New fuel cell technology used to replace APU in new boeing 737 and Essay

New fuel cell technology used to replace APU in new boeing 737 and airbus A320 - Essay Example It is monitored and controlled by the Electronic Controller. There are actually many different kinds of APUs used in the Boeing 737, created by a few different manufacturers. The AlliedSignal APU has the highest power rating at 90kVA up to 31,000 ft. (Brady, 1999); this power rating drops at higher altitude. Fuel cell technology is currently able to match this 90 kilo-Volt-Ampere power rating, in order to replace this APU. This has been demonstrated in test flights of hydrogen-powered aircraft, as described below. ‘The SOFC uses jet fuel as the reformer in the proton exchange membrane to give a 440kW APU that is 75% efficient compared to the conventional 40-45% efficient APUs. This would give a typical fuel saving of 1,360t for a 737 over a year. It is actually a hybrid gas turbine / fuel cell due to the sudden surges in demand eg engine starts and gear retraction etc. The SOFC will use air from a compressor passed through a heat exchanger for its gas turbine section. A potential drawback is that it has a 40min start-up time, so it would have to remain on for the whole day and depending upon its noise levels this could be a problem at airports which require the APU to be shutdown during the turnaround. ‘ The efficiency of SOFCs over conventional APUs is large; although the long start-up time might be prohibitable. The technology needed for a SOFC APU to replace the current Boeing APU may be available by 2010, but it could take much longer. Boeing was working in conjunction with Airbus to develop the necessary technologies to replace the APUs with fuel cell technology, since they essentially share the same supplier pool, but they were ready to split when it came to time to develop competitive finished products. The technology for building hydrogen-fueled aircraft has already been demonstrated. The Airbus A320 Fuel Cell Demonstrator was first publicly presented in Berlin in 2008. The fuel cell system provides 20kW of