Dynamic reheating and self-pressurization strategy of cryo-compressed hydrogen supply system for fuel cell heavy trucks

Fuel cell heavy trucks present a pivotal means for road transportation decarbonization. Cryo-compressed hydrogen (CcH2) emerges as a promising solution for hydrogen storage due to its high energy capacity and low boil-off, making it well-suited for on-board storage. However, fluctuations in temperature and pressure can lead to challenges such as inadequate hydrogen flow during the supply process. To ensure efficient and stable supply, supplementary heat must be integrated into the system design. This work investigates the energy dynamics of the CcH2supply process and conducts dynamic reheating calculations accordingly. Initially, a thermodynamic model of the hydrogen supply process within the CcH2vessel is established based on the throttling process of the hydrogen supply system. Internal hydrogen temperature and pressure changes can be modelled and predicted in the step. Subsequently, an engineering thermodynamic model of the CcH2vessel is developed, considering factors such as the actual heat capacity of the hydrogen vessel and low-temperature heat exchange. The required heat flow of the system is determined. Finally, a dynamic reheating and self-pressurization strategy by partial gas reflux heat is proposed. This strategy discussed the required reflux heating of the system at varying hydrogen supply states and flow rates to achieve dynamic regulation of the hydrogen state. The results demonstrate that dynamic reheating and self-pressurization strategy stabilizes the hydrogen supply state, significantly improving hydrogen supply efficiency and utilization rates.