Experimental and numerical investigation of a shaped microchannel evaporator for a micro Rankine cycle application

Azarkish, Hassan; Arslan, Selin; Behzadmehr, A.; Sheikholeslami, Tahereh Fanaei; Sarvari, S. M. Hosseini; Fréchette, Luc

doi:10.1016/j.ijthermalsci.2015.05.010

Cited by 7 publications

(4 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…More detailed information about these boundary conditions and solving method of the Eq. 4are presented elsewhere [3,13,17]. Permeability is a key parameter to determine and optimize the liquid flow rate through the micropillar array.…”

Section: Modelingmentioning

confidence: 99%

“…They have been proposed and studied mainly for cooling of advanced semiconductor devices [1]. Another application for thin film evaporation is to provide a controllable flow of fully evaporated steam for micro chemical processing and micro heat engines [2,3]. One approach consists of conducting the phase change in microchannels, but it has often lead to inconsistent vapor quality at the exit.…”

Section: Introductionmentioning

confidence: 99%

“…One approach consists of conducting the phase change in microchannels, but it has often lead to inconsistent vapor quality at the exit. Alternatively, shaped microchannels have been shown to provide fully evaporate steam, using surface tension and a streamwise temperature gradient [2,3]. Experimental results showed that a limited range of evaporation mass flow rate can be achieved with this method due to its limited liquid thin film area.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Modeling the Performance of Bi-Textured Micropillar Array as a Wicked Evaporator

Azarkish

Behzadmehr

Fréchette

2016

Volume 2: Heat Transfer in Multiphase Systems; Gas Turbine Heat Transfer; Manufacturing and Materials Processing; Heat Transfer

View full text Add to dashboard Cite

In the present work, the performance of bi-textured micro pillar arrays has been modeled as a wicked evaporator to provide steam flow via the thin film evaporation mechanism. Bi-textured micro pillar evaporator consists of an array with rough hydrophilic pillar bases and smooth hydrophobic tips. Water wicks between the rough hydrophilic sections of the micro pillar array to cover the surface, and vaporizes from the thin films that are formed in the vicinity of the pillar walls. The stability of the phase change mechanism is increased due to the change in direction of the capillary forces at the rough-smooth interface of micro pillars. The experimental results show that the pure evaporation mechanism occurs for a surface temperature above saturation on the bi-textured micro pillar array. The numerical analysis shows that there are optimal micro pillar dimensions for each surface temperature. The evaporation mass flow rate at the optimum dimensions is higher than the pool boiling mass flow rate on a bare surface at the same surface temperature. However, the wicked evaporator performance decreases for larger evaporator sizes.

show abstract

Section: Modelingmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Modeling the Performance of Bi-Textured Micropillar Array as a Wicked Evaporator

Azarkish

Behzadmehr

Fréchette

2016

Volume 2: Heat Transfer in Multiphase Systems; Gas Turbine Heat Transfer; Manufacturing and Materials Processing; Heat Transfer

View full text Add to dashboard Cite

show abstract

“…Controlling one dimension in micro levels is the task for most cases which makes micro-slits a common geometry for multiple applications; such as microbial fuel cells [1], methanol steam reforming and hydro-energy applications [2], and evaporators for micro-power generation systems [3]. In slit geometry, characteristic flow dimensions are represented by the hydraulic diameter defined as D H ¼ (4A)/W, where A is the cross-sectional area and W is the wetted perimeter.…”

Section: Introductionmentioning

confidence: 99%

The extended Graetz problem for micro-slit geometries; analytical coupling of rarefaction, axial conduction and viscous dissipation

Kalyoncu

Barışık

2016

International Journal of Thermal Sciences

View full text Add to dashboard Cite

a b s t r a c tIn order to support the recent MEMS and Lab-on-a-chip technologies, we studied heat transport in micro-scale slit channel gas flows. Since the micro convection transport phenomena diverges from conventional macro-scale transport due to rarefaction, axial conduction and viscous heating, an accurate understanding requires a complete coupling of these effects. For such cases, we studied heat transfer in hydrodynamically developed, thermally developing gas flows in micro-slits at various flow conditions. The analytical solution of the energy equation considered both the heat conduction in the axial direction and heat dissipation of viscous forces. Furthermore, updated boundary conditions of velocity slip and temperature jump were applied based on Knudsen number of flow in order to account for the nonequilibrium gas dynamics. Local Nusselt number (Nu) values were calculated as a function of Peclet (Pe), Knudsen (Kn) and Brinkman (Br) numbers which were selected carefully according to possible micro-flow cases. Strong variation of Nu in thermal development length was found to dominate heat transfer behavior of micro-slits with short heating lengths for early slip flow regime. For this instance, influence of axial conduction and viscous dissipation was equally important. On the other hand, high Kn slip flow suppressed the axial conduction while viscous heating in a small surface-gas temperature difference case mostly determined the fully developed Nu and average heat transfer behavior as a function of Kn value.

show abstract

Pool boiling heat transfer enhancement by porous interconnected microchannel nets at different liquid subcooling

Zhang

Tang

Zeng

et al. 2016

Applied Thermal Engineering

View full text Add to dashboard Cite

Experimental and numerical investigation of a shaped microchannel evaporator for a micro Rankine cycle application

Cited by 7 publications

References 36 publications

Modeling the Performance of Bi-Textured Micropillar Array as a Wicked Evaporator

Modeling the Performance of Bi-Textured Micropillar Array as a Wicked Evaporator

The extended Graetz problem for micro-slit geometries; analytical coupling of rarefaction, axial conduction and viscous dissipation

Pool boiling heat transfer enhancement by porous interconnected microchannel nets at different liquid subcooling

Contact Info

Product

Resources

About