An experimental investigation of the transient characteristics on a flat-plate heat pipe during startup and shutdown operations

Authors
Citation
Y. Wang et K. Vafai, An experimental investigation of the transient characteristics on a flat-plate heat pipe during startup and shutdown operations, J HEAT TRAN, 122(3), 2000, pp. 525-535
Citations number
19
Categorie Soggetti
Mechanical Engineering
Journal title
JOURNAL OF HEAT TRANSFER-TRANSACTIONS OF THE ASME
ISSN journal
00221481 → ACNP
Volume
122
Issue
3
Year of publication
2000
Pages
525 - 535
Database
ISI
SICI code
0022-1481(200008)122:3<525:AEIOTT>2.0.ZU;2-V
Abstract
This work presents an experimental investigation of the thermal performance of a flat-plate heat pipe during startup and shutdown operations. Using th e analytical model developed in a previously study, analytical and experime ntal results on the effect of input power and cooling heat transfer coeffic ient on the thermal performance of the heat pipe are presented and discusse d. The results indicate that the wick in the evaporator section provides th e largest resistance to the heat transfer process followed by the wick in t he condenser section. It is found that the heat transfer coefficient has an insignificant effect on the maximum temperature difference across the heat pipe where this difference refers to the maximum difference on the outside surfaces of the flat-plate heat pipe. However, as expected, the input heat flux has a substantial effect on the temperature rise where the temperatur e rise refers to the temperature increase on the outside surface of the hea t pipe. It is found that the temperature difference across the heat pipe de pends mainly on the input power. The heat transfer coefficient strongly aff ects the item it takes to reach steady state while input power has a substa ntially smaller effect. Empirical correlations for the maximum temperature rise, the maximum temperature difference and the time constants are obtaine d. The experimental results are compared with the analytical results and ar e found to be in very good agreement.