Abstract

Coldplates are a crucial component in various cooling applications, such as cooling data center servers and power electronics. The unprecedented growth in electronics power density, along with the resulting ultrahigh heat fluxes, demands a transition from single-phase forced convection to two-phase flow boiling heat transfer. The majority of studies in the literature have focused on flow boiling in fin-enhanced silicon microgaps and microchannels, with only a few addressing flow boiling in millimeter-scale heat sinks. In the present study, flow boiling of HFE-7200 dielectric fluid in a millimeter-scale pin-fin coldplate is experimentally investigated under nonuniform heating conditions. Four background heaters represent the low-dissipating-power devices. On the other hand, five hotspot heaters mimic the high-heat-flux devices and generate heat fluxes ranging from 50 W/cm2 to 1000 W/cm2, corresponding to hotspot heat inputs ranging from 62.5 W to 1.25 kW, respectively. The coldplate's thermohydraulic performance is investigated for various flow rates and inlet temperature ranging from 0.5 L/min to 1.5 L/min and from 25 °C to 60 °C, respectively. A high-speed camera is utilized for a narrow field of view (FOV) flow visualization at a frame rate of 2229 fps while a digital camera is used for a wider FOV at 60 fps. Flow visualization demonstrated the transition between bubbly, slug/churn, and stratified two-phase flow regimes.

References

1.
Tullius
,
J.
,
Tullius
,
T.
, and
Bayazitoglu
,
Y.
,
2012
, “
Optimization of Short Micro Pin Fins in Minichannels
,”
Int. J. Heat Mass Transfer
,
55
(
15–16
), pp.
3921
3932
.10.1016/j.ijheatmasstransfer.2012.03.022
2.
Wan
,
Z.
, and
Joshi
,
Y.
,
2017
, “
Pressure Drop and Heat Transfer Characteristics of Pin Fin Enhanced Microgaps in Single Phase Microfluidic Cooling
,”
Int. J. Heat Mass Transfer
,
115
, pp.
115
126
.10.1016/j.ijheatmasstransfer.2017.06.117
3.
Wojtan
,
L.
,
Ursenbacher
,
T.
, and
Thome
,
J. R.
,
2005
, “
Investigation of Flow Boiling in Horizontal Tubes: Part I—A New Diabatic Two-Phase Flow Pattern Map
,”
Int. J. Heat Mass Transfer
,
48
(
14
), pp.
2955
2969
.10.1016/j.ijheatmasstransfer.2004.12.012
4.
Kim
,
S.-M.
, and
Mudawar
,
I.
,
2013
, “
Universal Approach to Predicting Saturated Flow Boiling Heat Transfer in Mini/Micro-Channels - Part II. Two-Phase Heat Transfer Coefficient
,”
Int. J. Heat Mass Transfer
,
64
, pp.
1239
1256
.10.1016/j.ijheatmasstransfer.2013.04.014
5.
Ghiaasiaan
,
S. M.
,
2007
,
Two-Phase Flow, Boiling, and Condensation: In Conventional and Miniature Systems
,
Cambridge University Press
, Cambridge, UK.
6.
Liang
,
G.
, and
Mudawar
,
I.
,
2020
, “
Review of Channel Flow Boiling Enhancement by Surface Modification, and Instability Suppression Schemes
,”
Int. J. Heat Mass Transfer
,
146
, p.
118864
.10.1016/j.ijheatmasstransfer.2019.118864
7.
Koşar
,
A.
, and
Peles
,
Y.
,
2006
, “
Convective Flow of Refrigerant (R-123) Across a Bank of Micro Pin Fins
,”
Int. J. Heat Mass Transfer
,
49
(
17–18
), pp.
3142
3155
.10.1016/j.ijheatmasstransfer.2006.02.013
8.
Koşar
,
A.
, and
Peles
,
Y.
,
2007
, “
Boiling Heat Transfer in a Hydrofoil-Based Micro Pin Fin Heat Sink
,”
Int. J. Heat Mass Transfer
,
50
(
5–6
), pp.
1018
1034
.10.1016/j.ijheatmasstransfer.2006.07.032
9.
Woodcock
,
C.
,
Yu
,
X.
,
Plawsky
,
J.
, and
Peles
,
Y.
,
2015
, “
Piranha Pin Fin (PPF) - Advanced Flow Boiling Microstructures With Low Surface Tension Dielectric Fluids
,”
Int. J. Heat Mass Transfer
,
90
, pp.
591
604
.10.1016/j.ijheatmasstransfer.2015.06.072
10.
Asrar
,
P.
,
Zhang
,
X.
,
Green
,
C. E.
,
Bakir
,
M.
, and
Joshi
,
Y. K.
,
2018
, “
Flow Boiling of R245fa in a Microgap With Staggered Circular Cylindrical Pin Fins
,”
Int. J. Heat Mass Transfer
,
121
, pp.
329
342
.10.1016/j.ijheatmasstransfer.2017.12.117
11.
Han
,
X.
,
Fedorov
,
A.
, and
Joshi
,
Y.
,
2016
, “
Flow Boiling in Microgaps for Thermal Management of High Heat Flux Microsystems
,”
ASME J. Electron. Packag.
,
138
(
4
), p.
040801
.10.1115/1.4034317
12.
Mohammadi
,
A.
, and
Koşar
,
A.
,
2018
, “
Review on Heat and Fluid Flow in Micro Pin Fin Heat Sinks Under Single-Phase and Two-Phase Flow Conditions
,”
Nanoscale Microscale Thermophys. Eng.
,
22
(
3
), pp.
153
197
.10.1080/15567265.2018.1475525
13.
McNeil
,
D.
,
Raeisi
,
A.
,
Kew
,
P.
, and
Bobbili
,
P.
,
2010
, “
A Comparison of Flow Boiling Heat-Transfer in in-Line Mini Pin Fin and Plane Channel Flows
,”
Appl. Therm. Eng.
,
30
(
16
), pp.
2412
2425
.10.1016/j.applthermaleng.2010.06.011
14.
McNeil
,
D.
,
Raeisi
,
A.
,
Kew
,
P.
, and
Hamed
,
R.
,
2014
, “
An Investigation Into Flow Boiling Heat Transfer and Pressure Drop in a Pin-Finned Heat Sink
,”
Int. J. Multiphase Flow
,
67
, pp.
65
84
.10.1016/j.ijmultiphaseflow.2014.06.012
15.
Hu
,
B.
,
Qi
,
D.
,
Xu
,
Y.
,
Lin
,
M.
, and
Wang
,
Q.
,
2023
, “
A Comparative Study of Flow Boiling Heat Transfer and Pressure Drop Characteristics in a Pin-Finned Heat Sink at Horizontal/Vertical Upward Flow Orientations
,”
ASME J. Heat Mass Transfer-Trans. ASME
,
146
(
1
), p.
011006
.10.1115/1.4063765
16.
Reeser
,
A.
,
Bar-Cohen
,
A.
, and
Hetsroni
,
G.
,
2014
, “
High Quality Flow Boiling Heat Transfer and Pressure Drop in Microgap Pin Fin Arrays
,”
Int. J. Heat Mass Transfer
,
78
, pp.
974
985
.10.1016/j.ijheatmasstransfer.2014.05.021
17.
Krishnamurthy
,
S.
, and
Peles
,
Y.
,
2008
, “
Flow Boiling of Water in a Circular Staggered Micro-Pin Fin Heat Sink
,”
Int. J. Heat Mass Transfer
,
51
(
5–6
), pp.
1349
1364
.10.1016/j.ijheatmasstransfer.2007.11.026
18.
Qu
,
W.
, and
Siu-Ho
,
A.
,
2009
, “
Experimental Study of Saturated Flow Boiling Heat Transfer in an Array of Staggered Micro-Pin-Fins
,”
Int. J. Heat Mass Transfer
,
52
(
7–8
), pp.
1853
1863
.10.1016/j.ijheatmasstransfer.2008.10.008
19.
Osman
,
A.
, and
Joshi
,
Y.
,
2022
, “
Simulation and Experimental Investigation of Single and Two-Phase Cold Plate Using HFE-7200 With Discrete Heat Sources
,” 28th International Workshop on Thermal Investigations of ICs and Systems (
THERMINIC
), Dublin, Ireland, Sept. 28–30, pp.
1
7
.10.1109/THERMINIC57263.2022.9950676
20.
Holman
,
J. P.
,
1966
, “
Experimental Methods for Engineers
,”
McGraw-Hill
,
New York
.
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