Fine-resolution two-phase flow heat transfer coefficient measurements of refrigerants in multi-microchannel evaporators

Szczukiewicz, Sylwia; Borhani, Navid; Thome, John R.

doi:10.1016/j.ijheatmasstransfer.2013.08.078

Cited by 49 publications

(18 citation statements)

References 43 publications

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“…Indeed, mass flux is not an influential parameter and the heat flux has the only effect of shifting the curves vertically (see Fig. 9(a) in [34]). In the micro-pin fins flow configuration, the shapes of gives a higher heat removal capability than multi-microchannels over a wide range of operating conditions.…”

Section: Heat Transfer Coefficientmentioning

confidence: 99%

Two-phase operational maps, pressure drop, and heat transfer for flow boiling of R236fa in a micro-pin fin evaporator

Falsetti

Jafarpoorchekab

Magnini

et al. 2017

International Journal of Heat and Mass Transfer

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Cooling the new generation of 3D high power electronic chips is one of the leading challenges in microelectronics, as it is a key to achieve high computational performance at lower cooling system power consumption, thus reducing the operating cost. Two-phase flow boiling in two micro-pin fins heat sinks is studied here for this cooling process. Each micro-evaporator has a heated area of 1 cm 2 and contains 66 rows of cylindrical micro-pin fins with an in-line configuration and diameter, height and pitch of respectively 50 µm, 100 µm and 91.7 µm. The fluid tested is refrigerant R236fa. Channel

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Section: Heat Transfer Coefficientmentioning

confidence: 99%

Two-phase operational maps, pressure drop, and heat transfer for flow boiling of R236fa in a micro-pin fin evaporator

Falsetti

Jafarpoorchekab

Magnini

et al. 2017

International Journal of Heat and Mass Transfer

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show abstract

“…high aspect ratio rectangular fins in silicon and copper in particular. Vakili-Farahani et al (2012) and Szczukiewicz et al (2013) also found that this adaption works well for noncircular microchannels for an aluminum multiport tube test section and for a multimicrochannel test section with square channels of only 100 by 100 microns, respectively. These adaptions and comparisons will be discussed below.…”

Section: Results For Non-circular Microchannelsmentioning

confidence: 81%

“…In order to handle the other relevant flow regimes in microscale channels, notably isolated bubble flow and elongated bubble flow, these annular flow models have been recently extended (Costa-Patry et al, 2011a,b 2012Vakili-Farahani et al, 2012 andSzczukiewicz et al, 2013) by combining them with the Lockhart and Martinelli (1949) method to predict the pressure gradient, and with the Cooper (1984) nucleate pool boiling correlation and the three-zone convective heat transfer model (Thome et al, 2004) to predict the heat transfer coefficient in the isolated bubble flow regime and in the elongated bubble flow regime, respectively.…”

Section: Results For Non-circular Microchannelsmentioning

confidence: 99%

See 1 more Smart Citation

Unified Modeling Suite for Two-Phase Flow, Convective Boiling, and Condensation in Macro- and Microchannels

Thome

Cioncolini

2016

Heat Transfer Engineering

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The present paper focuses on the unified modeling suite for annular flow that the authors have and continue to develop. Annular flow is of fundamental importance to the thermal design and simulation of microevaporators and micro-condensers for compact two-phase cooling systems of high heat flux components for the thermal management of computer chips, power electronics, laser diodes and high energy physics particle detectors. First, the unified suite of methods is presented, illustrating in particular the most recent updates. Then, results for convective evaporation of refrigerants in non-circular multi-microchannel configurations for microelectronics cooling are presented and discussed. The annular flow suite includes models to predict the void fraction, the entrained liquid fraction, the wall shear stress and pressure gradient, and a turbulence model for momentum and heat transport inside the annular liquid film. The turbulence model, in particular, allows prediction of the local average liquid film thicknesses and the local heat transfer coefficients during convective evaporation and condensation. The benefit of a unified modeling suite is that all the included prediction methods are consistently formulated and are proven to work well together, and provide a platform for continued advancement based on the other models in the suite.

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“…Therefore, the inlet plenum configuration influences the two-phase flow topology and its dynamics along the channels, affecting, consequently, the heat transfer coefficient, pressure drop and critical heat flux. Szczukiewicz et al (2013aSzczukiewicz et al ( , 2013bSzczukiewicz et al ( , 2013cSzczukiewicz et al ( , 2014 observed significant mal-distribution effects of the refrigerant among the channels and its harmful effect to the temperature distribution on the footprint surface of a heat sink based on parallel microchannels. By adding restrictions to the flow at the inlet of each microchannel, Szczukiewicz et al (2014) equalized the two-phase flow distribution among the channels and minimized thermal instability effects.…”

Section: Introductionmentioning

confidence: 99%

COMPARATIVE ANALYSES OF THE THERMAL PERFORMANCE OF REFRIGERANTS R134A, R245fa, R407C AND R600a DURING FLOW BOILING IN A MICROCHANNELS HEAT SINK

Leão

Marchetto

Ribatski

2018

RETERM

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A comparative study of the performance of of refrigerants R134a, R407C, R245fa and R600a during flow boiling was performed for a 123x494 µm2 heat sink composed of 50 parallel rectangular microchannels. Heat transfer experimental results for heat fluxes up to 310 kW/m2, mass velocities from 300 to 800 kg/(m2 s), liquid subcoolings of 5 and 10 °C and saturation temperature close to 30 ºC were obtained. Global heat transfer coefficients (footprint) up to 10 kW/(m2 °C) were found. The liquid superheating necessary for the onset of nucleate boiling (ONB) was also characterized, and the fluids R245fa and R407C presented the highest and lowest, respectively, superheating to trigger the boiling process. Moreover, for a fixed averaged vapor quality, the average effective heat transfer coefficient increases with increasing mass velocity and liquid subcooling. The refrigerants R600a and R407C presented the highest and the lowest heat transfer coefficients, respectively. Five heat transfer predictive methods from literature provided accurate predictions of the data for R134a, R245fa and R600a, capturing most of the data trends. No one method provided accurate predictions of the heat transfer coefficient data of R407C.

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Fine-resolution two-phase flow heat transfer coefficient measurements of refrigerants in multi-microchannel evaporators

Cited by 49 publications

References 43 publications

Two-phase operational maps, pressure drop, and heat transfer for flow boiling of R236fa in a micro-pin fin evaporator

Two-phase operational maps, pressure drop, and heat transfer for flow boiling of R236fa in a micro-pin fin evaporator

Unified Modeling Suite for Two-Phase Flow, Convective Boiling, and Condensation in Macro- and Microchannels

COMPARATIVE ANALYSES OF THE THERMAL PERFORMANCE OF REFRIGERANTS R134A, R245fa, R407C AND R600a DURING FLOW BOILING IN A MICROCHANNELS HEAT SINK

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