Download or read book Filmwise Condensation of Steam on Low Integral Finned Tubes written by Ioannis V. Georgiadis and published by . This book was released on 1984 with total page 167 pages. Available in PDF, EPUB and Kindle. Book excerpt: Filmwise condensation heat-transfer measurements of steam were made on horizontal tubes under vacuum and near-atmospheric pressures. Data were taken for smooth tube and for 21 tubes which contained rectangularly-shaped, low integral fins. The fin geometry was systematically varied in order to investigate the dependence of the steam-side heat-transfer coefficient on fin spacing, thickness and height. The condensation process was found to be most sensitive to fin spacing and to be weakly dependent on fin thickness. When the fin height was increased from 1.0 to 2.0 mm, the increase in the heat-transfer coefficient was about 20 percent, while the increase in condensing area was 51 percent. The best performing finned tube had a fin height of 1.5 mm, a fin thickness of 1.0 mm and a fin height of 2.0 mm. It showed an enhancement over the smooth tube of between 4 to 5 under vacuum conditions and around 6 at atmospheric conditions. Thus, the use of finned tubes may result in a significant reduction in size and weight of present-day steam condensers. Originator-supplied key words include: Steam, Condensation, Filmwise, Tube, Low Integral Fin, Heat-Transfer Coefficient, Enhancement.
Download or read book Film Condensation of Steam on Low integral Finned Tubes with Drainage Strips written by Oguz Cakan and published by . This book was released on 1986 with total page 105 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Further Studies in Filmwise Condensation of Steam on Horizontal Finned Tubes written by Keith Andrew Swensen and published by . This book was released on 1992 with total page 127 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Further Developments of Filmwise Condensation of Steam on Horizontal Integral Finned Tubes written by Mark Brady Guttendorf and published by . This book was released on 1990 with total page 170 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effect of Fin Height on Film Condensation of Steam on Stainless Steel Integral fin Tubes written by George A. Incheck and published by . This book was released on 1995 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Condensation heat transfer performance on a series of horizontal stainless-steel integral-fin tubes was experimentally studied at both atmospheric and vacuum pressure conditions to examine the effects of fin height on tubes of low thermal conductivity. Eight tubes with rectangular fin heights ranging from 0.16 to 1.42 mm and a smooth tube were tested. The fin thickness and spacing and tube inside and root diameters were kept constant at 1.0, 1.5, 13.1, and 14.2 mm respectively. The overall heat transfer coefficient was determined from experimentation and the outside heat transfer coefficient was then determined using the modified Wilson plot technique. A fin height of approximately 0.30 mm provided the maximum heat transfer at both vacuum and atmospheric conditions. Heat transfer performance declined steadily for further increases in fin height. The experimental results were compared to the predictions of the Beatty and Katz and Briggs and Rose models. Neither model satisfactorily predicted performance for the full range of fin heights tested.
Download or read book Filmwise Condensation on Low Integral fin Tubes of Different Diameter written by Thomas Louis Van Petten and published by . This book was released on 1988 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Some Aspects of Film Condensation of Steam on Finned Tubes written by James M. Coumes and published by . This book was released on 1989 with total page 148 pages. Available in PDF, EPUB and Kindle. Book excerpt: Heat-transfer measurements were made for filmwise condensation of steam on smooth tubes and finned tubes with rectangular-shaped fins. The influence of fin root diameter on a single horizontal finned tube was examined by taking data for two families of tubes whose fin root diameters were 12.7 and 19.05 mm. Each family of tubes had fins that were 1 mm thick and 1 mm high, but with fin spacings of 0.25, 0.50, 1.0, 1.5, 2.0, and 4.0 mm. To compare results being obtained in a concurrent research project with Queen Mary College (University of London), data were collected on two tubes whose fin root diameters were 12.7 mm, and which had fin thickness of 0.5 mm, fin heights of 1.59 mm, and fin spacings of 1.0 mm. A comparison of the enhancement ratios (based on constant vapor-side temperature drop) with past Naval Postgraduate School (nps) studies showed good agreement. The apparatus was then modified in order to study the effects of condensate inundation.
Download or read book Film Condensation of Steam on Externally Finned Horizontal Tubes written by Frederick A. Flook and published by . This book was released on 1985 with total page 147 pages. Available in PDF, EPUB and Kindle. Book excerpt: Filmwise condensation measurements of steam were made on horizontal finned tubes under vacuum and near-atmospheric conditions. Data were obtained for copper tubes with fins of rectangular, triangular, trapezoidal, and parabolic cross sections, and for a commercially-available finned tube. A stainless steel finned tube was also tested to investigate the effect of thermal conductivity. Maximum enhancements of about 4.8 were obtained under vacuum conditions, and about 6.9 at atmospheric pressure, compared to a smooth tube having an outside diameter equal to the root diameter of the finned tubes. The optimum fin spacing was found to be about 2.0 mm for rectangularly shaped-fins with a fin-thickness of 1.0 mm, and fin height of 0.5 and 1.5 mm. Fins with a parabolic shape were shown to perform better than fins of rectangular shape, and fins were shown to degrade the performance of stainless steel tubes. The effects of vapor shear were also shown to have only a small influence on the steam-side heat transfer coefficient. A theoretical model proposed by Webb et al. was found to underpredict the experimental data. Several suggestions to modify this model are described. Keywords: External fin; Heat transfer coefficient; Enhancement, Condenser tubes (Theses).
Download or read book Innovative Heat Exchangers written by Hans-Jörg Bart and published by Springer. This book was released on 2017-12-30 with total page 398 pages. Available in PDF, EPUB and Kindle. Book excerpt: This accessible book presents unconventional technologies in heat exchanger design that have the capacity to provide solutions to major concerns within the process and power-generating industries. Demonstrating the advantages and limits of these innovative heat exchangers, it also discusses micro- and nanostructure surfaces and micro-scale equipment, and introduces pillow-plate, helical and expanded metal baffle concepts. It offers step-by-step worked examples, which provide instructions for developing an initial configuration and are supported by clear, detailed drawings and pictures. Various types of heat exchangers are available, and they are widely used in all fields of industry for cooling or heating purposes, including in combustion engines. The market in 2012 was estimated to be U$ 42.7 billion and the global demand for heat exchangers is experiencing an annual growth of about 7.8 %. The market value is expected to reach U$ 57.9 billion in 2016, and approach U$ 78.16 billion in 2020. Providing a valuable introduction to students and researchers, this book offers clear and concise information to thermal engineers, mechanical engineers, process engineers and heat exchanger specialists.
Download or read book Effect of Fin Height on Film Condensation of Steam on Stainless Steel Integral fin Tubes written by George A. Incheck and published by . This book was released on 1995 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt: Condensation heat transfer performance on a series of horizontal stainless-steel integral-fin tubes was experimentally studied at both atmospheric and vacuum pressure conditions to examine the effects of fin height on tubes of low thermal conductivity. Eight tubes with rectangular fin heights ranging from 0.16 to 1.42 mm and a smooth tube were tested. The fin thickness and spacing and tube inside and root diameters were kept constant at 1.0, 1.5, 13.1, and 14.2 mm respectively. The overall heat transfer coefficient was determined from experimentation and the outside heat transfer coefficient was then determined using the modified Wilson plot technique. A fin height of approximately 0.30 mm provided the maximum heat transfer at both vacuum and atmospheric conditions. Heat transfer performance declined steadily for further increases in fin height. The experimental results were compared to the predictions of the Beatty and Katz and Briggs and Rose models. Neither model satisfactorily predicted performance for the full range of fin heights tested.
Download or read book Film Condensation of Steam on Externally Finned Horizontal Tubes written by and published by . This book was released on 1985 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Filmwise condensation measurements of steam were made on horizontal finned tubes under vacuum and near-atmospheric conditions. Data were obtained for copper tubes with fins of rectangular, triangular, trapezoidal, and parabolic cross sections, and for a commercially-available finned tube. A stainless steel finned tube was also tested to investigate the effect of thermal conductivity. Maximum enhancements of about 4.8 were obtained under vacuum conditions, and about 6.9 at atmospheric pressure, compared to a smooth tube having an outside diameter equal to the root diameter of the finned tubes. The optimum fin spacing was found to be about 2.0 mm for rectangularly shaped-fins with a fin-thickness of 1.0 mm, and fin height of 0.5 and 1.5 mm. Fins with a parabolic shape were shown to perform better than fins of rectangular shape, and fins were shown to degrade the performance of stainless steel tubes. The effects of vapor shear were also shown to have only a small influence on the steam-side heat transfer coefficient. A theoretical model proposed by Webb et al. was found to underpredict the experimental data. Several suggestions to modify this model are described. Keywords: External fin; Heat transfer coefficient; Enhancement, Condenser tubes (Theses).
Download or read book Heat Exchangers written by S. M. Sohel Murshed and published by BoD – Books on Demand. This book was released on 2017-04-26 with total page 219 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents contributions from renowned experts addressing research and development related to the two important areas of heat exchangers, which are advanced features and applications. This book is intended to be a useful source of information for researchers, postgraduate students, academics, and engineers working in the field of heat exchangers research and development.
Download or read book The Influence of Wall Conductivity on Film Condensation with Integral Fin Tubes written by Robert Lee Cobb and published by . This book was released on 1993 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Heat transfer performance of steam condensing on horizontal finned tubes made of copper, aluminum, copper nickel(90/10), and stainless steel(316) was studied using a condenser test rig at both vacuum and atmospheric conditions. Integral fin tubes included conventional rectangular shaped fins as well as rectangular fins having a radiussed root geometry (ie, a fillet radius equal to half the fin spacing). All finned tubes had inner and outer diameters of 12.70mm and 15.88mm respectively, and had a fin thickness of l.0mm and a fin spacing of 1.5mm. The overall heat transfer coefficient (U sub o) was determined experimentally and the outside heat transfer coefficient (ho) was obtained utilizing a modified Wilson Plot procedure. Results indicated that the performance of a finned tube was strongly dependent on the tube material and weakly dependent on fin geometry. Radiussing the fin root to remove condensate between fins in the unflooded portion (ie, top portion) of a finned tube reduced the heat transfer performance compared to a conventional rectangular shaped integral fin. Experimental data were compared to the models of Beatty and Katz as well as to a modified model of Rose.
Download or read book Filmwise Condensation on Integral fin Tubes written by and published by . This book was released on 1990 with total page 768 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Film Condensation of Steam on Externally Enhanced Horizontal Tubes written by Evagelos S. Mitrou and published by . This book was released on 1986 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Heat-transfer measurements were made for filmwise condensation of steam on externally enhanced horizontal tubes under vacuum and at atmospheric pressure. Data were obtained for copper tubes with circular fins of rectangular, triangular, trapezoidal, and parabolic cross sections for spiral fins of triangular cross section, for commercially available finned tubes and for wire-wrapped tubes. Four spirally finned tubes from each of Cu, Cu-ni, A1 and stainless steel and two tubes with fins of rectangular cross section from each of Cu-Ni and A1 were manufactured and tested to investigate the effect of thermal conductivity. Among sprially finned tubes, the optimum fin pitch was found to be 1.6 mm. The tubes with a parabolic fin shape showed the best performance with steam-side enhancements of 4.1 and 6.2 under vacuum and at the atmospheric pressure respectively. Enhancement ratios as high as 3.5 and 2.1 were obtained under vacuum and at atmospheric pressure, respectively, for the commercially available finned tubes. The heat-transfer performance decreased with decreasing tube metal thermal conductivity. For the wire-wrapped tubes, an optimum pitch to wire diameter ratio of about 5.1 was found, with steam-side enhancements of about 1.9 and 2.2 under vacuum and at atmospheric pressure, respectively. A recent theoretical analysis of laminar film of low-surface-tension fluids on wire-wrapped tubes was modified to include the condensate retention of the tube due to the high surface tension of water. Agreement between this modified analysis and the experimental data was favorable. Keywords: Heat transfer coefficient.
Download or read book Two Phase Heat Transfer Enhancement written by Sujoy Kumar Saha and published by Springer. This book was released on 2019-07-04 with total page 121 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Brief concerns heat transfer and pressure drop in heat transfer enhancement for boiling and condensation. The authors divide their topic into six areas: abrasive treatment and coatings, combined structured and porous surfaces, basic principles of boiling mechanism, vapor space condensation, convective vaporization, and forced condensation inside tubes. Within this framework, the book examines range of specific phenomena including abrasive treatment, open grooves, 3D cavities, etched surfaces, electroplating, pierced 3D cover sheets, attached wire and screen promoters, non-wetting coatings, oxide and ceramic coatings, porous surfaces, structured surfaces (integral roughness), combined structured and porous surfaces, composite surfaces, single-tube pool boiling tests, theoretical fundamentals like liquid superheat, effect of cavity shape and contact angle on superheat, entrapment of vapor in cavities, nucleation at a surface cavity, effect of dissolved gases, bubble departure diameter, bubble dynamics, boiling hysteresis and orientation effects, basic principles of boiling mechanism, visualization and mechanism of boiling in subsurface tunnels, and Chien and Webb parametric boiling studies.
Download or read book Filmwise Condensation of Steam on Externally Finned Horizontal Tubes written by William M. Poole and published by . This book was released on 1983 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt: The film-condensation characteristics of a smooth tube and six externally-finned tubes having fins 1 mm high and 1 mm thick, and ptiches of 1.5, 2.0, 2.5, 3.0, 5.0, and 10.0 mm, were experimentally tested. A smooth copper tube with an active length of 133.5 mm, an outside diameter of 19.05 mm, and an inside diameter of 12.7 mm was first tested to correlate the inside heat-transfer coefficient using the Sieder-Tate equation. The leading coefficient for this equation was found to be 0.034 + or - 0.001, and was used to derive the external condensing coefficient for all of the tubes by subtracting the inside and wall resistances from the measured overall resistance. The condensing coefficient was measured, both at atmospheric pressure and vacuum (84 mm hg), with the heat flux as a variable. Condensation data taken for the smooth tube were compared with data in the literature to check the reliability of the apparatus and the data-reduction procedures. The data for the finned tubes showed an optimum pitch of 2.5 mm. (Author).
