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