Cryo-compressed vessels have many advantages in storing hydrogen for automotive applications because of large storing density and thermal endurance. However, the cooling power of venting hydrogen in the processes of dormancy and discharge is not fully utilized. A throttling valve can be used to recycle the cooling power. A thermodynamic model is established to analyze the behavior of hydrogen in the insulated pressure vessel with a throttling valve. Different initial pressures and release pressures of hydrogen in the vessel are studied in the processes of dormancy, discharge and driving. The dormancy can be extended 55% with a throttling valve in the vessels of 2 MPa release pressure. The cooling capacity of the throttling valve decreases with the increase of the initial pressure. Simulations of hydrogen storage during the actual driving are performed at different initial pressures. The throttling valve in the lowinitial- pressure vessel can reduce the upper pressure limit of the vessel by 50% which reduces the manufacturing costs obviously. This work introduces the great potential of the throttling valve in the vessel for automotive applications.
Keywords cro-compressed hydrogen, throttling valve, hydrogen storage, dormancy