Pool boiling heat transfer characteristics of a biosurfactant particle deposited heating surface

摘要

The present work reports an experimental investigation of pool boiling of deionized water on a surfactant particle deposited heating surfaces. Heating surfaces made of copper are prepared by depositing surfactant particles through pool boiling of biosurfactant (Rhamnolipid) solutions at different concentrations (100-400 ppm of surfactant particles). Pool boiling experiments of deionized water have been performed with surfactant deposited heating surfaces, and results have been compared with the pool boiling of deionized water on a plain heating surface. Characterization of surfactant deposited heating surfaces indicates the presence of other elements like carbon, oxygen, silicon, chlorine, and potassium. The roughness of surfactant treated surfaces are 4-10 times more than the fresh heating surface, and their wettabilities are more than the fresh heating surface. Surfactant treated surfaces show a maximum 188% enhancement in heat transfer coefficient and 152% enhancement in critical heat flux as compared to the fresh heating surface. Porous structures are formed on the surfactant treated surfaces during boiling with the deionized water, which helps in heat transfer and critical heat flux enhancement through capillary wicking effects at high heat flux. However, no heat transfer enhancement has been observed when fresh pool boiling experiments of biosurfactant solutions have been performed with the surfactant deposited heating surfaces.