VAPORIZATION HEAT TRANSFER IN BIPOROUS WICKS OF HEAT PIPE EVAPORATORS

摘要

A biporous wick is a porous medium that has two characteristic capillary pore radii. The high vaporization heat transfer performance of biporous wicks results from the characteristics of the two-level pore sizes. Based on analyses of the interior processes in biporous wicks, an Evaporation-Boiling-Evaporation (EBE) physical model for thick biporous wicks and an evaporation model for thin biporous wicks are presented. Distinguishing their applicable areas depends on which occurs early: receding of the evaporating menisci into the large pores or forming of bubbles on the heated surface. A simplified calculation method of predicting heat transfer performance for the EBE model is developed. Preliminary results demonstrate that the behavior of vaporization heat transfer in biporous wicks is well modeled.