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1 Gas Turbine Introduction
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Transcript of 1 Gas Turbine Introduction
Dr. Eng. Walid Abdelghaffar
Dr. Walid AbdelghaffarGas Turbine Components
Gas Turbine HistoryGas Turbine History
Dr. Walid AbdelghaffarGas Turbine Components
Gas Turbine HistoryGas Turbine History
HERO’S AEOLIPILE
Hero’s Aeolipile
(Ancient Egyptian Scientist)
300AD – 250BC
Dr. Walid AbdelghaffarGas Turbine Components
Gas Turbine HistoryGas Turbine History
Chimney Jack designed by Leonardo da Vinci (1500AD)
Dr. Walid AbdelghaffarGas Turbine Components
Gas Turbine HistoryGas Turbine History
Branca’s Jet Turbine (1500AD)
Dr. Walid AbdelghaffarGas Turbine Components
Gas Turbine HistoryGas Turbine History
Newton’s Steam Wagon
Dr. Walid AbdelghaffarGas Turbine Components
Gas Turbine HistoryGas Turbine History
1791 - John Barber- First Patent using Thermodynamic Cycle of GTE.
1930 - Sir Frank Whittle First Patent of a Jet Aircraft Engine.
1937 - First used GTE used to power a ship.
1941 - GE Contracted for an American version of Brit- DesignedWhittle engine.
1941 - Westinghouse builds first American GTE.
1967 - US Navy - Asheville class patrol gunboats
Dr. Walid AbdelghaffarGas Turbine Components
IntroductionGas turbines are designed for many different purposes. In the petroleum industry they are commonly used to drive:
· compressors for transporting gas through pipelines
· generators that produce electrical power
Gas Turbine Engine Design
Dr. Walid AbdelghaffarGas Turbine Components
Engine Design : SectionsThe purpose of a gas turbine engine is to create energy to turn a shaft that drives other rotating equipment such as compressors and generators.
The figure shows a two-shaft turbine engine.
A gas turbine engine is divided into five sections:· air inlet section· compressor section · combustion section· turbine section· exhaust section
Dr. Walid AbdelghaffarGas Turbine Components
The sections of a gas turbine are contained in the engine case. The engine case is a horizontal tube-like container that is open at both ends.
Each section of the gas turbine has a specific function. Engine Design: Air Inlet & CompressorsHuge quantities of air enter the case through an opening at the front end called the engine air inlet.
After passing through the engine air inlet, the air flows to the compressor section. The compressor section contains the first moving part, the compressor.
Compressor wheels increase the pressure of the incoming air.
Dr. Walid AbdelghaffarGas Turbine Components
Engine Design: CombustionThe compressed air flows to the combustion section of the gas turbine engine.
As the compressed air enters the combustion chambers, fuel is added through nozzles. The result is a mixture of fuel and air.
The fuel and air mixture is ignited and burns, creating hot gases. The hot, expanding gases flow into the turbine section of the engine.
Dr. Walid AbdelghaffarGas Turbine Components
Engine Design: Turbine & Exhaust
The turbine rotors get power from the flow of gases. This flow of gases into the turbine section causes the turbine rotors to turn. A single shaft gas turbine has only one major moving part - the rotor shaft.
The turbine rotors and the compressor are mounted on opposite ends of the same rotor shaft. This allows the turbine rotors and compressor to work as a unit.
When the gases leave the turbine section, they return to the atmosphere through the exhaust section.
Dr. Walid AbdelghaffarGas Turbine Components
Air Entry and Compression :
The engine case of the gas turbine is a tube-like container that is open at both ends and narrow in the center.
The front end of the case contains the compressor. The compressor draws air into the case and increases the air pressure by compressing (or reducing) its volume.
In the figure, the electric fan acts as a compressor.
Dr. Walid AbdelghaffarGas Turbine Components
Combustion
In the narrow section of the case, the air is compressed.
Fuel gas is injected into the compressed air through fuel nozzles. The fuel and air are mixed together and ignited.
Burning the fuel and air mixture creates hot combustion gases. The heat increases the temperature and available energy of the gases.
A turbine captures this energy and changes it into mechanical energy.
Dr. Walid AbdelghaffarGas Turbine Components
Turbine Rotation
The turbine in the rear of the engine case extracts mechanical energy from the flow of the gases acting on the blades.
The turbine rotates because of the pressure and velocity of the hot expanding gases acting on the blades of the turbine.
As the hot gases pass through the turbine, the energy in the gas is reduced.
The gases exit the rear of the case and into the atmosphere.
Dr. Walid AbdelghaffarGas Turbine Components
Turbine Rotation
The turbine in the rear of the engine case extracts mechanical energy from the flow of the gases acting on the blades.
The turbine rotates because of the pressure and velocity of the hot expanding gases acting on the blades of the turbine.
As the hot gases pass through the turbine, the energy in the gas is reduced.
The gases exit the rear of the case and into the atmosphere.
Dr. Walid AbdelghaffarGas Turbine Components
Turbine Rotor
The turbine uses energy from the thrust force created by the expanding gases. This energy is changed into shaft horsepower to drive the turbine compressor, the engine accessories, and the load. Most of this energy is expended to drive the turbine compressor.
(Contd.)
Dr. Walid AbdelghaffarGas Turbine Components
The main parts of a turbine are :
· rotor shaft · rotor disc · rotor blades
The rotor blades (sometimes called buckets) are attached to the rotor disc. The rotor disc is mounted on the rotor shaft. The entire assembly of blades and disc is often called a rotor.
Dr. Walid AbdelghaffarGas Turbine Components
Basic OperationThe figure shows how all the components of the gas turbine engine work together. The fan has been replaced by a single set of compressor blades.
The compressor creates the compressed air that is needed for combustion.
Fuel gas is mixed with the compressed air and is ignited. The burning mixture creates a force in the rear of the engine case. The force is changed into rotating mechanical energy that turns the turbine.
(Contd. )
Dr. Walid AbdelghaffarGas Turbine Components
The turbine turns the rotor shaft that is shared by the compressor and the turbine. The compressor and turbine are connected to the same rotor shaft. The rotating force of the turbine is used to drive the compressor.
Dr. Walid AbdelghaffarGas Turbine Components
Front and Rear Drive Gas TurbinesSome of the rotating energy created by the gas turbine can be used to drive a gear box or generator connected to either end of the rotor shaft.
Depending upon where the load is connected to the rotor shaft, the gas turbine is referred to as a
· front end drive · rear end drive
(Contd.)
Dr. Walid AbdelghaffarGas Turbine Components
If the shaft is lengthened on the compressor end of the engine, it is a front end drive or a cold end drive.
If the shaft is lengthened on the turbine end of the engine, it is a rear end drive or a hot end drive.
Dr. Walid AbdelghaffarGas Turbine Components
Multiple Stage Compressors
Gas turbine manufacturers may place more than one set of compressor and turbine stages in an engine as shown in the figure.
The additional stages in the compressor section provide more compression of the air before combustion.
More than one stage is used in the turbine section to extract as much power as possible from the hot, expanding gases.
The gas turbine in the figure is a two-stage turbine driving a three-stage compressor.
Dr. Walid AbdelghaffarGas Turbine Components
Laws and PrinciplesLaws and Principles
Dr. Walid AbdelghaffarGas Turbine Components
Laws and PrinciplesLaws and Principles
Bernoulli’s Principle:
If an incompressible fluid flowing through a tube reaches a constriction, or narrowing of the tube, the
velocity of fluid flowing through the constriction increases and the pressure decreases.
Dr. Walid AbdelghaffarGas Turbine Components
Laws and PrinciplesLaws and Principles
Bernoulli’s Principle:
Dr. Walid AbdelghaffarGas Turbine Components
Laws and PrinciplesLaws and Principles
Boyle’s Law:
The volume of an enclosed gas varies inversely with the applied pressure, provided the temperature
remains constant.
Dr. Walid AbdelghaffarGas Turbine Components
Laws and PrinciplesLaws and Principles
Charles’ Law:
If the pressure is constant, the volume of an enclosed dry gas varies directly with the absolute temperature.
Dr. Walid AbdelghaffarGas Turbine Components
Laws and PrinciplesLaws and Principles
Pascal’s Law:
Pressure exerted at any point upon an enclosed liquid is transmitted undiminished in all directions.
Dr. Walid AbdelghaffarGas Turbine Components
Laws and PrinciplesLaws and Principles
Newton’s Laws of Motion:
First Law - A body at rest tends to Stay at rest. A body in motion tends to remain in motion.
Second Law - Imbalance of force on a body tends to produce an acceleration in the direction of the force. The acceleration, if any, is directly proportional to the force and inversely proportional to the mass of the body.
Third Law - For every action there is an equal and opposite reaction.
Dr. Walid AbdelghaffarGas Turbine Components
Laws and PrinciplesLaws and Principles
Brayton CycleBrayton Cycle
Dr. Walid AbdelghaffarGas Turbine Components
Laws and PrinciplesLaws and Principles
AA
BB CC
DD
Brayton Brayton CycleCycle
Dr. Walid AbdelghaffarGas Turbine Components
Laws and PrinciplesLaws and Principles
AA
BB CC
DD
Brayton CycleBrayton Cycle
COMPRESSOR
Dr. Walid AbdelghaffarGas Turbine Components
Laws and PrinciplesLaws and Principles
AA
BB CC
DD
Brayton CycleBrayton Cycle
Dr. Walid AbdelghaffarGas Turbine Components
Laws and PrinciplesLaws and Principles
AA
BB CC
DD
Brayton CycleBrayton Cycle
( COMBUSTOR )
Dr. Walid AbdelghaffarGas Turbine Components
Laws and PrinciplesLaws and Principles
AA
BB CC
DD
Brayton CycleBrayton Cycle
CONVERGENT-DIVERGENT PROCESS
Dr. Walid AbdelghaffarGas Turbine Components
Laws and PrinciplesLaws and Principles
AA
BB CC
DD
Brayton CycleBrayton CycleCONVERGENT-DIVERGENT PROCESS
Dr. Walid AbdelghaffarGas Turbine Components
Laws and PrinciplesLaws and Principles
C O N V E R G E N T -D IV E R G E N T P R O C E S S
AABB CC
DDBrayton CycleBrayton Cycle
( HP TURBINE)
Dr. Walid AbdelghaffarGas Turbine Components
Basic Engine TheoryBasic Engine Theory
Dr. Walid AbdelghaffarGas Turbine Components
Basic Engine TheoryBasic Engine Theory
There Are Two Factors Required For Proper Operation:
1. Newton’s Third Law.
2. Convergent-Divergent Process
A. Convergent Means Approaching Nearer Together.
B. Divergent Means Moving Away From Each Other.
C. Bernoulli’s Principle Used In This Process.
Dr. Walid AbdelghaffarGas Turbine Components
Basic Engine TheoryBasic Engine Theory
1. Air taken into inlet duct by compressor 1. Air taken into inlet duct by compressor -- Pressure Pressure raised and discharged into combustion chamber.raised and discharged into combustion chamber.
2. Fuel nozzles admit fuel 2. Fuel nozzles admit fuel -- FuelFuel--air mixture ignited by air mixture ignited by igniters and combustion occurs.igniters and combustion occurs.
3. Hot and expanding gases directed aft thru turbine 3. Hot and expanding gases directed aft thru turbine rotor assembly rotor assembly -- Thermal and kinetic energy converted Thermal and kinetic energy converted to mechanical energy.to mechanical energy.
4. Gases directed to exhaust duct.4. Gases directed to exhaust duct.
Dr. Walid AbdelghaffarGas Turbine Components
Basic Engine TheoryBasic Engine Theory
PR
ESSU
RE
PR
ESSU
RE
TEMPERATURETEMPERATUREAA
BB CC
DD
Brayton CycleBrayton Cycle
PR
ESSU
RE
PR
ESSU
RE
Dr. Walid AbdelghaffarGas Turbine Components
Basic Engine TheoryBasic Engine Theory
Dr. Walid AbdelghaffarGas Turbine Components
Basic Engine TheoryBasic Engine Theory
COMBUSTIONCOMBUSTION
Dr. Walid AbdelghaffarGas Turbine Components
Basic Engine TheoryBasic Engine Theory
EEXXPPAANNSSIIOONN
Dr. Walid AbdelghaffarGas Turbine Components
Basic Engine TheoryBasic Engine Theory
COMBUSTIONCOMBUSTION
EEXXPPAANNSSIIOONN
Dr. Walid AbdelghaffarGas Turbine Components
Conditions and Design Limits Conditions and Design Limits Affect PerformanceAffect Performance
Dr. Walid AbdelghaffarGas Turbine Components
DIRTY COMPRESSOR
Conditions and Design Limits Conditions and Design Limits Affect PerformanceAffect Performance
Dr. Walid AbdelghaffarGas Turbine Components
Conditions and Design Limits Conditions and Design Limits Affect PerformanceAffect Performance
HIGH AMBIENT TEMPERATURE
Dr. Walid AbdelghaffarGas Turbine Components
Conditions and Design Limits Conditions and Design Limits Affect PerformanceAffect Performance
COMPONENT DESIGN LIMITS
Dr. Walid AbdelghaffarGas Turbine Components
Dr. Walid AbdelghaffarGas Turbine Components
Dr. Walid AbdelghaffarGas Turbine Components
Dr. Walid AbdelghaffarGas Turbine Components
Dr. Walid AbdelghaffarGas Turbine Components
Dr. Walid AbdelghaffarGas Turbine Components
Dr. Walid AbdelghaffarGas Turbine Components
Dr. Walid AbdelghaffarGas Turbine Components
Dr. Walid AbdelghaffarGas Turbine Components
Dr. Walid AbdelghaffarGas Turbine Components
Compressor
Combustion
Turbine
Exhaust
Dr. Walid AbdelghaffarGas Turbine Components
Dr. Walid AbdelghaffarGas Turbine Components
Dr. Walid AbdelghaffarGas Turbine Components
Dr. Walid AbdelghaffarGas Turbine Components
Dr. Walid AbdelghaffarGas Turbine Components
Dr. Walid AbdelghaffarGas Turbine Components
Dr. Walid AbdelghaffarGas Turbine Components
Dr. Walid AbdelghaffarGas Turbine Components
Dr. Walid AbdelghaffarGas Turbine Components
Dr. Walid AbdelghaffarGas Turbine Components
Dr. Walid AbdelghaffarGas Turbine Components
Dr. Walid AbdelghaffarGas Turbine Components
Dr. Walid AbdelghaffarGas Turbine Components
Dr. Walid AbdelghaffarGas Turbine Components
Dr. Walid AbdelghaffarGas Turbine Components
Dr. Walid AbdelghaffarGas Turbine Components
Dr. Walid AbdelghaffarGas Turbine Components
Gas Turbine AdvantagesGas Turbine Advantages
1. High Power-to-weight Ratio.
2. Operates on Cheaper and Safer Fuel.
3. Smoothness of Operation.
4. Economical In Terms of Horsepower-per-dollar.
5. Increasing Reliability = Cost-effective.
6. Fuel Economy.
Dr. Walid AbdelghaffarGas Turbine Components
Gas Turbine DisadvantagesGas Turbine Disadvantages
1. Parts are under high stress.
2. Produce high pitched noise.
3. Requires large intake and exhaust ducting.
4. Exhaust heat.
5. Requirement for depot maintenance and repair of major casualties.
Dr. Eng. Walid Abdelghaffar