A double-wall CFPR hydrogen storage and distribution system as a structural component in aircraft applications
Topic(s) : Material and Structural Behavior - Simulation & Testing
Co-authors :
Nithya SINDHE NARAYANA RAO (GERMANY), Ulrich BLASS (GERMANY), Thomas PFAFF , Uwe SCHMITT , Thomas / Nicole VINAY NAGARAJ / MOTSCH-EICHMANN (GERMANY), Joachim HAUSMANN (GERMANY)Abstract :
The storage and distribution of hydrogen in aircraft can only be operated efficiently if lightweight construction methods are available, e.g., based on fiber-reinforced plastic (FRP) composites manufactured in efficient production processes. The conventional ‘Type 4’ pressure vessels are produced by winding the fiber reinforcement over a liner (plastic or metal). The manufacturing by the winding process poses significant limitations with regard to the geometry. A cylindrical Type 4 vessel cannot be manufactured arbitrarily small in diameter since the fibers must be wound over a turning zone at the dome area of the pressure vessel to integrate the load introduction elements (metallic bosses or fittings). It is essential to maintain a certain winding angle to realize the dome area; therefore, the fibers in the vessel cannot be oriented in a purely axial direction. If it is possible to produce lightweight pressure vessels with an almost freely selectable diameter and length in an economical process with purely axial layers in addition to the circumferential layers, they can also be used as structural load-bearing components in the aircraft. The CFRP hydrogen pipelines and tanks can be used as structural members in the fuselage (for example, as floor beam struts) or in the wing (for example, as spars). To increase the volumetric storage density, hydrogen can be stored at cryogenic temperatures as liquid hydrogen (LH2) or cryo-compressed hydrogen (CcH2). The main challenge in such vessel construction is therefore the ability to maintain hydrogen at cryogenic temperatures (-252°C).
A concept is presented for a pipeline designed for hydrogen distribution, both LH2 and CcH2, which overcomes the above challenges and disadvantages. In order to keep the hydrogen at the necessary low temperatures, the pipeline is made of a double-wall CFRP construction, as shown in Figure 1. The inner pressure tube is used to store the hydrogen and absorb the internal pressure. The outer shell provides the thermal insulation and the connection to surrounding systems. The working principle of ‘IVW Load Introduction’, patented at IVW, is used to transfer loads from the cylindrical area of the outer shell to the dome or fittings.
Figure 1: A double wall mechanically decoupled hydrogen distribution/storage system, as a structural component for example in aircraft wing.
The inner pressure vessel and outer shell are largely mechanically decoupled by an effective suspension system concept developed at IVW. As a result, the tank and pipeline can be designed as structural load-bearing components, and thus substitute the existing components for stiffening in aircrafts in the future.
A concept is presented for a pipeline designed for hydrogen distribution, both LH2 and CcH2, which overcomes the above challenges and disadvantages. In order to keep the hydrogen at the necessary low temperatures, the pipeline is made of a double-wall CFRP construction, as shown in Figure 1. The inner pressure tube is used to store the hydrogen and absorb the internal pressure. The outer shell provides the thermal insulation and the connection to surrounding systems. The working principle of ‘IVW Load Introduction’, patented at IVW, is used to transfer loads from the cylindrical area of the outer shell to the dome or fittings.
Figure 1: A double wall mechanically decoupled hydrogen distribution/storage system, as a structural component for example in aircraft wing.
The inner pressure vessel and outer shell are largely mechanically decoupled by an effective suspension system concept developed at IVW. As a result, the tank and pipeline can be designed as structural load-bearing components, and thus substitute the existing components for stiffening in aircrafts in the future.