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Gas Temperatures. Platen Super Heater:Inlet Temperature: 1236.4 0COutlet Temperature: 1077 0CFinal Super Heater:Inlet Temperature: 1077 0COutlet Temperature: 962.4 0CReheater:Inlet Temperature: 962.4 0COutlet Temperature: 724.3 0CLow Temperature Super Heater:Inlet Temperature: 724.30COutl
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1. Air-preheater for Conservation of Flue Gas Energy P M V Subbarao
Professor
Mechanical Engineering Department
2. Gas Temperatures Platen Super Heater:
Inlet Temperature: 1236.4 0C
Outlet Temperature: 1077 0C
Final Super Heater:
Inlet Temperature: 1077 0C
Outlet Temperature: 962.4 0C
Reheater:
Inlet Temperature: 962.4 0C
Outlet Temperature: 724.3 0C
Low Temperature Super Heater:
Inlet Temperature: 724.30C
Outlet Temperature: 481.3 0C
Economizer:
Inlet Temperature: 481.3 0C
Outlet Temperature: 328.5 0C
10. The Creative Design…… Heat exchanger is complete only if there are Donor, Receiver and Mediator in Equilibrium.
Presence of all the three necessary?
Time sharing & Space Sharing
Time Sharing : Donor And Mediator for sometime and Mediator and Receiver for sometime : Repeat!
Space sharing: All present always.
Central Limit Theorem : It is impossible to have time and space sharing in one system.
Time Sharing : Regenerators
Space Sharing : Recuperators
11. The concept of Time Sharing At any time:
The overall heat transfer coefficient, U
12. Stockholm 1920The Ljungström Air Preheater
13. Historical Significance of Landmark Throughout the history of boilers there have been many advancements in order to obtain a better performance and lower fuel consumption.
Ljungström Air Preheater invented by Fredrik Ljungström, then Technical Director at Aktiebolaget Ljungström Ångturbin (ALÅ) is the most successful invention.
The first installation in a commercial boiler saved as much as 25% of the fuel consumption.
In a modern Steam generator the Ljungström Air Preheater provides up to 20% of the total heat transfer in the boiler process, but the Ljungström Air Preheater only represents 2% of the investment.
14. Economic Impact of the Landmark The use of a Ljungström Air Preheater in a modern power plant saves a considerable quantity of fuel.
The cost of the preheater is generally recovered after only a few months.
The total world-wide fuel savings resulting from all Ljungström Air Preheaters which have been in service is equivalent to 4,500,000,000 tons of oil (1994).
An estimate shows that the Ljungström Air Preheaters in operation annually saves about $30 Billion US.
The distribution of thermal power capacity in which Ljungström Air Preheaters are installed over the world is shown in the table below.
16. Landmark Contribution to Developmentof New World Wide Industry The use of the Ljungström Air Preheater started in the 1920s throughout the whole world.
In the beginning the marketing of the Ljungström Air Preheater was made in close connection with ALÅ.
but most of the deliveries have actually been made through a network of licensees throughout the world.
17. Rotary or Regenerative Air Pre-Heater
18. Stationary-Plate Type Air Pre-Heater
19. Regenerative Pre-Heaters Rotates with a low speed
Rotor is divided into 12 or 24 sections and 12 or 24 radial divisions.
Each sector is divided into several trapezoidal sections with transverse division plates.
Heat storage pales are placed in these sections.
Weight : 500 tons.
This consists of : rotor, sealing apparatus, shell etc.
24. Leakage in APH
27. Multiple Channel RAPH
30. Fluid flows in rotary regenerator