To investigate the heat transfer performance of large diameter pulsating heat pipe(PHP)
an experimental device for closed PHP with 3 mm inner diameter was designed and constructed. The heat transfer performance of PHP was investigated within heat power range of 0-90 W. The influence of different heating modes on the performance of PHP was tested by analyzing the fluctuation characteristics of wall temperatures in the condensation section. The experimental results indicate that the PHP well performs in a wide charge ratio range of 27.5%-67.5%
and the thermal resistances get less than 0.4 ℃/W at all tested charge ratios. When the input heat power fluctuates
the thermal resistances of PHP get greater than those heated by constant heat power
and the difference between them decreases with the increasing heat power. If the heat power suddenly reaches beyond the starting power of the PHP
the PHP quickly starts up
but takes a long period to become stable. However
the PHP quickly tends to be stable for gradual heating-mode. The small charge ratio is suggested in the case of lower heat power
otherwise
both the heat capability of working fluid and heat transfer performance ought to be considered.
关键词
Keywords
references
GARIMELLA S V, FLEISCHER A S, MURTHY J Y, et al. Thermal challenges in next-generation electronic systems[J]. IEEE Trans on Components and Packaging Technologies, 2008, 31(4): 801-815.
HAN Xiaohong, MIN Xuwei, LI Peng. Experimental study on an thermosyphon loop with bubble pump effect[J]. Journal of Xi'an Jiaotong University, 2012, 46(3): 9-14.
AKACHI H, KANAGAW A. Structure of a heat pipe: USA, US4921041[P].1990-05-01.
XIAO L, CAO Y. Recent advances in pulsating heat pipes and its derivatives[J]. Journal of Enhanced Heat Transfer, 2012, 19(3): 213-231.
SHAFFI M B, FAGHRI A, ZHANG Y W. Thermal modeling of unlooped and looped pulsating heat pipes[J]. Journal of Heat Transfer, 2001, 123(6): 1159-1172.
HOSODA M, NISHIO S, SHIRAKASHI R. Study of meandering closed-loop heat-transport device(vapor-plug propagation phenomena)[J]. JSME International Journal: Series B Fluids and Thermal Engineering, 1999, 42(4): 737-744.
MA Yongxi, ZHANG Hong. Heat transfer characteristics of oscillating heat pipes with under-critical turns[J]. Journal of Beijing University of Chemical Technology: Natural Science, 2005, 32(4): 87-90.
MA Yongxi, ZHANG Hong. Theoretical deduction and analysis of equivalent thermal conductivity of oscillating heat pipes[J]. Chemical Engineering, 2006, 34(10): 17-20.
LIU S, LI J T, DONG X Y, et al. Experimental study of flow patterns and improved configurations for pulsating heat pipes[J]. Journal of Thermal Science, 2007, 16(1): 56-62.
CAI Q, CHEN C L, ASFIA J F. Heat transfer enhancement of planar heat pipe device[C]∥2006 International Mechanical Engineering Congress and Exposition. New York, USA: ASME, 2006: 153-158.
KIM J S, BUI N H, JUNG H S, et al. The study on pressure oscillation and heat transfer characteristics of oscillating capillary tube heat pipe[J]. KSME International Journal, 2003, 17(10): 1533-1542.
PARK Y, TANSHEN M R, NINE M J, et al. Characterizing pressure fluctuation into single-loop oscillating heat pipe[J]. Journal of Central South University, 2012, 19(9): 2578-2583.
YANG H H, KHANDEKAR S, GROLL M. Operational limit of closed loop pulsating heat pipes[J]. Applied Thermal Engineering, 2008, 28(1): 49-59.
CHAROENSAWAN P, TERDTOON P. Thermal performance of horizontal closed-loop oscillating heat pipes[J]. Applied Thermal Engineering, 2008, 28(5): 460-466.
RITTIDECH S, TERDTOON P, MURAKAMI M, et al. Correlation to predict heat transfer characteristics of a closed-end oscillating heat pipe at normal operating condition[J]. Applied Thermal Engineering, 2003, 23(4): 497-510.
MOHAMMADI M, MOHAMMADI M, SHAFII M B. Experimental investigation of a pulsating heat pipe using ferro fluid(magnetic nanofluid)[J]. Journal of Heat Transfer, 2012, 134(1): 014504.