing heat flux can lead to a dramatical increase of resuspension ratio. A semi-theoretical model was developed to predict the resuspension ratio, which agreed well with the experimental results.
研究领域:
热能工程
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纳米技术
·
传热学
✓ 已验证
DOI
高影响因子
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