A turbine is a machine that converts kinetic energy or pressure from fluids like water, steam, gas or air into rotational motion. There are different types of turbines including impulse turbines like Pelton and cross-flow turbines which use kinetic energy, and reaction turbines like Francis and Kaplan which use pressure changes. Advanced cycles have been developed for gas turbines like wet compression, steam injection and combined cycles to improve efficiency. Nano-turbines have also been designed but have much lower efficiencies than macro-scale turbines due to effects like water slippage and flow disruption at the nanoscale.

1. Advanced Turbine
Periyanayaga Kristy.A,
Ph.D. Research Scholar
SRM Universtiy
Chennai

2. Advanced Turbine
• Turbine Definition:
• A turbine is a rotary mechanical device that extracts energy from
a fast moving flow of water, steam, gas, air, or other fluid and
converts it into useful work.
• A turbine is a turbo-machine with at least one moving part
called a rotor assembly, which is a shaft or drum with blades
attached.
• Moving fluid acts on the blades so that they move and impart
rotational energy to the rotor.

3. Advanced Turbine – Working Principle
• The working principle is very much
simple.
• When the fluid strikes the blades of
the turbine, the blades are displaced,
which produces rotational energy.
• When the turbine shaft is directly
coupled to an electric gene- -rator
mechanical energy is converted into
electrical energy.
• This electrical power is known as
hydroelectric power.

4. Advanced Turbine
Fuel Natural gas
Frequency 60 Hz
Gross Electrical output 187.7 MW*
Gross Electrical efficiency 36.9 %
Gross Heat rate 9251 Btu/kWh
Turbine speed 3600 rpm
Compressor pressure ratio 32:1
Exhaust gas flow 445 kg/s
Exhaust gas temperature 612 °C
NOx emissions (corr. to 15% O2,dry) < 25 vppm
GT24 (ISO 2314 : 1989)

5. Advanced Turbine
Fuel Natural gas
Frequency 60 Hz
Gross Electrical output 187.7 MW*
Gross Electrical efficiency 36.9 %
Gross Heat rate 9251 Btu/kWh
Turbine speed 3600 rpm
Compressor pressure ratio 32:1
Exhaust gas flow 445 kg/s
Exhaust gas temperature 612 °C
NOx emissions (corr. to 15% O2,dry) < 25 vppm
9756 kJ/kWh

6. Advanced Turbine - Types
• Water Turbine :
A) impulse turbine
B) reaction turbine
• Steam Turbine
• Gas Turbine
• Wind Turbine
• Although the same principles apply to all turbines, their specific
designs differ sufficiently to merit separate descriptions.

7. Advanced Turbine – Impulse turbine
• In an impulse turbine, the fluid is forced to hit the turbine at high
speed.
Types of Impulse Turbines:
I. Pelton Turbine
II. Cross-flow Turbine

8. Advanced Turbine – Pelton turbine
• It is a type of tangential flow impulse turbine used to generate
electricity in the hydroelectric power plant.
• The Pelton turbine was discovered by the American engineer L.A.
Pelton The energy available at the inlet of the Pelton turbine is only
kinetic energy.
• The pressure at the inlet and outlet of the turbine is atmospheric
pressure.
• This type of turbine is used for high head.
• Main Parts of Pelton Turbine
• The various parts of the Pelton turbine are Nozzle and flow regulating
arrangement (spear), Runner and Buckets, Casing and Breaking Jet

9. Advanced Turbine – Pelton turbine
• Working principle of Pelton
turbine is simple.
• When a high speed water jet
injected through a nozzle hits
buckets of Pelton wheel; it
induces an impulsive force.
• This force makes the turbine
rotate. The rotating shaft runs
a generator and produces
electricity.
• In short, Pelton turbine
transforms kinetic energy of
water jet to rotational energy.

10. Advanced Turbine – Cross- Flow turbine
• As with a water wheel, the water is admitted at the turbine's edge. After passing
the runner, it leaves on the opposite side.
• Going through the runner twice provides additional efficiency.
• The cross-flow turbine is a low-speed machine that is well suited for locations
with a low head but high flow.

11. Advanced Turbine – Reaction Turbine
• In a reaction turbine, forces driving the rotor are achieved by the reaction
of an accelerating water flow in the runner while the pressure drops.
• In reaction turbines torque developed by reacting to the fluid's pressure.
• The pressure of the fluid changes as it passes through the turbine rotor
blades.
• Kaplan Turbine
• Francis Turbine
• Kinetic Turbine
Types of Reaction Turbines

12. Advanced Turbine – Kaplan Turbine
• The Kaplan turbine is a water turbine which has adjustable blades and is
used for low heads and high discharges.
• The Kaplan turbine is an inward flow reaction turbine, which means that
the working fluid changes pressure as it moves through the turbine and
gives up its energy.

13. Advanced Turbine – Francis Turbine
• The Francis turbine is a type of water turbine and are used for medium
head(45-400 m) and medium discharge.(10-700 m^3/s)
• The Francis turbine is a type of reaction turbine, a category of turbine in
which the working fluid comes to the turbine under immense pressure and
the energy is extracted by the turbine blades from the working fluid.

14. Advanced Turbine – Kinetic Turbines
• Kinetic energy turbines, also called free-flow turbines, generate
electricity from the kinetic energy present in flowing water.
• The systems may operate in rivers, man-made channels, tidal waters,
or ocean currents.
• Kinetic systems utilize the water stream's natural pathway.

15. Advanced Turbine – Steam Turbine
• A steam turbine is a device that extracts thermal energy from
pressurized steam and uses it to do mechanical work on a
rotating output shaft.
• Steam turbines are used for the generation of electricity in
thermal power plants, such as plants using coal fuel oil or
nuclear fuel.

16. Advanced Turbine – Gas Turbine
• A gas turbine, also called a combustion turbine, is a type of
internal combustion engine.
• Gas turbines are used to power aircraft, trains, ships,
electrical generators or even tanks.

17. Advanced Turbine
Developments in Gas Turbine Cycles
1. The wet compression (WC) cycle
2. The steam injected gas turbine (STIG) cycle
3. The integrated WC & STIG (SWC) cycle
4. Themo-chemical Recuperation cycles

18. Advanced Turbine
Wet compression
• One of the most effective ways to increase the gas turbine
power output is to reduce the amount of work required for
its compressor.
• A gas turbine compressor consumes about 30 to 50% of
work produced by the turbine.

19. Advanced Turbine
Intake Air
Inlet Duct
Water InjectionCompressor
Combustor
Fuel
Turbine
G
The wet compression (WC) cycle

20. Advanced Turbine
The wet compression (WC) cycle
• The wet compression cycle has the following
benefits over the simple cycle.
• Lower compressor work
• Higher turbine work
• Higher cycle efficiency

21. Advanced Turbine
The steam injected gas turbine (STIG) cycle
G
Compressor Turbine
Combustor
Fuel
Injection Steam
Exhaust
HRSG
water
pump
Intake Air
HRSG – Heat Recovery Steam Generator

22. Advanced Turbine
The steam injected gas turbine (STIG) cycle
• Steam injection into the combustion chamber of a gas turbine is one of
the ways to achieve power augmentation and efficiency gain.
• In a steam injected gas turbine (STIG), the heat of exhaust gasses of the
gas turbine is used to produce steam in a heat recovery steam generator.
• The steam is injected into the combustion chamber or before entering
the combustion chamber (i.e. in the compressor discharge).
• STIG cycle has higher cycle efficiency than the WC cycle.
• STIG cycle gives higher net work out put than the WC cycle up to a
pressure ratio of 7.

23. Advanced Turbine
G
Intake Air
Water injection
Inlet Duct
Compressor Turbine
Combustor
Fuel
Injection Steam
Exhaust
HRSG
water
pump
The integrated WC & STIG (SWC) cycle
HRSG – Heat Recovery Steam Generator

24. Advanced Turbine
The integrated WC & STIG (SWC) cycle
• It has the combined benefit of the advantage of higher
efficiency of STIG cycle and higher net work output of
WC cycle.
• But its cycle efficiency is less than that of the STIG
cycle owing to the need for higher heat input.

25. Advanced Turbine
Comparison of typical parameters of simple, WC,STIG and
SWC cycles.
cycle Pressure
ratio
PR
Evaporat
ive rate,
kg/k
Net
work
output,
MW
Cycle
efficienc
y
%
Fuel
mass
flow
rate,
kg/sec
Steam
mass
flow
rate,
kg/sec
simple 11 0 151.13 31.28 11.04 0
WC 11 7.5e-4 232.75 35.35 15.04 0
STIG 11 0 215.65 39.63 12.43 54.49
SWC 11 7.5e-4 303.11 38.16 18.15 54.49

26. Advanced Turbine
• There are many areas and challenges which can be explored further
to this work.
• They are:
• Economic feasibility of these cycles need to be studied.
• Compressor life reduction due to water injection. (because of the off
design running conditions that prevail in reality).
• The difficulties involved in designing a turbine to handle large mass
flow rates of combustion gasses and steam.
• The effect of steam injection in reducing Nitrogen Oxides (NOX)
emissions

27. Advanced Turbine – Wind Turbine
• A wind turbine is a device that converts kinetic energy from the
wind into electrical power .
• Conventional horizontal axis turbines can be divided into three
components:.
• Wind turbine used for charging batteries may be referred to as
a wind charger.

28. Advanced Turbine
• A designed nano-turbine constructed by a single-wall carbon
nanotube (CNT) and graphene sheets.
• This nano-turbine can largely unidirectionally rotate as driven by
a steady water flow.
• The mechanism by which the nano-device works at nanoscale
and the difference between the behavior of mechanical motion of
a nano-device and its macroscopic analogue still largely remain
elusive.
• The averaged rotation rate of the nano-turbine shows linear
relationship with the flow velocity through two orders of
magnitude.

29. Advanced Turbine
• Compared to the macroscopic counterpart, the rotation rate of
nano-turbine is much slower.
• Its efficiency of converting energy from fluid flow to the
mechanical motion is only 6.4% of that of an ideal macroscopic
counterpart.
• As indicated by the distribution of flow velocity, the
‘‘effective’’ driving flow velocity is remarkably smaller than
the bulk flow velocity and the ratio can be as low as 0.15.
• The disruption of water flow, together with the water slippage
at graphene surface and the dragging effect, should be related
to the much slower rotation rate.

30. Advanced Turbine
• The ratio of effective driving flow velocity decreases as the flow velocity increase,
suggesting that the linear relationship between rotation rate and flow velocity may
be more complicated. The water slippage and dragging, may get enhanced at the
same time.
• The top view (left) and side view (right) of the designed nano-turbine placed along
the z-axis, visualized with VMD40. The two fixed pole carbon atoms are shown as
the golden balls. The rotation of nano-turbine is driven by the water flow along the –
z-direction. The 2-A° slab above the turbine blade is shown as the green region.

31. Applications
• Almost all electrical power on earth is produced with a
turbine of some type.
• Very high efficiency turbines harness about 40% of the
thermal energy with the rest exhausted as waste heat.
• Most jet engines rely on turbines to supply mechanical
work from their working fluid and fuel as do all nuclear
ships and power plants.