Frost distribution characteristics of laminar airflow on cold surface of mini-channels

Kwon, Jeong Tae; Kim, Dong Hwi; Huh, Cheol; Koyama, Shigeru; Kwon, Young Chul

doi:10.1016/j.icheatmasstransfer.2011.04.007

Cited by 4 publications

(3 citation statements)

References 7 publications

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“…The fins are separately mounted with free gaps between adjacent tube rows. The fin number generally increases from bottom to top tube rows (except for the top row) to mitigate the frost maldistribution caused by the leading-edge effect [20]. In this model, the evaporator is divided into elements based on the fin distribution.…”

Section: Geometric Modelmentioning

confidence: 99%

“…To match the reduced frost formation in the vertical direction due to the leading-edge effect [20], the fin density is generally thinner in the upstream rows but denser downstream on the evaporator (except Row 7, considering the refrigerant migration during the starting stage of the compressor). However, too many fins in downstream tube rows can also cause severe frost blockage there, as shown in Figure 5.…”

Section: Setup Of Different Fin Distribution Schemesmentioning

confidence: 99%

See 1 more Smart Citation

Proposal, Robustness Analysis and Equivalent Implementation of Optimization Method for Row-by-Row Fin Distribution in Multi-Row Frosting Evaporator

Sun

Zhao

et al. 2021

Energies

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The evaporator in a frost-free refrigerator typically has more tube rows, but frost deposition reduces along the airflow direction. Correspondingly, the evaporator fin distribution is thinner in the upstream rows but denser downstream, and a good match between frost and fin distribution is achieved to recover evaporator capacity loss. However, quantitative design principles of non-uniform fin distribution are lacking. A quasi-static frosting evaporator model is established and experimentally verified considering a three-dimensional (3D) evaporator, 1D frost growth and 1D non-uniform fin distribution. An optimization method for row-by-row fin distribution of a multi-row frosting evaporator is proposed based on the air pressure drop’s increase rate. When the increase rate in the air pressure drop of each row is almost equal, the smallest overall evaporator pressure drop is obtained, leading to the highest air flowrate and the greatest evaporator capacity. By applying the method, the air flowrate and the evaporator capacity increase by 5.5% and 4.6%, respectively, compared to the original fin distribution scheme. Moreover, the robustness of the optimization method is validated under wide temperature and humidity operating conditions. An equivalent implementation under an initial no-frost condition is also proposed to facilitate the optimization method without calculating the whole frosting process.

show abstract

Section: Geometric Modelmentioning

confidence: 99%

Section: Setup Of Different Fin Distribution Schemesmentioning

confidence: 99%

Proposal, Robustness Analysis and Equivalent Implementation of Optimization Method for Row-by-Row Fin Distribution in Multi-Row Frosting Evaporator

Sun

Zhao

et al. 2021

Energies

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show abstract

“…For the latter four simple structures with uneven surface temperatures or air side parameters, the relevant studies mainly focused on their frost distribution characteristics. For example, Kwon et al [14] found that the frost layer was not completely symmetric distribution based on the center base of a flat plate but slightly thicker at its air side entrance. For a round tube, Ramirez-Hernandez et al [15] indicated that frost layer was thicker around its windward side, and the difference in frost layer thickness between windward and leeward sides decreased with an increase in Reynolds number.…”

Section: Introductionmentioning

confidence: 99%

Cold Plate Temperature Effect on Droplet and Frost Crystal Behaviors at the Early Condensation Frosting Stage Considering Plate Edge Effect

Zhang¹,

Song²,

Tianzhuo³

et al. 2022

Eng. Sci.

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The condensation frosting phenomenon commonly exists in engineering applications, and the relevant studies on flat plates with fixed surface temperatures are the most concerned in related fields. The existing studies usually focus on droplet condensation and frozen characteristics in the center region of cold plates and cannot reveal those near the plate edge. Therefore, a systematic study from droplet condensation to frost layer growth stages in the edge region of a cold plate was conducted in this paper. The experimental results showed that the frozen stage period of the edge-affected zone was significantly smaller than that of the unaffected zone. The ratio of average freezing wave propagation velocity in the edge-affected zone to that in the unaffected zone at plate temperatures of -9.0, -14.0, and -19.0 o C were 7. 70, 5.56, and 5.11, respectively. Besides, the area-average equivalent diameter and coverage area ratio of droplets decreased with a decrease in plate temperature at the end of their respective droplet frozen stages. This study may help to better understand temporal and spatial condensation frosting characteristics on a horizontal cold plate with right-angle edges, and guide the establishment of a staged and divisional frosting model on cold plates.

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Effect of fin types of outdoor fan-supplied finned-tube heat exchanger on periodic frosting and defrosting performance of a residential air-source heat pump

Dong¹,

Zhao²,

Liu³

et al. 2014

Applied Thermal Engineering

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Frost distribution characteristics of laminar airflow on cold surface of mini-channels

Cited by 4 publications

References 7 publications

Proposal, Robustness Analysis and Equivalent Implementation of Optimization Method for Row-by-Row Fin Distribution in Multi-Row Frosting Evaporator

Proposal, Robustness Analysis and Equivalent Implementation of Optimization Method for Row-by-Row Fin Distribution in Multi-Row Frosting Evaporator

Cold Plate Temperature Effect on Droplet and Frost Crystal Behaviors at the Early Condensation Frosting Stage Considering Plate Edge Effect

Effect of fin types of outdoor fan-supplied finned-tube heat exchanger on periodic frosting and defrosting performance of a residential air-source heat pump

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