An experiment on nucleate pool boiling heat transfer of aqueous surfactant solutions

Based on thermo gravimetric analysis experiments of surfactants and thermal stability experiments of aqueous surfactant solutions, experiments for nucleate pool boiling of water with different aqueous surfactant, 99% sodium dodecyl sulfate(SDS), Triton X-100 and Triton X-114, were carried out under atmospheric pressure to investigate boiling heat transfer enhancement characteristics. Bubble behaviors were observed with high-speed digital camera. The results show that surfactants have good thermal stability when temperature is below 200°C, surface activity of surfactant solutions have significant changes after four days continuous boiling. Comparing with water, the optimal heat transfer enhancement is achieved near the critical micelle concentrations(CMC) of surfactants. The degree of heat transfer enhancement is different with different surfactants and is influenced by solubility characteristic, ionic nature and chemical structure of surfactants. Boiling in surfactant solutions, when compared with that in water, is observed to be more vigorous with smaller-sized, more regularly shaped and faster departure frequency bubbles, but the surfactant solutions of Triton X-100 and Triton X-114 become cloudy for the cloud point of surfactants.