ME350 Refrigeration and Air Conditioning Lecture Notes PDF

ME350 : Refrigeration and Air Conditioning ME103 What is Refrigeration and Air Conditioning ? M. D. Atrey INOX Chair Professor Department of Mechanical Engineering India...

ME350 : Refrigeration and Air Conditioning ME103 What is Refrigeration and Air Conditioning ? M. D. Atrey INOX Chair Professor Department of Mechanical Engineering Indian Institute of Technology Bombay Mumbai – 400076 INDIA  ME350 : Refrigeration and Air Conditioning Refrigeration - Definition Refrigeration is Cooling ???? Refrigeration is not cooling ? - Cooling of Coffee - Cooling of water by adding ice (?) Process of Cooling of fluids to temperatures lower than those available in the surroundings at a particular time and place. ME350 : Refrigeration and Air Conditioning Commercial Refrigerator and Air Conditioners  ME350 : Refrigeration and Air Conditioning Schematic of Refrigerator Evaporator coil Cooling adjustment knob Capillary expansion valve Condenser Compressor ME350 : Refrigeration and Air Conditioning Major components of Refrigerator ME350 : Refrigeration and Air Conditioning Technical Specification - Refrigerator Unit Volume 335 L Voltage 220 V Rated Current 1-2 A Watt 130 W Defrost Power 150 W Refrigerant R600a Conservation time from power 15 hours failure ME350 : Refrigeration and Air Conditioning ME350 : Refrigeration and Air Conditioning Primary and Secondary Refrigerants  ME350 : Refrigeration and Air Conditioning Primary and secondary refrigerants Primary refrigerants are used directly as working fluids in refrigeration systems They undergo phase change while providing refrigeration Secondary refrigerants are those liquids that are used to transport energy from one location to other They do not undergo phase change Water and brines are the commonly used secondary refrigerants  ME350 : Refrigeration and Air Conditioning Primary and secondary refrigerants If the operating temperatures are above 0℃, then pure water can be used as secondary refrigerant, for example in large air conditioning systems Antifreezes or brines are used when refrigeration is required at sub-zero temperatures. e.g. in cold storages The commonly used secondary refrigerants are the solutions of water and ethylene glycol, propylene glycol or calcium chloride Focus : primary refrigerants for vapour compression refrigeration systems only  ME350 : Refrigeration and Air Conditioning Advantages of Secondary Refrigerants Different rooms of building can be cooled up to different temperatures by adjusting the flow rates of secondary refrigerants. SR can be easily handled. SR can be easily controlled. Eliminates long refrigeration lines and thus reduces pressure drops.  ME350 : Refrigeration and Air Conditioning Refrigerant selection criteria Selection of refrigerant for a particular application is based on the following requirements: a) Thermodynamic and thermo-physical properties b) Environmental and safety properties c) Economics  ME350 : Refrigeration and Air Conditioning Environmental and safety properties Environment and Safety : Major factor in deciding the usefulness of a particular refrigerant The important environmental and safety properties are: Ozone depletion potential(ODP): Should be zero (i.e., no Chlorine or Bromine atoms) Global Warming Potential(GWP): Should be as small as possible Total Equivalent Warming Index(TEWI): Should be as small as possible  ME350 : Refrigeration and Air Conditioning Refrigerants CFC a) First developed by General Motor’s researchers in the 1920s and commercialized as Freons. b) Most stable – remain in atmosphere for many years, allowing them to diffuse to high altitudes c) Contains Chlorine, Fluorine, Carbon. d) CFCs break down, and Cl combines with and consumes some ozone HCFC a) Hydrogenated b) Not as stable – most of it breaks down before reaching high altitudes c) Contains Hydrogen, Chlorine, Fluorine, Carbon. d) Less damaging to ozone HFC a) Contains Hydrogen, Fluorine, Carbon. b) Contains no Cl (Chlorine) c) Causes no depletion of ozone  ME350 : Refrigeration and Air Conditioning Common refrigerant used in Air conditioning Atmospheric lifetime refers to the duration of time a greenhouse gas remains in the atmosphere before being decomposed by chemical processes ME350 : Refrigeration and Air Conditioning  ME350 : Refrigeration and Air Conditioning Air Conditioning Treatment of Air so as to simultaneously control its temperature and moisture content, quality and circulation as required by occupants or products in the space. ME350 : Refrigeration and Air Conditioning Schematic Air Conditioner ME350 : Refrigeration and Air Conditioning Split Air conditioner ME350 : Refrigeration and Air Conditioning Technical Specification - AC Name Unit Tonnage 1.2 TR Cooling 4.1 kW capacity Voltage 220 V Power input 1190 COP 3.45 Rated 5.25 A current Air flow 477 cfm Sound level 36 dB ME350 : Refrigeration and Air Conditioning Air conditioner  ME350 : Refrigeration and Air Conditioning AC rating Indian Seasonal Energy Efficiency Ratio (ISEER) is an evolved rating methodology for air conditioners that factors in variance in higher temperature in India and rates air conditioners accordingly. ME350 : Refrigeration and Air Conditioning AHU- Water as secondary refrigerant ME350 : Refrigeration and Air Conditioning ME350 : Refrigeration and Air Conditioning Thank you !  Cryogenics - Breaking the ICE ME 103 – Refrigeration A/C and Cryogenics Milind Atrey INOX Chair Professor of Cryogenics Refrigeration and Cryogenics Laboratory Department of Mechanical Engineering IIT Bombay, Mumbai Prof. M.D. Atrey Dept. of Mech Engg. IIT Bombay Cryogenics - Breaking the ICE What is Cryogenics ? Kryo - Very cold (frost) Genics - to produce “Science and art of producing cold”  Cryogenics - Breaking the ICE The Chronology Year Event 1877 Cailletet and Pictet liquefied Oxygen. 1879 Linde founded the Linde Eismaschinen AG. 1892 Dewar developed a vacuum insulated vessel for cryogenic fluid storage. 1895 Onnes established Leiden Laboratory. 1902 Claude established l’Air Liquide and developed air-liquefaction system. 1908 Onnes liquefied helium. 1911 Onnes discovered superconductivity. Prof. M D Atrey, Department of Mechanical Engineering, IIT 3 Bombay  Cryogenics - Breaking the ICE The Chronology Year Event 1926 Goddard test fired the first cryogenically propelled rocket. 1934 Kapitza designed the first expansion engine. 1952 National Institute of Standards & Technology (NIST), USA, Cryogenic Engineering Laboratory established. 1966 Development of Dilution refrigerator. 1975 Record high superconducting transition temperature (23 K) achieved. 1994 Matsubara developed a 4 K cryocooler Prof. Prof. M DM D Atrey, Atrey, Department Department of Mechanical of Mechanical Engineering, 4 IIT Engineering, IIT Bombay Bombay 4 Cryogenics - Breaking the ICE When Cryogenic Engineering was born Geneva, December 1877 Raoul Pictet  Cryogenics - Breaking the ICE Introduction Cryogenics is the science and technology associated with generation of low temperature below 123 K. 0K 123 K 300 K Cryogenics Refrigeration O2 (90.19 K) R134a (246.8 K) Air (78.6 K) R12 (243.3 K) R22 (233 K) N2 (77.36 K) Propane (231.1 K) H2 (20.39 K) He (4.2 K) Ethane (184 K) Prof. Prof. M DM D Atrey, Atrey, Department Department of Mechanical of Mechanical Engineering, 6 IIT Engineering, IIT Bombay Bombay 6  Cryogenics - Breaking the ICE Temperature Kelvin Celsius Rankine Fahrenheit (K) (°C) (°R) (°F) 0 -273.15 0 -459.67 273.15 0 491.67 32 373.15 100 671.67 212 Increment 1 K = 1°C = 1.8°R = 1.8°F Prof. M D Atrey, Department of Mechanical Engineering, IIT 7 Bombay  Cryogenics - Breaking the ICE Temperature The Kelvin Temperature Scale K = C + 273 (Note it is Kelvin, but not degree Kelvin). Room Temperature ~ 300 K Cryogen Temp Cost (K) (Rs/Lit) LN2 77.36 25 LH2 20.39 LHe 4.2 1500 Prof. M D Atrey, Department of Mechanical Engineering, IIT 8 Bombay  Cryogenics - Breaking the ICE Cryogen Cryogen Fluid with normal boiling point less than 123 K. Cryogen Boiling Point Triple Point (K) (K) Methane, CH4 111.67 90.69 Oxygen, O2 90.19 54.36 Argon, Ar 87.30 83.81 Air(N2+O2+Ar) 78.6 59.75 Prof. M D Atrey, Department of Mechanical Engineering, IIT 9 Bombay Cryogenics - Breaking the ICE Cryogen (contd..) Cryogen Boiling Point Triple Point (K) (K) Nitrogen, N2 77.36 63.15 Normal H2 20.39 13.96 He4 4.230 - He3 3.191 - Prof. M D Atrey, Department of Mechanical Engineering, IIT 10Bombay Cryogenics - Breaking the ICE T – s diagram of a cryogen 300 K, 1atm A Absolute Temperature B Isobar C Critical Point Liquid Normal F Boiling Point E Vapor L+V Entropy Prof. M D Atrey, Department of Mechanical Engineering, IIT 11 Bombay  Cryogenics - Breaking the ICE Properties of few Cryogens Sat. Liq. at LHe 4 LH2 LN2 LAir LOX 1atm Normal Boiling K 4.214 20.27 77.36 78.8 90.18 Point Critical Mpa 0.229 1.315 3.39 3.92 5.08 Pressure Density kg/m3 124.8 70.79 807.3 874 1141 Latent kJ/kg 20.90 443 199.3 205 213 Heat Prof. M D Atrey, Department of Mechanical Engineering, IIT 12Bombay  Cryogenics - Breaking the ICE T – s diagram of Helium Critical Pt. 2.29 atm, 5.2 K T – s chart for He – 4 1 atm, 4.2 Pressure (P) – atm Density – gm/mol-lit K Temp (T) – K Enthalpy (h) – J/gm- mol Entropy (s) – J/g- mol-K Prof. M D Atrey, Department of Mechanical Engineering, IIT 13Bombay  Cryogenics - Breaking the ICE T – s diagram of Nitrogen T – s chart for N2 Pressure (P) – atm Density – gm/mol-lit Temp (T) – K Enthalpy (h) – J/gm- mol Entropy (s) – J/g- mol-K Critical Pt. 33.9 atm, 126 K 1 atm, 77.36 K Prof. M D Atrey, Department of Mechanical Engineering, IIT 14Bombay  Cryogenics - Breaking the ICE Materials at Low temperature The properties of materials change, when cooled to cryogenic temperatures (demo video). The electrical resistance of a conductor decreases as the temperature decreases. Wires made of materials like Nb – Ti, exhibit zero resistance when subjected to LHe temperatures (superconductivity). Prof. M D Atrey, Department of Mechanical Engineering, IIT 15Bombay  Cryogenics - Breaking the ICE Superconductivity The electrical Electrical Resistance, Ohms resistance of a material decreases with the decrease in the temperature. Few of the materials, when cooled to lower temperatures, the Sudden drop resistance suddenly drops to zero at a Temperature, K particular temperature. Prof. M D Atrey, Department of Mechanical Engineering, IIT 16Bombay  Cryogenics - Breaking the ICE Superconductivity In 1911, Onnes discovered the phenomenon of Resistance, Ohms 0.13 Superconductivity. Mercury During his 0.1 investigation on mercury, he observed that the 0.05 resistance dropped to zero at 4.2 K. 4.0 4.1 4.2 4.3 Temperature, K Prof. M D Atrey, Department of Mechanical Engineering, IIT 17Bombay  Cryogenics - Breaking the ICE Superconductivity Jc The state of the SC is governed by three parameters. They are Temperature (K), Tc Current Density (A/mm2) and Magnetic Field (Tesla) as shown in the figure. Superconductivity Hc region The blue region in the figure is enclosed by the critical values of Tc, Jc and Hc. Prof. M D Atrey, Department of Mechanical Engineering, IIT 18Bombay  Cryogenics - Breaking the ICE High Tc and Low Tc Materials Superconducting materials are distinguished depending upon the critical temperature they exhibit. Earlier, the materials having transition temperature above 30 K are called as High Tc or HTS materials. Recently this value has been changed to 77 K, due to easy availability of LN2. Prof. M D Atrey, Department of Mechanical Engineering, IIT 19Bombay Cryogenics - Breaking the ICE Development of SCs T(K) Copper Oxide 273 Conductors 160 140 HgBaCaCuO 1993 & 1994 120 TlBaCaCuO 1988 100 under pressure BSCCO HTS YBCO 1987 80 60 Metallic Conductors 40 LaBaCuo NbN Nb3Sn Nb3Ge 20 LTS Pb NbTi Hg 1900 1911 1920 1940 1960 1980 2000 Year Prof. M D Atrey, Department of Mechanical Engineering, IIT 20Bombay Cryogenics - Breaking the ICE Meisner Effect At room temperature, if a material is subjected to a magnetic flux, the flux lines of force penetrate TRoom through the material. As soon as the material becomes superconducting, it repels the magnetic flux lines. This phenomenon is called as TC Meisner Effect and was first discovered by Meisner and Robert in the year 1933. Prof. M D Atrey, Department of Mechanical Engineering, IIT 21Bombay  Cryogenics - Breaking the ICE Cryogenics – Big Projects of Mankind CERN – Large Hadron Collider – Particle Physics Accelerators ITER – International thermonuclear Experimental Reactor India is a major contributor to these projects. Prof. M.D. Atrey Dept. of Mech Engg. IIT Bombay  Cryogenics - Breaking the ICE CERN European Organisation for Nuclear Research Founded in 1954 by 12 countries Today: 20 member states More than 7000 users from all over the world ~1000 MCHF / Year budget 1954: Convention establishing the Organization - original signatures 2004: The 20 member states Prof. M.D. Atrey Dept. of Mech Engg. IIT Bombay  Cryogenics - Breaking the ICE 1964 Gell-Mann The The Mendeleyev of particle physics constituents Quarks Proton of matter Today’s periodic system of the fundamental building blocks Prof. M.D. Atrey Dept. of Mech Engg. IIT Bombay  Cryogenics - Breaking the ICE Why accelerators? To investigate Particle Physics Particle physics looks at matter in its smallest dimensions Accelerators Microscopes Binoculars Telescopes Prof. M.D. Atrey Dept. of Mech Engg. IIT Bombay  Cryogenics - Breaking the ICE Methods of Particle Physics Concentrate energy on Collide particles (recreate particles (accelerator) conditions after Big Bang) E=mc2 Identify created particles in Detector (search for new clues) Prof. M.D. Atrey Dept. of Mech Engg. IIT Bombay  Cryogenics - Breaking the ICE CERN's mission: to build particle accelerators The Large Hadron Collider (LHC) set 80 – 150 m underground in a circular tunnel 27 km long will be the most powerful instrument ever built to investigate particles properties. Four gigantic underground caverns to host the huge detectors The highest energy of any accelerator in the world The most intense proton beams colliding head-on 800 million times per sec It will operate at a temperature colder than outer space Prof. M.D. Atrey Dept. of Mech Engg. IIT Bombay  Cryogenics - Breaking the ICE Preparing the LHC The LHC showed first operation in 2008. It will certainly change our view of the Universe. 27 km circumference 80-150m underground Prof. M.D. Atrey Dept. of Mech Engg. IIT Bombay  Cryogenics - Breaking the ICE Large Hadron Collider LHCb Atlas CMS Alice Prof. M.D. Atrey Dept. of Mech Engg. IIT Bombay  Cryogenics - Breaking the ICE Superfluid Helium Cooled Magnets T 1.9 K 2.728 K The coldest ring in the universe! Prof. M.D. Atrey Dept. of Mech Engg. IIT Bombay  Cryogenics - Breaking the ICE Prof. M.D. Atrey Dept. of Mech Engg. IIT Bombay  Cryogenics - Breaking the ICE ITER – International Thrmonuclear Experimental Reactor ITER is a joint international research and development project that aims to demonstrate the scientific and technical feasibility of fusion power. The partners are : EU, Japan, China, India, Korea, Russia and USA. ITER will be constructed in Europe, at Cadarache in the South of France. Fusion is the energy source of the sun and the stars. On earth, fusion research is aimed at demonstrating that this energy source can be used to produce electricity in a safe and environmentally benign way. Prof. M.D. Atrey Dept. of Mech Engg. IIT Bombay  Cryogenics - Breaking the ICE ITER – What is planned In ITER, scientists will study plasmas in conditions similar to those expected in a electricity-generating fusion power plant. It will generate 500 MW of fusion power for extended periods of time, ten times more than the energy input needed to keep the plasma at the right temperature. It will therefore be the first fusion experiment to produce net power. It will also test a number of key technologies, including the heating, control, diagnostic and remote maintenance that will be needed for a real fusion power station. Prof. M.D. Atrey Dept. of Mech Engg. IIT Bombay  Cryogenics - Breaking the ICE ITER – What is planned The overall programmatic objective of ITER is to demonstrate the scientific and technological feasibility of fusion energy for peaceful purposes. The ITER device is based on the tokamak concept, in which a hot gas is confined in a torus-shaped vessel using a magnetic field. The gas is heated to over 100 million degrees, and will produce 500 MW of fusion power. Prof. M.D. Atrey Dept. of Mech Engg. IIT Bombay  Cryogenics - Breaking the ICE Liquid Hydrogen Fuelled Car A hydrogen-powered car - virtually zero emissions vehicle A new injection process in which super- cooled liquid hydrogen is injected into the intake ducts where it mixes with air before entering the cylinders for ignition. Previously, the liquid hydrogen was heated to ambient temperature before combustion. This super-cooled mixture increases the cylinder charge, boosting both engine output and efficiency Prof. M.D. Atrey Dept. of Mech Engg. IIT Bombay  Cryogenics - Breaking the ICE Liquid Hydrogen – Fuel Cell Prof. M.D. Atrey Dept. of Mech Engg. IIT Bombay  Cryogenics - Breaking the ICE Hydrogen Cars Prof. M.D. Atrey Dept. of Mech Engg. IIT Bombay  Cryogenics - Breaking the ICE Magnetic Resonance Imaging (MRI) 1.5 T Superconducting magnets 1 W at 4 K Non-magnetic regenerators >7000 4 K cryocoolers since 1995 Prof. M.D. Atrey Dept. of Mech Engg. IIT Bombay  Cryogenics - Breaking the ICE Prof. M.D. Atrey Dept. of Mech Engg. IIT Bombay  Cryogenics - Breaking the ICE Cryogenic Engine India is the sixth country to have its own cryogenic stage with its own engine, after the United States, Russia, Japan, China and Europe. A cryogenic engine is powered by cryogenic propellants - liquid oxygen as oxidiser and liquid hydrogen as fuel. The cryogenic stage in a launch vehicle consists of the engine kept in a casing and the control, guidance and electronic systems associated with it. Chandrayan Prof. M.D. Atrey Dept. of Mech Engg. IIT Bombay  Cryogenics - Breaking the ICE Prof. M.D. Atrey Dept. of Mech Engg. IIT Bombay  Cryogenics - Breaking the ICE Liquid Hydrogen Fuelled Rocket Prof. M.D. Atrey Dept. of Mech Engg. IIT Bombay  Cryogenics - Breaking the ICE HTS Applications Ship Propulsion Motor Industrial Motor Ship Propulsion Generator Synchronous Condenser Prof. M.D. Atrey Dept. of Mech Engg. IIT Bombay  Cryogenics - Breaking the ICE Space Cryogenics Cooling Requirement for I-R detector and Sc devices Development of small cryocoolers for satellites-- Improvement of accuracy/reliability of earth observation Research on thermaly driven cooling system - Small sized thermal compressor - Cooling system with high reliability/long-life Research on cryogenic cooling system Prof. M.D. Atrey Dept. of Mech Engg. IIT Bombay  Cryogenics - Breaking the ICE Prof. M.D. Atrey Dept. of Mech Engg. IIT Bombay  Cryogenics - Breaking the ICE Cryosurgery Shorter hospital stay, usually overnight Shorter recovery time Less blood loss Less time is required to perform the surgery Less pain, and subsequently, less need for pain medication Cryosurgery is less invasive The procedure can be an alternative for Cryosurgery is the process of older people, and those who are too freezing tissue to destroy cancer fragile to undergo conventional surgery cells, and is used in patients for medical reasons with localized prostate and The technique has proven to be highly kidney cancer. effective in many cases Prof. M.D. Atrey Dept. of Mech Engg. IIT Bombay  Cryogenics - Breaking the ICE Cryogenic Catheter Progress in the development of a cryogenic catheter to treat heart arrhythmia is discussed. This system uses a mixed-gas Joule-Thomson refrigerator to cool the tip of a catheter that can be inserted into the body through the large veins leading into the heart. The cryogenic catheter is intended to treat heart arrhythmia characterized by an abnormally rapid heart rate, although the system has a wide variety of other medical applications. Prof. M.D. Atrey Dept. of Mech Engg. IIT Bombay  Cryogenics - Breaking the ICE Cryogenics in Food Preservation Cryogenic Coolers are screw based units designed for the continuous freezing or chilling of bulk products using liquid nitrogen refrigerant. Fast and efficient cooling is achieved by direct spraying of the liquid nitrogen over the product as it is mixed and transported. Food Preservation: Cooling of seafoods, Meat based products, Cheeses, Fast foods Flavour Retention: Spice chilling for retention of flavours during milling. Prof. M.D. Atrey Dept. of Mech Engg. IIT Bombay  Cryogenics - Breaking the ICE Medicine – Preservation and transport Prof. M.D. Atrey Dept. of Mech Engg. IIT Bombay  Cryogenics - Breaking the ICE Cryogenic Treatment of Metals The idea since 1940 Tools, die castings & their dies, forgings, jigs & fixtures, Cu welding electrodes etc. Guitar Strings – Life increased by 4 to 5 times with no need for tuning Racing car components e.g. Crank shafts, cam shafts, transmission High speed carbide drill bits – increased longitivity by 40% to 300% Prof. M.D. Atrey Dept. of Mech Engg. IIT Bombay  Cryogenics - Breaking the ICE Cryogenics – Summary of Uses Cryogenics – applications in Almost all the fields Superconductivity – based applications Cryocoolers – to replace lie Cryogens over a period of time MRI is the major user of Cryocoolers Generators, Motor, Transformers are future applications Medical Instruments in surgery are the future attractions Prof. M.D. Atrey Dept. of Mech Engg. IIT Bombay  Cryogenics - Breaking the ICE Thank U !