Thermal Group
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Transcript of Thermal Group
Thermal Turbomachine
sHistory, Types and Uses
Contents
I. Fans and Blowers
II. Compressors
III.Steam Turbines
IV. Gas Turbines
2
I. Fans and Blowers
Team Members:Ghada ZobeirNouran Ezz El DinNervien Islam
Fans and Blowers 3
Contents
1. Definition
2. History
3. Components
4. Fans
5. Performance Parameters
6. Blowers
Fans and Blowers 4
1. Definition
Fan: An mechanically powered device used to produce an airflow (compression ratio ~1.1)
Blower: A high pressure fan (compression ratio 1.11.2)
Fans and Blowers 5
2. History
Omar-Rajeen Jumala 1st working mechanical fan (1832)
1st mechanical fan Punkah Fan (Middle East 19th century)
Nicola Tesla (AC) and Thomas Edison (DC) Electric Power Electric Fans and blowers
Fans and Blowers 6
3. Components
Impeller or Rotor: A series of radial blades attached to a hub which creates the pressure difference.
Motor: provides mechanical power to rotate the blades.
Housing: Enclosure that protects the components.
Fans and Blowers 7
4. Fans
a. Centrifugal Fans
b. Axial Fans
Fans and Blowers 8
a. Centrifugal Fans
They throw air away from the blade tips.
3 typesRadial Blade
Forward Curved Blade
Backward Curved Blade
Fans and Blowers 9
b. Axial Fans
They force the air to move parallel to the rotating shaft.
3 types
Propeller Fans
Tube Axial Fans
Vane Axial Fans
Fans and Blowers 10
c. Comparison
Fans and Blowers 11
5. Performance Parameters
Fans and Blowers 12
6. Blowers
CentrifugalCentrifugal blowers look more
like centrifugal pumps than fans. The impeller is typically gear-driven and rotates as fast as 15,000 rpm.
Positive DisplacementPositive displacement blowers
have rotors, which "trap" air and push it through housing
Fans and Blowers 13
II. Compressors
Team MembersKarim EhabMohamed El LaithyEman SaudiMahmoud Ali Fouad
Compressors 14
Contents
1. Definition
2. Types
Compressors 15
1. Definition
Compressors: Mechanically powered gas mover with pressure ratio >1.2
Compressors 16
2. Types
Compressors 17
a. Centrifugal Compressors (Dynamic)
Design Impeller (rotating
vanes) similar to centrifugal fan (mostly backward curved blade fan)
Housing mounted static vanes (diffusers)
Compressors 18
a. Centrifugal Compressors (Dynamic)
AdvantagesHigh mass flow rate
Oil free gas flow (Good Sealing)
Low Life Cycle Cost (LCC) (High Reliability)
High Efficiency
Max compression ratio of 10:1
Compressors 19
a. Centrifugal Compressors (Dynamic)
DisadvantagesFixed head for all gases, and
variable pressure ratio for each gas. (Not used with Molecular weight less than 10 due to very low pressure ratio).
Needs multi-stage configuration for higher pressure ratio.
Compressors 20
b. Axial Compressors (Dynamic)
Design Rotor with
successive rows of blades
Stator blades diffusers, remove swirl, maintain axial flow
Blade aerodynamic design max thrust, min dragCompressors 21
b. Axial Compressors (Dynamic) Advantages
Higher efficiency than centrifugal compressors (+ 8~10%)
Small frontal area
High pressure rise
Compression ratio of 1.15-1.6 per stage
DisadvantagesHigh cost
High weight
High starting requirementsCompressors 22
c. Positive Displacement Compressors
Sliding vane compressor
Compressors 23
c. Positive Displacement Compressors
Lobe compressor
Compressors 24
c. Positive Displacement Compressors
Screw compressor
Compressors 25
c. Positive Displacement Compressors
Reciprocating compressor
Compressors 26
III. Steam Turbines
Team MembersAmr IbrahimRasha KamalDina El NaggarYahia Sowylam
Steam Turbines 27
Contents
1. Definition
2. History
3. Design
4. Types
5. Uses
Steam Turbines 28
1. Definition
A steam turbine is a mechanical device that extracts thermal energy from pressurized steam, and converts it into rotary motion
Steam Turbines 29
2. History
Hero of Alexandria’s Aeolipile (reaction turbine)
Steam Turbines 30
2. History
Sir Charles Parsons modern steam turbine 1884 7.5 kW of electricity.
7.5 kW 50,000 kW
Steam Turbines 31
3. Design
One set of stationary blades is connected to the casing
One set of rotating blades is connected to the shaft
Steam Turbines 32
4. Types
Steam Turbines are classified according to:a. Steam Supply and Exhaust
Conditions
b. Casing or Shaft Arrangements
N.B. Other types are stated in the gas turbine section.
Steam Turbines 33
a) Steam Supply and Exhaust Conditions Condensing: most electrical
power plants
Non-condensing (backpressure turbines): use exhaust steam in other processes (heating units, pulp and paper plants, desalination facilities)
Steam Turbines 34
a) Steam Supply and Exhaust Conditions Reheat turbine: reheat high
pressure exhaust to operate a low pressure turbine.
Steam Turbines 35
b) Casing or Shaft Arrangements Single casing units: single casing
and shaft are coupled to a generator
Tandem compound: two or more casings are directly coupled together to drive a single generator
Cross compound arrangement: two or more shafts not in line driving two or more generators that often operate at different speeds. Typically used for many large applications
Steam Turbines 36
5. Uses
Steam turbines are used for the generation of electricity in thermal power plants, such as plants using coal or fuel oil or nuclear power
Steam Turbines 37
5. Uses
Steam turbines may be used in combined cycles with a steam generator
Steam Turbines 38
5. Uses
Steam turbines are used as drivers for large ships
Steam Turbines 39
IV. Gas Turbine
Team Members:Mahmoud KoraïemMohamed El MohassebAmr Serry
Gas Turbine 40
Contents
1. Definition
2. History
3. Types and design
4. Applications
Gas Turbine 41
1. Definition
Compressor, combustion chamber and turbine arrangement.
Working fluid is air (compressor), air + combustion products (turbine)
Gas Turbine 42
2. History
1500 Leonardo Da Vinci chimney jack
Gas Turbine 43
2. History
1791 John Barber designed (UK) 1st gas turbine engine uses a compressor, combustion chamber, and a turbine (patent only)
Gas Turbine 44
2. History
1872 - 1904 F. Stolze designed (Germany) gas turbine with axial compressor (no useful power)
1906 Armengaud Lemale (France) centrifugal compressor (no useful power)
The lack of advanced knowledge of aerodynamic was the reason for the failure.
Gas Turbine 45
2. History
1910 Hanz Holzwarth (Germany) constant volume combustion (150 kW)
Gas Turbine 46
3. Types and Design
a. Axial gas turbine
b. Radial gas turbine
c. Bladeless gas turbine
(the difference is in the turbine stage only)
Gas Turbine 47
a. Axial Gas Turbines
Most common type
Easy multi-staging high overall pressure ratio
Wide range of applications
Gas Turbine 48
a. Axial Gas Turbines
Can be either impulse (Rateau, Curtis) turbine or reaction (Parson’s) type
Rateau stationary blades = nozzles
Curtis 1 nozzle (rest is anti-swirl)
Gas Turbine 49
a. Axial Gas Turbines Rateau stationary blades =
nozzles
Gas Turbine 50
a. Axial Gas Turbines Curtis 1 nozzle (rest is anti-
swirl)
Gas Turbine 51
a. Axial Gas Turbines Parson’s reaction turbine
Gas Turbine 52
a. Axial Gas Turbines Blades air cooled
Superalloys transition elements (Ni, Fe, Co) alloys are used with (Al, Ti or Nb) in FCC crystals
Gas Turbine 53
b. Radial Gas Turbines High pressure ratio per stage
Hard to multi-stage
Very Compact size
More efficient for small mass flow rate
Lower Thermal stresses (no need for air cooling)
Gas Turbine 54
c. Bladeless Turbine (Tesla’s)
Uses adhesive force of inlet gas to turn the disks
Ideal for extremely small flow applications
Efficiency (60~95%)
(steam turbine’s 80~98%)
Gas Turbine 55
4. Applications
Turboshaft engine (used in locomotive)
Gas Turbine 56
4. Applications
Turboprop engine
Gas Turbine 57
4. Applications
Turbofan engine
Gas Turbine 58
4. Applications
Turbojet engine
Gas Turbine 59
4. Applications
Combined power cycle (Gas turbine, steam turbine)
N.B. Advances in gas turbines are mainly dependant on cooling technology (axial), and compressor design (Wc = 60% Wt)
Gas Turbine 60
Any Questions?Fans and Blowers 61