1. Initial Designs of Turbines
P M V Subbarao
Professor
Mechanical Engineering Department
I I T Delhi
Basic Models for Harvesting of Fluid Energy ….

2. Basic Rules for Design of An Ideal Turbine Flow Path
Create highest usable form of a resource.
Creation of initial velocity/kinetic energy using Stator.
X1 (Impulse)+X2(Reaction)+(1-X1-X2)(centripetal)
Y1 (Radial)+(1-Y1 )(Axial)
Design of Flow Path using Conservation of rothalpy.
Design blade cascade using conservation of mass and momentum.
A design of an Ideal Machine …..
Each stage can do finite amount of action….!!!
Many stages are needed to complete the action….

3. Advanced 700 8C Pulverised Coal-fired Power Plant Project

4. Some Facts about Advanced Steam Turbines

5. Increased Magnitudes of Forces

6. 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.

7. Classification of Steam Turbine Flow Paths

8. Classification of Steam Turbine Flow Paths

9. Classification of Steam Turbine Flow Paths

10. Classification of Steam Turbine Flow Paths

11. The First Proposal on Infrastructure for Realization of Newton's’ Laws
Stator
Rotor

12. Axial Turbine Stator Exit/Rotor Inlet Velocity Triangle
Va1
Va1
Vw1
Vr1 a1 a1
Vw1 b1
Vf1
Vf1
Va0
Vf0

13. U
Vr1
Va1
Inlet Velocity Triangle
Va1
Vr1 U
Exit Velocity Triangle U
Vr2
Va2
Vr2
Kinematics of Flow Past A Rotor Blade

14. U
Vr1
Va1
Vr2
Va2 b1 a1 a2 b2
Va1: Inlet Absolute Velocity
Vr1: Inlet Relative Velocity
Vr2: Exit Relative Velocity
Va2:Exit Absolute Velocity
a1: Inlet Nozzle Angle.
b1: Inlet Blade Angle.
b2: Exit Blade Angle.
a2: inlet Nozzle Angle (next stage).
Isentropic Impulse Rotor

15. U
Vr1
Va1 b1 a1
Va2 a2
Vr2 b2
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: -Vr cos(b2) – Vr cos(b1).
- Vr(cos(b2) + cos(b1)).
Tangential Force,

16. 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:

17. Power Output of the blade :
For impulse blading with isentropic flow
For blading with frictional flow U
Vr1
Va1
Vr2
Va2 b1 a1 a2 b2

18. U
Vr1
Va1
Vr2
Va2 b1 a1 a2 b2

19. For a given shape of the blade, the efficiency is a strong function of U/Va1, called blade speed ratio, f

20. Condition for maximum efficiency:
Vr1
Va1
Vr2
Va2 b1 a1 a2 b2

21. Availability of Steam for Condenser Temperature of 450C
Turbine Inlet : 3500 kJ/kg
Turbine Exit
Specific
Available
Jet Velocity
Pressure
Temp
Enthalpy
Work
MPa C
kJ/kg
m/s 1
509.9
2464
1036
1439 2 5
528.4
2232
1268
1592 3 10
549.6
2135
1365
1652 4 15
569
2080
1420
1685 20
586.7
2041
1459
1708 6 25
602.9
2012
1488
1725 7 30
617.7
1989
1511
1738 8 35
631.3
1969
1531
1750

22. Classification of Steam Turbines

23. 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