Download or read book All Metal Compact Heat Exchanger for Space Cryocoolers written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-30 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report describes the development of a high performance, all metal compact heat exchanger. The device is designed for use in a reverse Brayton cryogenic cooler which provides five watts of refrigeration at 70 K. The heat exchanger consists of a stainless steel tube concentrically assembled within a second stainless steel tube. Approximately 300 pairs of slotted copper disks and matching annular slotted copper plates are positioned along the centerline axis of the concentric tubes. Each of the disks and plates has approximately 1200 precise slots machined by means of a special electric discharge process. Positioning of the disk and plate pairs is accomplished by means of dimples in the surface of the tubes. Mechanical and thermal connections between the tubes and plate/disk pairs are made by solder joints. The heat exchanger assembly is 9 cm in diameter by 50 cm in length and has a mass of 10 kg. The predicted thermal effectiveness is greater than 0.985 at design conditions. Pressure loss at design conditions is less than 5 kPa in both fluid passages. Tests were performed on a subassembly of plates integrally soldered to two end headers. The measured thermal effectiveness of the test article exceeded predicted levels. Pressure losses were negligibly higher than predictions. Swift, Walter L. and Valenzuela, Javier and Sixsmith, Herbert Unspecified Center NAS5-30172; PROJ. 3307; SBIR-09.07-3800...
Download or read book Compact Heat Exchangers written by Alexander Louis London and published by CRC Press. This book was released on 1990 with total page 798 pages. Available in PDF, EPUB and Kindle. Book excerpt: Heat exchangers are a crucial part of aerospace, marine, cryogenic and refrigeration technology. These essays cover such topics as complicated flow arrangements, complex extended surfaces, two-phase flow and irreversibility in heat exchangers, and single-phase heat transfer.
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 Compact Heat Exchangers written by J.E. Hesselgreaves and published by Butterworth-Heinemann. This book was released on 2016-09-26 with total page 504 pages. Available in PDF, EPUB and Kindle. Book excerpt: Compact Heat Exchangers: Selection, Design, and Operation, Second Edition, is fully revised to present the most recent and fundamental ideas and industrial concepts in compact heat exchanger technology. This complete reference compiles all aspects of theory, design rules, operational issues, and the most recent developments and technological advancements in compact heat exchangers. New to this edition is the inclusion of micro, sintered, and porous passage description and data, electronic cooling, and an introduction to convective heat transfer fundamentals. New revised content provides up-to-date coverage of industrially available exchangers, recent fouling theories, and reactor types, with summaries of off-design performance and system effects and installations issues in, for example, automobiles and aircraft. Hesselgreaves covers previously neglected approaches, such as 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 energy, according to interpretation. Contains revised content, covering industrially available exchangers, recent fouling theories, and reactor types Includes useful comparisons throughout with conventional heat exchangers to emphasize the benefits of CPHE applications Provides a thorough system view from commissioning, operation, maintenance, and design approaches to reduce fouling and fouling factors Compiles all aspects of theory, design rules, operational issues, and the most recent developments and technological advancements in compact heat exchangers
Download or read book Heat Exchangers written by Spencer T. Branson and published by . This book was released on 2011 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A heat exchanger is a device built for efficient heat transfer from one medium to another. The media may be separated by a solid wall, so that they never mix, or they may be in direct contact. They are widely used in space heating, refrigeration, air conditioning, power plants, chemical plants, petrochemical plants, petroleum refineries, natural gas processing, and sewage treatment. One common example of a heat exchanger is the radiator in a car, in which the heat source, being a hot engine-cooling fluid, water, transfers heat to air flowing through the radiator. This book presents current research data in the study of heat exchangers, including lightweight compact heat exchangers with open-cell metal; the NTU-effectiveness method to design and assess heat exchangers; a mathematical model for plate heat exchangers; and advances in design optimisation of shell and tube heat exchangers.
Download or read book Compact Heat Exchangers written by C. Ranganayakulu and published by John Wiley & Sons. This book was released on 2018-02-02 with total page 547 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive source of generalized design data for most widely used fin surfaces in CHEs Compact Heat Exchanger Analysis, Design and Optimization: FEM and CFD Approach brings new concepts of design data generation numerically (which is more cost effective than generic design data) and can be used by design and practicing engineers more effectively. The numerical methods/techniques are introduced for estimation of performance deteriorations like flow non-uniformity, temperature non-uniformity, and longitudinal heat conduction effects using FEM in CHE unit level and Colburn j factors and Fanning friction f factors data generation method for various types of CHE fins using CFD. In addition, worked examples for single and two-phase flow CHEs are provided and the complete qualification tests are given for CHEs use in aerospace applications. Chapters cover: Basic Heat Transfer; Compact Heat Exchangers; Fundamentals of Finite Element and Finite Volume Methods; Finite Element Analysis of Compact Heat Exchangers; Generation of Design Data by CFD Analysis; Thermal and Mechanical Design of Compact Heat Exchanger; and Manufacturing and Qualification Testing of Compact Heat Exchanger. Provides complete information about basic design of Compact Heat Exchangers Design and data generation is based on numerical techniques such as FEM and CFD methods rather than experimental or analytical ones Intricate design aspects included, covering complete cycle of design, manufacturing, and qualification of a Compact Heat Exchanger Appendices on basic essential fluid properties, metal characteristics, and derivation of Fourier series mathematical equation Compact Heat Exchanger Analysis, Design and Optimization: FEM and CFD Approach is ideal for senior undergraduate and graduate students studying equipment design and heat exchanger design.
Download or read book Compact Heat Exchangers written by William Morrow Kays and published by . This book was released on 1958 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Microtube Strip Heat Exchanger written by and published by . This book was released on 1992 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of this contract has been to explore the limits of miniaturization of heat exchangers with the goals of (1) improving the theoretical understanding of laminar heat exchangers, (2) evaluating various manufacturing difficulties, and (3) identifying major applications for the technology. A low-cost, ultra-compact heat exchanger could have an enormous impact on industry in the areas of cryocoolers and energy conversion. Compact cryocoolers based on the reverse Brayton cycle (RBC) would become practical with the availability of compact heat exchangers. Many experts believe that hardware advances in personal computer technology will rapidly slow down in four to six years unless lowcost, portable cryocoolers suitable for the desktop supercomputer can be developed. Compact refrigeration systems would permit dramatic advances in high-performance computer work stations with conventional'' microprocessors operating at 150 K, and especially with low-cost cryocoolers below 77 K. NASA has also expressed strong interest in our MTS exchanger for space-based RBC cryocoolers for sensor cooling. We have demonstrated feasibility of higher specific conductance by a factor of five than any other work in high-temperature gas-to-gas exchangers. These laminar-flow, microtube exchangers exhibit extremely low pressure drop compared to alternative compact designs under similar conditions because of their much shorter flow length and larger total flow area for lower flow velocities. The design appears to be amenable to mass production techniques, but considerable process development remains. The reduction in materials usage and the improved heat exchanger performance promise to be of enormous significance in advanced engine designs and in cryogenics.
Download or read book Compact Heat Exchangers written by William Morrow Kays and published by . This book was released on 1964 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Two Phase Cryogenic Heat Exchanger for the Thermodynamic Vent System written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2019-01-18 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: A two-phase cryogenic heat exchanger for a thermodynamic vent system was designed and analyzed, and the predicted performance was compared with test results. A method for determining the required size of the Joule-Thomson device was also developed. Numerous sensitivity studies were performed to show that the design was robust and possessed a comfortable capacity margin. The comparison with the test results showed very similar heat extraction performance for similar inlet conditions. It was also shown that estimates for Joule- Thomson device flow rates and exit quality can vary significantly and these need to be accommodated for with a robust system design. Christie, Robert J. Glenn Research Center NASA/TM-2011-217220, E-17903
Download or read book Compact Heat Exchangers written by William Morrow Kays and published by . This book was released on 1958 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Compact Heat Exchangers for the Process Industries written by Kenneth J. Bell and published by Begell House Publishers. This book was released on 1997 with total page 616 pages. Available in PDF, EPUB and Kindle. Book excerpt: Compact Heat Exchangers (CHEs) are characterized by large heat transfer area per unit volume of exchanger, resulting in reduced space, weight, and usually reduced energy requirements and cost compared to conventional designs. The objectives of this conference were to identify existing forms of CHEs with their potential use and benefits, to identify the new forms of CHEs, and to identify and discuss barriers and critical issues preventing the broader use of CHEs for the process industry applications.
Download or read book Compact Heat Exchangers written by W. M. Kays and published by . This book was released on 1982 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Industrial Heat Exchangers written by Graham Walker and published by . This book was released on 1982 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Recent Developments in Compact High Duty Heat Exchangers written by Institution of Mechanical Engineers (Great Britain). Thermodynamics and Fluid Mechanics Group and published by . This book was released on 1973 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Learning from Experiences with Compact Heat Exchangers written by David Reay and published by . This book was released on 1999 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Micro Scale Regenerative Heat Exchanger written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-21 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: A micro-scale regenerative heat exchanger has been designed, optimized and fabricated for use in a micro-Stirling device. Novel design and fabrication techniques enabled the minimization of axial heat conduction losses and pressure drop, while maximizing thermal regenerative performance. The fabricated prototype is comprised of ten separate assembled layers of alternating metal-dielectric composite. Each layer is offset to minimize conduction losses and maximize heat transfer by boundary layer disruption. A grating pattern of 100 micron square non-contiguous flow passages were formed with a nominal 20 micron wall thickness, and an overall assembled ten-layer thickness of 900 microns. Application of the micro heat exchanger is envisioned in the areas of micro-refrigerators/coolers, micropower devices, and micro-fluidic devices. Moran, Matthew E. and Stelter, Stephan and Stelter, Manfred Glenn Research Center NASA/TM-2004-213353, AIAA Paper 2004-6730, E-114821
