A plane is being designed that will be similar in size and range to a Boeing 787-800 that will run on hydrogen fuel. The hydrogen will be stored cryogenically as a liquid in external fuel tanks located on the wings. The fuel tanks require insulation to maintain cryogenic conditions and prevent excessive boiloff of hydrogen and pressure buildup within the fuel tanks. This report details a one-dimensional, steady-state analysis of the heat transfer across the tank structure to determine the relationship between the thickness of the insulation layer on the tank and the boiloff rate of the liquid hydrogen. Expanded Polystyrene (EPS) was determined to be the best insulation material, and at cruise conditions of 35,000 ft, required an insulation thickness of 3.97 inches and weight of 624 lbs per tank to maintain a boiloff rate below 50% of the idle fuel usage rate. At on-ground idle conditions on a hot day, EPS was found to require an insulation thickness 1.37 inches and weight of 191 lbs per tank to maintain a boiloff rate below 50% of the idle fuel usage rate.
Mechanical Engineering and Material Sciences Independent Study
Date of Submission
McFarland, Claire and Agarwal, Ramesh K., "A Simple Model of Thermal Insulation Design for Cryogenic Liquid Hydrogen Tank" (2022). Mechanical Engineering and Materials Science Independent Study. 176.