Airbus has partnered Parker Aerospace to develop a hydrogen-based replacement system for today's auxiliary power unit that could find its first application on the projected next-generation single-aisle aircraft.
The objective is to take the airframer's previous research into fuel-cell technology further and build a technology demonstrator that can be flight tested around 2015 and offered to a new aircraft development team at "technology readiness level 6" approximately one year later, said Axel Krein, Airbus's senior vice-president for research and technology.
Unlike today's APUs, the new system will not only generate electricity and, if still needed, bleed air, but also portable water and oxygen-depleted air (inert gas) as byproducts of the chemical reaction between hydrogen, which will come from a fuel tank, and oxygen in the ambient air.
While the water can be fed into the aircraft's fresh water system, the inert gas could be used for the fire-suppression equipment in the main fuel tanks and cargo compartments.
This would lead to a fundamental change in the aircraft's systems architecture and rule out a retrofit option for existing models, including the forthcoming A350 and A320neo.
A first application could be on the projected narrowbody successor A30X, Krein said. Airbus has progressively pushed the arrival of that aircraft generation back and currently predicts its service entry at around 2030.
The challenge is to optimise the aircraft's overall architecture for the new system. The fuel-cell technology should deliver a fuel-burn reduction on a standard short- to medium-haul mission of 10-15%, said Krein.
However, the overall benefit would depend on how cost effectively the hydrogen system can be introduced to the aircraft and ground operations. The main problems are to reduce the fuel cell system's weight and its maintenance costs.
While Parker will supply the fuel-cell system and manage different subsystem suppliers, Airbus will be responsible for the overall aircraft system architecture.
Source: Flight Daily News