A NEW ANALYTICAL MODEL FOR HEAT TRANSFER IN POOL BOILING

In this paper, dependence of active nucleation site density on boiling surfaces are developed. For pool boiling heat transfer, a mathematical model is derived based on statistical treatment using the probability density function of the cavity mouth radius and existing correlation for active nucleation site density, the volume of single bubble at departure, the bubble departure diameter and the bubble departure frequency. The proposed model is expressed as a function of wall superheat, the contact angle, maximum and minimum active cavities, and physical properties of fluid. It is shown that the wall heat flux can be determined by the consideration of the variation of the cavity mouth radius. A good agreement between the proposed model predictions and experimental data is found for different contact angles. It also turns out that the present model explains well the mechanism on how wettability affects the pool boiling.

[1]  L. Tadrist,et al.  Nucleate Boiling on a Single Site: Contact Angle Analysis for a Quasi-2D Growing Vapour Bubble , 2009 .

[2]  Mamoru Ishii,et al.  Active nucleation site density in boiling systems , 2003 .

[3]  A. R. Balakrishnan,et al.  Nucleation site density in pool boiling of saturated pure liquids: Effect of surface microroughness and surface and liquid physical properties , 1997 .

[4]  V. Dhir,et al.  Framework for a Unified Model for Nucleate and Transition Pool Boiling , 1989 .

[5]  K. Bier,et al.  POOL BOILING HEAT TRANSFER AND SIZE OF ACTIVE NUCLEATION CENTERS FOR HORIZONTAL PLATES WITH DIFFERENT SURFACE ROUGHNESS , 1978 .

[6]  Y. Hsu.  On the Size Range of Active Nucleation Cavities on a Heating Surface , 1962 .

[7]  D. D. Paul,et al.  A statistical analysis of saturated nucleate boiling along a heated wire , 1983 .

[8]  C.W.M. van der Geld.  Bubble detachment criteria: some criticism of ‘Das Abreissen von Dampfblasen an festen Heizflächen’ , 1996 .

[9]  S. Bankoff.  Entrapment of gas in the spreading of a liquid over a rough surface , 1958 .

[10]  Mamoru Ishii,et al.  Interfacial area and nucleation site density in boiling systems , 1983 .

[11]  Nilanjana G. Basu,et al.  Onset of Nucleate Boiling and Active Nucleation Site Density During Subcooled Flow Boiling , 2002 .

[12]  B. Mikic,et al.  A New Correlation of Pool-Boiling Data Including the Effect of Heating Surface Characteristics , 1969 .

[13]  P. Griffith,et al.  The mechanism of heat transfer in nucleate pool boiling—Part I: Bubble initiaton, growth and departure , 1965 .

[14]  V. Dhir,et al.  Effect of Surface Wettability on Active Nucleation Site Density During Pool Boiling of Water on a Ve , 1993 .

[15]  J. Klausner,et al.  Nucleation Site Density in Forced Convection Boiling , 1993 .

[16]  H. No,et al.  A Nucleate Boiling Limitation Model for the Prediction of Pool Boiling CHF , 2007 .

[17]  W. Baines,et al.  Bubble departure from cavities , 2001 .

[18]  K. Cornwell,et al.  BOILING SURFACE TOPOGRAPHY , 1978 .

[19]  S. Yang,et al.  A mathematical model of the pool boiling nucleation site density in terms of the surface characteristics , 1988 .