Rear center fuel tank adds roughly 20k liters and extends range by 1k NM

11 pointsposted 5 hours ago
by r2sk5t

9 Comments

netsharc

3 hours ago

> In addition, a new galley air cooling system will also be certified, which features lighter and more efficient refrigeration units for very long flights.

I wonder how they work.. considering outside air is way below freezing ar cruising altitude, I guess radiators?

Could the refrigerant be brought close to the plane's skin to cool it?

gosub100

3 hours ago

Maybe the refrigeration is shared with the galley (food storage), and/or is only needed when the plane is on the ground?

lazide

3 hours ago

Or just… computer controlled air vents?

r2sk5t

3 hours ago

At altitude you can reject heat straight to the aircraft skin. Some designs run an internal heat sink on the ground and during climb, watch altitude, and only switch on the skin-exchanger coolant pump once outside is cold enough to cool the loop for free.

The reason it stays a refrigeration unit and not just vents is the ground case. Gate on a hot day, doors open, no ram air, warm soak: that's the worst case, and where the compressor has to work. One published point-of-use chiller design specs roughly double the load on the ground vs in cruise (order of 700 W vs 300 to 400 W per unit). So the vapor cycle is sized for the ground, and most of a 20 hour flight is spent in the regime where you barely need it.

And these aren't fridge boxes at each cart. It's a central vapor-cycle chiller cooling a glycol/water loop piped to air chillers at the galleys; the carts get chilled air. The heat comes off the condenser and goes to ram air, a skin exchanger, the cargo hold, or back into the ECS, depending on the aircraft. Which one the new ULR units use, Airbus hasn't said. For a 22 hour flight the interesting number isn't peak capacity, it's efficiency and weight in cruise, which is probably what "lighter and more efficient for very long flights" is pointing at.

beaviskhan

an hour ago

> flight times of up to 22 hours

Making flight connections is never fun, but this sounds absolutely brutal.

wildzzz

an hour ago

I'd love to visit Australia and SE Asia but am hesitant with those long flights. I'd probably be fine with layflat seats but those are well beyond what I'd ever consider paying for an airline ticket.