Effects of inclination on the frosting process on cold surface of copper heat exchanger

Chen, Aiqiang; Meng, Yu Gang; Liu, Bin; Yang, Lijun; Miao, Zengxiang

doi:10.1016/j.enbuild.2020.110628

Cited by 10 publications

(4 citation statements)

References 31 publications

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“…To analyze the defrosting characteristics of the evaporator, it is necessary to accurately judge the initial condition of defrosting, that is, the frosting status on the surface of the evaporator [ 16 ]. Many scholars have conducted experimental research on simple geometric shapes, such as flat plates, cylinders, and other structures.…”

Section: Introductionmentioning

confidence: 99%

Analysis on frosting of heat exchanger and numerical simulation of heat transfer characteristics using BP neural network learning algorithm

Yu¹,

Luo²,

Chu

2021

PLoS ONE

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The study is aimed at the frosting problem of the air source heat pump in the low temperature and high humidity environment, which reduces the service life of the system. First, the frosting characteristics at the evaporator side of the air source heat pump system are analyzed. Then, a new defrost technology is proposed, and dimensional theory and neural network are combined to predict the transfer performance of the new system. Finally, an adaptive network control algorithm is proposed to predict the frosting amount. This algorithm optimizes the traditional neural network algorithm control process, and it is more flexible, objective, and reliable in the selection of the hidden layer, the acquisition of the optimal function, and the selection of the corresponding learning rate. Through model performance, regression analysis, and heat transfer characteristics simulation, the effectiveness of this method is further confirmed. It is found that, the new air source heat pump defrost system can provide auxiliary heat, effectively regulating the temperature and humidity. The mean square error is 0.019827, and the heat pump can operate efficiently under frosting conditions. The defrost system is easy to operate, and facilitates manufactures designing for different regions under different conditions. This research provides reference for energy conservation, emission reduction, and sustainable economic development.

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Section: Introductionmentioning

confidence: 99%

Analysis on frosting of heat exchanger and numerical simulation of heat transfer characteristics using BP neural network learning algorithm

Yu¹,

Luo²,

Chu

2021

PLoS ONE

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“…In fact, tilt angle does have a significant effect on the frosting process. It changes both the surface temperature due to radiative cooling [31] and the ability to form, grow and freeze water droplets [32]. Finding optimal position at night to address both safety and minimal frost coverage is therefore a perspective to mitigate frost-induced losses.…”

Section: Appendixmentioning

confidence: 99%

Analysis and Modeling of CPV Performance Loss Factors in Humid Continental Climate

Talebi,

Volatier,

Hamon

et al. 2024

IEEE J. Photovoltaics

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Abstract-Local climate and environmental conditions can impact the performance of concentrator photovoltaic (CPV) systems. There is a lack of experimental performance analysis of CPV systems, especially in the region with high snowfall and very low temperature in winters. In this paper, we present first a CPV system performance in humid continental climate and identify snow and frost as sources of losses that are not considered in conventional predictive models. We propose then a method to account for the negative effect of snow and frost on the system, by adding monthly soiling factors in the predictive model. The monthly soiling factors are modeled based on average monthly snow fall and ambient temperature. Applying this method, decrease in Root Mean Square Error (RMSE) between predicted and actual energy production from 24.51 to 5.07 % validates our model in humid continental climate for CPV systems.

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“…Because of the deformation of the droplets, the released surface energy was able to promote droplets with a large surface-to-volume ratio to roll or jump easily, which enabled the droplets to automatically detach from the surface. Under external intervention, such as changing the substrate inclination angle, , purging with wind, or using structurally designed substrates, , this effect could be enhanced. Superhydrophobic surfaces greatly promote the movement of melting droplets and even make them fall off before completely melting, which effectively keep the substrate clean.…”

Section: Introductionmentioning

confidence: 99%

Melting Process of Frozen Sessile Droplets on Superhydrophobic Surfaces

Cui,

Wang,

Che

2023

Langmuir

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Superhydrophobic surfaces can exhibit icephobicity in many ways due to their large contact angles and small rolling angles. The melting process of frozen droplets on superhydrophobic surfaces is still unclear, hindering the understanding of surface icephobicity. In this experimental study of the melting process of frozen sessile droplets on superhydrophobic surfaces, we find two types of melting morphologies with opposite vortex directions on a single-scale nanostructured (SN) superhydrophobic substrate and a hierarchical-scale micronanostructured (HMN) superhydrophobic substrate. Melting pattern visualizations and flow field measurements showed Marangoni convection and natural convection occurring in the melting sessile droplets. For the HMN superhydrophobic substrate, the internal flow was found to be dominated by Marangoni convection due to the temperature gradient along the surface of the droplet. For the SN superhydrophobic substrate, Marangoni convection was inhibited by the superhydrophobic particles at the surface of the droplet, which were shed from the fragile superhydrophobic substrate during the freezing−melting process, as confirmed by surface characterizations of the substrate and flow measurements of a water pool. These results will help researchers better understand the melting process of frozen droplets and in designing novel icephobic surfaces for numerous applications.

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Effects of inclination on the frosting process on cold surface of copper heat exchanger

Cited by 10 publications

References 31 publications

Analysis on frosting of heat exchanger and numerical simulation of heat transfer characteristics using BP neural network learning algorithm

Analysis on frosting of heat exchanger and numerical simulation of heat transfer characteristics using BP neural network learning algorithm

Analysis and Modeling of CPV Performance Loss Factors in Humid Continental Climate

Melting Process of Frozen Sessile Droplets on Superhydrophobic Surfaces

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