Download or read book Numerical Modelling and Experimental Testing of Heat Exchangers written by Dawid Taler and published by . This book was released on 2019 with total page 598 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents new methods of numerical modelling of tube heat exchangers, which can be used to perform design and operation calculations of exchangers characterized by a complex flow system. It also proposes new heat transfer correlations for laminar, transition and turbulent flows. A large part of the book is devoted to experimental testing of heat exchangers, and methods for assessing the indirect measurement uncertainty are presented. Further, it describes a new method for parallel determination of the Nusselt number correlations on both sides of the tube walls based on the nonlinear least squares method and presents the application of computational fluid dynamic (CFD) modeling to determine the air-side Nusselt number correlations. Lastly, it develops a control system based on the mathematical model of the car radiator and compares this with the digital proportional-integral-derivative (PID) controller. The book is intended for students, academics and researchers, as well as for designers and manufacturers of heat exchangers.
Download or read book Numerical Modelling and Experimental Testing of Heat Exchangers written by Dawid Taler and published by Springer. This book was released on 2018-05-17 with total page 598 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents new methods of numerical modelling of tube heat exchangers, which can be used to perform design and operation calculations of exchangers characterized by a complex flow system. It also proposes new heat transfer correlations for laminar, transition and turbulent flows. A large part of the book is devoted to experimental testing of heat exchangers, and methods for assessing the indirect measurement uncertainty are presented. Further, it describes a new method for parallel determination of the Nusselt number correlations on both sides of the tube walls based on the nonlinear least squares method and presents the application of computational fluid dynamic (CFD) modeling to determine the air-side Nusselt number correlations. Lastly, it develops a control system based on the mathematical model of the car radiator and compares this with the digital proportional-integral-derivative (PID) controller. The book is intended for students, academics and researchers, as well as for designers and manufacturers of heat exchangers.
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.
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.
Download or read book Numerical Simulation of Heat Exchangers written by W. J. Minkowycz and published by CRC Press. This book was released on 2017-04-07 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book deals with certain aspects of material science, particularly with the release of thermal energy associated with bond breaking. It clearly establishes the connection between heat transfer rates and product quality. The editors then sharply draw the thermal distinctions between the various categories of welding processes, and demonstrate how these distinctions are translated into simulation model uniqueness. The book discusses the incorporation of radiative heat transfer processes into the simulation model.
Download or read book Experimental Evaluation and Numerical Modeling of a Water Source Heat Pump Evaporator written by Paul Morency Means and published by . This book was released on 1980 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt: Water source heat pumps are increasingly being used for residential and commercial space heating. Typically, these heat pumps are capable of both heating and cooling, and historically the design emphasis has been on improving the units' cooling performance. Recently, there has been more interest in improving the heating performance, however, in order to optimize the design for improved heating performance data on the heat pump components operating in the heating mode are required. These data have not been available for the waterto- refrigerant heat exchangers typically installed in unitary water source heat pumps. The purpose of this work is to provide performance data on such heat exchangers operating as evaporators (data is available for the heat exchangers operating as condensers) and to provide a numerical model by which a limited amount of evaporator data might be expanded for system modeling and optimization studies. A well instrumented water-to-water heat pump was assembled for the purpose of testing two such water-to-refrigerant heat exchangers to determine their heat transfer and refrigerant pressure drop characteristics as evaporators. The overall heat transfer coefficient for each of the two heat exchangers was found to be a strong function of both the water and refrigerant flow rates and a relatively weak function of the refrigerant evaporation temperature. The refrigerant pressure drop was determined to be highly dependent on the refrigerant flow rate and only slightly dependent on the evaporator temperature. The overall heat transfer coefficient showed an apparent difference between parallel and counter flow conditions. This coefficient, as defined by the log-mean temperature difference, was slightly higher for the counter flow condition. A numerical model of the evaporator was developed and compared with the experimental results. The model follows a numerical solution in which the governing equations (continuity, momentum, and energy) are solved for a finite control volume and an appropriate finitedifference scheme is used to continue the solution step-wise along the length of the heat exchanger. The numerical model accurately predicts the effect of flow rate and temperature on refrigerant pressure drop and the effect of water flow rate and direction on the overall heat transfer coefficient. The model does not accurately predict the effect of evaporator temperature and refrigerant flow rate on the heat transfer coefficient.
Download or read book Advanced Computational Methods and Experiments in Heat Transfer X written by Bengt Sundén and published by WIT Press. This book was released on 2008-06-19 with total page 241 pages. Available in PDF, EPUB and Kindle. Book excerpt: In engineering design and development, reliable and accurate computational methods are requested to replace or complement expensive and time consuming experimental trial and error work. Tremendous advancements have been achieved during recent years due to improved numerical solutions of non-linear partial differential equations and computer developments to achieve efficient and rapid calculations. Nevertheless, to further progress in computational methods will require developments in theoretical and predictive procedures – both basic and innovative – and in applied research. Accurate experimental investigations are needed to validate the numerical calculations. This book contains the edited versions of the papers presented at the Tenth International Conference on Advanced Computational Methods and Experimental Measurements in Heat Transfer and Mass Transfer held in Maribor, Slovenia in July 2008. The objective of this conference series is to provide a forum for presentation and discussion of advanced topics, new approaches and application of advanced computational methods and experimental measurements to heat and mass transfer problems. The contributed papers are grouped in the following appropriate sections to provide better access for readers: Natural and forced convection; Heat exchangers; Advances in computational methods; Heat recovery; Heat transfer; Modelling and experiments.
Download or read book Heat Exchangers Design Experiment and Simulation written by and published by . This book was released on 19?? with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Thermal Performance Modeling of Cross Flow Heat Exchangers written by Luben Cabezas-Gómez and published by Springer. This book was released on 2014-08-18 with total page 233 pages. Available in PDF, EPUB and Kindle. Book excerpt: This monograph introduces a numerical computational methodology for thermal performance modeling of cross-flow heat exchangers, with applications in chemical, refrigeration and automobile industries. This methodology allows obtaining effectiveness-number of transfer units (e-NTU) data and has been used for simulating several standard and complex flow arrangements configurations of cross-flow heat exchangers. Simulated results have been validated through comparisons with results from available exact and approximate analytical solutions. Very accurate results have been obtained over wide ranges of NTU and C* values in all cases. The proposed procedure constitutes a useful research tool for both theoretical and experimental studies of cross-flow heat exchangers. The following are the unique features of the book: - The monograph includes the computational code named HETE (Heat Exchanger Thermal Effectiveness) in Chapter 5. A version of this code is available for downloading. - The computational procedure could be used for reducing experimental data using the effectiveness - NTU (e-NTU) method in research and industrial laboratories. - Even after more than one century in heat exchanger research, the search for new flow arrangements with higher effectiveness still is an unsolved problem. The present methodology could be a useful tool in pursuing that goal.
Download or read book Thermal Performance Modeling of Cross Flow Heat Exchangers written by Luben Cabezas-Gómez and published by Springer. This book was released on 2014-10-08 with total page 226 pages. Available in PDF, EPUB and Kindle. Book excerpt: This monograph introduces a numerical computational methodology for thermal performance modeling of cross-flow heat exchangers, with applications in chemical, refrigeration and automobile industries. This methodology allows obtaining effectiveness-number of transfer units (e-NTU) data and has been used for simulating several standard and complex flow arrangements configurations of cross-flow heat exchangers. Simulated results have been validated through comparisons with results from available exact and approximate analytical solutions. Very accurate results have been obtained over wide ranges of NTU and C* values in all cases. The proposed procedure constitutes a useful research tool for both theoretical and experimental studies of cross-flow heat exchangers. The following are the unique features of the book: - The monograph includes the computational code named HETE (Heat Exchanger Thermal Effectiveness) in Chapter 5. A version of this code is available for downloading. - The computational procedure could be used for reducing experimental data using the effectiveness - NTU (e-NTU) method in research and industrial laboratories. - Even after more than one century in heat exchanger research, the search for new flow arrangements with higher effectiveness still is an unsolved problem. The present methodology could be a useful tool in pursuing that goal.
Download or read book Numerical Simulation of Heat Exchanger written by and published by . This book was released on 1985 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Accurate and detailed knowledge of the fluid flow field and thermal distribution inside a heat exchanger becomes invaluable as a large, efficient, and reliable unit is sought. This information is needed to provide proper evaluation of the thermal and structural performance characteristics of a heat exchanger. It is to be noted that an analytical prediction method, when properly validated, will greatly reduce the need for model testing, facilitate interpolating and extrapolating test data, aid in optimizing heat-exchanger design and performance, and provide scaling capability. Thus tremendous savings of cost and time are realized. With the advent of large digital computers and advances in the development of computational fluid mechanics, it has become possible to predict analytically, through numerical solution, the conservation equations of mass, momentum, and energy for both the shellside and tubeside fluids. The numerical modeling technique will be a valuable, cost-effective design tool for development of advanced heat exchangers.
Download or read book Two Phase Heat Transfer Mechanisms Within Plate Heat Exchangers written by and published by . This book was released on 2016 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mots-clés de l'auteur: adiabatic two-phase pressure drops ; compact plate heat exchanger ; general prediction methods ; local heat transfer coefficient ; local infrared measurements ; modeling ; numerical simulations.
Download or read book Heat Transfer written by Aziz Belmiloudi and published by BoD – Books on Demand. This book was released on 2011-01-28 with total page 670 pages. Available in PDF, EPUB and Kindle. Book excerpt: Over the past few decades there has been a prolific increase in research and development in area of heat transfer, heat exchangers and their associated technologies. This book is a collection of current research in the above mentioned areas and discusses experimental, theoretical and calculation approaches and industrial utilizations with modern ideas and methods to study heat transfer for single and multiphase systems. The topics considered include various basic concepts of heat transfer, the fundamental modes of heat transfer (namely conduction, convection and radiation), thermophysical properties, condensation, boiling, freezing, innovative experiments, measurement analysis, theoretical models and simulations, with many real-world problems and important modern applications. The book is divided in four sections : "Heat Transfer in Micro Systems", "Boiling, Freezing and Condensation Heat Transfer", "Heat Transfer and its Assessment", "Heat Transfer Calculations", and each section discusses a wide variety of techniques, methods and applications in accordance with the subjects. The combination of theoretical and experimental investigations with many important practical applications of current interest will make this book of interest to researchers, scientists, engineers and graduate students, who make use of experimental and theoretical investigations, assessment and enhancement techniques in this multidisciplinary field as well as to researchers in mathematical modelling, computer simulations and information sciences, who make use of experimental and theoretical investigations as a means of critical assessment of models and results derived from advanced numerical simulations and improvement of the developed models and numerical methods.
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.
Download or read book Numerical Modelling of Geothermal Borehole Heat Exchanger Systems written by Miaomiao He and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The large proportion of energy used in the built environment has made improving energy efficiency in buildings, in particular their heating, ventilation, and air conditioning (HVAC) systems, a policy objective for reducing energy consumption and CO2 emissions nationally and internationally. Ground source heat pump (GSHP) systems, due to their high coefficient of performance (COP) and low CO2 emissions are consequently, receiving increasing attention. This work is concerned with the modelling of borehole heat exchangers (BHEs), the commonest form of ground heat exchangers found in GSHP systems. Their careful design is critical to both the short timescale and long timescale performance of geothermal heat pump systems. Unlike conventional components of HVAC systems, BHEs cannot be designed on the basis of peak load data but require3application of dynamic thermal models that are able to take account of the heat transfer inside the borehole as well as the surrounding ground. The finite volume method has been applied to develop a dynamic three-dimensional (3D) model for a single BHE and BHE arrays. The multi-block boundary fitted structured mesh used in this model allows the complex geometries around the pipes in BHEs and the surrounding ground around the borehole to be represented exactly. The transport of the fluid circulating along the pipe loop has been simulated explicitly in this model. The ground underneath the borehole has also been represented in this model. Validation of the 3D model has been carried out by reference to analytical models of borehole thermal resistance and fluid transport in pipes, as well as experimental data. In this work, the 3D numerical model has been applied to investigate the three-dimensional characteristics of heat transfer in and around a BHE at both short and long timescales. By implementing a two-dimensional (2D) model using the same numerical method and comparing the simulation results from the 3D and 2D models, the most significant three-dimensional effects have been identified and quantified. The findings have highlighted some of the limitations of 2D models, and based on the findings, methods to improve the accuracy of a 2D model have been suggested and validated. Furthermore, the 3D and 2D finite volume models have been applied to simulate an integrated GSHP system and their effects on overall system performance predictions have been investigated. The 3D numerical model has also been applied to examine thermal interactions within BHE arrays and to evaluate the assumptions of the line source model and their implications in the analysis of thermal response test data.
Download or read book Geothermal Energy Update written by and published by . This book was released on 1976 with total page 668 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 1990 with total page 480 pages. Available in PDF, EPUB and Kindle. Book excerpt:
