Thermal performance enhancement and optimization of two-phase closed thermosyphon with graphene-nanoplatelets coatings

Ng, Ving Onn; Yu, Hao; Wu, Heng An; Hung, Yew Mun

doi:10.1016/j.enconman.2021.114039

Cited by 34 publications

(9 citation statements)

References 57 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Previous research [42,43] suggested designing the thermosyphon so that the evaporator section area is smaller than that of the condenser section. This makes it possible to generate a higher heat flux in the evaporator, increase the thermal driving force in the system and increase the efficiency of the thermosyphon.…”

Section: Computational Domainmentioning

confidence: 99%

Numerical Study of a Cooling System Using Phase Change of a Refrigerant in a Thermosyphon

Czerwiński

Wołoszyn

2021

Energies

View full text Add to dashboard Cite

With the increasing trend toward the miniaturization of electronic devices, the issue of heat dissipation becomes essential. The use of phase changes in a two-phase closed thermosyphon (TPCT) enables a significant reduction in the heat generated even at high temperatures. In this paper, we propose a modification of the evaporation–condensation model implemented in ANSYS Fluent. The modification was to manipulate the value of the mass transfer time relaxation parameter for evaporation and condensation. The developed model in the form of a UDF script allowed the introduction of additional source equations, and the obtained solution is compared with the results available in the literature. The variable value of the mass transfer time relaxation parameter during condensation rc depending on the density of the liquid and vapour phase was taken into account in the calculations. However, compared to previous numerical studies, more accurate modelling of the phase change phenomenon of the medium in the thermosyphon was possible by adopting a mass transfer time relaxation parameter during evaporation re = 1. The assumption of ten-fold higher values resulted in overestimated temperature values in all sections of the thermosyphon. Hence, the coefficient re should be selected individually depending on the case under study. A too large value may cause difficulties in obtaining the convergence of solutions, which, in the case of numerical grids with many elements (especially three-dimensional), significantly increases the computation time.

show abstract

Section: Computational Domainmentioning

confidence: 99%

Numerical Study of a Cooling System Using Phase Change of a Refrigerant in a Thermosyphon

Czerwiński

Wołoszyn

2021

Energies

View full text Add to dashboard Cite

show abstract

“…The single-layer honey-lattice arrangement of graphene and its derivatives allows remarkable physical and thermal properties [ 1 , 2 , 3 , 4 ]. Due to its high thermal conductivity, graphene and its derivatives manifest as excellent heat-conducting materials for electronics cooling applications [ 5 , 6 , 7 , 8 , 9 , 10 ]. However, there is a limitation to the thermal conductivity of graphene derivatives in these practical applications.…”

Section: Introductionmentioning

confidence: 99%

“…The ultrafast water permeation property of graphene-based materials has been extensively utilized in various applications, such as desalination [ 36 , 37 , 38 , 39 ], nanofiltration [ 40 , 41 , 42 , 43 ] and phase-change heat transfer [ 9 , 15 , 29 ] systems. Among the carbon nanomaterials, the GNPs are found to exhibit the most superior ultrafast water permeation property [ 44 , 45 , 46 ].…”

Section: Introductionmentioning

confidence: 99%

Remarkable Thermal Performance Enhancement of Micro Heat Pipes with Graphene-Nanoplatelet Nano-Wicks

Gan¹,

Hung²

2023

Nanomaterials

Self Cite

View full text Add to dashboard Cite

The ultrafast water permeation property of graphene nanoplatelets (GNPs) synergically enhances the evaporation and water circulation processes in a micro heat pipe (MHP). An MHP is a promising phase-change heat-transfer device capable of transferring large amounts of heat energy efficiently. The hydrophobic, atomically smooth carbon walls of GNPs nanostructures provide a network of nanocapillaries that allows water molecules to intercalate frictionlessly among the graphene layers. Together with the attraction force of the oxygenated functional groups, a series of hydrophobic and hydrophilic surfaces are formed that significantly improve the water circulation rate. The intercalation of water molecules encourages the formation of water-thin film for film-wise evaporation. The effect of nano-wick thickness on the thermal performance of the MHP is investigated. A thinner GNP nano-wick is more favorable to film-wise evaporation while a thicker nano-wick promotes a higher water circulation rate from the condenser to the evaporator, leading to the existence of an optimal thickness. By benchmarking with the uncoated MHP, the thermal conductance of an MHP with a 46.9-µm GNP nano-wick manifests a maximum enhancement of 128%. This study provides insights on the feasible implementation of GNP nano-wicks into a highly efficient micro-scale electronics cooling device for environmental sustainability.

show abstract

“…The experimental results showed that when the input heat power is 300 W and the solid holdup is 5%, the overall thermal resistance can be reduced to 27.67% in the case of glass beads with a diameter of 200 mm. Ng et al [15] studied the effect of graphene-nanoparticles (GNPs) coatings with different wettability on heat pipe heat transfer performance. The experimental results showed that the heat pipe with cured GNPs coating has 31% higher thermal conductivity and 37% lower thermal resistance.…”

Section: Introductionmentioning

confidence: 99%

Heat Transfer Enhancement in Gravity Heat Pipes Using AAO Nanostructure Generated on Condenser Section Inner Surface

Kuo

Weng

2021

Processes

View full text Add to dashboard Cite

This study mainly focuses on the influence of anodic aluminum oxide (AAO) nanostructure generated on condenser section inner surface on the heat transfer performance of gravity heat pipes. AAO nanotubes were first grown by anodizing the inner wall surface of the condenser section of aluminum alloy gravity heat pipes through different anodizing voltages and treatment times. The nanostructure effect on the temperature distribution and overall thermal resistance was then investigated by using a thermal performance test system under different input heat powers. The experimental results showed that the generation of AAO nanostructure on the inner surface significantly enhances heat transfer performance; that is, the temperature difference between the evaporator and condenser sections and overall thermal resistance are reduced. Such an effect can be more significant in the case of a lower heat source. The percentage decreases in temperature difference and overall thermal resistance can be reduced by up to 58.83% and 58.79%, respectively, compared to the unprocessed heat pipe.

show abstract

Thermal performance enhancement and optimization of two-phase closed thermosyphon with graphene-nanoplatelets coatings

Cited by 34 publications

References 57 publications

Numerical Study of a Cooling System Using Phase Change of a Refrigerant in a Thermosyphon

Numerical Study of a Cooling System Using Phase Change of a Refrigerant in a Thermosyphon

Remarkable Thermal Performance Enhancement of Micro Heat Pipes with Graphene-Nanoplatelet Nano-Wicks

Heat Transfer Enhancement in Gravity Heat Pipes Using AAO Nanostructure Generated on Condenser Section Inner Surface

Contact Info

Product

Resources

About