Development of Steam

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Development of Steam Gas Turbines

• P M V Subbarao
• Professor
• Mechanical Engineering Department

Basic Elements of Industrial Revolution
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Steam Vs Gas Turbines
Steam Turbine Gas Turbine
External Combustion Internal Combustion
Works at the mercy of Heat Transfer No impact of Heat Transfer
Heavy infrastructure Light infrastructure
Working fluid is recycled Working fluid is refreshed
Working fluid behaves cleverly and suitably changes its phase Remains gaseous.
Very low internal consumption of work. Huge internal consumption of work.
Relative more efficient Relatively pure efficiency.
Best suited for Stationary Power Packs Best suited for Mobile Stations
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Historical Debate Steam Turbine Vs Gas Turbine

• Experience gained from a large number of
  exhaust-gas turbines for diesel engines, a temp.
  of 538C was considered absolutely safe for
  uncooled heat resisting steel turbine blades.
• This would result in obtainable outputs of
  2000-8000 KW with compressor turbine efficiencies
  of 73-75, and an overall cycle efficiency of
  17-18.
• First Gas turbine electro locomotive 2500 HP
  ordered from BBC by Swiss Federal Railways
• The advent of high pressure and temperature steam
  turbine with regenerative heating of the
  condensate and air pre-heating, resulted in
  coupling efficiencies of approx. 25.

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• The gas turbine having been considered
  competitive with steam turbine plant of 18 which
  was considered not quite satisfactory.
• The Gas turbine was unable to compete with
  modern base load steam turbines of 25
  efficiency.
• There was a continuous development in steam power
  plant which led to increase of Power Generation
  Efficiencies of 35
• This hard reality required consideration of a
  different application for the gas turbine.

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First turbojet-powered aircraft Ohains engine
on He 178
The worlds first aircraft to fly purely on
turbojet power, the Heinkel He 178. Its first
true flight was on 27 August, 1939.
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Rankine Cycle for Nuclear Power Plant
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Rankine Cycle for Geothermal Power Plant
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Ranking Cycle for Solar Thermal Power Plant
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Ranking Cycle for Biomass Thermal Power Plant
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How to select the Principle of Torque Creation ?

• Impact of Cycle Thermodynamics ..

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Constant Pressure Steam Generation Process
W J M Rankine 1860
Theory of flowing Steam Generation
0
Constant Pressure Steam Generation
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Knowledge for Use Design
Constant Pressure Steam Generation
Practical way of understanding the utilization of
fuel energy
Is it possible to get high temperature with same
amount of burnt fuel? What decides the maximum
possible increase for same amount of burnt fuel?
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Knowledge for Conservation
Creation of Temperature at constant pressure
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Steam Generation Expenditure Vs Wastage
Vapour
Liquid Vapour
h
Liquid
s
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Variable Pressure Steam Gneration
s
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Analysis of Steam Generation at Various Pressures
Increase in Specific Increase in Specific Specific
Pressure Enthalpy Entropy Temp Volume
MPa kJ/kg kJ/kg/K C m3/kg
1 1 3500 7.79 509.9 0.3588
2 5 3500 7.06 528.4 0.07149
3 10 3500 6.755 549.6 0.03562
4 15 3500 6.582 569 0.02369
5 20 3500 6.461 586.7 0.01776
6 25 3500 6.37 602.9 0.01422
7 30 3500 6.297 617.7 0.01187
8 35 3500 6.235 631.3 0.0102
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More Availability of Energy
         
    Specific Specific Specific
Temp Pressure Volume Enthalpy Entropy
C MPa m3/kg kJ/kg kJ/kg/K
575 5 0.0762 3608 7.191
575 10 0.03701 3563 6.831
575 12.5 0.02917 3540 6.707
575 15 0.02393 3516 6.601
575 17.5 0.02019 3492 6.507
575 20 0.01738 3467 6.422
575 22.5 0.0152 3441 6.344
575 25 0.01345 3415 6.271
575 30 0.01083 3362 6.138
575 35 0.008957 3307 6.015
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Behavior of Vapour At Increasing Pressures
All these show that the sensitivity of the fluid
increases with increasing pressure.
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Creation/Reduction of Wastage
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Less Fuel for Creation of Same Temperature
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Availability of Steam for Condenser Temperature
of 450C
Turbine Inlet 3500 kJ/kg Turbine Inlet 3500 kJ/kg Turbine Inlet 3500 kJ/kg Turbine Inlet 3500 kJ/kg Turbine Exit Turbine Exit
Specific Specific Specific Available
Pressure Entropy Temp Volume Enthalpy Quality Work
MPa kJ/kg/K C m3/kg kJ/kg kJ/kg
1 1 7.79 509.9 0.3588 2464 0.9502 1036
2 5 7.06 528.4 0.07149 2232 0.8532 1268
3 10 6.755 549.6 0.03562 2135 0.8127 1365
4 15 6.582 569 0.02369 2080 0.7897 1420
5 20 6.461 586.7 0.01776 2041 0.7736 1459
6 25 6.37 602.9 0.01422 2012 0.7615 1488
7 30 6.297 617.7 0.01187 1989 0.7518 1511
8 35 6.235 631.3 0.0102 1969 0.7436 1531
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Progress in Rankine Cycle
Year 1907 1919 1938 1950 1958 1959 1966 1973 1975
MW 5 20 30 60 120 200 500 660 1300
p,MPa 1.3 1.4 4.1 6.2 10.3 16.2 15.9 15.9 24.1
Th oC 260 316 454 482 538 566 566 565 538
Tr oC -- -- -- -- 538 538 566 565 538
FHW -- 2 3 4 6 6 7 8 8
Pc,kPa 13.5 5.1 4.5 3.4 3.7 3.7 4.4 5.4 5.1
h, -- 17 27.6 30.5 35.6 37.5 39.8 39.5 40
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Steam Path in Modern Turbines
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Steam Conditions Recent Installations of The
World
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Advanced 700 8C Pulverised Coal-fired Power Plant
Project