• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2009년 춘계학술대회논문집
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• pp.341-346
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• 2009

The purpose of the present study is to investigate the flow resistance and the heat transfer characteristics of oval fin-tube heat exchanger. Six kinds of oval fin having the same fin area and the different diameter ratio tested numerically. Test data for the heat transfer, pressure drop and fin temperature were shown and discussed. The pressure drop and heat transfer increased for increasing the oval fin diameter ratio(diameter of span-wise direction to diameter of longitudinal diameter) up to 50% and 45% respectively.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2008년도 학술대회
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• pp.137-142
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• 2008

The purpose of the present study is to investigate the convective heat transfer characteristics and the validity of fin efficiency of the circular finned-tube heat exchanger by using commercial CFD code. The heat transfer coefficient obtained by using the laminar model was 22% overestimated to the experimental data. The fin surface temperature compared with the experimental data measured by the liquid crystal method. The fin efficiency by the present numerical experiment, defined as normalized and averaged fin surface temperature, was greater than the theoretical fin efficiency and the difference is increased at high value of the factor m.

• 설비공학논문집
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• 제17권11호
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• pp.974-980
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• 2005

The optimization of design factors on the frosting performance of a fin-tube heat exchanger is carried out using Taguchi method. The fin spacings of the heat exchanger are selected as design factors. Optimum values of the design factors under operating conditions of a household refrigerator/freezer are proposed. The average heat transfer rate and operating time of the optimum models, compared to those of a reference model, are increased at most by $6.5\%$ and $12.9\%$, respectively.

• 설비공학논문집
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• 제17권11호
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• pp.965-973
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• 2005

This paper proposes a mathematical model for predicting the frosting performance on a fin-tube heat exchanger. The model consists of empirical correlations of average heat transfer coefficients for the plate and tube surfaces and a diffusion equation inside the frost layer. The numerical results are compared with experimental data for the frost thickness, the frosting rate and the heat transfer rate to validate the proposed model. The results are in good agreement with the experimental data, and show that this model can be applied to predict frosting performance of common fin-tube heat exchanger.

• 대한기계학회논문집B
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• 제24권8호
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• pp.1062-1068
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• 2000

The effect of heat exchanger surface treatment on the frosting/defrosting behavior in a fin-tube heat exchanger is investigated experimentally. It is found that the hydrophilic surface mainly influences on the frosting behavior, however, the hydrophobic surface gives some influence on the defrosting behavior. In view of frosting performance, surface-treated heat exchanger with either hydrophilic or hydrophobic characteristic shows a little improvement in the thermal performance than the aluminium heat exchanger with no surface treatment. The result reveals that the heat exchanger with hydrophobic surface treatment is more effective in view of the defrosting efficiency and time. The amounts of residual water on the surface-treated heat exchangers are shown to be smaller than those of the bare heat exchanger, therefore further improvements on the performance of re-operations are expected.

• 설비공학논문집
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• 제11권6호
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• pp.921-927
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• 1999

In this study, the defrosting behaviors according to the surface characteristics in the fin-tube heat exchanger is experimentally examined. It is found that the draining rate of the hydrophilic and hydrophobic heat exchangers are evenly dispersed during defrosting, compared with that of the bare one. It is caused by the high density frost for the hydrophilic heat exchanger, and surface characteristic for the hydrophobic heat exchanger, respectively. The rest period of the hydrophilic and hydrophobic heat exchangers are shorter and their weight of residual water are smaller than those of the bare heat exchanger The hydrophilic and hydrophobic heat exchangers are more effective than the bare one in terms of defrosting efficiency, and the hydrophobic heat exchanger is better than the hydrophilic one.

• 대한설비공학회지:설비저널
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• 제27권3호
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• pp.232-242
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• 1998

• 설비공학논문집
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• 제15권9호
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• pp.762-767
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• 2003

An experimental study was conducted to investigate the heat transfer characteristics of a circular finned-tube heat exchanger. The nineteen cases of configuration varying fin material, fin outer diameter and fin pitch were tested by means of the experiment and the numerical calculation. The measured heat transfer data for the circular finned-tube heat exchanger were provided. A transition of heat transfer was found in the case of low fin pitch. The thermal conductivity of fin affected on the pure heat transfer coefficient.

• 에너지공학
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• 제9권3호
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• pp.192-201
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• 2000

증발기와 응축기로 폐회로 냉동 시스템을 구성하여 기존 사용 냉매인 R22와 대체냉매로써 부각되고 있는 R407C, R410A를 사용하여 여러 가지 관 직경과 휜 형상을 가지는 열교환기에 대한 열전달량, 질량유량, 열교환기를 지나가는 냉매의 온도분포 그리고 공기측 압력강하를 측정하였다. 모든 열교환기에서 냉매의 질량유량이 증가함에 따라 열전달량은 증가하였다. R22와 R407C의 경우에 증발기측에서는 거의 같은 열전달량을 나타냈고 응축기측에서는 R407C가 전체적으로 열전달량이 높게 나타났다. 그리고 열교환기의 전달량은 유로의 형상보다는 냉매의 질량유량과 전열면적에 더 많은 영향을 받는다. 공기측 압력 강하는 열수가 많은 열교환기의 경우가 작게 나타났으며 슬릿휜을 가지는 열교환기의 압력강하가 가장 크고 웨이비휜을 가지는 열교환기가 가장 작게 나타났다.

• 한국전산유체공학회지
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• 제15권2호
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• pp.1-6
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• 2010

The purpose of the present study is to investigate the flow resistance and the heat transfer characteristics of oval fin-tube heat exchanger. Six kinds of oval fin having the same fin area and different diameter ratio tested numerically. Test data for the heat transfer, pressure drop and fin temperature were shown and discussed. The pressure drop and heat transfer increased for increasing the oval fin diameter ratio(diameter of span-wise direction to diameter of longitudinal diameter) up to 50% and 45% respectively.