An Experimental Study Of Heat Transfer Characteristics And Steam Carrying Effects On Nucleate Pool Boiling For Aqueous Surfactant Solutions

With the development of our country's economy,requirements for the energy resource increase rapidly.Boiling heat transfer with small temperature difference has greatly economic significance for both the reasonable utilization of available energy and the exploitation of new energy.In this paper,surface tension,thermal stability,performance of nucleate pool boiling and mass distribution ratio during evaporation process of anionic surfactant sodium dodecyl sulfate(SDS),nonionic surfactant Triton X-100 and Triton X-114 which are representative and industrial applicated extensively and their aqueous solutions were studied experimentally under laboratorial conditions.The principles of surfactant liquid-vapor and solid-liquid interracial adsorption,the heat transfer in nucleate pool boiling and water entrained by steam were used to analyzing the effects of surfactants on nucleate pool boiling heat transfer and mass distribution ratio during evaporation process of aqueous surfactant solutions.The results show that surface tension and wettability of solid-liquid interface are lowered down when surfactant is added into water,and then departure diameters decreased,departure frequency and the number of active nucleate sites increased about steamed bubble.So that heat exchange is enhanced.The optimizing concentration of surfactant is near the critical micelle concentration(cmc);the coefficient of heat exchange here could be increased by 30%～140%to water in same condition.Triton X-100 shows better prospect in industrial application among the three surfactants because its lower cmc,better thermal stability and lower mass distribution ratio,at the same time,more significant improvement in heat exchange.