11 What is Cryogenics? • Kryo – Very cold (frost) • Genics – to produce • Cryogenics is the science and technology associated with generation of low temperature below 123 K. 2 Prof. M D Atrey, Department of Mechanical Engineering, IIT Bombay Course outline • This course is aimed at students who are interested to study the science and technology of low temperatures. • The purpose of this course is to give an introductory knowledge of Cryogenic Engineering. 3 Prof. M D Atrey, Department of Mechanical Engineering, IIT Bombay 4 Prof. M D Atrey. Department of Mechanical Engineering. • This course will interest students wishing to embark on a research career in Cryogenic Engineering. Course outline • The course is both theoretical as well as mathematical. It will engross the students. IIT Bombay . Course prerequisite • Engineering Mathematics. • Thermodynamics. IIT Bombay . Department of Mechanical Engineering. • Heat Transfer. 5 Prof. M D Atrey. • Refrigeration. Department of Mechanical Engineering. IIT Bombay . 6 Prof. Points to remember • Each lecture presentation ends with a self assessment test based on that particular lecture. M D Atrey. • A greater insight into the subject can be obtained by referring to the books specified. • The best knowledge is gained when the student solves the self assessment honestly and with proper understanding. M D Atrey. Department of Mechanical Engineering. an example tutorial problem is solved with a detailed explanation. • Before each assignment. • The best knowledge is gained when the student solves the assignment problems honestly and with proper understanding of concepts. Points to remember • Assignments are included where ever necessary in order to have a clear understanding of concepts. 7 Prof. IIT Bombay . Barron. Flynn. New York (1989). ”Cryogenic Process Engineering “. Plenum Press. 8 Prof. “Cryogenics Systems”. Mir Publishers. M D Atrey. Books/References Text books/References • Randall F. Moscow. • Pipkov. IIT Bombay . Second Edition. • Timmerhaus. Oxford University Press. New York (1985). Department of Mechanical Engineering. “ Fundamentals of Vacuum Engineering “. • G. “Cryocooler. 9 Prof. New York (2005). “Cryocooler. Books/References Text books/References • Thomas M.Part 2” Plenum Press. second edition. “Cryogenic Engineering”. New York (1983).M Walker. New York (1983). Flynn. • G.M Walker. IIT Bombay . CRC press.Part 1 Fundamentals” Plenum Press. M D Atrey. Department of Mechanical Engineering. • Proceedings of International Cryogenic Engineering Conference and International Cryogenic Materials Conference. M D Atrey. Department of Mechanical Engineering. • Proceedings of International Cryocooler Conference. Books/References Additional Readings • Proceedings of Advances in Cryogenic Engineering. 10 Prof. IIT Bombay . • Indian Journal of Cryogenics. 11 Prof. M D Atrey. Department of Mechanical Engineering. IIT Bombay . Books/References Additional Readings • Cryogenics Journal. Course syllabus • The course syllabus is as follows. Department of Mechanical Engineering. M D Atrey. IIT Bombay . Sr No Topic Introduction to Cryogenics and its 1 Applications 2 Properties of Cryogenic Fluids Properties of Materials at Cryogenic 3 Temperature Gas-Liquefaction and Refrigeration 4 Systems 5 Gas Separation 12 Prof. IIT Bombay . M D Atrey. Department of Mechanical Engineering. Course syllabus (contd) Sr No Topic 6 Cryocoolers 7 Cryogenic Insulations 8 Vacuum Technology 9 Instrumentation in Cryogenics 10 Safety in Cryogenics 13 Prof. M D Atrey. IIT Bombay . Department of Mechanical Engineering. Applications – Space Space • Rocket propulsion • Cooling of Infra-Red (IR) sensor • Space simulation 14 Prof. 15 Prof. Department of Mechanical Engineering. • Liquid Hydrogen is used as a fuel to propel the rocket. IIT Bombay . Applications – Space • Cryogenic engines are powered by cryogenic propellants. • Liquid Oxygen is used as an oxidizer. M D Atrey. The cold space is simulated at cryogenic temperatures by use of LN2. are some of the major applications of cryogenics. Cold probes. IIT Bombay . etc. 16 Prof. • Development of miniature and small cryocoolers for satellites for an improved accuracy and reliability of earth observation. Telescopes. Department of Mechanical Engineering. M D Atrey. • Space simulations chambers are realistic environment for space craft. Applications – Space • Cooling of IR detectors. Applications – Space • The levels of vacuum required in space simulation chambers are vey high. 17 Prof. Department of Mechanical Engineering. IIT Bombay . • This is achieved by the use of cryo pumps and turbo molecular pumps. M D Atrey. M D Atrey. IIT Bombay . Department of Mechanical Engineering. Applications – Mechanical Mechanical • Magnetic Separation • Heat treatment • Recycling 18 Prof. . M D Atrey. • The lives of the tools. die castings & their dies. Department of Mechanical Engineering. IIT Bombay . improving the quality of ultra-high purity quartz etc. jigs & fixtures etc increase when subjected to cryogenic heat treatment.Superconducting Magnet ensures proper separation. 19 Prof. Applications – Mechanical • Magnetic separation technique is used in variety of applications like enhancing the brightness of kaolin. • The life of guitar strings increases by 4 to 5 times with no need for tuning. forgings. Department of Mechanical Engineering. IIT Bombay . 20 Prof.turns the scrap into raw material by subjecting it to cryogenic temperatures. M D Atrey. • This is mostly used for PVC. rubbers. Applications – Mechanical • Cryogenic recycling . IIT Bombay . M D Atrey. Applications – Medicine Medicine • Cryosurgery • Cell preservation • Food preservation 21 Prof. Department of Mechanical Engineering. skin disorders. • It is generally used in patients with localized prostate and kidney cancer. IIT Bombay . Applications – Medicine • Cryosurgery is a novel technique in which the harmful tissues are destroyed by freezing them to cryogenic temperature. and small recovery time. • Cryosurgery has shorter hospital stay. 22 Prof. retinal problems. M D Atrey. Department of Mechanical Engineering. etc. less blood loss. IIT Bombay . • Systems are developed to preserve blood cells. 23 Prof. Applications – Medicine • Preserving food at low temperature is a well known technique. plasma cells. M D Atrey. meat (sea export). Department of Mechanical Engineering. • Cooling of sea foods. milk products for long time preservation is achieved by use of LN2. human organs and animal organs at cryogenic temperatures. IIT Bombay .Applications – Gas Industry Gas Industry • Liquefaction • Separation • Storage 24 Prof. M D Atrey. Department of Mechanical Engineering. IIT Bombay . 25 Prof. • The use of inert gases in welding industry has initiated higher demand for gas production in the recent past. LH2 are used in rocket propulsion while LH2 is being considered for automobile. Department of Mechanical Engineering. • Cryogens like LOX. Applications – Gas Industry • The transportation of gases across the world is done in liquid state. This is done by storing the liquid at cryogenic temperature. M D Atrey. Basic Oxygen Furnace (BOF) uses oxygen instead of air. M D Atrey. Applications – Gas Industry • Liquid nitrogen is used as precoolant in most of the cryogenic systems. 26 Prof. IIT Bombay . • Nitrogen and argon are primarily used to provide an inert atmosphere in chemical. • Steel industry – Oxygen is used in the production of steel. Department of Mechanical Engineering. metallurgical and welding industries. Applications – Supercond. Department of Mechanical Engineering. MRI • Maglev Locomotion • Transformer & Generators 27 Prof. M D Atrey. Superconductivity • NMR. IIT Bombay . Department of Mechanical Engineering. M D Atrey. IIT Bombay . Applications – Supercond. rF Coil • The NMR (Nuclear Magnetic Resonance) is Magnetic scanning used by the coil pharmaceutical industry to study Magnet the molecular LHe structure. LN2 Sample tube Sample 28 Prof. M D Atrey. rF Coil • It has a superconducting magnet (10 T ~25 Magnetic scanning T) and the coil accuracy of measurement Magnet increases with LHe field strength. IIT Bombay . Applications – Supercond. Department of Mechanical Engineering. LN2 Sample tube Sample 29 Prof. 40K shield • The MRI (Magnetic Cryocooler Resonance Imaging) machines are used for 20K body scanning. IIT Bombay . Department of Mechanical Engineering. • The SC magnets for both NMR and MRI machines are cooled by LHe liquid Helium. M D Atrey. 30 Prof. Applications – Supercond. Applications – Supercond. IIT Bombay . 31 Prof. M D Atrey. • This results in no contact motion and therefore no friction. • The train gets levitated from the guide way by using electromagnetic forces between superconducting magnets on the vehicle and coils on the ground. Department of Mechanical Engineering. • Maglev Train runs on the principle of Magnetic Levitation. IIT Bombay . • Superconducting transformers and LN2 Inlet generators have coils LN2 Outlet Cryostat (and cores sometimes) maintained at low Cryocooler temperature to (LN2 vessel) Core minimize the I2R (copper) losses. M D Atrey. Applications – Supercond. Winding 32 Prof. Department of Mechanical Engineering. M D Atrey. Department of Mechanical Engineering. IIT Bombay .Applications – High E Physics High Energy Physics • CERN • ITER 33 Prof. • It consists of a 27Km accelerator ring with four detectors. Applications – High E Physics • CERN is an European organisation for nuclear research which was founded in 1954. • All the magnet systems (SC) and its accessories are kept at 1. M D Atrey.9 K using the liquid helium. IIT Bombay . 34 Prof. Department of Mechanical Engineering. Applications – High E Physics • A liquid nitrogen layer (77 K) is used as shielding for liquid helium. Department of Mechanical Engineering. 35 Prof. M D Atrey. • It is an experiment seeking answers to Big Bang theory and collision of atomic particles. IIT Bombay . 36 Prof. Applications – High E Physics • ITER (International Thermonuclear Experimental Reactor) is an engineering project for nuclear fusion reactor. Department of Mechanical Engineering. • The superconducting magnets are maintained at low temperature by gaseous helium. M D Atrey. IIT Bombay . • The experiments are carried out to enable mankind to generate energy for future. Applications – Summary Space Mechanical • Rocket propulsion • Magnetic Separation • Cooling of IR sensor • Manufacturing • Space simulation • Heat treatment Medicine • Recycling • Cryosurgery High Energy Physics • Cell preservation • ITER • Food preservation • CERN Gas Industry Superconductivity • Liquefaction • NMR. IIT Bombay . Department of Mechanical Engineering. MRI • Separation • Maglev Locomotion • Storage • SC Transformer & Generator 37 Prof. M D Atrey. Thank You! 38 Prof. M D Atrey. Department of Mechanical Engineering. IIT Bombay .
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