Download or read book Investigation of Hydrophobic Coatings in Air Cooled Condensers for Heat Transfer Applications written by Kuok Kong Cheng and published by . This book was released on 2012 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt: In recent years, industries are replacing traditional fluoride based refrigerants for different alternative such as hydrocarbons and water based refrigerants in HVAC applications due to environmental concerns. Air cooled condensers are widely used in HVAC applications and there are ongoing researches to improve the thermodynamic efficiencies for these devices and environmental friendly at the same time. For internal condensations, there are several ways to enhance heat transfer performances, such as coil inserts and surface micro structures. Many of the researches focus on condenser surface modifications mainly on internal machined microstructure patterns. It was found that such techniques improve heat transfer performances up to 400 % compared with smooth surfaces due to enhance mixing and drainage. However, such techniques do not work with all geometries such as micro-channels and other complicated shapes. In the field of external condensation studies, dropwise condensations (DWC) are found to enhance heat transfer coefficients about 300 % to 400 % compared to filmwise condensation (FWC) in most researches. In order to promote DWC, hydrophobic coatings are applied to the condensing surface in most cases. Coatings techniques are solution based and could be easily applied to different geometries. Techniques for promoting DWC for external condensations can be applied to internal condensation as well. The objective of this project is to investigate heat transfer enhancements of DWC promoters has on internal condensation via model based on external DWC and FWC heat transfer models; experiments with hydrophobic coatings inside (coatings provided by NEI Corporation) as well as finned non-coated finned copper and aluminum tubes were conducted with water, n -hexane and n -heptane were carried out to investigate the effects of such promoters; experimental results were compared with establish correlations and models developed in this project. Models developed in this project suggest that DWC promoters could potentially enhance heat flux and heat transfer coefficients compared with FWC. It was found that hydrophobic coatings enhance heat flux and internal heat transfer coefficients by 20 % and 50 % for water and such coatings have negligible effects on n -hexane and n -heptane. Also, most established correlations over predict heat transfer coefficients at low mass flow in water, n -hexane and n -heptane
Download or read book An Investigation of a Method of Increasing the Heat Transfer and Condensation in an Air Cooled Steam Condenser written by Charles V. Bengle and published by . This book was released on 1938 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Inventory of Energy Research and Development 1973 1975 written by Oak Ridge National Laboratory and published by . This book was released on 1976 with total page 1440 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The CRC Handbook of Mechanical Engineering written by D. Yogi Goswami and published by CRC Press. This book was released on 2004-09-29 with total page 2690 pages. Available in PDF, EPUB and Kindle. Book excerpt: The second edition of this standard-setting handbook provides and all-encompassing reference for the practicing engineer in industry, government, and academia, with relevant background and up-to-date information on the most important topics of modern mechanical engineering. These topics include modern manufacturing and design, robotics, computer engineering, environmental engineering, economics, patent law, and communication/information systems. The final chapter and appendix provide information regarding physical properties and mathematical and computational methods. New topics include nanotechnology, MEMS, electronic packaging, global climate change, electric and hybrid vehicles, and bioengineering.
Download or read book Journal of Heat Transfer written by and published by . This book was released on 1987 with total page 1096 pages. Available in PDF, EPUB and Kindle. Book excerpt: Publishes research on energy transfer in equipment and applied thermodynamic processes in all fields of mechanical engineering and related industries. Topic areas include aerospace heat transfer; environmental heat transfer; gas turbine heat transfer; heat and mass transfer in biotechnology; heat transfer in electronic equipment; heat transfer in energy systems; heat transfer in fire and combustion systems; and heat transfer in manufacturing and materials processing.
Download or read book Dropwise Condensation of Water and Low Surface Tension Fluids on Structured Surfaces written by Yajing Zhao (S.M.) and published by . This book was released on 2018 with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt: Condensation is a ubiquitous process often observed in nature and our daily lives. The large amount of latent heat released during the condensation process has been harnessed in many industrial processes such as power generation, building heating and cooling, desalination, dew harvesting, thermal management, and refrigeration. Condensation has two modes: dropwise mode and filmwise mode. Although it has been known for decades that dropwise condensation outperforms filmwise condensation in heat transfer owing to the droplet shedding effects which can efficiently reduce thermal resistance, filmwise condensation still dominates industrial applications currently due to the high costs, low robustness and technical challenges of manufacturing dropwise coatings. During water condensation, dropwise mode can be readily promoted with thin hydrophobic coatings. Superhydrophobic surfaces made out of hydrophobic coatings on micro-or-nano-engineered surfaces have shown further heat transfer enhancement in dropwise condensation of water; however, the applications of these micro- or nanoscale structured surface designs have been restricted by the high manufacturing expenses and short range of subcooling limit. Recent studies have shown that the combination of millimeter sized geometric features and plain hydrophobic coatings can effectively manipulate droplet distribution of water condensate, which provides opportunities to locally facilitate dropwise condensation at relatively low manufacturing expenses as compared to those delicate micro- and nano-structured hydrophobic surfaces. Low surface tension fluids such as hydrocarbons pose a unique challenge to achieving dropwise condensation, because common hydrophobic coatings are not capable of repelling low surface tension fluids. Recent development in lubricant infused surfaces (LIS) offers promising solutions to achieving dropwise condensation of low surface tension fluids by replacing the solid-condensate interface in conventional hydrophobic coatings with a smooth lubricant-condensate interface. However, only a few experimental studies have applied LIS to promoting dropwise condensation of low surface tension fluids (y as low as 15 mN/m). In this work, we investigated dropwise condensation of both water (y ~ 72 mN/m) and a low surface tension fluid, namely butane (y - 13 mN/m) on structured surfaces. For water condensation, we studied the effects of millimeter sized geometric structures on dropwise condensation heat transfer under two different environments: pure vapor and an air-vapor mixture. Our experimental results show that, although convex structures enable faster droplet growth in an air-vapor mixture, the same structures impose the opposite effect during pure vapor condensation, hindering droplet growth. We developed a numerical model for each case to predict the heat flux distribution along the structured surface, and the model shows good agreement with experimental results. This work demonstrates that the effects of geometric features on dropwise condensation are not invariable but rather dependent on the scenario of resistances to heat and mass transfer in the system. For butane condensation, based on a design guideline we recently developed for lubricant infused surfaces, we successfully designed an energy-favorable combination of lubricant and structured solid substrate, which was further demonstrated to promote dropwise condensation of butane. The fundamental understanding of dropwise condensation of water and low surface tension fluids on structured surfaces developed in this study provides useful guidelines for condensation applications including power generation, desalination, dew harvesting, and thermal management.
Download or read book Nanotechnology for Energy Sustainability written by Baldev Raj and published by John Wiley & Sons. This book was released on 2017-01-30 with total page 1284 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dieses Referenzwerk in drei handlichen Bänden bietet einen detaillierten Überblick über Anwendungen der Nanotechnologie im Bereich Nachhaltigkeit in der Energieversorgung. Der erste Band dieses klar strukturierten Nachschlagewerks behandelt nach der Einleitung die Themen Energieerzeugung, erneuerbare Energien, Energiespeicherung, Energieverteilung sowie Energieumwandlung und Energy-Harvesting. Im zweiten Band werden auf Nanotechnologie basierte Materialen, Energieeinsparung und -management, technologische und urheberrechtlich relevante Fragen, Märkte und Umweltsanierung erörtert. Der dritte Band wirft einen Blick in die Zukunft, auf technologische Fortschritte und gibt Empfehlungen. Ein wichtiges Handbuch für alle Experten auf diesem Gebiet, von Forschern und Ingenieuren im wissenschaftlichen Bereich bis hin zu Entwicklern in der Industrie.
Download or read book Organometallic Polymer Coatings for Geothermal Fluid Sprayed Air Cooled Condensers Preprint written by and published by . This book was released on 2002 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Researchers are developing polymer-based coating systems to reduce scaling and corrosion of air-cooled condensers that use a geothermal fluid spray for heat transfer augmentation.
Download or read book An Evaluation of Heat transfer Deterioration of Hydrophobic Coatings During Dropwise Condensation of Steam written by John D. Bowen and published by . This book was released on 1986 with total page 119 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modeling Investigation and Formulation of Hydrophobic Coatings for Potential Self cleaning Applications written by PABLO FABIAN RIOS and published by . This book was released on 2007 with total page 253 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Bulletin de L Institut International Du Froid written by and published by . This book was released on 2007 with total page 652 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Heat Exchanger Technology written by Duncan Chisholm and published by . This book was released on 1988 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Inverse Heat Transfer Problems written by Oleg M. Alifanov and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt: This research monograph presents a systematic treatment of the theory of the propagation of transient electromagnetic fields (such as optical pulses) through dielectric media which exhibit both dispersion a.nd absorption. The work divides naturally into two parts. Part I presents a summary of the fundamental theory of the radiation and propagation of rather general electromagnetic waves in causal, linear media which are homogeneous and isotropic but which otherwise have rather general dispersive and absorbing properties. In Part II, we specialize to the propagation of a plane, transient electromagnetic field in a homogeneous dielectric. Although we have made some contributions to the fundamental theory given in Part I, most of the results of our own research appear in Part II. The purpose of the theory presented in Part II is to predict and to explain in explicit detail the dynamics of the field after it has propagated far enough through the medium to be in the mature-dispersion regime. It is the subject of a classic theory, based on the research conducted by A. Sommerfeld and L.
Download or read book Engineering written by and published by . This book was released on 1968-10 with total page 1204 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Handbook of Thermal Science and Engineering written by and published by Springer. This book was released on 2018-07-31 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Handbook provides researchers, faculty, design engineers in industrial R&D, and practicing engineers in the field concise treatments of advanced and more-recently established topics in thermal science and engineering, with an important emphasis on micro- and nanosystems, not covered in earlier references on applied thermal science, heat transfer or relevant aspects of mechanical/chemical engineering. Major sections address new developments in heat transfer, transport phenomena, single- and multiphase flows with energy transfer, thermal-bioengineering, thermal radiation, combined mode heat transfer, coupled heat and mass transfer, and energy systems. Energy transport at the macro-scale and micro/nano-scales is also included. The internationally recognized team of authors adopt a consistent and systematic approach and writing style, including ample cross reference among topics, offering readers a user-friendly knowledgebase greater than the sum of its parts, perfect for frequent consultation. The Handbook of Thermal Science and Engineering is ideal for academic and professional readers in the traditional and emerging areas of mechanical engineering, chemical engineering, aerospace engineering, bioengineering, electronics fabrication, energy, and manufacturing concerned with the influence thermal phenomena.
Download or read book Principles and Practice of Variable Pressure Environmental Scanning Electron Microscopy VP ESEM written by Debbie Stokes and published by John Wiley & Sons. This book was released on 2008-12-22 with total page 247 pages. Available in PDF, EPUB and Kindle. Book excerpt: Offers a simple starting point to VPSEM, especially for new users, technicians and students containing clear, concise explanations Crucially, the principles and applications outlined in this book are completely generic: i.e. applicable to all types of VPSEM, irrespective of manufacturer. Information presented will enable reader to turn principles into practice Published in association with the Royal Microscopical Society (RMS) -www.rms.org.uk
Download or read book Process Intensification written by David Reay and published by Butterworth-Heinemann. This book was released on 2013-06-05 with total page 624 pages. Available in PDF, EPUB and Kindle. Book excerpt: Process Intensification: Engineering for Efficiency, Sustainability and Flexibility is the first book to provide a practical working guide to understanding process intensification (PI) and developing successful PI solutions and applications in chemical process, civil, environmental, energy, pharmaceutical, biological, and biochemical systems. Process intensification is a chemical and process design approach that leads to substantially smaller, cleaner, safer, and more energy efficient process technology. It improves process flexibility, product quality, speed to market and inherent safety, with a reduced environmental footprint. This book represents a valuable resource for engineers working with leading-edge process technologies, and those involved research and development of chemical, process, environmental, pharmaceutical, and bioscience systems. - No other reference covers both the technology and application of PI, addressing fundamentals, industry applications, and including a development and implementation guide - Covers hot and high growth topics, including emission prevention, sustainable design, and pinch analysis - World-class authors: Colin Ramshaw pioneered PI at ICI and is widely credited as the father of the technology
