Presentation on theme: "Fluid Dynamics to Create High Performance Steam & Gas Turbines P M V Subbarao Professor Mechanical Engineering Department Realization of Thermodynamic."— Presentation transcript:
Fluid Dynamics to Create High Performance Steam & Gas Turbines P M V Subbarao Professor Mechanical Engineering Department Realization of Thermodynamic Understanding ……
Advanced 700 8C Pulverised Coal-fired Power Plant Project
Some Facts about Advanced Steam Turbines
Increased Magnitudes of Forces
The First Proposal on Infrastructure for Realization of Newton's’ Laws Stator Rotor
Axial Turbine Stator Exit/Rotor Inlet Velocity Triangle V a0 V f0 V a1 V f1 V w1 V a1 V r1 11 V w1 V f1 11 11
U V r1 V r2 V a1 UV r1 V a1 Inlet Velocity Triangle Exit Velocity Triangle U V r2 V a2 Kinematics of Flow Past A Rotor Blade
U V r1 V a1 V r2 V a2 11 11 22 22 V a1 : Inlet Absolute Velocity V r1 : Inlet Relative Velocity V r2 : Exit Relative Velocity V a2 :Exit Absolute Velocity 1 : Inlet Nozzle Angle. 1 : Inlet Blade Angle. 2 : Exit Blade Angle. 2 : inlet Nozzle Angle (next stage).
Newton’s Second Law for an Impulse Blade: The tangential force acting on the jet is: F = mass flow rate X Change of velocity in the tangential direction Change in velocity in tangential direction: -V r2 cos( 2 ) – V r1 cos( 1 ). -(V r2 cos( 2 ) + V r1 cos( 1 )). Tangential Force, UV r1 V a1 11 11 V a2 22 V r2 22
The reaction to this force provides the driving thrust on the wheel. The driving force on wheel Power Output of the blade : Diagram Efficiency or Blade efficiency:
Power Output of the blade : For impulse blading with inviscid flow For blading with frictional flow U V r1 V a1 V r2 V a2 11 11 22 22
U V r1 V a1 V r2 V a2 11 11 22 22
For a given shape of the blade, the efficiency is a strong function of U/V a1 called blade speed ratio,
Condition for maximum efficiency: Maximum efficiency: U V r1 V a1 V r2 V a2 11 11 22 22
Availability of Steam for Condenser Temperature of 45 0 C Turbine Inlet : 3500 kJ/kgTurbine Exit SpecificAvailableJet Velocity PressureTempEnthalpyWork MPaCkJ/kg m/s
de Laval Turbine : The First Design for Steam Turbine de Laval turbine is an impulse turbine : An enormous velocity (30,000 revolutions per minute in the 5 H. P. size) is requisite for high efficiency, and the machine has therefore to be geared down to be of practical use.
Creation of Wonderful Concept with Deep Fluid Dynamics & it is Still Valid?!?!?! The creator had a long term vision in Developing a Sustainable & Economically Viable Non- biological Beast……
An Invention that Made abundance of Electricity at Very Cheap The modern steam turbine was invented in 1884 by the Englishman Sir Charles Parsons. The first model was connected to a dynamo that generated 7.5 kW (10 hp) of electricity. The invention of Parson's steam turbine made cheap and plentiful electricity possible and revolutionized marine transport and naval warfare. His patent was licensed and the turbine scaled-up shortly after by an American, George Westinghouse. The Parson's turbine also turned out to be easy to scale up.
A Device Easy to Scale up Parsons had the satisfaction of seeing his invention adopted for all major world power stations, and the size of generators had increased from his first 7.5 kW set up to units of 50,000 kW capacity. Within Parson's lifetime the generating capacity of a unit was scaled up by about 10,000 times. The total output from turbo-generators constructed by his firm C. A. Parsons and Company and by their licensees, for land purposes alone, had exceeded thirty million horse- power.
Classification of Steam Turbines
The most powerful steam turbine-generator in the world at the time of it's construction:1903 Built in 1903, the 5,000-kilowatt Curtis steam turbine-generator was the most powerful in the world. It stood just 25 feet high, much shorter than the 60 feet reciprocating engine-generator of a similar capacity