Showing papers on "Subcooling published in 2021"
TL;DR: In this article, a type of open-ring pin fin microchannels (ORPFM) was proposed and developed for advanced microchannel heat sinks, which consist of an internal cavity for bubble nucleation and two inner small and outside large rings with separated and converged flow passages.
38 citations
TL;DR: In this article, a heating strategy has been developed for the battery operated at low temperature, which can intelligently control the thermal storage and release of an inorganic phase change material (PCM): CaCl2·6H2O - carboxymethyl cellulose (CMC).
37 citations
TL;DR: In this article, the authors proposed a new high aspect ratio groove-wall microchannel (height=200mm, width=80μm, length=10mm, AR=2.5), which features a series of rectangular grooves etched on the plain side walls.
31 citations
TL;DR: In this article, an experimental investigation of flow boiling in a rectangular vertical narrow microchannel with the heterogeneous wetting surfaces and original silicon surface was conducted with deionized water as the working fluid.
29 citations
TL;DR: In this article, forced convective flow boiling heat transfer under subcooled region was analyzed with Al2O3/water nanofluid flow in a horizontal tube using Zeta potential analysis.
28 citations
TL;DR: In this paper, the influence of a primary nozzle on steam ejector performance considering phase change processes is analyzed and validated in detail against experimental data of supersonic nozzles and steam ejectors available in the literature.
28 citations
TL;DR: In this article, a flat-plate loop heat pipe with long heat transfer distance was constructed to test the performance limit of the biporous wick, and the working performance was improved for the wick could be quickly infiltrated by the subcooled fluid.
27 citations
TL;DR: In this paper, an experimental study of two-phase cooling heat sink using the dielectric working fluid Novec/HFE-7000 is performed, where liquid flow is directed into microchannel fins through multiple impinging jets.
27 citations
TL;DR: In this paper, a constructal design of high heat flux two-stacked horizontal microchannel heat sinks is presented for cooling of electronic devices using ANSYS Computational Fluid Dynamics (CFD) code for subcooled nucleate boiling.
24 citations
TL;DR: In this article, a sapphire cell was developed to test the memory effect of gas hydrate under linear cooling ramp conditions and showed little evidence of the strengthening of hydrate memory effect with the increase of cooling/heating circles.
24 citations
TL;DR: In this article, the authors investigated the influence of wettability on the two-phase flow boiling for open microchannels configuration and found that the two phase pressure drop was dominated by vapor acceleration loss that was related to the vaporization efficiency.
TL;DR: In this paper, the oblique arrangement of nanowires has been demonstrated to own anti-vapor penetration and microdrop self-transport functions under high subcooling, unaffected by the microscale gaps.
Abstract: It is well-known that microscale gaps or defects are ubiquitous and can be penetrated by vapor, resulting in the failure of superhydrophobic effect and undesired condensate flooding under high subcooling. Here, we propose and demonstrate that such problem can be solved by the oblique arrangement of nanowires. Such a structure has been demonstrated to own anti-vapor- penetration and microdrop self-transport functions under high subcooling, unaffected by the microscale gaps. This is because vapor molecules can be intercepted by oblique nanowires and preferentially nucleate at near-surface locations, avoiding the penetration of vapor into the microscale gaps. As-formed microdrops can suspend upon the nanowires and have low solid-liquid adhesion. Besides, oblique nanowires can generate asymmetric surface tension and microdrop coalescence can release driving energy, both of which facilitate the microdrop self-removal via sweeping and jumping ways. This new design idea helps develop more advanced condensation mass and heat transfer interfaces.
TL;DR: In this paper, a new water flow configuration for water-heating process is proposed for transcritical CO2 heat pump combined with a dedicated mechanical subcooling (DMS) subsystem.
TL;DR: In this paper, a novel scheme for studying the effect of microstructure surface roughness on sub-cooled flow boiling is developed, and the results of this newly developed scheme are compared with the traditional method and a smooth surface.
TL;DR: In this article, an experimental investigation of key parameters influencing CHF for confined round single jets and jet arrays impinging normally onto square heated surfaces is performed using R-134a, a fluid widely used for thermal management of electronic and power devices, especially in aerospace applications.
TL;DR: In this paper, a hierarchical manifold microchannel (MMC) heat sink with stacked configuration is proposed, which mitigates flow maldistribution by optimizing the flow path.
TL;DR: In this paper, different configurations of an all-in-one R744 transcritical unit providing refrigeration, heating and air conditioning to a real Greek supermarket store (METRO S.A.) in Athens are studied, using the softwares Engineering Equation Solver and EnergyPlus.
TL;DR: In this paper, a subcooling booster-assisted ejector refrigeration cycle (SBERC) was proposed for refrigeration applications in the field of solar-driven air conditioning.
TL;DR: In this paper, a constant volume chamber with a high-speed camera was used to investigate the flash boiling spray of butanol isomers and gasoline surrogate blends, and the results reveal that flash boiling injection leads to lower apparent flame speed and flame area compared to subcooled injection due to the lean-like burn condition, and yellow flame spots are diminished.
TL;DR: In this article, three CO2 transcritical systems with two-compressors are discussed and compared with CO2 single-stage compression transcritical heat pump system under three different heat sinks.
TL;DR: In this article, the authors explored the development of a vastly more powerful charging cable thermal management scheme to achieve this higher current threshold, where subcooled flow boiling is proposed as the primary means to dissipating the larger amounts of heat generated at higher currents.
08 Jan 2021
TL;DR: In this article, the authors reviewed the published literature concerning interfacial heat transfer and bubble dynamics in the process of bubble condensation and found that there is still a shortage of investigation focused on the variation of thermal boundary layer and turbulence formed near the bubble at the micro-scale.
Abstract: Condensation of vapor bubbles in a subcooled liquid is known to influence heat transfer and pressure oscillation in subcooled boiling and direct contact condensation. This study reviews the published literature concerning interfacial heat transfer and bubble dynamics in the process of bubble condensation. The correlations for bubble condensation are analyzed and evaluated with a database covering a wide range of Reynolds, Jacob, and Prandtl numbers. Then, the investigations addressing bubble dynamics are reviewed, which focus on the bubble condensation patterns, motion, collapse, and the pressure oscillations induced by bubble condensation, as well as the effect of noncondensable gas and field. Despite the extensive experiments of bubble condensation available in the literature, it is shown that there is still a shortage of investigation focused on the variation of thermal boundary layer and turbulence formed near the bubble at the micro-scale, which could help to develop the prediction method of bubble condensation in the future. The transportation of noncondensable gas inside the mixture bubble and effect of capillary waves formed on the bubble surface on the actual vapor-liquid contact area and thermal boundary are also suggested to be further investigated to gain the thorough understanding of the bubble condensation process.
TL;DR: In this article, the heat transfer coefficient (HTC) on the enhanced plate-fluid contact surface was computed from the Robin boundary condition, and the inverse heat conduction problem was solved by the Finite Element Method with the shape functions based on the Hermite interpolation and the Trefftz functions.
TL;DR: In this article, an experimental study on the ultra-thin flat heat pipe with a single-layer wire mesh core is carried out through a visual experimental platform, and it is found that the peak value of temperature fluctuation is affected by thermal load.
TL;DR: In this article, the influence of micropillar spacing and surface subcooling on the droplet dynamics and heat transfer performance is investigated using microscopic visualization techniques, and the microscopic modeling of condensation heat transfer on the microstructured surfaces is performed using the mesoscopic lattice Boltzmann method.
TL;DR: In this paper, a wall boiling model under two fluid framework was established, and the validation was performed against the sub-cooled boiling experiment conducted by Bartolemei et al. In this work, a typical structure with four parallel coolant channels were modeled, and two kinds of flow blockage conditions, including the thin-wall blockage and plate-bending blockage, were performed to investigate the influence of blockage on the flow and heat transfer features.
TL;DR: In this article, a flow condensation experimental study with binary mixture in a horizontal rectangle 1-mm-channel was carried out, and the flow patterns, heat transfer characteristics and frictional pressure gradients were analyzed based on the parametric study.
TL;DR: In this paper, the authors investigated the effect of graphene functionalized surface wettability on the performance of flow boiling and showed that the super-hydrophilic GNP coating showed the highest boiling heat transfer coefficient with a maximum enhancement of 64.9 %.
TL;DR: In this article, phase change material nano-emulsions (PCMEs) were designed and characterized as possible heat transfer media to be used at 21 and 55°C, by investigating two commercial phase change materials melting at these temperatures.
TL;DR: In this paper, the authors reviewed the recent research progress in this field, including the condensation regime maps and flow patterns, the flow and heat transfer characteristics of the steam jet, and the pressure oscillations inside the discharge pipes or near a steam jet.