Enhancement of loop heat pipe performance with the application of micro/nano hybrid structures
(2018) In International Journal of Heat and Mass Transfer 127. p.1248-1263- Abstract
To further improve the flat-type loop heat pipe (LHP) performance, this study evaluates the practical potential of use of highly enhanced boiling structures. It is found that in our proposed new heat pipe (NHP) system, the working fluid from the evaporator outlet to the condenser inlet is in a liquid–vapor two phase flow, which is different from the classical LHP theory. A new P-T diagram is developed to better understand the thermal and hydraulic process during the NHP steady operation. In this study, by using the laser ablation technique two different types of micro- and nanoscale hybrid structures are synthesized on the boiling pool substrate. It is indicated that the formed valleys with a larger opening width play an important role... (More)
To further improve the flat-type loop heat pipe (LHP) performance, this study evaluates the practical potential of use of highly enhanced boiling structures. It is found that in our proposed new heat pipe (NHP) system, the working fluid from the evaporator outlet to the condenser inlet is in a liquid–vapor two phase flow, which is different from the classical LHP theory. A new P-T diagram is developed to better understand the thermal and hydraulic process during the NHP steady operation. In this study, by using the laser ablation technique two different types of micro- and nanoscale hybrid structures are synthesized on the boiling pool substrate. It is indicated that the formed valleys with a larger opening width play an important role in more effectively improving the bubble nucleation and bubble growth at the micrometer sites, which can subsequently lead to an increased number of active nucleation sites. The best loop performance is obtained with the micro-cone structured substrate at a heat load of 140 W, at which the maximum boiling pool heat transfer coefficient of 42.17 kW/m2·K is achieved. Compared with the polishing Cu substrate, it is enhanced by 110%. When maintaining the boiling pool temperature lower than 85 °C, the proposed new heat pipe system can tolerate a maximum heat flux of 35.12 W/cm2, which is larger than that of the most conventional LHPs with methanol as the working fluid.
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- author
- Wang, Xueli LU ; Wei, Jinjia ; Deng, Yueping ; Wu, Zan LU and Sundén, Bengt LU
- organization
- publishing date
- 2018-12-01
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Heat pipe performance enhancement, Heat transfer coefficient, Micro/nano hybrid structures, Thermal and hydraulic process, Thermal resistance
- in
- International Journal of Heat and Mass Transfer
- volume
- 127
- pages
- 16 pages
- publisher
- Pergamon Press Ltd.
- external identifiers
-
- scopus:85049941622
- ISSN
- 0017-9310
- DOI
- 10.1016/j.ijheatmasstransfer.2018.06.138
- language
- English
- LU publication?
- yes
- id
- 88fe9ee7-f398-41f2-a05d-724d9950018a
- date added to LUP
- 2018-07-31 12:20:06
- date last changed
- 2023-11-17 22:14:15
@article{88fe9ee7-f398-41f2-a05d-724d9950018a,
abstract = {{<p>To further improve the flat-type loop heat pipe (LHP) performance, this study evaluates the practical potential of use of highly enhanced boiling structures. It is found that in our proposed new heat pipe (NHP) system, the working fluid from the evaporator outlet to the condenser inlet is in a liquid–vapor two phase flow, which is different from the classical LHP theory. A new P-T diagram is developed to better understand the thermal and hydraulic process during the NHP steady operation. In this study, by using the laser ablation technique two different types of micro- and nanoscale hybrid structures are synthesized on the boiling pool substrate. It is indicated that the formed valleys with a larger opening width play an important role in more effectively improving the bubble nucleation and bubble growth at the micrometer sites, which can subsequently lead to an increased number of active nucleation sites. The best loop performance is obtained with the micro-cone structured substrate at a heat load of 140 W, at which the maximum boiling pool heat transfer coefficient of 42.17 kW/m<sup>2</sup>·K is achieved. Compared with the polishing Cu substrate, it is enhanced by 110%. When maintaining the boiling pool temperature lower than 85 °C, the proposed new heat pipe system can tolerate a maximum heat flux of 35.12 W/cm<sup>2</sup>, which is larger than that of the most conventional LHPs with methanol as the working fluid.</p>}},
author = {{Wang, Xueli and Wei, Jinjia and Deng, Yueping and Wu, Zan and Sundén, Bengt}},
issn = {{0017-9310}},
keywords = {{Heat pipe performance enhancement; Heat transfer coefficient; Micro/nano hybrid structures; Thermal and hydraulic process; Thermal resistance}},
language = {{eng}},
month = {{12}},
pages = {{1248--1263}},
publisher = {{Pergamon Press Ltd.}},
series = {{International Journal of Heat and Mass Transfer}},
title = {{Enhancement of loop heat pipe performance with the application of micro/nano hybrid structures}},
url = {{http://dx.doi.org/10.1016/j.ijheatmasstransfer.2018.06.138}},
doi = {{10.1016/j.ijheatmasstransfer.2018.06.138}},
volume = {{127}},
year = {{2018}},
}