787 Bleedless AC
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Joined: Jun 2003
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From: Straya
787 Bleedless AC
So we know that the 787 will feature bleedless engines for fuel efficiency...
I understand electric starting, electric anti-ice, but how will it be air conditioned/pressurised?
Of course tapping off hot bleed air from your powerplant then cooling is not the most efficient way of seeing to our respiratory needs, but how are Boeing planning on doing it?
I understand electric starting, electric anti-ice, but how will it be air conditioned/pressurised?
Of course tapping off hot bleed air from your powerplant then cooling is not the most efficient way of seeing to our respiratory needs, but how are Boeing planning on doing it?
Joined: Aug 1998
Posts: 320
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From: australia
Guys,
Also heard the cabin altitude in the 787 will be something in the order of 4000 above sea level instead of the normal 8000 above sea level, could they be using a newer vapour style aircon system???
What is the backup hydraulic's pressure for the FBW sytem of the A380, heard it was 5000 PSI?????
don't know not rated on any of the A3xx familys????
Also heard the cabin altitude in the 787 will be something in the order of 4000 above sea level instead of the normal 8000 above sea level, could they be using a newer vapour style aircon system???
What is the backup hydraulic's pressure for the FBW sytem of the A380, heard it was 5000 PSI?????
don't know not rated on any of the A3xx familys????
Joined: May 2002
Posts: 104
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From: Florida
I just had a briefing by Boeing and the cabin will be 6000'.
The reason for the 6000' was that they can lower it from 8000 since the carbon-reinforced plastic can withstand the differential pressure, a metal cabin would have to be a lot heavier than the current cabins to get the strength required to sustain the pressure. The reason that an electrical press and a/c system is better is that with electrical systems you can match the demand and requirements much more closely. A pneumatic system is less efficient and a lot heavier and more complicated!
The fusleage barrel that they just rolled out in a single piece (7m x 5m or something like that) would have had 1200 pieces in a metal fuselage barrel and would have been held together by 40,000 rivets...so there are lots of reasons for the move to the carbon reinforced plastic (or is it plastic reinforced carbon ;-) )
The reason for the 6000' was that they can lower it from 8000 since the carbon-reinforced plastic can withstand the differential pressure, a metal cabin would have to be a lot heavier than the current cabins to get the strength required to sustain the pressure. The reason that an electrical press and a/c system is better is that with electrical systems you can match the demand and requirements much more closely. A pneumatic system is less efficient and a lot heavier and more complicated!
The fusleage barrel that they just rolled out in a single piece (7m x 5m or something like that) would have had 1200 pieces in a metal fuselage barrel and would have been held together by 40,000 rivets...so there are lots of reasons for the move to the carbon reinforced plastic (or is it plastic reinforced carbon ;-) )
