Midnight Mike
2006-12-12, 08:30 AM
787 special: Power to spare
Hamilton Sundstrand’s APU, designed solely to generate electrical rather than pneumatic power for the 787, is gearing up for flight tests in April
Unlike previous APUs, the 787 unit is designed solely with the intent of generating electrical rather than pneumatic power and does not therefore have either a load compressor or a bleed system.
Rated at 1,100shp (500kW), and driving dual 225kVA generators through a large gearbox, the APU was started electrically using a starter/generator for the first time on 31 October 2005 at its power systems facility in San Diego, California.
The APU itself is also controlled electrically, using a system similar to that developed for the APS2300 used on the Embraer 170. Goodrich turbine fuel technology division supplies the drive-integrated fuel injection system for the APS5000, which includes both fuel atomisers and flexible manifolds.
The APU incorporates a single-stage centrifugal compressor with a pressure ratio in excess of 8:1, and a two-stage power turbine section. Other features include a low-emissions combustor and a low-noise eductor oil-cooler, which will duct the exhaust aft and upwards to reduce ramp noise.
http://www.flightglobal.com/Articles/20 ... spare.html (http://www.flightglobal.com/Articles/2006/09/26/Navigation/177/209176/787+special+Power+to+spare.html)
Hamilton Sundstrand’s APU, designed solely to generate electrical rather than pneumatic power for the 787, is gearing up for flight tests in April
Unlike previous APUs, the 787 unit is designed solely with the intent of generating electrical rather than pneumatic power and does not therefore have either a load compressor or a bleed system.
Rated at 1,100shp (500kW), and driving dual 225kVA generators through a large gearbox, the APU was started electrically using a starter/generator for the first time on 31 October 2005 at its power systems facility in San Diego, California.
The APU itself is also controlled electrically, using a system similar to that developed for the APS2300 used on the Embraer 170. Goodrich turbine fuel technology division supplies the drive-integrated fuel injection system for the APS5000, which includes both fuel atomisers and flexible manifolds.
The APU incorporates a single-stage centrifugal compressor with a pressure ratio in excess of 8:1, and a two-stage power turbine section. Other features include a low-emissions combustor and a low-noise eductor oil-cooler, which will duct the exhaust aft and upwards to reduce ramp noise.
http://www.flightglobal.com/Articles/20 ... spare.html (http://www.flightglobal.com/Articles/2006/09/26/Navigation/177/209176/787+special+Power+to+spare.html)