Engineering examples of unsustainable development Prof R Shanthini

Engineering examples of unsustainable development Prof. R. Shanthini 23 June 2019 1

How is electricity generated from non-renewable energy sources (oil, coal or natural gas)? Diesel Generator Gas Turbine (GT) Prof. R. Shanthini 23 June 2019 Combined Power Plant (GT & ST) Steam Turbine (ST) 2

Electric AC Generator Prof. R. Shanthini 23 June 2019 3 http: //www. aerospaceweb. org/question/propulsion/q 0209. shtml

Electric AC Generator Prof. R. Shanthini 23 June 2019 4 http: //hyperphysics. phy-astr. gsu. edu/hbase/magnetic/genhow. html#c 1

Electric AC Generator Prof. R. Shanthini 23 June 2019 5 http: //hyperphysics. phy-astr. gsu. edu/hbase/magnetic/motorac. html#c 2

Human powered electric generator We need a rotating shaft? Electrical output N Rotating wire loop S Magnet How to rotate the wire loop? Prof. R. Shanthini 23 June 2019 6 http: //electron 9. phys. utk. edu/phys 136 d/modules/m 8/images/gen. gif

Wind turbine gives a rotating shaft Prof. R. Shanthini 23 June 2019 7 http: //www. electricityforum. com/images/motor-eout. gif

Water turbine could also give a rotating shaft Prof. R. Shanthini 23 June 2019 8

Diesel generator It is a diesel engine coupled to a electric generator. Diesel engine provides the rotating shaft. Prof. R. Shanthini 23 June 2019 9 http: //www. rkm. com. au/animations/animation-diesel-engine. html

Diesel generator Prof. R. Shanthini 23 June 2019 10 http: //www. rkm. com. au/animations/animation-diesel-engine. html

Diesel generator (four stoke) Starting position Prof. R. Shanthini 23 June 2019 Intake stroke Compression stroke 11 http: //en. wikipedia. org/wiki/Four-stroke_engine

Diesel generator (four stroke) Fuel ignition Prof. R. Shanthini 23 June 2019 Power stroke Exhaust stroke 12 http: //en. wikipedia. org/wiki/Four-stroke_engine

Diesel generator (four stroke) Prof. R. Shanthini 23 June 2019 13 http: //www. myrctoys. com/engines/ottomotor_e. swf

Diesel generator (four stroke) Prof. R. Shanthini 14 23 June 2019 http: //xorl. wordpress. com/2011/03/05/the-basics-of-4 -stroke-internal-combustion-engines/

Diesel generator (four stroke) Prof. R. Shanthini 23 June 2019 15 http: //www. grc. nasa. gov/WWW/k-12/airplane/engparts. html

Gas Turbine Power Plant fuel compressed air Compressor Combustion Chamber hot gases Gas Turbine Gen fresh air Prof. R. Shanthini 23 June 2019 gases to the stack 16

Gas turbine to produce electricity Prof. R. Shanthini 23 June 2019 17 http: //en. wikipedia. org/wiki/Turboshaft

Gas turbine driving a jet engine Prof. R. Shanthini 23 June 2019 18

Gas Turbine Power Plant Prof. R. Shanthini 23 June 2019 19

Gas Turbine Power Plant (QCC) in fuel compressed air Combustion Chamber Compressor hot gases (WGT) out Gas Turbine (WC) in fresh air Prof. R. Shanthini 23 June 2019 Gen gases to the stack 20

Gas Turbine Power Plant (QCC) in fuel compressed air Combustion Chamber hot gases Compressor (WGT) out Gas Turbine (WC) in fresh air Prof. R. Shanthini 23 June 2019 Useful work output = ? Total heat input = ? Total energy loss = ? Gen gases to the stack 21

Gas Turbine Power Plant Useful work output = (WGT) (WC) in out Total heat input = (QCC) in goes to electricity generation comes with the fuel Thermal efficiency of the GT power plant ηthermal Prof. R. Shanthini 23 June 2019 (WGT) = out - (WC) (QCC) in in 22

Gas Turbine Power Plant ηthermal = (WGT) out (QCC) Energy wasted: = (QCC) - (WC) in - in = 22 – 28% in [ (W GT) out - (WC) in ] = 72 – 78% of heat released by the fuel Prof. R. Shanthini 23 June 2019 for 50 to 100 MW plant 23

Heat engine converts heat into work Hot reservoir at TH K Qin Wout Qout ηthermal Wout = Qin ηCarnot = 1 - TC TH ηthermal < ηCarnot Cold reservoir at TC K Prof. R. Shanthini 23 June 2019 24

Gas Turbine Power Plant Carnot efficiency of the GT power plant ηCarnot = 1 - TC TH Lowest temperature (exhaust gas temperature) Highest temperature (combustion chamber temperature) ηCarnot = Maximum possible work output Total heat input Maximum possible work output = Prof. R. Shanthini 23 June 2019 ηCarnot (QCC) in 25

Gas Turbine Power Plant Second-law efficiency of GT power plant = = Useful work output Maximum possible work output ηthermal (QCC) ηCarnot (QCC) ηthermal = η Carnot Prof. R. Shanthini 23 June 2019 in in <1 26

Steam turbine (pump is missing) Prof. R. Shanthini 23 June 2019 27 http: //www. bizaims. com/files/generator. JPG

Steam Turbine Power Plant Steam Turbine Gen Prof. R. Shanthini 23 June 2019 28

Steam Turbine Power Plant hot gases compressed Steam Generator water superheated steam Steam Turbine Pump C Gen saturated water Prof. R. Shanthini 23 June 2019 Condenser cooling water saturated steam 29

Steam turbine to produce electricity Oil could be used instead of coal. R. Shanthini 15 Aug Prof. R. 2010 Shanthini 23 June 2019 30 Steam engines are also used to power the train.

(QSG) Steam Turbine Power Plant in hot gases compressed Steam Generator water Pump C WP in superheated steam (WST) out Steam Turbine Gen saturated water Prof. R. Shanthini 23 June 2019 Condenser cooling water saturated steam 31

Steam Turbine Power Plant ηthermal = (WST) out (QSG) - (WP) in = 30 – 40% in Energy wasted: = (QSG) in- [ (W ST) out - (WP) in ] = 60 – 70% of heat released by the fuel Prof. R. Shanthini 23 June 2019 for 200 to 800 MW plant 32