Challenges of hydrogen composite cryogenic storage for aeronautics
Topic(s) : Industrial applications
Co-authors :
Laure MORETTI (FRANCE), Chloé MESICAbstract :
In the frame of the net zero carbon emission by 2050 commitment by the aeronautic industry, Airbus launched the ZEROe project with the ambition to bring the world’s first hydrogen-powered commercial aircraft by 2035. Cryogenic storage of liquid hydrogen (LH2) is one of the key steps toward a ZEROe aircraft. The current technology considered for the aircraft is a metallic double wall tank, also called Dewar, as illustrated in Figure 1.
The complex architecture of such a tank involves a consequent weight that challenges the performance of the aircraft. Composite materials are a great opportunity to reduce the gravimetric index of such a tank. However, the maturity of cryogenic composite tanks is much lower than a stainless steel tank or even an aluminum one.
The Dewar tank considered for the ZEROe application is a vacuum insulated tank as illustrated in Figure 2. It is made of two skins, an inner vessel containing the hydrogen and an outer jacket surrounding it. Between those two skins the vacuum combined with an insulation layer ensures the insulation of the tank and maintains its cryogenic temperature. To guarantee the tightness and insulation stability during the life of the tank, the composite materials selected need to prevent any leak of H2, prevent any degradation of the vacuum and maintain this at cryogenic conditions during the life of the aircraft. This configuration differs from the cryogenic composite tanks considered for space applications and presents new challenges.
The work presented provides an overview of the architecture of the LH2 composite tank and the main challenges identified for an aeronautic application. Among those, a focus will be given to two key phenomena. First, the mismatch of the properties, especially of thermal expansion, between the fibers and the matrix of the composite and the reduced strain at failure of the resins at low temperatures can generate cracks in our materials [2]. Those cracks can percolate and create a leak pathway which cannot be tolerated for our application. Secondly, composite materials are prone to outgassing and higher permeation than metallic materials [3], which can jeopardize the vacuum insulation of the tank. The development of a cryogenic composite tank for aeronautic applications requires the understanding of the multi-physical phenomena involved to identify promising materials. The current state of the art on composite material testing and sizing methods will need to be revisited according to those findings. The work presented provides an insight into the key characteristics and test developments needed for the maturation of the composite LH2 tank. It concludes on development and collaboration needs within the composite community.
The complex architecture of such a tank involves a consequent weight that challenges the performance of the aircraft. Composite materials are a great opportunity to reduce the gravimetric index of such a tank. However, the maturity of cryogenic composite tanks is much lower than a stainless steel tank or even an aluminum one.
The Dewar tank considered for the ZEROe application is a vacuum insulated tank as illustrated in Figure 2. It is made of two skins, an inner vessel containing the hydrogen and an outer jacket surrounding it. Between those two skins the vacuum combined with an insulation layer ensures the insulation of the tank and maintains its cryogenic temperature. To guarantee the tightness and insulation stability during the life of the tank, the composite materials selected need to prevent any leak of H2, prevent any degradation of the vacuum and maintain this at cryogenic conditions during the life of the aircraft. This configuration differs from the cryogenic composite tanks considered for space applications and presents new challenges.
The work presented provides an overview of the architecture of the LH2 composite tank and the main challenges identified for an aeronautic application. Among those, a focus will be given to two key phenomena. First, the mismatch of the properties, especially of thermal expansion, between the fibers and the matrix of the composite and the reduced strain at failure of the resins at low temperatures can generate cracks in our materials [2]. Those cracks can percolate and create a leak pathway which cannot be tolerated for our application. Secondly, composite materials are prone to outgassing and higher permeation than metallic materials [3], which can jeopardize the vacuum insulation of the tank. The development of a cryogenic composite tank for aeronautic applications requires the understanding of the multi-physical phenomena involved to identify promising materials. The current state of the art on composite material testing and sizing methods will need to be revisited according to those findings. The work presented provides an insight into the key characteristics and test developments needed for the maturation of the composite LH2 tank. It concludes on development and collaboration needs within the composite community.