Simulation of boil-off losses during transfer at a LH2 based hydrogen refueling station

Petitpas's model ignores the insulation in the energy balance and assumes a constant rate of heat ingress into the tank.

“This model ignores the insulation in the energy balance, instead assuming a constant rate of heat ingress into the tank; 50 W was found to yield the closest estimate to the experimental data.”

Tools that can accurately estimate BOG production are particularly important in the context of industrial-scale LH2 storage, as the capital expense to design and implement such systems is large, and experimental testing at a relevant pilot-scale can be cost-prohibitive with the results obtained making it difficult to translate to full-scale if their description is entirely empirical.

“Tools that can accurately estimate BOG production are particularly important in the context of industrial-scale LH 2 storage, as the capital expense to design and implement such systems is large, and experimental testing at a relevant pilot-scale can be cost-prohibitive with the results obtained making it difficult to translate to full-scale if their description is entirely empirical [27,28].”

In the work of Petitpas, a 12.5 m3 LH2 Dewar tank with a 2 m internal diameter at the Lawrence Livermore Cryogenic Hydrogen Test Facility was subjected to ambient heat ingress to measure the change in liquid volume over summer versus winter.

“In the work of Petitpas [27], a 12.5 m 3 LH 2 Dewar tank with a 2 m internal diameter at the Lawrence Livermore Cryogenic Hydrogen Test Facility was subjected to ambient heat ingress to measure the change in liquid volume over summer versus winter.”

U_VL = 0.15 W/m2/K was chosen for the model because it best matched the vapor temperature data reported by Petitpas.

“A vapor-liquid heat transfer coefficient, U VL = 0.15 W/m 2 /K was chosen as this best matched the vapor temperature data reported by Petitpas [27].”

Throughout the Petitpas experiment, the system remained static, meaning no mass transfer across the system boundary occurred.

“Throughout the experiment, the system remained 'static', meaning no mass transfer across the system boundary (such as refuelling) occurred.”

Petitpas presented a model to estimate the boil-off losses based on their experimental data.

“Petitpas also presented a model to estimate the boil-off losses based on their experimental data.”

In Petitpas's model, 50 W was found to yield the closest estimate to the experimental data.

“This model ignores the insulation in the energy balance, instead assuming a constant rate of heat ingress into the tank; 50 W was found to yield the closest estimate to the experimental data.”