Read Books Online and Download eBooks, EPub, PDF, Mobi, Kindle, Text Full Free.
Mechanical Characterization And Simulation Modeling Of Printed Circuit Heat Exchangers For High Temperature Nuclear Application
Download Mechanical Characterization And Simulation Modeling Of Printed Circuit Heat Exchangers For High Temperature Nuclear Application full books in PDF, epub, and Kindle. Read online Mechanical Characterization And Simulation Modeling Of Printed Circuit Heat Exchangers For High Temperature Nuclear Application ebook anywhere anytime directly on your device. Fast Download speed and no annoying ads. We cannot guarantee that every ebooks is available!
Book Synopsis Mechanical Characterization and Simulation Modeling of Printed Circuit Heat Exchangers for High Temperature Nuclear Application by : Heramb Prakash Mahajan
Download or read book Mechanical Characterization and Simulation Modeling of Printed Circuit Heat Exchangers for High Temperature Nuclear Application written by Heramb Prakash Mahajan and published by . This book was released on 2021 with total page 253 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Thermohydraulic and Mechanical Modeling of Printed Circuit Heat Exchangers for Next Generation Nuclear Service by : Ian William Jentz
Download or read book Thermohydraulic and Mechanical Modeling of Printed Circuit Heat Exchangers for Next Generation Nuclear Service written by Ian William Jentz and published by . This book was released on 2021 with total page 227 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this work an approach to thermodyraulic and mechanical modeling of a full 3-dimensional Printed Circuit Heat Exchanger is presented. A new approach to Finite Element analysis of the fluid and structure using homogenization of micro-channel behavior is developed. The accuracy of the thermohydrualic model is verified against experiment for a large range of flow conditions. Using the results from the thermohydraulic model as input to the mechanical FE model allows loading and stress within the PCHE to by resolved. Coupling of the thermodynamic and mechanical models allows the performance and mechanical integrity of all parts of the PCHE to be evaluated simultaneously. Motivation for using airfoil PCHEs in s-CO2 applications is given and the design of PCHEs are briefly discussed. A thermohydraulic model using a homogenized heat exchanger thermohydraulics (HHXT) approach has been developed for PCHE applications. The HHXT model provides a fully resolved PCHE model without the complexity inherent in resolving all facets of the micro-channel geometry throughout the core. The HHXT approach expands on previous work by Urquiza in homogenizing the PCHE micro-channel core as an anisotropic media. Flow distribution in the PCHE is determined using a porous media approach. Heat transfer between fluids is modeled using heat transfer coefficients and is coupled to a conduction model of the solid PCHE body. The Homogenized Heatexchanger Thermohydraulics model properly resolves American Society of Mechanical Engineers Boiler and Pressure Vessel Code (BPVC) Sec-3 loading conditions without the complexity inherent in resolving all facets of the PCHE geometry. The accuracy of the model is verified through experimental validation. A purpose designed zig-zag channel test PCHE was tested over a wide range of flow, using 60 separate tests with Reynolds number ranging from 1,790 to 64,200. Embedded fiber-optic temperature sensors measured 2-dimensional temperature distribution within the test recuperator. Along with measurement of inlet and outlet conditions, the internal temperature measurements provide 7,542 distributed measurements for each flow rate tested. This allowed the verification of HHXT against a large set of data. Combined modelling and measurement allowed for better insight into PCHE performance. The interaction of side entrance and transition regions could be resolved. Flow redistribution within the cold CO2 of the zig-zag PCHE was found to be a major factor in the distribution of temperature. Mechanical analysis per BPVC section III design by analysis rules is demonstrated. Linearized stress analysis was used to break the stress within micro-channel walls into membrane and bending components needed in BPVC stress intensity calculations. A homogenized approach to modeling mechanical loads in the full 3-dimensional PCHE is used. The method consisted of separate micro-channel structure and PCHE structure analyses. The resulting model resolved pressurization and thermal stresses within the zig-zag test PCHE. Stress intensities within 108,000 distinct micro-channel walls could be determined. Thermal stress arising from the differential expansion of the PCHE body was found to contribute the most stress. The zig-zag test PCHE meets BPVC section III stress intensity limits at design operating conditions. Additionally the measurement of airfoil micro-channel heat transfer and hydraulic performance is made. As direct internal measurement of bulk CO2 or fluid-wall temperatures within the channels of the airfoil PCHE is not possible, convective heat transfer is calculated from inlet and outlet CO2 conditions and simple models of heat transfer within the recuperator. Since CO2 properties changed over the length of the recuperator, a 1D discrete model of the recuperator for calculating localized values of j and f is presented.
Book Synopsis Numerical Modeling and Performance Analysis of Printed Circuit Heat Exchanger for Very High-temperature Reactors by : Justin T. Figley
Download or read book Numerical Modeling and Performance Analysis of Printed Circuit Heat Exchanger for Very High-temperature Reactors written by Justin T. Figley and published by . This book was released on 2009 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Very High Temperature Reactors (VHTRs) operate at high temperatures (1,173-1,223 K) and require intermediate heat exchangers to transfer thermal energy to a hydrogen production plant or power conversion system. A promising plate-type compact heat exchanger for these applications is the Printed Circuit Heat Exchanger (PCHE). The objective of this study is to numerically model an Alloy 617 PCHE core with Helium as the working fluid using Fluent(TM)computational fluid dynamics software. The PCHE dimensions and operating conditions are those of a high-temperature helium test facility under construction at The Ohio State University. The test conditions considered are based upon the nominal design conditions of the test facility: operating pressure up to 3 MPa, mass flow rates of 10 to 80 kg/h, and hot and cold side inlet temperatures of 1,173 and 813 K, respectively. These operating conditions correspond to laminar and laminar-to-turbulent transitional flows within the fluid passages of the PCHEs being fabricated and modeled. The overall heat transfer coefficient ranges from 563-1697 W/m2K. The maximum effectiveness achieved is 85%. The maximum pressure drop of this PCHE is found to be approximately 1.5% of the operating pressure. The thermal duty of the heat exchanger ranges from 4.45 to 28.73 kW. The critical Reynolds number is found to be approximately 2800 for the semicircular channel as opposed to 2300 for a circular channel. CFD simulations carried out for laminar flow operating conditions are within good agreement with the predictions made using published correlations and empirical data. CFD simulations carried out for low Reynolds number laminar-to-turbulent transition cases are not accurately predicted by the correlations recommended in the published literature.
Book Synopsis Heat Exchangers by : S. M. Sohel Murshed
Download or read book Heat Exchangers written by S. M. Sohel Murshed and published by BoD – Books on Demand. This book was released on 2017-04-27 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presenting contributions from renowned experts in the field, this book covers research and development in fundamental areas of heat exchangers, which include: design and theoretical development, experiments, numerical modeling and simulations. This book is intended to be a useful reference source and guide to researchers, postgraduate students, and engineers in the fields of heat exchangers, cooling, and thermal management.
Book Synopsis Numerical Modeling of a Printed Circuit Heat Exchanger Based on Experimental Results from the High-temperature Helium Test Facility by : Kevin R. Wegman
Download or read book Numerical Modeling of a Printed Circuit Heat Exchanger Based on Experimental Results from the High-temperature Helium Test Facility written by Kevin R. Wegman and published by . This book was released on 2016 with total page 127 pages. Available in PDF, EPUB and Kindle. Book excerpt: The U.S. Department of Energy’s Generation IV Program has identified six advanced reactor technologies to be investigated for possible deployment in both energy and process heat generation. Most of these reactor concepts, such as the Very-High-Temperature Reactor (VHTR) and the Molten Salt Reactor (MSR), operate at high temperatures and/or pressures, requiring intermediate heat exchangers (IHXs) to transfer heat from the primary loop to secondary and tertiary loops. The VHTR has a design core outlet temperature of up to 1000 °C, and thus a robust high temperature IHX is required for full VHTR technology maturity. One such candidate for the IHX in these advanced reactors is the printed circuit heat exchanger (PCHE). The PCHE has an extremely high effectiveness and compactness, and the fabrication methods lead to great robustness as well. In this study, numerical simulations using a commercial code, COMSOL Multiphysics, were investigated and compared to the experimental results obtained from straight channel PCHE testing at the High-Temperature Helium test Facility (HTHF) at The Ohio State University (OSU). A post-machining analysis was completed for the frontal face geometry of the PCHE flow channels, and the results were compared to the nominal geometric values. The actual channel diameter was found to be 2.04±0.12 mm, compared to the nominal value of 2.0 mm, and the actual channel height was found to be 0.9±0.11 mm, compared to the nominal value of 1.0 mm. These new values were tested in the numerical model geometry as well as the nominal values. Three model were created for numerical investigation of the experimental results; a two-channel model, a two-plate model and a full-geometry model. A grid sensitivity study was completed for the two-channel model using a laminar flow model. Results were obtained for the two-channel model and was compared to the results obtained in the experiment. The heat transfer characteristics were over predicted in the numerical results, while the numerical pressure drops predicted the experimental values well. Preliminary results using a coarsened mesh were obtained for the two-plate and full-geometry model. A methodology for calculations of local friction factor and Nusselt number effects from numerical data is presented, and the resulting analyses are discussed. The globally calculated values are compared to the locally calculated values. The global and locally calculated results do not always match, explained by numerical errors related to the use of differentials for first ordered mesh cell elements.
Book Synopsis Design, Modeling and Characterization of a Multiscale Heat Exchanger for High-temperature, High-pressure Applications by : Chad T. Wilson
Download or read book Design, Modeling and Characterization of a Multiscale Heat Exchanger for High-temperature, High-pressure Applications written by Chad T. Wilson and published by . This book was released on 2021 with total page 63 pages. Available in PDF, EPUB and Kindle. Book excerpt: Heat exchangers are devices that facilitate thermal energy transfer between two or more mediums and which function as key components in many industrial processes, such as steam power plants, refrigeration, chemical plants, nuclear plants, refineries, and next-generation renewable energy storage processes. Recent advancements in power generation techniques and heat engine cycle structures offer potential improvements to the efficiency of each process but require components capable of operating in increasingly demanding environments. Specifically, the shift to high-temperature, high-pressure thermodynamic cycles for improved efficiency has offered a new opportunity for device-level innovations, including producing a heat exchanger that supersedes classical material and design operating limits. Previous work has attempted to infiltrate this new market by developing heat exchangers using costly metal materials in mature architectures that achieve low power densities. Silicon carbide, while well known as a high-temperature material, has rarely been used under such loading conditions due to its low resistance to fracture and high tensile stress concentrations featured in existing heat exchanger designs. In this thesis, we present the design, structural modelling, and initial characterization of a multiscale ceramic heat exchanger, capable of operating in extreme environments with high power densities and a safety factor against mechanical failure. The heat exchanger device is evaluated for a supercritical CO2 Brayton cycle, using air and sCO2 as working fluids at 80 bar, 1300 °C and 250 bar, 300 °C, respectively. A multiscale channel design, enabled by ceramic co-extrusion, results in a counterflow heat exchanger core with both high thermal performance and high mechanical strength during steady state operation. For coupling this core to typical power-cycle tubing we designed manufacturable ceramic headers, whose geometry was optimized to minimize both pressure loss and flow maldistribution of the working fluids. To evaluate prototypes of our design, we constructed a test setup and experimentally quantified the performance of initial heat exchanger core components. Our design offers a practical solution to address the material limitations imposed by high-temperature, high-pressure thermodynamic cycles while predicting efficiency and performance improvements compared to current state-of-the-art heat exchanger alternatives.
Book Synopsis Design, Fabrication, Testing, and Modeling of a High-temperature Printed Circuit Heat Exchanger by : Minghui Chen
Download or read book Design, Fabrication, Testing, and Modeling of a High-temperature Printed Circuit Heat Exchanger written by Minghui Chen and published by . This book was released on 2015 with total page 90 pages. Available in PDF, EPUB and Kindle. Book excerpt: One of the very-high-temperature reactor (VHTR) missions is to produce electricity and/or to provide process heat for applications with high efficiency. The electricity generation or process heat applications of these advanced reactors greatly rely on an effective intermediate heat exchanger (IHX) that transfers heat from the primary fluid (i.e., helium) to the secondary fluid, which can be helium, molten salt, water/steam, or supercritical carbon dioxide. The IHX performance is directly related to the efficiency and safety of the overall nuclear system. A printed circuit heat exchanger (PCHE) is one of the leading IHX candidates due to its high effectiveness and compactness, as well as its robustness. In the current study, a scaled-down PCHE was fabricated using Alloy 617 plates and Alloy 800H headers. The PCHE fabrication processes, i.e., photochemical etching, diffusion bonding and brazing, are described. This PCHE has eight hot and eight cold plates with 11 semicircular wavy (zigzag) channels in each plate with the following channel dimensions: 1.2 mm hydraulic diameter, 24.6 mm pitch in the flow (stream-wise) direction, 2.5 mm pitch in the span-wise direction, and 15o wavy pitch angle. The thermal-hydraulic performance of the PCHE is investigated experimentally in the high-temperature helium test facility (HTHF) at The Ohio State University. The PCHE inlet temperatures and pressures are varied up to 350 oC/2 MPa for the cold side and 700 oC/2 MPa for the hot side, respectively, while the maximum mass flow rate of helium reaches 30 kg/h. The corresponding maximum channel Reynolds number for both the hot and cold sides is about 3,000, including the laminar flow and laminar-to-turbulent transitional flow regimes. Comparisons between the obtained experimental data and available empirical correlations in the literature have been carried out. Both hot-side and cold-side friction characteristics of the PCHE with the wavy channels follow the trend established in the empirical model well, while large deviation is presented in the low Reynolds number region. Heat transfer characteristics obtained from model available in the literature show a discrepancy from the experimental results. Large deviation appears in the low Reynolds number region as well. A new heat transfer correlation based on experimental data has been subsequently proposed for the current wavy-channel PCHE. Finally, transients that involve variations of the mass flow rate and temperature on the hot and cold sides of the scaled-down PCHE are investigated by numerical method. A dynamic model has been verified using a commercial software DYNSIM and validated using the experimental data. The model predicts the dynamic trends well and is available for use in the future.
Book Synopsis Compact Heat Exchangers by : J.E. Hesselgreaves
Download or read book Compact Heat Exchangers written by J.E. Hesselgreaves and published by Elsevier. This book was released on 2001-05-08 with total page 417 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the ideas and industrial concepts in compact heat exchanger technology that have been developed in the last 10 years or so. Historically, the development and application of compact heat exchangers and their surfaces has taken place in a piecemeal fashion in a number of rather unrelated areas, principally those of the automotive and prime mover, aerospace, cryogenic and refrigeration sectors. Much detailed technology, familiar in one sector, progressed only slowly over the boundary into another sector. This compartmentalisation was a feature both of the user industries themselves, and also of the supplier, or manufacturing industries. These barriers are now breaking down, with valuable cross-fertilisation taking place. One of the industrial sectors that is waking up to the challenges of compact heat exchangers is that broadly defined as the process sector. If there is a bias in the book, it is towards this sector. Here, in many cases, the technical challenges are severe, since high pressures and temperatures are often involved, and working fluids can be corrosive, reactive or toxic. The opportunities, however, are correspondingly high, since compacts can offer a combination of lower capital or installed cost, lower temperature differences (and hence running costs), and lower inventory. In some cases they give the opportunity for a radical re-think of the process design, by the introduction of process intensification (PI) concepts such as combining process elements in one unit. An example of this is reaction and heat exchange, which offers, among other advantages, significantly lower by-product production.To stimulate future research, the author includes coverage of hitherto neglected approaches, such as that of the Second Law (of Thermodynamics), pioneered by Bejan and co- workers. The justification for this is that there is increasing interest in life-cycle and sustainable approaches to industrial activity as a whole, often involving exergy (Second Law) analysis. Heat exchangers, being fundamental components of energy and process systems, are both savers and spenders of exergy, according to interpretation.
Book Synopsis Applications of Finite Element Modeling for Mechanical and Mechatronic Systems by : Marek Krawczuk
Download or read book Applications of Finite Element Modeling for Mechanical and Mechatronic Systems written by Marek Krawczuk and published by MDPI. This book was released on 2021-09-02 with total page 392 pages. Available in PDF, EPUB and Kindle. Book excerpt: Modern engineering practice requires advanced numerical modeling because, among other things, it reduces the costs associated with prototyping or predicting the occurrence of potentially dangerous situations during operation in certain defined conditions. Thus far, different methods have been used to implement the real structure into the numerical version. The most popular uses have been variations of the finite element method (FEM). The aim of this Special Issue has been to familiarize the reader with the latest applications of the FEM for the modeling and analysis of diverse mechanical problems. Authors are encouraged to provide a concise description of the specific application or a potential application of the Special Issue.
Download or read book Księga pamiątkowa rzemiosła written by and published by . This book was released on 1948 with total page 439 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Scientific and Technical Aerospace Reports by :
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1992 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Modeling a Printed Circuit Heat Exchanger with RELAP5-3D for the Next Generation Nuclear Plant by :
Download or read book Modeling a Printed Circuit Heat Exchanger with RELAP5-3D for the Next Generation Nuclear Plant written by and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The main purpose of this report is to design a printed circuit heat exchanger (PCHE) for the Next Generation Nuclear Plant and carry out Loss of Coolant Accident (LOCA) simulation using RELAP5-3D. Helium was chosen as the coolant in the primary and secondary sides of the heat exchanger. The design of PCHE is critical for the LOCA simulations. For purposes of simplicity, a straight channel configuration was assumed. A parallel intermediate heat exchanger configuration was assumed for the RELAP5 model design. The RELAP5 modeling also required the semicircular channels in the heat exchanger to be mapped to rectangular channels. The initial RELAP5 run outputs steady state conditions which were then compared to the heat exchanger performance theory to ensure accurate design is being simulated. An exponential loss of pressure transient was simulated. This LOCA describes a loss of coolant pressure in the primary side over a 20 second time period. The results for the simulation indicate that heat is initially transferred from the primary loop to the secondary loop, but after the loss of pressure occurs, heat transfers from the secondary loop to the primary loop.
Book Synopsis Fundamentals and Applications of Supercritical Carbon Dioxide (SCO2) Based Power Cycles by : Klaus Brun
Download or read book Fundamentals and Applications of Supercritical Carbon Dioxide (SCO2) Based Power Cycles written by Klaus Brun and published by Woodhead Publishing. This book was released on 2017-01-09 with total page 464 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fundamentals and Applications of Supercritical Carbon Dioxide (SCO2) Based Power Cycles aims to provide engineers and researchers with an authoritative overview of research and technology in this area. Part One introduces the technology and reviews the properties of SCO2 relevant to power cycles. Other sections of the book address components for SCO2 power cycles, such as turbomachinery expanders, compressors, recuperators, and design challenges, such as the need for high-temperature materials. Chapters on key applications, including waste heat, nuclear power, fossil energy, geothermal and concentrated solar power are also included. The final section addresses major international research programs. Readers will learn about the attractive features of SC02 power cycles, which include a lower capital cost potential than the traditional cycle, and the compounding performance benefits from a more efficient thermodynamic cycle on balance of plant requirements, fuel use, and emissions. Represents the first book to focus exclusively on SC02 power cycles Contains detailed coverage of cycle fundamentals, key components, and design challenges Addresses the wide range of applications of SC02 power cycles, from more efficient electricity generation, to ship propulsion
Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1992 with total page 348 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energy Research Abstracts written by and published by . This book was released on 1983 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Book Synopsis Masters Theses in the Pure and Applied Sciences by : Wade H. Shafer
Download or read book Masters Theses in the Pure and Applied Sciences written by Wade H. Shafer and published by Springer. This book was released on 1990-01-31 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt: Masters Theses in the Pure and Applied Sciences was first conceived, published, and disseminated by the Center for Information and Numerical Data Analysis and Synthesis (CINDAS) * at Purdue University in 1 957, starting its coverage of theses with the academic year 1955. Beginning with Volume 13, the printing and dissemination phases of the activity were transferred to University Microfilms/Xerox of Ann Arbor, Michigan, with the thought that such an arrangement would be more beneficial to the academic and general scientific and technical community. After five years of this joint undertaking we had concluded that it was in the interest of all con cerned if the printing and distribution of the volumes were handled by an interna tional publishing house to assure improved service and broader dissemination. Hence, starting with Volume 18, Masters Theses in the Pure and Applied Sciences has been disseminated on a worldwide basis by Plenum Publishing Cor poration of New York, and in the same year the coverage was broadened to include Canadian universities. All back issues can also be ordered from Plenum. We have reported in Volume 32 (thesis year 1987) a total of 12,483 theses titles from 22 Canadian and 176 United States universities. We are sure that this broader base for these titles reported will greatly enhance the value of this important annual reference work. While Volume 32 reports theses submitted in 1987, on occasion, certain univer sities do report theses submitted in previous years but not reported at the time.
Book Synopsis Fundamentals of Heat Exchanger Design by : Ramesh K. Shah
Download or read book Fundamentals of Heat Exchanger Design written by Ramesh K. Shah and published by John Wiley & Sons. This book was released on 2003-08-11 with total page 978 pages. Available in PDF, EPUB and Kindle. Book excerpt: Comprehensive and unique source integrates the material usually distributed among a half a dozen sources. * Presents a unified approach to modeling of new designs and develops the skills for complex engineering analysis. * Provides industrial insight to the applications of the basic theory developed.
