3. What exactly is the turbine?
Turbine is an engine
that converts energy of
fluid into mechanical
energy
The steam turbine is
steam driven rotary
engine.
4. Principle of steam turbine:
The steam energy is converted mechanical work
by expansion through the turbine.
Expansion takes place through a series of fixed
blades(nozzles) and moving blades.
In each row fixed blade and moving blade are
called stage.
6. Steam turbine:
Steam Turbine System:
•
Widely used in CHP(combined heat and power)
applications.
•
Oldest prime mover technology
•
Capacities: 50 kW to hundreds of MWs
•
Thermodynamic cycle is the “Rankin cycle” that uses a
boiler
•
Most common types
• Back pressure steam turbine
• Extraction condensing steam turbine
6
7. Steam turbine:
Back Pressure Steam Turbine
•
Steam exits the turbine at a higher pressure that the
atmospheric
HP Steam
Boiler
Advantages:
-Simple configuration
-Low capital cost
-Low need of cooling water
-High total efficiency
Turbine
Fuel
Condensate
Process
LP
Steam
Disadvantages:
-Larger steam turbine
Figure: Back pressure steam turbine
7
8. Steam turbine:
Extraction Condensing Steam
Turbine
HP Steam
• Steam obtained by
extraction from an
intermediate stage
• Remaining steam is
exhausted
• Relatively high
capital cost, lower
total efficiency
Boiler
Turbine
Fuel
LP Steam
Condensate
Process
Condenser
Figure: Extraction condensing steam turbine
8
11. STEAM TURBINE 600 MW
Generator rated speed
3000
rpm
Generator manufacturer
Electrosila
No. of bleedings
8
Length of the turbine
36.362 m
No. of stages
HPT
17 ( 1st Impulse & rest Reaction)
IPT
11x2 ( All impulse)
LPT-1
5x2 ( All impulse)
LPT-2
5x2 ( All impulse)
Total
59
Inlet Steam Pr: 247 Ksc
Inlet Steam Temp: 537 Deg C
12. Types of steam turbine:
There are two main types
1. Impulse steam turbine
2. Reaction steam turbine
13. Impulse steam turbine:
The basic idea of an impulse turbine is that
a jet of steam from a fixed nozzle pushes
against the rotor blades and impels them
forward.
The velocity of steam is twice as fast as the
velocity of blade.
Pressure drops take place in the fixed blade
(nozzle).
14. PRESSURE-VELOCITY DIAGRAM
FOR
A MOVING IMPULSE BLADE
DIRECTION OF SPIN
REPRESENTS MOVING
IMPULSE BLADES
PRESSURE
TURBINE
SHAFT
ENTRANCE
HIGH VELOCITY
STEAM INLET
EXIT
LOW VELOCITY
STEAM EXHAUST
VELOCITY
PES
14
16. Reaction steam turbine:
A reaction turbine utilizes a jet of
steam that flows from a nozzle on the
rotor.
Actually, the steam is directed into the
moving blades by fixed blades
designed to expand the steam.
The result is a small increase in
velocity over that of the moving
blades.
17. PRESSURE-VELOCITY DIAGRAM
FOR
A MOVING REACTION BLADE
DIRECTION OF SPIN
REPRESENTS MOVING
REACTION BLADES
PRESSURE
TURBINE
SHAFT
ENTRANCE
HIGH PRESSURE
HIGH VELOCITY
STEAM INLET
EXIT
LOW PRESSURE
LOW VELOCITY
STEAM EXHAUST
VELOCITY
PES
17