Heat transfer characteristics of two-phase closed thermosyphons modified with inner surfaces of various wettabilities

Zhao, Zhong; Jiang, Pengpeng; Zhou, Yadong; Zhang, Yong; Zhang, Yanrui

doi:10.1016/j.icheatmasstransfer.2019.03.006

Cited by 35 publications

(3 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…During the experiment, strict insulation measures are taken on the outside of the evaporator section, the adiabatic section and the cooling water jacket in order to ensure minimum heat loss. The heat-balance method [9] is used to determine the heat loss of the system. The power relative error is defined as the ratio of the difference between the input heat Q e in the evaporator section and the released heat Q c in the condenser section to the input heat Q e , and calculated using Equation (2) as:…”

Section: Data Reduction and Problem Descriptionmentioning

confidence: 99%

See 1 more Smart Citation

Investigation of Start-Up Characteristics of Thermosyphons Modified with Different Hydrophilic and Hydrophobic Inner Surfaces

Zhao

Jiang

et al. 2020

Energies

Self Cite

View full text Add to dashboard Cite

In this paper, the influence of wettability properties on the start-up characteristics of two-phase closed thermosyphons (TPCTs) is investigated. Chemical coating and etching techniques are performed to prepare the surfaces with different wettabilities that is quantified in the form of the contact angle (CA). The 12 TPCTs are processed including the same CA and a different CA combination on the inner surfaces inside both the evaporator and the condenser sections. For TPCTs with the same wettability properties, the introduction of hydrophilic properties inside the evaporator section not only significantly reduces the start-up time but also decreases the start-up temperature. For example, the start-up time of a TPCT with CA = 28° at 40 W, 60 W and 80 W is 46%, 50% and 55% shorter than that of a TPCT with a smooth surface and the wall superheat degrees is 55%, 39% and 28% lower, respectively. For TPCTs with combined hydrophilic and hydrophobic properties, the start-up time spent on the evaporator section with hydrophilic properties is shorter than that of the hydrophobic evaporator section and the smaller CA on the condenser section shows better results. The start-up time of a TPCT with CA = 28° on the evaporator section and CA = 105° on the condenser section has the best start-up process at 40 W, 60 W and 80 W which is 14%, 22% and 26% shorter than that of a TPCT with smooth surface. Thus, the hydrophilic and hydrophobic modifications play a significant role in promoting the start-up process of a TPCT.

show abstract

Section: Data Reduction and Problem Descriptionmentioning

confidence: 99%

“…By coating various ratios of materials, such as N-butyl, stearic acid, xylenes and acetone, the CAs of surfaces are approximately 61 • , 79 • , 105 • , 117 • and 142 • , respectively. Detailed surface modification methods have been described in the authors' previous work [9].…”

Section: Surface Modificationmentioning

confidence: 99%

Investigation of Start-Up Characteristics of Thermosyphons Modified with Different Hydrophilic and Hydrophobic Inner Surfaces

Zhao

Jiang

et al. 2020

Energies

Self Cite

View full text Add to dashboard Cite

show abstract

“…In this study, to enhance the heat transfer performance of the TPCT of Co = 0.245, hydrophilic surface modification was additionally applied to the evaporator inner surface in addition to the CNF fluid. Previous studies have attempted to improve the heat transfer coefficient of conventional TPCT (Co < 0.11) by reducing the wettability of the condenser inner surface [ 18 , 19 , 20 ] or improving the wettability of the evaporator’s inner surface [ 18 , 19 , 21 ]. In this study, because the focus was on improving the boiling heat transfer performance, surface modification was applied only to the evaporator’s inner surface.…”

Section: Introductionmentioning

confidence: 99%

Heat Transfer Enhancement of Small-Diameter Two-Phase Closed Thermosyphon Using Cellulose Nanofiber and Hydrophilic Surface Modification

et al. 2021

View full text Add to dashboard Cite

In this study, we observed the Geyser phenomenon that occurs in a small-diameter two-phase closed thermosyphon (confinement number of 0.245). This phenomenon interferes with the natural circulation of the internal working fluid and increases the thermal resistance of the system. This study attempts to improve the thermal performance of the system using cellulose nanofiber as the working fluid and hydrophilic surface modification at the inner surface of the evaporator section. As a result, the total thermal resistance showed average reduction rates of 47.51%, 36.69%, and 22.56% at filling ratios of 0.25, 0.5, and 0.75, respectively.

show abstract

Thermal performances and characteristics of thermosyphon heat pipe using alumina nanofluids

Shuoman

Abdelaziz²,

Abdel‐Samad

2021

Heat Mass Transfer

View full text Add to dashboard Cite

Heat transfer characteristics of two-phase closed thermosyphons modified with inner surfaces of various wettabilities

Cited by 35 publications

References 25 publications

Investigation of Start-Up Characteristics of Thermosyphons Modified with Different Hydrophilic and Hydrophobic Inner Surfaces

Investigation of Start-Up Characteristics of Thermosyphons Modified with Different Hydrophilic and Hydrophobic Inner Surfaces

Heat Transfer Enhancement of Small-Diameter Two-Phase Closed Thermosyphon Using Cellulose Nanofiber and Hydrophilic Surface Modification

Thermal performances and characteristics of thermosyphon heat pipe using alumina nanofluids

Contact Info

Product

Resources

About