Numerical prediction of frost properties and performance of fin–tube heat exchanger with plain fin under frosting

Abstract The present study predicted and verified the local frost thicknesses, blockage ratio, and local and total heat transfer rates of a fin–tube heat exchanger under standard and high frosting conditions. Local frost properties were predicted for each segment. The reduction of air volume flow rate and local different air velocities in the segment were obtained by applying Δ P – V ˙ a curve and the maximum frost thickness. The local heat transfer rate was predicted by using the ɛ-NTU method and local average frost thickness. The predicted maximum frost thicknesses showed a deviation of 5.5% from the measured values. Maximum frost thicknesses immediately after each U-bend were thicker than those immediately before each U-bend. The predicted blockage ratios agreed with the measured data within 10%. Non-uniform profiles of the local heat transfer rates of heat exchanger under frosting condition were property predicted. The predicted total heat transfer rate agreed with the measured data within 6%.

[1]  Frank P. Incropera,et al.  Fundamentals of Heat and Mass Transfer , 1981 .

[2]  Alvin C.K. Lai,et al.  Dynamic behavior of a direct expansion evaporator under frosting condition. Part I. Distributed model , 2006 .

[3]  Diogo L. da Silva,et al.  First-principles modeling of frost accumulation on fan-supplied tube-fin evaporators , 2011 .

[4]  Huee-Youl Ye,et al.  Performance prediction of a fin-and-tube heat exchanger considering air-flow reduction due to the frost accumulation , 2013 .

[5]  S. T. Ro,et al.  Analysis of the frost growth on a flat plate by simple models of saturation and supersaturation , 2005 .

[6]  Robert J. Moffat,et al.  Describing the Uncertainties in Experimental Results , 1988 .

[7]  A. London,et al.  Compact heat exchangers , 1960 .

[8]  Simon Song,et al.  Modeling for predicting frosting behavior of a fin-tube heat exchanger , 2006 .

[9]  Robert W. Besant,et al.  Fan supplied heat exchanger fin performance under frosting conditions , 2003 .

[10]  Nilufer Egrican,et al.  Frost formation on fin-and-tube heat exchangers. Part I—Modeling of frost formation on fin-and-tube heat exchangers , 2004 .

[11]  Chi-Chuan Wang,et al.  Heat transfer and friction characteristics of plain fin-and-tube heat exchangers, part II: Correlation , 2000 .

[12]  Jerald D. Parker,et al.  Heating, Ventilating, and Air Conditioning: Analysis and Design , 1977 .

[13]  Lorenzo Cremaschi,et al.  Modeling non-uniform frost growth on a fin-and-tube heat exchanger , 2011 .

[14]  Ralph L. Webb,et al.  Mass transfer on and within a frost layer , 2004 .

[15]  J. D. Parker,et al.  Frost Formation With Varying Environmental Parameters , 1975 .

[16]  L. Cremaschi,et al.  Comparison of Frost and Defrost Performance Between Microchannel Coil and Fin-and-Tube Coil for Heat Pump Systems , 2011 .

[17]  Tae-Hee Lee,et al.  A one-dimensional model for frost formation on a cold flat surface , 1997 .

[18]  Gregory Nellis,et al.  Comparison of parallel- and counter-flow circuiting in an industrial evaporator under frosting conditions , 2007 .

[19]  Carolus Theodorus Sanders,et al.  The influence of frost formation and defrosting on the performance of air coolers , 1974 .

[20]  Alvin C.K. Lai,et al.  An improved model for predicting performance of finned tube heat exchanger under frosting condition, with frost thickness variation along fin , 2006 .

[21]  Christian Jallut,et al.  Modelling of frost growth and densification , 1997 .