To achieve rapid filling of 35 MPa on-board hydrogen cylinders, a 130 L two-dimensional axisymmetric model was constructed, and Fluent was used to simulate the coupled changes of temperature and pressure inside the cylinder during stepwise filling. The results show that the higher the precooling temperature, the higher the final temperature of the cylinder. Therefore, -40℃ was determined as the precooling temperature in accordance with the SAE J2601 standard. Under the conditions of initial pressure 2 MPa, initial temperature 20℃, and precooling temperature -40℃, the final temperature exceeds 85℃ when filling at a constant flow rate of 0.3 kg/s. In contrast, the "three-stage equal-flow filling" strategy (0.3, 0.2, 0.1 kg/s) can stably control the peak temperature of hydrogen inside the cylinder at 80℃ (below the 85℃ limit) and complete full filling in only 112 seconds, resolving the conflict between rapid filling and safe temperature control. This strategy can reduce operating costs, accelerate popularization, drive industrial chain development and cost reduction, and inject impetus into the sustainable development of the hydrogen energy economy.
 

Stepwise filling, Fluent,Hydrogen,On-board hydrogen cylinder