Development of Steam & Gas Turbines P M V Subbarao Professor Mechanical Engineering Department Basic Elements of Industrial Revolution……
Steam Vs Gas Turbines Steam Turbine Gas Turbine External CombustionInternal Combustion Works at the mercy of Heat TransferNo impact of Heat Transfer Heavy infrastructureLight infrastructure Working fluid is recycledWorking 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 efficientRelatively pure efficiency. Best suited for Stationary Power PacksBest suited for Mobile Stations
Historical Debate : Steam Turbine Vs Gas Turbine Experience gained from a large number of exhaust-gas turbines for diesel engines, a temp. of 538°C 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%.
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.
First turbojet-powered aircraft – Ohain’s engine on He 178 The world’s first aircraft to fly purely on turbojet power, the Heinkel He 178. Its first true flight was on 27 August, 1939.
How to select the Principle of Torque Creation ? Impact of Cycle Thermodynamics …..
Constant Pressure Steam Generation Process W J M Rankine ~ 1860 Constant Pressure Steam Generation: =0 Theory of flowing Steam Generation
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?
Knowledge for Conservation Creation of Temperature at constant pressure :
Steam Generation : Expenditure Vs Wastage h s Liquid Liquid +Vapour Vapour
Increase in Specific Specific PressureEnthalpyEntropyTempVolume MPakJ/kgkJ/kg/KCm3/kg 1135007.79509.90.3588 2535007.06528.40.07149 31035006.755549.60.03562 41535006.5825690.02369 52035006.461586.70.01776 62535006.37602.90.01422 73035006.297617.70.01187 83535006.235631.30.0102 Analysis of Steam Generation at Various Pressures
More Availability of Energy Specific TempPressureVolumeEnthalpyEntropy CMPam3/kgkJ/kgkJ/kg/K 57550.076236087.191 575100.0370135636.831 57512.50.0291735406.707 575150.0239335166.601 57517.50.0201934926.507 575200.0173834676.422 57522.50.015234416.344 575250.0134534156.271 575300.0108333626.138 575350.00895733076.015
Behavior of Vapour At Increasing Pressures All these show that the sensitivity of the fluid increases with increasing pressure.
Availability of Steam for Condenser Temperature of 45 0 C Turbine Inlet : 3500 kJ/kgTurbine Exit Specific Available PressureEntropyTempVolumeEnthalpyQualityWork MPakJ/kg/KCm3/kgkJ/kg 117.79509.90.358824640.95021036 257.06528.40.0714922320.85321268 3106.755549.60.0356221350.81271365 4156.5825690.0236920800.78971420 5206.461586.70.0177620410.77361459 6256.37602.90.0142220120.76151488 7306.297617.70.0118719890.75181511 8356.235631.30.010219690.74361531
Progress in Rankine Cycle Year 1907 19191938195019581959196619731975 MW52030601202005006601300 p,MPa22.214.171.124.210.316.215.9 24.1 T h o C260316454482538566 565538 T r o C-- 538 566565538 FHW--23466788 Pc,kPa126.96.36.199.43.7 188.8.131.52 ,% --~1727.630.535.637.539.839.540