1. Prof. R. Shanthini Nov 12, 2012 1 An engineering example for unsustainable development

2. Prof. R. Shanthini Nov 12, 2012 2 How is electricity generated from non-renewable energy sources (oil, coal or natural gas)? Diesel Generator Gas Turbine (GT) Steam Turbine (ST) Combined Power Plant (GT & ST)

3. Prof. R. Shanthini Nov 12, 2012 3 Electric Generator

4. Prof. R. Shanthini Nov 12, 2012 4 http://electron9.phys.utk.edu/phys136d/modules/m8/images/gen.gif Magnet Rotating wire loop Electrical output S N How to rotate the wire loop? Electric Generator We need a rotating shaft?

5. Prof. R. Shanthini Nov 12, 2012 5 http://www.electricityforum.com/images/motor-eout.gif Wind turbine gives a rotating shaft

6. Prof. R. Shanthini Nov 12, 2012 6 Water turbine could also give a rotating shaft

7. Prof. R. Shanthini Nov 12, 2012 7 Diesel generator It is a diesel engine coupled to a electric generator. Diesel engine provides the rotating shaft. http://www.rkm.com.au/animations/animation-diesel-engine.html

8. Prof. R. Shanthini Nov 12, 2012 8 Diesel generator It is a diesel engine coupled to a electric generator. Diesel engine provides the rotating shaft. http://www.rkm.com.au/animations/animation-diesel-engine.html

9. Prof. R. Shanthini Nov 12, 2012 9 Diesel generator http://www.myrctoys.com/engines/ottomotor_e.swf

10. Prof. R. Shanthini Nov 12, 2012 10 Comp- ressor fresh air Combustion Chamber fuel Gas Turbine gases to the stack Gen compressed air hot gases Gas Turbine Power Plant

11. Prof. R. Shanthini Nov 12, 2012 11 Gas turbine to produce electricity

12. Prof. R. Shanthini Nov 12, 2012 12 Gas turbine driving a jet engine

13. Prof. R. Shanthini Nov 12, 2012 13 Gas Turbine Power Plant

14. Prof. R. Shanthini Nov 12, 2012 14 Comp- ressor fresh air Combustion Chamber fuel Gas Turbine gases to the stack Gen compressed air hot gases Gas Turbine Power Plant (W GT ) out (W C ) in (Q CC ) in

15. Prof. R. Shanthini Nov 12, 2012 15 Comp- ressor fresh air Combustion Chamber fuel Gas Turbine gases to the stack Gen compressed air hot gases Gas Turbine Power Plant (W GT ) out (W C ) in (Q CC ) in Useful work output = ? Total heat input = ? Total energy loss = ?

16. Prof. R. Shanthini Nov 12, 2012 16 Gas Turbine Power Plant Useful work output = Total heat input = Thermal efficiency of the GT power plant (W GT ) out (W C ) in (Q CC ) in - (Q CC ) in (W GT ) out (W C ) in - η thermal = goes to electricity generation comes with the fuel

17. Prof. R. Shanthini Nov 12, 2012 17 = = 22 – 28% Energy wasted: - [] = = 72 – 78% of heat released by the fuel for 50 to 100 MW plant (Q CC ) in (W GT ) out (W C ) in - (Q CC ) in (W GT ) out (W C ) in - η thermal Gas Turbine Power Plant

18. Prof. R. Shanthini Nov 12, 2012 18 = TCTC 1 - THTH Hot reservoir at T H K Heat engine converts heat into work Cold reservoir at T C K η thermal = W out Q in W out Q in Q out < η thermal η Carnot

19. Prof. R. Shanthini Nov 12, 2012 19 η Carnot = Carnot efficiency of the GT power plant Gas Turbine Power Plant TCTC THTH 1 - Lowest temperature (exhaust gas temperature) Highest temperature (combustion chamber temperature) η Carnot = = (Q CC ) in Maximum possible work output Total heat input Maximum possible work output η Carnot

20. Prof. R. Shanthini Nov 12, 2012 20 Gas Turbine Power Plant Second-law efficiency of GT power plant (Q CC ) in η Carnot = Maximum possible work output Useful work output = (Q CC ) in η thermal η Carnot = η thermal < 1

21. Prof. R. Shanthini Nov 12, 2012 21 Steam turbine http://www.bizaims.com/files/generator.JPG

22. Prof. R. Shanthini Nov 12, 2012 22 Steam Turbine Gen Steam Turbine Power Plant

23. Prof. R. Shanthini Nov 12, 2012 23 C saturated water hot gases Steam Turbine Gen compressed water superheated steam Condenser Pump cooling water saturated steam Steam Generator Steam Turbine Power Plant

24. Prof. R. Shanthini Nov 12, 2012 24 R. Shanthini 15 Aug 2010 Steam turbine to produce electricity Oil could be used instead of coal. Steam engines are also used to power the train.

25. Prof. R. Shanthini Nov 12, 2012 25 Steam Turbine Power Plant C saturated water Gen compressed water superheated steam cooling water (W ST ) out Pump Steam Turbine Condenser Steam Generator saturated steam (Q SG ) in hot gases W P in

26. Prof. R. Shanthini Nov 12, 2012 26 η thermal = (W ST ) out (W P ) in (Q SG ) in - = 30 – 40% Energy wasted: (Q SG ) in - [ (W ST ) out - (W P ) in ] = = 60 – 70% of heat released by the fuel for 200 to 800 MW plant Steam Turbine Power Plant

27. Prof. R. Shanthini Nov 12, 2012 27 atmospheric air fuel GT gases to the stack C hot gases ST cooling water Combined Power Plant

28. Prof. R. Shanthini Nov 12, 2012 28 atmospheric air fuel GT gases to the Stack ST C hot gases ST cooling water Combined Power Plant

29. Prof. R. Shanthini Nov 12, 2012 29 Combined Power Plant

30. Prof. R. Shanthini Nov 12, 2012 30 Combined Power Plant

31. Prof. R. Shanthini Nov 12, 2012 31 η thermal = Heat released by fuel Useful work output at GT & ST = 36 – 50% Energy wasted: = 50 – 64% of heat released by the fuel for 300 to 600 MW plant Combined Power Plant

32. Prof. R. Shanthini Nov 12, 2012 32 Nuclear Power Plant C Pressurized water ST cooling water CORE Control rods Containment PWR

33. Prof. R. Shanthini Nov 12, 2012 33 R. Shanthini 15 Aug 2010 Nuclear power plant to produce electricity

34. Prof. R. Shanthini Nov 12, 2012 34 = 31 – 34% Energy wasted: = 66 – 69% of heat released by the fuel for 500 to 1100 MW plant Nuclear Power Plant η thermal = Heat released by fuel Useful work output at ST

35. Prof. R. Shanthini Nov 12, 2012 35 According to the 2 nd Law of Thermodynamics when heat is converted into work, part of the heat energy must be wasted Power generation type Unit size (MW) Energy Wasted (MW) Diesel engine10 - 307 – 22 Gas Turbine50 - 10036 – 78 Steam Turbine200 - 800120 – 560 Combined (ST & GT)300 - 600150 – 380 Nuclear (BWR & PWR)500 - 1100330 – 760

36. Prof. R. Shanthini Nov 12, 2012 36 50% - 70% lost in producing electricity 2% - 20% lost in transmitting electricity Generation, transmission and end-use losses

37. Prof. R. Shanthini Nov 12, 2012 37 Electric power sector 70% energy losses Transportation sector Industrial sector Residential & Commercial sector 80% energy losses 25% energy losses 20% energy losses Typical energy losses in an industrialised country

38. Prof. R. Shanthini Nov 12, 2012 38 A user of a car always asks for some minimum requirements while using a car. - The drive should be smooth and easy - The car should maintain a good speed so as to cope up with other cars in traffic - Easy and fast refuelling of cars - A good mileage - Less pollution

39. Prof. R. Shanthini Nov 12, 2012 39 E ff Carnot = TCTC 1 - THTH TCTC THTH = Flame temperature (800 o C) = Exhaust Temperature (40 o C) E ff Carnot = 313 K 1 - 1073 K 71% ≈ Vehicles mostly uses Internal Combustion Engines

40. Prof. R. Shanthini Nov 12, 2012 40 A Typical Car: 100 kJ 63 kJ 18 kJ 17 kJ 2 kJ Engine losses in fuel energy conversion, In engine cooling and with exhaust gases Energy for accessories Standby Idle Fuel Energy 6 kJ 12 kJ Driveline losses 2.5 kJ 4 kJ 5.5 kJ Aerodynamic drags Rolling resistance Braking Source: http://www.fueleconomy.gov/feg/atv.shtml Urban Driving

41. Prof. R. Shanthini Nov 12, 2012 41 A Typical Car: 100 kJ 69 kJ 25 kJ 4 kJ 2 kJ Engine losses in fuel energy conversion, In engine cooling and with exhaust gases Energy for accessories Standby Idle Fuel Energy 5 kJ 20 kJ Driveline losses 11 kJ 7 kJ 2 kJ Aerodynamic drags Rolling resistance Braking Source: http://www.fueleconomy.gov/feg/atv.shtml Highway Driving

42. Prof. R. Shanthini Nov 12, 2012 42 Take 10 mins. Discussion Point 4: Is there a problem in burning oil and coal to make electricity and to drive automobiles in such an inefficient manner?

43. Prof. R. Shanthini Nov 12, 2012 43 Carbon dioxide Global warming Climate change Kyoto protocol etc. Fossil fuel use Fossil fuel use March of the Penguins Erin Brockovich The Big Ask The Story of Stuff and more…. should be watched under parental care