Fouling of structured surfaces during pool boiling of aqueous solutions [Elektronische Ressource] / Mohamed Esawy. Betreuer: Hans Müller-Steinhagen

Fouling of Structured Surfaces during Pool Boiling of Aqueous Solutions A Dissertation accepted by the Faculty of Energy Technology, Process Engineering and Biological Engineering of the University of Stuttgart in Partial Fulfillment of the Requirements for the Degree of Doctor of Engineering Sciences (Dr.-Ing.) by Mohamed Esawy, B. Sc., M. Sc. born in El-Sharkia, Egypt Institute for Thermodynamics and Thermal Engineering University of Stuttgart, Germany September 2011 Supervisor : Prof. Dr. Dr.-Ing. habil. H. Müller-Steinhagen Co-Referee : Prof. Dr.-Ing. Stephan Scholl Date of Oral Examination: 30. September, 2011 Abstract iABSTRACT Bubble characteristics in terms of density, size, frequency and motion are key factors that contribute to the superiority of nucleate pool boiling over the other modes of heat transfer. Nevertheless, if heat transfer occurs in an environment which is prone to fouling, the very same parameters may lead to accelerated deposit formation due to concentration effects beneath the growing bubbles. This has led heat exchanger designers frequently to maintain the surface temperature below the boiling point if fouling occurs, e.g. in thermal seawater desalination plants.