Frost retardation on fin-tube heat exchangers using mass transfer characteristics with respect to air velocity

2014 ◽  
Vol 79 ◽  
pp. 689-693 ◽  
Author(s):  
Huee-Youl Ye ◽  
Jin-Seong Park ◽  
Kwan-Soo Lee
Keyword(s):  
Mass Transfer ◽  
Heat Exchangers ◽  
Air Velocity ◽  
Transfer Characteristics ◽  
Fin Tube

A Fully Wet and Fully Dry Tiny Circular Fin Method for Heat and Mass Transfer Characteristics for Plain Fin-and-Tube Heat Exchangers Under Dehumidifying Conditions

2006 ◽  
Vol 129 (9) ◽  
pp. 1256-1267 ◽  
Author(s):  
Worachest Pirompugd ◽  
Chi-Chuan Wang ◽  
Somchai Wongwises
Keyword(s):  
Heat Transfer ◽  
Mass Transfer ◽  
Heat Exchanger ◽  
Heat And Mass Transfer ◽  
Heat Exchangers ◽  
Heat Transfer Characteristic ◽  
Transfer Characteristic ◽  
Tube Heat Exchanger ◽  
Mass Transfer Characteristic ◽  
Transfer Characteristics

This study proposes a new method, namely the “fully wet and fully dry tiny circular fin method,” for analyzing the heat and mass transfer characteristics of plain fin-and-tube heat exchangers under dehumidifying conditions. The present method is developed from the tube-by-tube method proposed in the previous study by the same authors. The analysis of the fin-and-tube heat exchangers is carried out by dividing the heat exchanger into many tiny segments. A tiny segment will be assumed with fully wet or fully dry conditions. This method is capable of handling the plain fin-and-tube heat exchanger under fully wet and partially wet conditions. The heat and mass transfer characteristics are presented in dimensionless terms. The ratio of the heat transfer characteristic to mass transfer characteristic is also studied. Based on the reduced results, it is found that the heat transfer and mass transfer characteristics are insensitive to changes in fin spacing. The influence of the inlet relative humidity on the heat transfer characteristic is rather small. For one and two row configurations, a considerable increase of the mass transfer characteristic is encountered when partially wet conditions take place. The heat transfer characteristic is about the same in fully wet and partially wet conditions provided that the number of tube rows is equal to or greater than four. Correlations are proposed to describe the heat and mass characteristics for the present plain fin configuration.

Heat and Mass Transfer Characteristics of a Finned-Tube Evaporator Under Frosting Conditions

2001 ◽  
Author(s):  
Y. H. Kim ◽  
Y. J. Park ◽  
Y. C. Kim ◽  
S. C. Shim ◽  
S. K. Oh ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Mass Transfer ◽  
Heat And Mass Transfer ◽  
Air Temperature ◽  
Early Stage ◽  
Finned Tube ◽  
Airflow Rate ◽  
Air Velocity ◽  
Frost Formation ◽  
Transfer Characteristics

Abstract An experimental study was performed to investigate the heat and mass transfer characteristics of a finned-tube evaporator coil utilized in a domestic refrigerator under frosting conditions. Airside heat transfer coefficient was measured as a function of air temperature, humidity ratio, air velocity, and evaporating temperature. In addition, frost thickness was monitored and measured by visualization tests during frosting operation. Based on the experimental results, the degradation of heat transfer performance due to frost formation was explored as a function of operating parameters. The rate of frost formation on the evaporator increases at relatively high humidity, high airflow rate, low inlet air temperature and low refrigerant temperature. As the frost thickness increases, airflow rate gradually decreases, while the capacity increases at the early stage of frost formation and then significantly drops.

Study on the Air-Side Heat Transfer and Pressure Drop for Fin-Tube Heat Exchangers

2002 ◽  
Author(s):  
Ji Hwan Jeong ◽  
Keun Sun Chang ◽  
Young Chel Kweon ◽  
Sang Jae Lee ◽  
Min Kyu Lee
Keyword(s):  
Heat Transfer ◽  
Numerical Analysis ◽  
Pressure Drop ◽  
Heat Exchangers ◽  
Unit Area ◽  
Numerical Results ◽  
Experimental Measurements ◽  
Air Velocity ◽  
Fin Tube ◽  
Good Agreement

Experimental measurements and numerical analysis have been carried out in order to investigate performances of air-side heat transfer and pressure drop for six types of heat exhcangers with various fin shapes. An air-enthalpy calorimeter is used in this work. Numerical analysis shows a good agreement with experimental measurements. Measurements for six types of heat exchangers at various air-velocity are compared with each other. Heat transfer per unit area appears to be nearly the same in the range of 0.7~0.9 m/s while it varies within 3% at 1.5 m/s. The numerical results show that most of heat transfer takes place through fins for all types and majority of heat transfer happens from the 1st row.

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