Research Papers

Flow Boiling Heat Transfer and Pressure Drops of R1234ze(E) in a Silicon Micro-pin Fin Evaporator

[+] Author and Article Information
C. Falsetti

Laboratory of Heat and Mass Transfer (LTCM),
Ecole Polytechnique Fédérale de
Lausanne (EPFL),
Station 9,
Lausanne CH-1015, Switzerland
e-mail: chiara.falsetti@epfl.ch

M. Magnini

Laboratory of Heat and Mass Transfer (LTCM),
Ecole Polytechnique Fédérale de
Lausanne (EPFL),
Station 9,
Lausanne CH-1015, Switzerland
e-mail: mirco.magnini@epfl.ch

J. R. Thome

Laboratory of Heat and Mass Transfer (LTCM),
Ecole Polytechnique Fédérale de
Lausanne (EPFL),
Station 9,
Lausanne CH-1015, Switzerland
e-mail: john.thome@epfl.ch

Contributed by the Electronic and Photonic Packaging Division of ASME for publication in the JOURNAL OF ELECTRONIC PACKAGING. Manuscript received February 27, 2017; final manuscript received June 21, 2017; published online July 10, 2017. Assoc. Editor: Mehdi Asheghi.

J. Electron. Packag 139(3), 031008 (Jul 10, 2017) (8 pages) Paper No: EP-17-1023; doi: 10.1115/1.4037152 History: Received February 27, 2017; Revised June 21, 2017

The development of newer and more efficient cooling techniques to sustain the increasing power density of high-performance computing systems is becoming one of the major challenges in the development of microelectronics. In this framework, two-phase cooling is a promising solution for dissipating the greater amount of generated heat. In the present study, an experimental investigation of two-phase flow boiling in a micro-pin fin evaporator is performed. The micro-evaporator has a heated area of 1 cm2 containing 66 rows of cylindrical in-line micro-pin fins with diameter, height, and pitch of, respectively, 50 μm, 100 μm, and 91.7 μm. The working fluid is R1234ze(E) tested over a wide range of conditions: mass fluxes varying from 750 kg/m2 s to 1750 kg/m2 s and heat fluxes ranging from 20 W/cm2 to 44 W/cm2. The effects of saturation temperature on the heat transfer are investigated by testing three different outlet saturation temperatures: 25 °C, 30 °C, and 35 °C. In order to assess the thermal–hydraulic performance of the current heat sink, the total pressure drops are directly measured, while local values of heat transfer coefficient are evaluated by coupling high-speed flow visualization with infrared temperature measurements. According to the experimental results, the mass flux has the most significant impact on the heat transfer coefficient while heat flux is a less influential parameter. The vapor quality varies in a range between 0 and 0.45. The heat transfer coefficient in the subcooled region reaches a maximum value of about 12 kW/m2 K, whilst in two-phase flow it goes up to 30 kW/m2 K.

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Madhour, Y. , Zervas, M. , Schlottig, G. , Brunschwiler, T. , Leblebici, Y. , Thome, J. R. , and Michel, B. , 2013, “ Integration of Intra Chip Stack Fluidic Cooling Using Thin-Layer Solder Bonding,” IEEE International 3D Systems Integration Conference (3DIC), San Francisco, CA, Oct. 2–4.
Brunschwiler, T. , Sridhar, A. , Ong, C. L. , and Schlottig, G. , 2016, “ Benchmarking Study on the Thermal Management Landscape for Three-Dimensional Integrated Circuits: From Back-Side to Volumetric Heat Removal,” ASME J. Electron. Packag., 138(1), p. 010911. [CrossRef]
Kosar, A. , Mishra, C. , and Peles, Y. , 2005, “ Laminar Flow Across a Bank of Low Aspect Ratio Micro Pin Fins,” ASME J. Fluids Eng., 127(3), pp. 419–430. [CrossRef]
Kosar, 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. [CrossRef]
Prasher, R. , Chang, J.-Y. , Myers, A. , Chau, D. , and He, D. , 2007, “ Nusselt Number and Friction Factor of Staggered Arrays of Low Aspect Ratio Micropin-Fins Under Cross Flow for Water as Fluid,” ASME J. Heat Transfer, 129(2), pp. 141–153. [CrossRef]
Brunschwiler, T. , Michel, B. , Rothuizen, H. , Kloter, U. , Wunderle, B. , Oppermann, H. , and Reichl, H. , 2009, “ Interlayer Cooling Potential in Vertically Integrated Packages,” Microsyst. Technol., 15(1), pp. 57–74. [CrossRef]
Qu, W. , and Siu-Ho, A. , 2008, “ Liquid Single Phase Flow in an Array of Micro-Pin-Fins—Part I: Heat Transfer Characteristics,” ASME J. Heat Transfer, 130(12), p. 122402. [CrossRef]
Mita, J. , Qu, W. , and Siu-Ho, A. , 2015, “ Pressure Drop of Water Flow Across a Micro-Pin Fin Array—Part 1: Isothermal Liquid Single-Phase Flow,” ASME J. Heat Transfer, 89, pp. 1073–1082. [CrossRef]
Kosar, 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. [CrossRef]
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. [CrossRef]
Kosar, A. , and Peles, Y. , 2010, “ Flow Boiling Heat Transfer on Micro Pin Fins Entrenched in a Microchannel,” ASME J. Heat Transfer, 132(4), p. 041007. [CrossRef]
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. [CrossRef]
Isaacs, S. , Kim, Y. , McNamara, A. J. , Joshi, Y. , Zhang, Y. , and Bakir, M. S. , 2012, “ Two-Phase Flow and Heat Transfer in pin-Fin Enhanced Micro-Gaps,” 13th IEEE Intersociety Conference on Thermal and Thermomechanical Phenomena in Electronic Systems (ITherm), San Diego, CA, May 30–June 1.
David, T. , Mendler, D. , Mosyak, A. , Bar-Cohen, A. , and Hetsroni, G. , 2014, “ Thermal Management of Time-Varying High Heat Flux Electronic Devices,” ASME J. Electron. Packag., 136(2), p. 021003. [CrossRef]
Reeser, A. , Bar-Cohen, A. , and Hetsroni, G. , 2014, “ High Quality ow Boiling Heat Transfer and Pressure Drop in Microgap Pin Fin Arrays,” Int. J. Heat Mass Transfer, 78, pp. 974–985. [CrossRef]
Falsetti, C. , Jafarpoorchekab, H. , Magnini, M. , Borhani, N. , and Thome, J. R. , 2017, “ Two-Phase Operational Maps, Pressure Drop, and Heat Transfer for Flow Boiling of R236fa in a Micro-Pin Fin Evaporator,” Int. J. Heat Mass Transfer, 107, pp. 805–819. [CrossRef]
Park, J. E. , Thome, J. R. , and Michael, B. , 2009, “ Effect of Inlet Orifices on Saturated CHF and flow Visualization in Multi-Microchannel Heat Sinks,” 25th Annual IEEE Semiconductor Thermal Measurement and Management Symposium (SEMI-THERM), San Jose, CA, Mar. 15–19.
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. [CrossRef]
Kline, S. J. , and McClintock, F. A. , 1953, “ Describing Uncertainties in Single-Sample Experiments,” Mech. Eng., 75, pp. 3–8.
Lee, P. , and Garimella, V. , 2008, “ Saturated Flow Boiling Heat Transfer and Pressure Drop in Silicon Microchannel Arrays,” Int. J. Heat Mass Transfer, 51(3–4), pp. 789–806. [CrossRef]
Renfer, A. , Tiwari, M. K. , Brunschwiler, T. , Michel, B. , and Poulikakos, D. , 2011, “ Experimental Investigation Into Vortex Structure and Pressure Drop Across Microcavities in 3D Integrated Liquid Electronics,” Exp. Fluids, 51(3), pp. 731–741. [CrossRef]
Nieuwstadt, F. T. , Boersma, B. J. , and Westerweel, J. , 2015, Turbulence: Introduction to Theory and Applications of Turbulent Flows, Springer, Cham, Switzerland, pp. 48–50.
Short, B. E. , Raad, P. E. , and Price, D. C. , 2002, “ Performance of Pin Fin Cast Aluminium Coldwalls—Part 2: Colburn j-Factor Correlations,” J. Thermophys. Heat Transfer, 16(3), pp. 397–403. [CrossRef]
Chyu, M. K. , Hsing, Y. C. , Shih, T. I. P. , and Natarajan, V. , 1999, “ Heat Transfer Contributions of Pins and Endwall in Pin-Fin Arrays: Effects of Thermal Boundary Condition Modelling,” ASME J. Turbomach., 121(2), pp. 257–263. [CrossRef]
Zukauskas, A. , and Ulinskas, R. , 1972, “ Heat Transfer From Tubes in Cross Flow,” Adv. Heat Transfer, 8, pp. 93–160.
Borhani, N. , Agostini, B. , and Thome, J. R. , 2010, “ A Novel Time Strip Flow Visualisation Technique for Investigation of Intermittent Dewetting and Dryout in Elongated Bubble Flow in a Microchannel Evaporator,” Int. J. Heat Mass Transfer, 53(21–22), pp. 4809–4818. [CrossRef]
Szczukiewicz, S. , Borhani, N. , and Thome, J. R. , 2013, “ Two-Phase Heat Transfer and High-Speed Visualization of Refrigerant Flows in 100 × 100 μm Silicon Multi-Microchannels,” Int. J. Refrig., 36(2), pp. 402–413. [CrossRef]
Ong, C. L. , and Thome, J. R. , 2011, “ Macro-to-Microchannel Transition in Two-Phase Flow—Part 2: Flow Boiling Heat Transfer and Critical Heat Flux,” Exp. Therm. Fluid Sci., 35(6), pp. 873–886. [CrossRef]
Huang, H. , and Thome, J. R. , 2016, “ Local Measurements and a New Flow Pattern Based Model for Subcooled and Saturated Flow Boiling Heat Transfer in Multi-Microchannel Evaporators,” Int. J. Heat Mass Transfer, 103, pp. 701–714. [CrossRef]


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Fig. 1

Schematic of the experimental flow loop

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Fig. 2

Test section top side (a), bottom side (b), micro-pin fins geometry and configuration of the heated area (c and d)

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Fig. 3

Experimental repeatability of the heat transfer coefficient versus vapor quality

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Fig. 4

Total single-phase pressure drops versus mass flux

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Fig. 5

Friction factor versus Reynolds number

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Fig. 6

Average Nusselt number versus Reynolds number. Comparison with existing correlations.

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Fig. 7

Total two-phase pressure drop versus outlet vapor quality varying the test conditions

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Fig. 8

(a) Micro-evaporator base temperature measured with the IR camera, (b) corresponding heat transfer coefficient calculated with the explained data reduction, (c) screenshot from the high-speed camera, and (d) local heat transfer coefficient averaged along the widthwise direction, under the test conditions of G = 1000 kg/m2 s, q = 28 W/cm2, and Tsat = 35 °C. Flow is from the left to the right.

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Fig. 9

Local heat transfer coefficient versus vapor quality. Effects of heat flux when G = 1000 kg/m2 s (a), and G = 1500 kg/m2 s (b). Tsat = 35 °C.

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Fig. 10

Local heat transfer coefficient versus vapor quality. Effects of mass flux when q = 28 W/cm2 (a), and G = 40 W/cm2 (b). Tsat = 35 °C.

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Fig. 11

Local heat transfer coefficient along the streamwise direction, with flow visualization screenshots obtained by means of the high-speed camera. Tsat = 35 °C.

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Fig. 12

Local heat transfer coefficient versus vapor quality. Effects of the outlet saturation temperature. Test conditions: G = 1500 kg/m2 s, q = 40 W/cm2.




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