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Air conditioning in indian railways PEE


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Air conditioning in Indian railways

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Air conditioning in indian railways PEE

  1. 1. Air- Conditioning
  2. 2. Introduction What you will know at the end of session? 1. Organizational Set up & a bit of history 2. Basic concepts in Air-conditioning. 3. Capacity and Settings of AC coaches 4. System of Generation 5. Generation in EOG coaches 6. How AC works in AC coach 7. Development of RMPU 8. LHB coaches & Double Decker AC train 9. Take tour of LHB coach
  3. 3. Introduction Sr.DEE/Chg CTA SSE Control HQ RB Organization DEE/AEE
  4. 4. Introduction A view at Coaching depot
  5. 5. Introduction A view at Coaching depot
  6. 6. Introduction A view at Coaching depot Sick line of depot
  7. 7. Introduction HISTORY OF AC COACHES
  8. 8. Air-Conditioning The first Indian air-conditioned train was Frontier Mail which was introduced in 1934. Earlier, the AC coaches of the train were kept cool by using ice blocks. These were replenished at several halts along the line. A battery operated blower constantly blew air into these receptacles, and the cold air entered the insulated cars through vents. British officers used to travel by Frontier Mail. It was a challenge to maintain the temperature of the AC coaches. History of AC coaches
  9. 9. Air-Conditioning The Frontier Mail was one of the first trains in India to get an air conditioned car. The AC car started running from 1934. History of AC coaches
  10. 10. Air-Conditioning The North-Western Railway introduced air-conditioned stock in the late 1930's (the earliest was probably the Frontier Mail in 1936 or 1937). In 1952-53 there were air-conditioned services between Bombay and Howrah, Delhi and Madras (Grand Trunk Exp.), Bombay and Delhi, Bombay-Amritsar (Frontier Mail), Bombay-Viramgam (Saurashtra Mail), and Bombay- Ahmedabad (Gujarat Mail). These all used AC units that were mounted beneath the coach body (underslung), interconnected by pipes. More on history of AC coaches
  11. 11. Air-Conditioning The first fully air-conditioned train was introduced in 1956 between Howrah and Delhi. Popularly known as the AC Express, it ran on the Grand Chord. Later there were two, one running on the Grand Chord and the other on the Main Line. Another train popularly known as the AC Express was the Dakshin Exp. between Madras and New Delhi in the 1960s. AC Chair Car stock was introduced around 1955. Until about 1979, air-conditioning was available only in these and in AC First Class cars. Around 1979 the first two-tier AC coaches were introduced. The first 3-tier AC coaches were introduced in 1993 (RCF) More on history of AC coaches
  12. 12. Air-Conditioning BASIC AIRCONDITIONING Concept of Human Comfort
  13. 13. Air-Conditioing Difference between Air Conditioning & Refrigeration Factors of Comfort Temperature Humidity Air Flow Noise Purity of Air
  14. 14. Air-Conditioning Air-conditioning – comfort factors • Factors deciding comfort level • temperature • humidity • draft (velocity of air) • purity of air • Noise • Humidity – ratio of the moisture contained in a given quantity to the quantity of moisture required to saturate that quantity at a particular temp. It is termed as Relative Humidity (RH).
  15. 15. Air-Conditioning Unit of Refrigeration • Unit of Refrigeration – in ton (TR) • It refers to the latent heat required to melt a ton of ice at 32 degree F in 24 hours • 1 ton = 2000 lbs • Latent heat of Water to freeze -144 BTU/Lb 1 TR = 2000X144 =12000 BTU/Hr 24 = 3000 k Cal/Hr
  16. 16. Air-Conditioning 1TR of Refrigeration capacity? 1 TR Can Cater to Approx. 100 SQFT. (Area) or 1200 CUFT. (Space)
  17. 17. Air-Conditioning Relative Humidity Air has capacity to trap moisture. Its capacity to trap moisture varies with temperature. Temperature 1 Cuf of air 70 deg.F 4 grains 80 deg.F 11 grains 90 deg.F 19 grains 1 kg of water = 15400 grains of moisture
  18. 18. Air-Conditioning Outside ambient air (say 100 deg. F with 95% RH) is sent over the evaporator at 40 deg. F, moisture is condensed. When this air goes inside the AC compartment it rises to 70 deg. F and as there is now less moisture, the RH becomes 50 % inside. Method to control RH
  19. 19. Air-Conditioning Refrigerant • Freon 12 or Freon 22 (Chloro- difluoromethane) gases • These are chemical Compounds. Freon is the Trade name. In India the Trade name is Mafron. Manufactured by Navin Fluorine Industries • To be re planned by non CFC gases by 2012 - to reduce Ozone layer depletion • R-134 (Tetrafluroethane) a is being used now (Non CFL)
  21. 21. Air-Conditioning Capacity of AC Coaches As per heat load calculation, Load and Plant capacity of various Coaches LOAD CAPACITY • AC II tier 8 TR 2 Plants x 5.3 TR • AC Ist 5.3 TR 1 Plant x 6.7 TR • AC Chair Car/III tier 2 Plants x 6.7 TR
  22. 22. Air-Conditioning Other settings in AC Coach • Fresh air requirement – Smoking not permitted 0.35 meter cube/min/ passenger – Smoking permitted 0.7 meter cube/min/ – passenger • Air Velocity – up to 0.2m/sec inside the compartment – 4 m/sec at the diffuser
  23. 23. Air-Conditioning Temperature settings in AC Coach Low Medium High • I AC Cooling 220 C 240 C 260 C Heating 170 C 190 C 210 C • II AC Cooling - 240 C 260 C III AC Heating - 190 C 210 C
  25. 25. Air-Conditioning Air- Conditioned Coaches • Air-conditioned Coaches broadly classified as- • Self generating type • Power for AC equipments is supplied by axle driven alternators at 110V DC • End-on generation type • Power from diesel generated sets (DG sets) at both ends at 750 V AC 3 phase 50 Hz. • AC equipments operate at 415 V 3 phase 50 Hz. AC
  27. 27. Air-Conditioning Supply System in End-on-generation Coaches • Power supply for air-conditioning, lights and fans is obtained by tapping from one of the two feeders of 750 V, 3 phase, 50 HZ emanating from the Power Car • Each coach is provided with 50KVA transformer which steps down voltage to 415 V, 3 phase • All AC equipments i.e. compressor, condenser, evaporator, heater etc. work on 415V, 3 phase
  28. 28. Air-Conditioning Supply System in EOG Coaches contd… • For supply to lights and fans, each coach is provided with a step down transformer of capacity 3 KVA - steps down the voltage from 415 V, 3 phase to 190 V, 3 phase. •110 V a.c. supply is provided for lamps and fans by connecting them between line and neutral of the secondary side of transformer
  29. 29. Air-Conditioning Supply System in EOG Coaches contd… A 24 V emergency battery of 90 Ah capacity has been provided on the under frame along with a battery charger. The battery supplies the emergency lights provided in the Coach in the event of a. c. power failure.
  30. 30. Air-Conditioning Battery Charging at the Terminal Stations For pre-cooling , AC Coaches are provided with • One 200A capacity battery charger • The battery charger takes 440 V, 3 phase supply through special battery charging sockets mounted diagonally one on each end wall. • The battery charger consists of a transformer and a simple diode bridge rectifier.
  31. 31. Air-Conditioning Refrigeration cycle Refrigeration cycle – conventional coach Heating cycle – conventional coach Air-conditioning system working
  32. 32. Air-Conditioning Equipments of AC System Compressor – compresses & delivers gas into condensers at a high pressure & high temperature Condenser – it cools the hot gas and liquidates it under pressure Expansion Valve – It controls and regulates the rate of flow of liquid freon under high pressure Evaporator –the cooling unit in which liquid freon under low pressure evaporates & in-doing so takes away the latent heat thereby cooling the medium surrounding the cooling coil
  33. 33. Air-Conditioning • In conventional type – AC equipments provided on under-frame • Operates on 110 V DC supply through 18/25 KW alternators • Thermostat senses the inside temperature of the coach • Battery charger is provided on under-frame for charging the batteries • Pre-cooling sockets are provided on either side of the coach for pre-cooling purpose AC system in conventional type Coaches
  34. 34. Air-Conditioning Under slung Type AC System
  35. 35. Air-Conditioning BRUSH LESS ALTERNATOR
  36. 36. Air-Conditioning Refrigerant gas leakage from pipes and joints Heavy weight - coach tare weight increases Large space occupation by the equipments Maintenance problems - Huge skilled manpower required Consumes more power - Less energy efficient Under-slung equipments get hit by ballast, CRO Accumulated dust affects heat transfer Drawbacks of Conventional AC system
  37. 37. Air-Conditioning Development of RMPU • Reliable static Inverters (for conversion of 110 volt dc into 3-phase ac) • Use of 3- phase brushless compact motors possible. • Development of Package Units for Rolling Stock applications • Disadvantages of Opentype (underslung) eliminated. • Weight advantage - one Ton against three Tons)
  38. 38. Air-Conditioning RMPU of 5.2 introduced in the year 1992 with 25 KW alternator • AC II tier & AC III tier - Two units of 7.0 TR • First AC - one unit of 7 TR • Mounted above the toilets on both ends supplying conditioned air in the tapered duct to serve the coach end to end Roof-Mounted Packaged Unit (RMPU)
  39. 39. Air-Conditioning Roof-Mounted Packaged Unit (RMPU) Top view
  40. 40. Air-Conditioning LOOK ONTO THE COMPRESSORS
  41. 41. Air-Conditioning Comparison of RMPU with Conventional under-frame AC system RMPU Conventional AC Weight 900 Kgs (2 units) 2700 kgs Installation time 4 hrs 4 days Refrigerant R – 134a R – 12 Refrigerant charge 2.85 Kgs 15 Kgs Danger due to cattle run over / flood Nil Heavy Down time for repairs 4 hrs. Very long time
  42. 42. Air-Conditioning Linke Hoffman Bosch (LHB) coaches • State of the art coaches Rajdhani / Shatabdi Exp. Trains  Modern passenger amenities • Technology transfer M/s Alstom – LHB of Germany • Manufactured at RCF, Kapurthala From the year 2003
  43. 43. Air-Conditioning LHB Coaches Aesthetically superior Interiors Very low noise Fire retardant materials Modular toilets with controlled discharge Light weight
  45. 45. Air-Conditioning Basic Components of LHB Coach
  46. 46. Air-Conditioning Basic Components of LHB Coach
  47. 47. Air-Conditioning Basic Components of LHB Coach
  48. 48. Air-Conditioning Basic Components of LHB Coach