5. Definition Fan: An mechanically powered device used to produce an airflow (compression ratio ~1.1) Blower: A high pressure fan (compression ratio 1.1ï 1.2) 5 Fans and Blowers
6. History Omar-RajeenJumalaï 1st working mechanical fan (1832) 1st mechanical fan ï Punkah Fan (Middle East 19th century) Nicola Tesla (AC) and Thomas Edison (DC) ï Electric Power ï Electric Fans and blowers 6 Fans and Blowers
7. 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. 7 Fans and Blowers
13. Blowers Centrifugal Centrifugal blowers look more like centrifugal pumps than fans. The impeller is typically gear-driven and rotates as fast as 15,000 rpm. Positive Displacement Positive displacement blowers have rotors, which "trap" air and push it through housing 13 Fans and Blowers
14. Compressors Team Members Karim Ehab Mohamed El Laithy EmanSaudi Mahmoud Ali Fouad 14 Compressors
18. Centrifugal Compressors (Dynamic) Design Impeller (rotating vanes) ï similar to centrifugal fan (mostly backward curved blade fan) Housing ï mounted static vanes (diffusers) 18 Compressors
19. Centrifugal Compressors (Dynamic) Advantages High mass flow rate Oil free gas flow (Good Sealing) Low Life Cycle Cost (LCC) (High Reliability) High Efficiency Max compression ratio of 10:1 19 Compressors
20. Centrifugal Compressors (Dynamic) Disadvantages Fixed 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. 20 Compressors
21. Axial Compressors (Dynamic) Design Rotor with successive rows of blades Stator blades ï diffusers, remove swirl, maintain axial flow Blade aerodynamic design ï max thrust, min drag 21 Compressors
22. 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 Disadvantages High cost High weight High starting requirements 22 Compressors
29. Definition A steam turbine is a mechanical device that extracts thermal energy from pressurized steam, and converts it into rotary motion 29 Steam Turbines
30. History Hero of Alexandriaâs Aeolipile (reaction turbine) 30 Steam Turbines
31. History Sir Charles Parsons ï modern steam turbine ï 1884 ï 7.5Â kW of electricity. 7.5Â kW ï 50,000 kW 31 Steam Turbines
32. Design One set of stationary blades is connected to the casing One set of rotating blades is connected to the shaft 32 Steam Turbines
33. Types Steam Turbines are classified according to: Steam Supply and Exhaust Conditions Casing or Shaft Arrangements N.B. Other types are stated in the gas turbine section. 33 Steam Turbines
34. 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) 34 Steam Turbines
35. Steam Supply and Exhaust Conditions Reheat turbine: reheat high pressure exhaust to operate a low pressure turbine. 35 Steam Turbines
36. 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 36 Steam Turbines
37. 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 37 Steam Turbines
38. Uses Steam turbines may be used in combined cycles with a steam generator 38 Steam Turbines
42. Definition Compressor, combustion chamber and turbine arrangement. Working fluid is air (compressor), air + combustion products (turbine) 42 Gas Turbine
43. History 1500 ï Leonardo Da Vinci ï chimney jack 43 Gas Turbine
44. History 1791 ï John Barber designed (UK) ï 1st gas turbine engine ï uses a compressor, combustion chamber, and a turbine (patent only) 44 Gas Turbine
45. History 1872 - 1904 ï F. Stolze designed (Germany) ï gas turbine with axial compressor (no useful power) 1906 ï ArmengaudLemale (France) ï centrifugal compressor (no useful power) The lack of advanced knowledge of aerodynamic was the reason for the failure. 45 Gas Turbine
47. Types and Design Axial gas turbine Radial gas turbine Bladeless gas turbine (the difference is in the turbine stage only) 47 Gas Turbine
48. Axial Gas Turbines Most common type Easy multi-stagingï high overall pressure ratio Wide range of applications 48 Gas Turbine
49. Axial Gas Turbines Can be either impulse (Rateau, Curtis) turbine or reaction (Parsonâs) type Rateau ï stationary blades = nozzles Curtis ï 1 nozzle (rest is anti-swirl) 49 Gas Turbine
53. Axial Gas Turbines Blades ï air cooled Superalloys ï transition elements (Ni, Fe, Co) alloys are used with (Al, Ti or Nb) in FCC crystals 53 Gas Turbine
54. 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) 54 Gas Turbine
55. Bladeless Turbine (Teslaâs) Uses adhesive force of inlet gas to turn the disks Ideal for extremely small flow applications Efficiency (60~95%) (steam turbineâs 80~98%) 55 Gas Turbine
60. 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) 60 Gas Turbine