In this Master’s Thesis we have been researching the boiling phenomena of high-carbon alcohol aqueous solutions in microchannels. We have focused on the effect of pressure, temperature and volume flow rate of the working fluid on boiling process in microchannels. 6% aqueous solution of butanol, 2% aqueous solution of pentanol, 0.6% aqueous solution of hexanol, 0.15% aqueous solution of heptanol, distilled and degassed water were used as working fluids. Test section consisted of microchannels with 50 × 50 µm cross section. At the onset of boiling of water the temperature at 1.00 ml/min was 105 °C, the pressure risen from 0.50 to 0.69 bar. With 6% aqueous solution of butanol the boiling temperature was 163 °C and the pressure grown from 0.30 to 2.92 bar. At 2% aqueous solution of pentanol the temperature at the onset of boiling was 129 °C and the pressure went from 0.33 to 2.02 bar. At 0.6% aqueous solution of hexanol the temperature at the star of boiling was 136 °C and the pressure went from 0.28 to 2.09 bar and at 0.15% aqueous solution of heptanol 108 °C and the pressure went from 0.38 to 0.79 bar. In comparison to boiling of water we could see that the boiling meniscus elongation speed at 6% aqueous solution of butanol is much faster and the boiling itself was more eruptive.
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