Download or read book Numerical Modeling and Experimental Testing of a Mixed Gas Joule Thomson Cryocooler written by John Frank Pettitt and published by . This book was released on 2006 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Progress in Mixed gas Joule Thomson Cryocooling written by Jennifer AmbeLyn Detlor and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Miniature Joule-Thomson (JT) cryocoolers are attractive for many applications due to their small size and resulting fast cool-down time. Finned-tube heat exchangers are the most widely used heat exchanger for miniature JT cryocoolers. The basic configuration, known as a Giauque-Hampson (GH) or coiled tube heat exchanger, involves the high-pressure stream flowing through a finned-tube that is helically coiled upon a cylindrical core while the low-pressure stream flows over the fins in the annular space created by the core and the inner diameter of a shell. Recent advances in technology have increased interest in JT cryocoolers that can provide cooling potential in the temperature ranges of 125 to 150 K. To achieve high efficiency and use a low-cost compressor, the JT cryocooler must provide cooling at low values of pressure ratios and operating pressure. To provide cooling under these conditions, a proper gas mixture must be selected as the working fluid. While it has been suggested that the heat transfer coefficient (htc) of the return stream is a key parameter affecting the behavior of the entire heat exchanger of a mixed-gas Joule-Thomson (MGJT) cryocooler, there is still no data or theory in open literature that characterizes the heat transfer and pressure drop characteristics of two-phase multi-component mixtures on the shell side in these heat exchangers. Beyond the broad goal of investigating gas mixture selection for MGJT cryocoolers, the experimental work in this study aimed to gain insight into these thermal characteristics by developing a test facility capable of measuring the two-phase htc for this geometry at operating conditions of interest to MGJT cryocooling. The capabilities of the test facility were demonstrated with a semi-flammable mixture. The size of the GH heat exchanger prototype and operating parameters of the test facility were consistent with those of interest for MGJT cryocoolers. Measurements of the two-phase htc of the mixed gas on the shell-side of the GH heat exchanger prototype were collected. For the mixture examined, the two-phase htc was found to be between 12 to 19 W/m2-K with uncertainties of approximately 12% for qualities in the range of 0.31 to 0.62. This data reveals that the shell side is the dominant thermal resistance for these operating conditions, even though the fins provide a larger surface area. Therefore, the htc of the mixed gas on the shell-side is crucial for cryocooler design and predicting the overall performance. While only a small amount of data was collected in this study, the data collected clearly demonstrates the need for and importance of developing accurate correlations for two-phase multi-component mixtures on the shell-side of GH heat exchangers for operating conditions consistent with MGJT cryocoolers. A large data collection campaign is proposed and enabled by the test facility developed in this work. Only with these correlations can the effects of the mixture selection on the pressure drop and the effectiveness of the heat exchanger be considered in the design of a MGJT cryocooler for optimal performance.
Download or read book Cryocoolers 10 written by Ronald G. Jr. Ross and published by Springer Science & Business Media. This book was released on 2007-05-08 with total page 850 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cryocoolers 10 is the premier archival publication of the latest advances and performance of small cryogenic refrigerators designed to provide localized cooling for military, space, semi-conductor, medical, computing, and high-temperature superconductor cryogenic applications in the 2-200 K temperature range. Composed of papers written by leading engineers and scientists in the field, Cryocoolers 10 reports the most recent advances in cryocooler development, contains extensive performance test results and comparisons, and relates the latest experience in integrating cryocoolers into advanced applications.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1992 with total page 1572 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 2010 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book International Aerospace Abstracts written by and published by . This book was released on 1999 with total page 1048 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Cryocoolers 13 written by Ronald G. Ross and published by Springer Science & Business Media. This book was released on 2007-02-15 with total page 710 pages. Available in PDF, EPUB and Kindle. Book excerpt: The last two years have witnessed a continuation in the breakthrough shift toward pulse tube cryocoolers for long-life, high-reliability cryocooler applications. New this year are papers de scribing the development of very large pulse tube cryocoolers to provide up to 1500 watts of cooling for industrial applications such as cooling the superconducting magnets of Mag-lev trains, coolmg superconducting cables for the power mdustry, and liquefymg natural gas. Pulse tube coolers can be driven by several competing compressor technologies. One class of pulse tube coolers is referred to as "Stirling type" because they are based on the linear Oxford Stirling-cooler type compressor; these generally provide coolmg m the 30 to 100 K temperature range and operate ^t frequencies from 30 to 60 Hz. A second type of pulse tube cooler is the so-called "Gifford-McMahon type. " Pulse tube coolers of this type use a G-M type compressor and lower frequency operation (~1 Hz) to achieve temperatures in the 2 to 10 K temperature range. The third type of pulse tube cooler is driven by a thermoacoustic oscillator, a heat engine that functions well in remote environments where electricity is not readily available. All three types are described, and in total, nearly half of this proceedings covers new developments in the pulse tube arena. Complementing the work on low-temperature pulse tube and Gifford-McMahon cryocoolers is substantial continued progress on rare earth regenerator materials.
Download or read book Miniature Joule Thomson Cryocooling written by Ben-Zion Maytal and published by Springer Science & Business Media. This book was released on 2012-09-18 with total page 410 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is the first in English being entirely dedicated to Miniature Joule-Thomson Cryocooling. The category of Joule-Thomson (JT) cryocoolers takes us back to the roots of cryogenics, in 1895, with figures like Linde and Hampson. The "cold finger" of these cryocoolers is compact, lacks moving parts, and sustains a large heat flux extraction at a steady temperature. Potentially, they cool down unbeatably fast. For example, cooling to below 100 K (minus 173 Celsius) might be accomplished within only a few seconds by liquefying argon. A level of about 120 K can be reached almost instantly with krypton. Indeed, the species of coolant plays a central role dictating the size, the intensity and the level of cryocooling. It is the JT effect that drives these cryocoolers and reflects the deviation of the "real" gas from the ideal gas properties. The nine chapters of the book are arranged in five parts. •The Common Principle of Cyrocoolers shared across the broad variety of cryocooler types •Theoretical Aspects: the JT effect and its inversion, cooling potential of coolants, the liquefaction process, sizing of heat exchangers, level of pressurization, discharge of pressure vessels • Practical Aspects: modes of operation (fast cooldown, continuous, multi-staging, hybrid cryocoolers), pressure sources, configuration, construction and technologies, flow adjustment, MEMS, open and closed cycle, cooldown process and similarity, transient behavior • Mixed Coolant cryocooling: theory, practice and applications • Special Topics: real gas choked flow rates, gas purity, clog formation, optimal fixed orifice, modeling, cryosurgical devices, warming by the inverse JT effect The theoretical aspects may be of interest not only to those working with cryocoolers but also for others with a general interest in "real" gas thermodynamics, such as, for example, the inversion of the JT effect in its differential and integral forms, and the exceptional behavior of the quantum gases. A detailed list of references for each chapter comprises a broad literature survey. It consists of more than 1,200 relevant publications and 450 related patents. The systematically organized content, arranged under a thorough hierarchy of headings, supported by 227 figures and 41 tables, and accompanied by various chronological notes of evolution, enables readers a friendly interaction with the book. Dr. Ben-Zion Maytal is a Senior Researcher at Rafael-Advanced Defense Systems, Ltd., and an Adjunct Senior Teaching Fellow at the Technion-Israel Institute of Technology, Haifa, Israel. Prof. John M. Pfotenhauer holds a joint appointment in the Departments of Mechanical Engineering and Engineering Physics at the University of Wisconsin - Madison.
Download or read book NASA SP written by and published by . This book was released on 1992 with total page 512 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental Techniques for Low Temperature Measurements written by Jack Ekin and published by Oxford University Press. This book was released on 2006-10-12 with total page 704 pages. Available in PDF, EPUB and Kindle. Book excerpt: Publisher description
Download or read book Cryocoolers written by Milind D. Atrey and published by Springer Nature. This book was released on 2020-02-24 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book serves as an introduction to cryocooler technology and describes the principle applications of cryocoolers across a broad range of fields. It covers the specific requirements of these applications, and describes how the advantages and disadvantages of different cryocooler systems are taken into consideration. For example, Stirling coolers tend to be used only in space applications because of their high coefficient of performance, low weight and proven reliability, whilst Gifford-McMahon coolers are used for ground applications, such as in cryopumps and MRI shield cooling applications. Joule-Thomson cryocoolers are used in missile technology because of the fast cool down requirements. The cryocooler field is fast developing and the number of applications are growing because of the increasing costs of the cryogens such as Helium and Neon. The first chapter of the book introduces the different types of cryocoolers, their classification, working principles, and their design aspects, and briefly mentions some of the applications of these systems. This introductory chapter is followed by a number of contributions from prominent international researchers, each describing a specific field of application, the cooling requirements and the cryocooler systems employed. These areas of application include gas liquefaction, space technology, medical science, dilution refrigerators, missile systems, and physics research including particle accelerators. Each chapter describes the cooling requirements based on the end use, the approximate cooling load calculations, the criteria for cryocooler selection, the arrangement for cryocooler placement, the connection of the cooler to the object to be cooled, and includes genuine case studies. Intended primarily for researchers working on cryocoolers, the book will also serve as an introduction to cryocooler technology for students, and a useful reference for those using cryocooler systems in any area of application.
Download or read book Refrigeration Air Conditioning and Heat Pumps written by G F Hundy and published by Butterworth-Heinemann. This book was released on 2016-03-07 with total page 512 pages. Available in PDF, EPUB and Kindle. Book excerpt: Refrigeration, Air Conditioning and Heat Pumps, Fifth Edition, provides a comprehensive introduction to the principles and practice of refrigeration. Clear and comprehensive, it is suitable for both trainee and professional HVAC engineers, with a straightforward approach that also helps inexperienced readers gain a comprehensive introduction to the fundamentals of the technology. With its concise style and broad scope, the book covers most of the equipment and applications professionals will encounter. The simplicity of the descriptions helps users understand, specify, commission, use, and maintain these systems. It is a must-have text for anyone who needs thorough, foundational information on refrigeration and air conditioning, but without textbook pedagogy. It includes detailed technicalities or product-specific information. New material to this edition includes the latest developments in refrigerants and lubricants, together with updated information on compressors, heat exchangers, liquid chillers, electronic expansion valves, controls, and cold storage. In addition, efficiency, environmental impact, split systems, retail refrigeration (supermarket systems and cold rooms), industrial systems, fans, air infiltration, and noise are also included. Full theoretical and practical treatment of current issues and trends in refrigeration and air conditioning technology Meets the needs of industry practitioners and system designers who need a rigorous, but accessible reference to the latest developments in refrigeration and AC that is supported by coverage at a level not found in typical course textbooks New edition features updated content on refrigerants, microchannel technology, noise, condensers, data centers, and electronic control
Download or read book Aeronautical Engineering written by and published by . This book was released on 1992 with total page 1020 pages. Available in PDF, EPUB and Kindle. Book excerpt: A selection of annotated references to unclassified reports and journal articles that were introduced into the NASA scientific and technical information system and announced in Scientific and technical aerospace reports (STAR) and International aerospace abstracts (IAA)
Download or read book Electrical Electronics Abstracts written by and published by . This book was released on 1997 with total page 2304 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Physics Briefs written by and published by . This book was released on 1994 with total page 1170 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Physics of Cryogenics written by Bahman Zohuri and published by Elsevier. This book was released on 2017-11-17 with total page 728 pages. Available in PDF, EPUB and Kindle. Book excerpt: Physics of Cryogenics: An Ultralow Temperature Phenomenon discusses the significant number of advances that have been made during the last few years in a variety of cryocoolers, such as Brayton, Joule-Thomson, Stirling, pulse tube, Gifford-McMahon and magnetic refrigerators. The book reviews various approaches taken to improve reliability, a major driving force for new research areas. The advantages and disadvantages of different cycles are compared, and the latest improvements in each of these cryocoolers is discussed. The book starts with the thermodynamic fundamentals, followed by the definition of cryogenic and the associated science behind low temperature phenomena and properties. This book is an ideal resource for scientists, engineers and graduate and senior undergraduate students who need a better understanding of the science of cryogenics and related thermodynamics. Defines the fundamentals of thermodynamics that are associated with cryogenic processes Provides an overview of the history of the development of cryogenic technology Includes new, low temperature tables written by the author Deals with the application of cryogenics to preserve objects at very low temperature Explains how cryogenic phenomena work for human cell and human body preservations and new medical approaches
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1986 with total page 1362 pages. Available in PDF, EPUB and Kindle. Book excerpt:
