Flow Boiling of ethanol/water binary mixture in a square microchannel

Abstract

Two-phase flow heat transfer was examined in a single 5mm inner hydraulic diameter square channel at a vertical orientation. Ethanol, deionized water and 5% v/v ethanol/water mixture were used as working fluids. Three mass fluxes (0.33, 0.66 and 1.00 kg/m2s) were tested as well as three heat fluxes (2.8, 4.2 and 6.1 kW/m2). Experiments were conducted in a controlled temperature environment (40oC) and high speed imaging, channel wall temperatures and local heat transfer coefficients were examined. The addition of ethanol into water (5% v/v ethanol/water mixture) was found to enhance heat transfer resulting in higher heat transfer coefficients than both of its pure components.