Critical heat flux prediction model of pool boiling heat transfer on the micro-pillar surfaces

Abstract

An pool boiling heat transfer experimental investigation was studied on the surfaces with micro-pillars using FC-72 as working fluid. The pool boiling experiment was conducted under the saturated and subcooled conditions (ΔTsub = 25 K). It can be found that the critical heat flux (CHF) of surfaces wtih micro-pillars is higher than that of smooth chip, and the surface area enhancement ratio and the arrangement of the micro-pillars have significant effects on the CHF. The replenished liquid velocity ul is proposed to evaluate the wicking effect. A new prediction model is established to predict the CHF of surfaces with micro-pillars considering the effect of replenished liquid velocity ul, vapor column radius rv and vapor column spacing λb. The results show that the new CHF prediction model can effectively reflect the impact of the micro-pillars on CHF, and the experimental data can be predicted with an error band of ± 10%, indicating a good predicted ability.