A New Analytical Model for High Heat Flux in Pool Boiling

Guo-Ping Jiang ； Bo-Qi Xiao ； Ji-Chao Liu

《Research Journal of Applied Sciences, Engineering and Technology》 4卷19期 (2012/10) Pp. 3760-3767

並列摘要

In this study, first the empirical correlations and primary models of Critical Heat Flux (CHF) are introduced, then a new fractal model for critical heat flux is proposed. Algebraic expressions for the fractal dimension of nucleation sites are derived based on the fractal distribution of nucleation sites, which are shown to be a strong function of wall superheat. The new fractal model for critical heat flux is found to be a function of wall superheat. The contact angel of the fluid and the physical properties of the fluid and empirical constant have an important effect on critical heat flux. It turns out that the present model well explains the mechanism on how parameter such as surface wettability influences CHF. The present model shows the surface wettability plays no significant role. The expressions of active nucleation site are applies to CHF which are predicted in the proposed model quantitatively. The predicted critical heat flux from a boiling surface based on the proposed fractal model is compared with existing experimental data. An excellent agreement between the new model predictions and experimental data is found. The validity of the new fractal model is thus verified.

並列關鍵字

Critical heat flux ； fractal model ； heat transfer rates ； pool boiling ； thermodynamics