Evaporation and boiling crisis of droplets alcohol solution

S.Y Misyura,V.S Morozov

doi:10.1051/matecconf/201711001059

Abstract

Evaporation and boiling crisis of droplets ethanol aqueous solution were studied experimentally. The evaporation intensity depends on the nucleate boiling, solution diffusion, a change in physical characteristics with time and droplet interfacial surface area. At nucleate boiling in a droplet, most evaporation relates to a growth in the droplet surface area and only 20 % relates to the diffusion effect and a variation in the thermophysical coefficients. At boiling crisis, experimental dependence for vapor layer height on overheating was observed. At Leidenfrost temperature, the height of the vapor layer was many times higher than the surface microroughness value of the wall. There are oscillates of liquid-vapor interface, and this increases the transitional temperature range associated with a boiling crisis of droplets.

Highlights

The evaporation of solutions is widely applied in microelectronics, energy apparatuses and chemical technologies
Predictions for Leidenfrost point (LFP) can be obtained on the basis of understanding of boiling key mechanisms
At desorption of droplet solution there are salt spot and crystals, which depend on the wettability

Summary

Introduction

The evaporation of solutions is widely applied in microelectronics, energy apparatuses and chemical technologies. There is boiling crisis at high heat fluxes. The formed vapor layer during the crisis reduces the heat transfer coefficient by several orders, resulting the wall overheating and wall destruction.

Results

Conclusion