Periodic Reporting for period 1 - BRAVA (Breakthrough Fuel Cell Technologies for Aviation)
Okres sprawozdawczy: 2022-12-01 do 2024-06-30
The intention of BRAVA is to develop breakthrough technologies for a Fuel Cell based Power Generation System (PGS) for aviation. The overall target is a high-performance PGS with a power range of over 2 MW. The foreseen future MW system will be a multi-stack aircraft PGS. Airbus intends to use several of such multi-MW FC-based PGSs to propel an aircraft capable of carrying up to 100 passengers on distances of up to 1,000 nautical miles.
The Proton Exchange Membrane Fuel Cell technology emerging from the automotive industry is a baseline for the aeronautic industry. But while automotive industry fuel cell (FC) systems are usually limited to 100 kW, aircrafts require a significantly greater amount of power (multi-MW) and must operate at both different temperatures and pressures, keeping the system’s safety and reliability levels to aeronautical standards at the same time.
Advances in the FC stack and balance of plant components, the thermal management system, heat exchanger design and technology, and air supply system architecture, are key building blocks for this multi-MW FC based PGS. Therefore the project focuses on:
• New catalysts and membranes with higher performance, durability and higher operating temperature capability to enable integration into new Membrane Electrode Assemblies to reach high efficiency, low weight, compactness and long lifetime;
• 2-Phase cooling based thermal management system (including a newly designed fuel cell stack) for compactness, weight reduction and hence improved fuel consumption;
• Additive manufactured heat exchangers for increased heat rejection, compactness, lightweight and low drag;
• A new air supply architecture and components designed and optimized to provide low parasitic power and weight reduction and thus enabling lower fuel consumption and equipment cost;
• Assessment of all new BRAVA technologies in a complete power generation system.
Each of the breakthrough technologies for these FC system subsystems will be advanced to a high technology readiness level and be validated in its relevant environments. The new BRAVA technologies will enable the design of smaller, lighter and more efficient fuel cell system architectures.
The Proton Exchange Membrane Fuel Cell technology emerging from the automotive industry is a baseline for the aeronautic industry. But while automotive industry fuel cell (FC) systems are usually limited to 100 kW, aircrafts require a significantly greater amount of power (multi-MW) and must operate at both different temperatures and pressures, keeping the system’s safety and reliability levels to aeronautical standards at the same time.
Advances in the FC stack and balance of plant components, the thermal management system, heat exchanger design and technology, and air supply system architecture, are key building blocks for this multi-MW FC based PGS. Therefore the project focuses on:
• New catalysts and membranes with higher performance, durability and higher operating temperature capability to enable integration into new Membrane Electrode Assemblies to reach high efficiency, low weight, compactness and long lifetime;
• 2-Phase cooling based thermal management system (including a newly designed fuel cell stack) for compactness, weight reduction and hence improved fuel consumption;
• Additive manufactured heat exchangers for increased heat rejection, compactness, lightweight and low drag;
• A new air supply architecture and components designed and optimized to provide low parasitic power and weight reduction and thus enabling lower fuel consumption and equipment cost;
• Assessment of all new BRAVA technologies in a complete power generation system.
Each of the breakthrough technologies for these FC system subsystems will be advanced to a high technology readiness level and be validated in its relevant environments. The new BRAVA technologies will enable the design of smaller, lighter and more efficient fuel cell system architectures.
In BRAVA the following work was performed:
• The modular system architecture of the PGS to balance weight and achieve safety requirements based on a high-level architecture for FC powered aircraft capable of carrying up to 100 passengers with ranges up to 1,000 NM was defined and the requirements of a Power Generation system (PGS) to meet the KPIs and compatible with aircraft certification was made, while based on this PGS requirement definition the cascading requirements for TMS, two-phase (2-PC) cooling, FC stack and air supply system were made and reported.
• Regarding a small scale prototype of a modified FC stack with 2-PC cooling, CFD and thermal FEM modelling was done and all materials to be used were selected. Preliminary tests showed a stable and homogeneous temperature distribution to be possible in the FC stack.
• A detailed design of a 200 kW 2-PC demonstrator was finished and simulations of a 1926 kW system were completed as a model for the complete 2-PC system.
• Design of sub-scale and mid-scale Additive Manufactured (AM) heat exchanger was carried out and the test-rig for testing these sub- and mid-scale AM heat exchangers was built to perform several tests on them.
• Various synthesis methods for high efficiency catalysts for the oxygen reduction reaction were explored and two catalysts were down selected for > 1g scale synthesis for MEA testing and towards upscaled synthesis to 10 g. Aquivion ionomers with different equivalent weight (720 and 790) were proposed as electrode binder for CCM preparation.
• Three polyamide-imide grades to produce thin, ultralight nanofiber reinforcement were screened by electrospinning and one was selected and reinforcement upscaling trials were initiated.
• The preliminary scalable air supply system design capable of provide compressed, purified and temperature conditioned air to a FC system for all aviation relevant conditions (at FL250) was made and the development and validation of novel air supply components was initiated.
• To improve the KPIs of a 1.2MW FC PGS further, anode and cathode architectural developments were investigated with results in the publicly available deliverables D6.1 and D6.2.
• The modular system architecture of the PGS to balance weight and achieve safety requirements based on a high-level architecture for FC powered aircraft capable of carrying up to 100 passengers with ranges up to 1,000 NM was defined and the requirements of a Power Generation system (PGS) to meet the KPIs and compatible with aircraft certification was made, while based on this PGS requirement definition the cascading requirements for TMS, two-phase (2-PC) cooling, FC stack and air supply system were made and reported.
• Regarding a small scale prototype of a modified FC stack with 2-PC cooling, CFD and thermal FEM modelling was done and all materials to be used were selected. Preliminary tests showed a stable and homogeneous temperature distribution to be possible in the FC stack.
• A detailed design of a 200 kW 2-PC demonstrator was finished and simulations of a 1926 kW system were completed as a model for the complete 2-PC system.
• Design of sub-scale and mid-scale Additive Manufactured (AM) heat exchanger was carried out and the test-rig for testing these sub- and mid-scale AM heat exchangers was built to perform several tests on them.
• Various synthesis methods for high efficiency catalysts for the oxygen reduction reaction were explored and two catalysts were down selected for > 1g scale synthesis for MEA testing and towards upscaled synthesis to 10 g. Aquivion ionomers with different equivalent weight (720 and 790) were proposed as electrode binder for CCM preparation.
• Three polyamide-imide grades to produce thin, ultralight nanofiber reinforcement were screened by electrospinning and one was selected and reinforcement upscaling trials were initiated.
• The preliminary scalable air supply system design capable of provide compressed, purified and temperature conditioned air to a FC system for all aviation relevant conditions (at FL250) was made and the development and validation of novel air supply components was initiated.
• To improve the KPIs of a 1.2MW FC PGS further, anode and cathode architectural developments were investigated with results in the publicly available deliverables D6.1 and D6.2.
The outcome of this project will enable Airbus as an aircraft OEM to come close to the start of a serial production of a hydrogen propulsion aircraft. This new aircraft type will enable airliners to comply with EU targets and to be able to fly from and to destinations in Europe with low emission. Nevertheless a mandatory support of the European Commission is needed where appropriate, regarding input for policies including international coordination and extracting benefits for Europe. This includes the wider spread of hydrogen valleys and the increased demand of LH2 around airports, as Airbus cannot force the market uptake to a hydrogen economy. This known chicken and egg issue cannot be overcome, if hydrogen is not available in the needed order of magnitude at a comparable price to kerosene for the airliners.