Integration and Design of Cryogenic Hydrogen Fuel Systems for Sustainable Commercial Aviation

Abstract

The transition to hydrogen-powered aircraft offers an opportunity to significantly reduce carbon emissions in commercial aviation. The use of renewable hydrogen in commercial aviation has the potential to significantly reduce the carbon footprint of the industry. Aviation currently accounts for around 3% of global carbon emissions, a figure that is projected to grow without the adoption of sustainable fuels like hydrogen [1]. Hydrogen can be stored as a compressed gas at high pressure and as a liquid at cryogenic temperatures. However, the unique properties of hydrogen, particularly its low density and cryogenic storage requirements need a complete redesign of aircraft fuel systems. The low density of hydrogen necessitates larger storage volumes compared to conventional fuels, and cryogenic storage requires maintaining extremely low temperatures to prevent boil-off, which can lead to significant fuel loss [2]. This research aims to develop innovative fuel system designs that can efficiently store and deliver cryogenic liquid hydrogen. Numerous tank designs including cylindrical, spherical, and double-walled configurations will be explored. Cylindrical tanks are commonly used for high-pressure gas storage and must be designed to withstand pressure loads effectively. Spherical tanks offer a lower surface area-to-volume ratio, which is advantageous for reducing heat transfer and boil-off. Double-walled configurations provide additional insulation and structural integrity, essential for maintaining cryogenic temperatures [3]. Additionally, effective heat management is crucial in hydrogen fuel systems. The research will explore strategies to recover waste heat from fuel cells or combustion processes, which can be utilized to improve overall system efficiency. This is particularly important in preventing excessive boil-off in cryogenic tanks, which can lead to increased pressure and potential safety issues. By conceiving aircraft designs optimized for either direct liquid hydrogen combustion or fuel cell propulsion, this research aims to create sustainable aviation solutions. Furthermore, this study will develop a detailed thermodynamic model to simulate the behaviour of cryogenic hydrogen fuel systems under various operating conditions, including heat transfer, phase changes and boil-off effects. The goal is to optimize the design and operation of hydrogen fuel systems to achieve maximum efficiency and safety. The findings from this research aim to provide a comprehensive framework for the future of hydrogen-powered commercial aviation. By addressing the unique challenges of hydrogen storage and fuel system design, the study seeks to contribute to the development of sustainable aviation solutions that can significantly reduce the carbon footprint of the airline industry.