Download or read book The Effect of Condensate Inundation on Steam Condensation Heat Transfer in a Tube Bundle written by S. K. Brower and published by . This book was released on 1985 with total page 105 pages. Available in PDF, EPUB and Kindle. Book excerpt: Steam-condensation heat-transfer measurements were made using a 5-tube in-line test condenser with an additional perforated tube to simulate up to 30 active tubes. Results were obtained for smooth tubes wire-wrapped tubes and dropwise-coated tubes. The average outside heat-transfer coefficient for 30 smooth tubes was 0.64 times the Nusselt coefficient fo the first tube. A total of eight wire-diameter and wire-pitch combinations were tested: 1.6-mm-diameter wire wrapped at 16 mm, 7.6 mm and 4 mm wire pitches, 1.0-mm-diameter wire wrapped at 8 mm, 4 mm and 2 mm wire pitches, and 0.5-mm-diameter wire wrapped at 4 and 2 mm wire pitches. The best bundle performance was obtained when the tubewere wrapped with 1.0-mm-diameter wire at a wire pitch of 4 mm. This combination resulted in an average outside heat-transfer coefficient for 30 tubes that was 1.15 times the value computed for the first time using the Nusselt theory. The average outside heat-transfer coefficient for 30 dropwise-coated tubes was 1.1 times the value of the heat-transfer coefficient for the first tube in the tube bundle. Using either wire-wrapped tubes or dropwise-coated tubes, it is possible to significantly reduce the condenser surface area and overall size. Keywords: Inundation, Smooth, wire-wrapped tubes. (Theses).
Download or read book The Effect of Condensate Inundation on Condensation Heat Transfer in Tube Bundles of Marine Condensers written by and published by . This book was released on 1980 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Experiments, under different conditions, were conducted to evaluate the effect of condensate inundation on condensation heat transfer in tube bundles of marine condensers. Five 15.9 mm. (5/8 in) nominal outside diameter, smooth stainless steel tubes were used in a vertical row to simulate an actual condenser. Tubes were located in an equilaterial triangular array with a spacing-to-diameter ratio of 1.5. Heat transfer performance was determined for each tube in bundle. Data was taken for condensing steam on the outside of each tube at about 21 KPa (3 psia) and at about 101 KPa (14.7 psia). Each tube was cooled by water on the inside at velocities of 0.78 to 6.22 m/sec (2.56 ft/sec to 20.42 ft/sec). The overall heat transfer coefficient was determined directly from experimental data. The inside and outside heat transfer coefficients were determined using the Wilson plot technique. Observation of condensate flow showed lateral droplet motion along the first three tubes in portions of the condenser under all conditions tested. Side drainage occurred only over the third and fourth tubes at a condensation pressure of about 21 KPa. The dominate mode of the flow at 101 KPa condensation pressure was gravitational flow. Outside heat transfer coefficients were higher than expected under all conditions when compared to the Nusselt theory. The reason for this is possibly due to secondary vapor flow. Recommendations to improve validations are provided. (Author).
Download or read book The Effect of Condensate Inundation on Condensation Heat Transfer in Tube Bundles of Marine Condensers written by Ismail Demirel and published by . This book was released on 1980 with total page 83 pages. Available in PDF, EPUB and Kindle. Book excerpt: Experiments, under different conditions, were conducted to evaluate the effect of condensate inundation on condensation heat transfer in tube bundles of marine condensers. Five 15.9 mm. (5/8 in) nominal outside diameter, smooth stainless steel tubes were used in a vertical row to simulate an actual condenser. Tubes were located in an equilaterial triangular array with a spacing-to-diameter ratio of 1.5. Heat transfer performance was determined for each tube in bundle. Data was taken for condensing steam on the outside of each tube at about 21 KPa (3 psia) and at about 101 KPa (14.7 psia). Each tube was cooled by water on the inside at velocities of 0.78 to 6.22 m/sec (2.56 ft/sec to 20.42 ft/sec). The overall heat transfer coefficient was determined directly from experimental data. The inside and outside heat transfer coefficients were determined using the Wilson plot technique. Observation of condensate flow showed lateral droplet motion along the first three tubes in portions of the condenser under all conditions tested. Side drainage occurred only over the third and fourth tubes at a condensation pressure of about 21 KPa. The dominate mode of the flow at 101 KPa condensation pressure was gravitational flow. Outside heat transfer coefficients were higher than expected under all conditions when compared to the Nusselt theory. The reason for this is possibly due to secondary vapor flow. Recommendations to improve validations are provided. (Author).
Download or read book The Effect of Condensate Inundation on Steam Condensation Heat Transfer to Wire Wrapped Tubing written by and published by . This book was released on 1983 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Steam condensation heat transfer measurements were made in a 5-tube test condenser having an additional perforated tube to simulate up to 30 active tubes. Results were obtained for smooth tubes and roped tubes wrapped with wire. A Sieder-Tate equation was used to correlate the inside heat-transfer coefficient. For smooth tubes, a leading coefficient of 0.029 was found, while it was 0.061 for the roped tubes. The average condensing coefficient measured for 30 smooth tubes was 0.59 times the Nusselt coefficient calculated for the first tube. When the smooth tubes were wrapped with wire, this ratio increased up to 0.86. Further, roped tubes without wire experienced a ratio of 0.63, while roped tubes wrapped with wire resulted in a ratio of 0.86. These preliminary data show that wire-wrapped tubes may lead to a significant reduction in condenser surface area. (Author).
Download or read book The Effect of Condensate Inundation on Steam Condensation Heat Transfer to Wire Wrapped Tubing written by Georgios Dimitriou Kanakis and published by . This book was released on 1983 with total page 161 pages. Available in PDF, EPUB and Kindle. Book excerpt: Steam condensation heat transfer measurements were made in a 5-tube test condenser having an additional perforated tube to simulate up to 30 active tubes. Results were obtained for smooth tubes and roped tubes wrapped with wire. A Sieder-Tate equation was used to correlate the inside heat-transfer coefficient. For smooth tubes, a leading coefficient of 0.029 was found, while it was 0.061 for the roped tubes. The average condensing coefficient measured for 30 smooth tubes was 0.59 times the Nusselt coefficient calculated for the first tube. When the smooth tubes were wrapped with wire, this ratio increased up to 0.86. Further, roped tubes without wire experienced a ratio of 0.63, while roped tubes wrapped with wire resulted in a ratio of 0.86. These preliminary data show that wire-wrapped tubes may lead to a significant reduction in condenser surface area. (Author).
Download or read book An Experimental Investigation of the Effect of Condensate Inundation on Heat Transfer in a Horizontal Tube Bundle written by Donald Eugene Eshleman and published by . This book was released on 1980 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt: A test facility to evaluate the effect of condensate inundation on heat transfer within a horizontal tube bundle was designed, constructed and validated. Five 15.9 mm (5/8 in.) nominal outside diameter, smooth stainless steel tubes were utilized in a vertical row. They were located in an equilateral triangular array with a spacing to diameter ratio of 1.5. Heat transfer performance was determined for each tube in the bundle. Data was taken by condensing steam at about 21 kPa (3 psia) on the outside of each tube. Each tube was cooled by water on the inside at velocities of 0.78 to 7.0 m/sec (2.56 to 23 ft/sec). The overall heat transfer coefficient was determined directly from experimental data. The inside and outside heat transfer coefficients were determined using the Wilson plot technique. Observation of condensate flow showed lateral droplet motion along the tube in portions of the condenser as well as side drainage, particularly over the first three tubes. Outside heat transfer coefficients were lower than expected when compared to Nusselt theory, possibly due to the effects of secondary vapor flow and/or non-condensable gases. Recommendations to improve validation are provided. (Author).
Download or read book An Experimental Investigation of the Effect of Condensate Inundation on Heat Transfer in a Horizontal Tube Bundle written by and published by . This book was released on 1980 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A test facility to evaluate the effect of condensate inundation on heat transfer within a horizontal tube bundle was designed, constructed and validated. Five 15.9 mm (5/8 in.) nominal outside diameter, smooth stainless steel tubes were utilized in a vertical row. They were located in an equilateral triangular array with a spacing to diameter ratio of 1.5. Heat transfer performance was determined for each tube in the bundle. Data was taken by condensing steam at about 21 kPa (3 psia) on the outside of each tube. Each tube was cooled by water on the inside at velocities of 0.78 to 7.0 m/sec (2.56 to 23 ft/sec). The overall heat transfer coefficient was determined directly from experimental data. The inside and outside heat transfer coefficients were determined using the Wilson plot technique. Observation of condensate flow showed lateral droplet motion along the tube in portions of the condenser as well as side drainage, particularly over the first three tubes. Outside heat transfer coefficients were lower than expected when compared to Nusselt theory, possibly due to the effects of secondary vapor flow and/or non-condensable gases. Recommendations to improve validation are provided. (Author).
Download or read book Effects of Condensate Inundation and Vapor Velocity on Heat Transfer in a Condenser Tube Bundle written by Paul Jeffrey Noftz and published by . This book was released on 1982 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt: A five-tube column test condenser was modified to facilitate easier tube removal and installation and to allow for the simulation of larger depth tube bundles. Heat transfer coefficients were then determined for sixty-two runs conducted at steam supply pressures of 35, 40, 45, and 50 psig with the system operated at test condenser pressures of approximately 2 and 15 psia. Each run was five minutes long with temperature, pressure, and flow rate data taken at one minute intervals. The results revealed that the average tube wall temperature and the heat transfer coefficients for a given tube of a tube bundle increased as the mean vapor velocity increased, but decreased as the amount of condensate inundation increased. The experimentally obtained values for the heat transfer coefficients were compatible with the Nusselt predictions for the runs conducted at 15 psia, but greatly exceeded the Nusselt predictions for the runs conducted at 2 psia. However, for the 2 psia runs, the heat transfer coefficients for the top tubes agreed closely with an experimental correlation proposed by Fujii. The simulation of a tube bundle of more than five active tubes per column at the 2 psia test condenser pressure demonstrated heat transfer coefficients closer to the Nusselt theory than when only five active tubes were considered.
Download or read book Condensation Heat Transfer Enhancement written by V. G. Rifert and published by WIT Press (UK). This book was released on 2004 with total page 402 pages. Available in PDF, EPUB and Kindle. Book excerpt: In processes with condensation of steam-to-gas compositions or refrigerative agents an intensification of condensation is often required because thermal resistance on the condensation side can be greater than the thermal resistance of the heat transfer wall on the cooling side. In this work, a pair of researchers from the National Technical U. of Ukraine and the State Academy of Refrigeration (Ukraine) provide information about the enhancement of condensation, including research results from the former USSR they feel deserves wider dissemination as well as discussion of different theoretical models of the condensation process. The US office of WIT Press is Computational Mechanics. Annotation : 2004 Book News, Inc., Portland, OR (booknews.com).
Download or read book Effect of Condensation on Performance and Design of Extended Surfaces written by and published by DIANE Publishing. This book was released on with total page 59 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Heat Transfer in Condensation and Boiling written by Samson Semenovich Kutateladze and published by . This book was released on 1959 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Condensers Theory and Practice written by David Butterworth and published by Thomas Telford Publishing. This book was released on 1983 with total page 700 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Condensation Heat Transfer written by P. J. Marto and published by . This book was released on 1979 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental Measurements of the Effects of Steam Velocity and Inundation on Condensation Heat Transfer written by A. A. Butcher and published by . This book was released on 1972 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Two Phase Flow Heat Exchangers written by Sadik Kakaç and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 1090 pages. Available in PDF, EPUB and Kindle. Book excerpt: Two-phase flow heat exchangers are vital components of systems for power generation, chemical processing, and thermal environment control. The art and science of the design of such heat exchangers have advanced considerably in recent years. This is due to better understanding of the fundamentals of two-phase flow and heat transfer in simple geometries, greater appreciation of these processes in complex goemetries, and enhanced predictive capability through use of complex computer codes. The subject is clearly of great fundamental and practical importance. The NATO ASIan Thermal-Hydraulic Fundamentals and Design of Two-Phase Flow Heat Exchangers was held in Povoa de Varzim (near Porto), Portugal, July 6-17, 1987. participating in the organization of" the ASI were the Department of Mechanical Engineering and the Clean Energy Research Institute, University of Miami; Universidade do Porto; and the Department of Mechanical Engineering, Aeronautical Eng ineer ing, and Mechanics, Rensselaer Polytechnic Institute. The ASI was arranged primarily as a high-level teaching activity by experts representing both academic and industrial viewpoints. The program included the presentation of invited lectures, a limited number of related technical papers and discussion sessions.
Download or read book Heat Transfer in Condensation and Boiling written by Karl Stephan and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 342 pages. Available in PDF, EPUB and Kindle. Book excerpt: I welcome the opportunity to have my book translated, because of the great emphasis on two-phase flow and heat transfer in the English-speaking world, as related to research, university education, and industrial practice. The 1988 Springer-Verlag edition of "Warmeiibergang beim Kondensieren und beim Sieden" has been enlarged to include additional material on falling film evaporation (Chapter 12) and pressure drop in two-phase flow (Chapter 13). Minor errors in the original text have also been corrected. I would like to express my sincere appreciation to Professor Green, Asso ciate Professor of German at Rensselaer, for his excellent translation and co operation. My thanks go also to Professor Bergles for his close attention to technical and linguistic details. He carefully read the typescript and made many comments and suggestions that helped to improve the manuscript. I hope that the English edition will meet with' a favorable reception and contribute to better understanding and to progress in the field of heat transfer in condensation and boiling. February 1992 K. Stephan Preface to the German-Language Edition This book is a continuation of the series "Heat and Mass Transfer" edited by U. Grigull, in which three volumes have already been published. Its aim is to acquaint students and practicing engineers with heat transfer during condensa tion and boiling, and is intended primarily for students and engineers in mechanical, chemical, electrical, and industrial processing engineering.
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.
