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An engineering example for unsustainable development. How is electricity generated from non-renewable energy sources (oil, coal or natural gas)?. Combined Power Plant (GT & ST). Diesel Generator. Gas Turbine (GT). Steam Turbine (ST). Electric Generator. Electrical output. N.
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How is electricity generated from non-renewable energy sources (oil, coal or natural gas)? Combined Power Plant (GT & ST) Diesel Generator Gas Turbine (GT) Steam Turbine (ST)
Electrical output N Rotating wire loop Magnet S Electric Generator We need a rotating shaft? How to rotate the wire loop? http://electron9.phys.utk.edu/phys136d/modules/m8/images/gen.gif
Wind turbine gives a rotating shaft http://www.electricityforum.com/images/motor-eout.gif
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
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
Diesel generator http://www.myrctoys.com/engines/ottomotor_e.swf
Gas Turbine Power Plant fuel hot gases Combustion Chamber compressed air Comp- ressor Gas Turbine Gen fresh air gases to the stack
Gas Turbine Power Plant (QCC) in (WGT) out (WC) in fuel hot gases Combustion Chamber compressed air Comp- ressor Gas Turbine Gen fresh air gases to the stack
Gas Turbine Power Plant (QCC) in (WGT) out (WC) in fuel hot gases Combustion Chamber compressed air Comp- ressor Gas Turbine Gen fresh air gases to the stack Useful work output = ? Total heat input = ? Total energy loss = ?
Gas Turbine Power Plant (WGT) (WGT) (WC) (WC) in in out out (QCC) (QCC) in in Useful work output = - goes to electricity generation Total heat input = comes with the fuel Thermal efficiency of the GT power plant - ηthermal =
Gas Turbine Power Plant (WGT) (WGT) (WC) (WC) in in out out 72 – 78% of heat released by the fuel 22 – 28% Energy wasted: (QCC) (QCC) in in - ηthermal = = [ ] - = - = for 50 to 100 MW plant
Heat engine converts heat into work Hot reservoir at TH K Wout ηthermal = Qin Qin TC - Wout ηCarnot 1 = TH Qout ηCarnot ηthermal < Cold reservoir at TC K
Gas Turbine Power Plant (QCC) in Carnot efficiency of the GT power plant Lowest temperature (exhaust gas temperature) TC ηCarnot 1 - = TH Highest temperature (combustion chamber temperature) Maximum possible work output ηCarnot = Total heat input ηCarnot = Maximum possible work output
Gas Turbine Power Plant (QCC) (QCC) in in Second-law efficiency of GT power plant Useful work output = Maximum possible work output ηthermal = ηCarnot ηthermal = < 1 ηCarnot
Steam turbine http://www.bizaims.com/files/generator.JPG
Steam Turbine Power Plant Steam Turbine Gen
Steam Turbine Power Plant hot gases superheated steam compressed water Steam Generator Steam Turbine C Pump Gen Condenser saturated water saturated steam cooling water
Steam turbine to produce electricity Oil could be used instead of coal. R. Shanthini 15 Aug 2010 Steam engines are also used to power the train.
(QSG) in (WST) out WP in Steam Turbine Power Plant hot gases superheated steam compressed water Steam Generator Steam Turbine C Pump Gen Condenser saturated water saturated steam cooling water
(WST) (WST) out out 60 – 70% of heat released by the fuel Energy wasted: 30 – 40% (QSG) (QSG) in in Steam Turbine Power Plant - (WP) ηthermal in = = [ ] - - (WP) = in = for 200 to 800 MW plant
fuel GT gases to the stack atmospheric air hot gases ST C cooling water Combined Power Plant
fuel GT gases to the Stack ST atmospheric air hot gases ST C cooling water Combined Power Plant
50 – 64% of heat released by the fuel Energy wasted: Combined Power Plant Useful work output at GT & ST ηthermal = Heat released by fuel 36 – 50% = = for 300 to 600 MW plant
ST cooling water Nuclear Power Plant Containment CORE Control rods PWR Pressurized water C
Nuclear power plant to produce electricity R. Shanthini 15 Aug 2010
66 – 69% of heat released by the fuel Energy wasted: Nuclear Power Plant Useful work output at ST ηthermal = Heat released by fuel = 31 – 34% = for 500 to 1100 MW plant
According to the 2nd Law of Thermodynamics when heat is converted into work, part of the heat energy must be wasted
50% - 70% lost in producing electricity 2% - 20% lost in transmitting electricity Generation, transmission and end-use losses
Typical energy losses in an industrialised country Electric power sector 70% energy losses Transportation sector 80% energy losses Residential & Commercial sector 25% energy losses Industrial sector 20% energy losses
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
Eff Eff TC - 1 = TH Carnot Vehicles mostly uses Internal Combustion Engines TH = Flame temperature (800oC) TC = Exhaust Temperature (40oC) 313 K = - 1 1073 K Carnot ≈ 71%
A Typical Car: Urban Driving Engine losses in fuel energy conversion, In engine cooling and with exhaust gases 63 kJ Driveline losses 6 kJ Fuel Energy 18 kJ Aerodynamic drags 2.5 kJ 100 kJ 12 kJ Rolling resistance 4 kJ 17 kJ Standby Idle 5.5 kJ Braking Energy for accessories 2 kJ Source: http://www.fueleconomy.gov/feg/atv.shtml
A Typical Car: Highway Driving Engine losses in fuel energy conversion, In engine cooling and with exhaust gases 69 kJ Driveline losses 5 kJ Fuel Energy 25 kJ Aerodynamic drags 11 kJ 100 kJ 20 kJ Rolling resistance 7 kJ 4 kJ Standby Idle 2 kJ Braking Energy for accessories 2 kJ Source: http://www.fueleconomy.gov/feg/atv.shtml
Discussion Point 4: Is there a problem in burning oil and coal to make electricity and to drive automobiles in such an inefficient manner? Take 10 mins.
March of the Penguins Erin Brockovich The Big Ask The Story of Stuff and more…. Fossil fuel use Carbon dioxide Global warming Climate change Kyoto protocol should be watched under parental care etc.