Gaseous hydrogen and hydrogen blends. Land vehicle fuel tanks

Steel pressure vessels are commonly used for the transport of pressurized gases, including gaseous hydrogen. In the majority of cases, these transport cylinders experience relatively few pressure cycles over their lifetime, perhaps as many as 25 per year, and generally significantly less. For fueling applications, as in fuel tanks on hydrogen-powered industrial trucks, the hydrogen fuel systems may experience thousands of cycles over their lifetime. Similarly, it can be anticipated that the use of tube trailers for large-scale distribution of gaseous hydrogen will require lifetimes of thousands of pressure cycles. This study investigates the fatigue life of steel pressure vessels that are similar to transport cylinders by subjecting full-scale vessels to pressure cycles with gaseous hydrogen between nominal pressure of 3 and 44 MPa. In addition to pressure cycling of vessels that are similar to those in service, engineered defects were machined on the inside of several pressure vessels to simulate manufacturing defects and to initiate failure after relatively low number of cycles. Failure was not observed in as-manufactured vessels with more than 55,000 pressure cycles, nor in vessels with relatively small, engineered defects subjected to more than 40,000 cycles. Large engineered defects (with depth greater than 5% of the wall thickness) resulted in failure after 8,000 to 15,000 pressure cycles. Defects machined to depths less than 5% wall thickness did not induce failures. Four pressure vessel failures were observed during the course of this project and, in all cases, failure occurred by leak before burst. The performance of the tested vessels is compared to two design approaches: fracture mechanics design approach and traditional fatigue analysis design approach. The results from this work have been used as the basis for the design rules for Type 1 fuel tanks in the standard entitled “Compressed Hydrogen-Powered Industrial Truck, On-board Fuel Storage and Handling Components (HPIT1)” from CSA America.

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Fatigue Properties of Liner Materials Used for 35MPa-Class On-Board Hydrogen Fuel Tanks

Volume 6: Materials and Fabrication ◽

10.1115/pvp2005-71735 ◽

2005 ◽

Cited By ~ 1

Author(s):

Shinichi Ohmiya ◽

Hideki Fujii

Keyword(s):

Stainless Steel ◽

Aluminum Alloy ◽

Fuel Cell ◽

Room Temperature ◽

Gaseous Hydrogen ◽

Fatigue Properties ◽

Fuel Cell Vehicles ◽

Hydrogen Fuel ◽

Fuel Tanks ◽

Materials Used

To evaluate mechanical properties of the materials used for hydrogen systems such as fuel cell vehicles and hydrogen fuel stations, mechanical testing facilities in gaseous hydrogen at up to 45MPa pressure were newly designed and installed, and fatigue properties, which is one of the key properties for the onboard fuel tanks in the fuel cell vehicles, were actually evaluated for two kinds of liner materials of the on-board CFRP fuel tanks; AA6061-T6 aluminum alloy and 316L type of austenitic stainless steel. Axial S-N fatigue tests (R = −1) were conducted in air and also in gaseous hydrogen at 45MPa pressure at room temperature, and quite similar S-N curves were obtained in both circumstances within the maximum number of cycles to failure of 105 for AA6061-T6. 316L also exhibited excellent fatigue life and was not fractured with maximum applied stress of 90% of 0.2% proof stress at 105 cysles. Clear difference was not observed in fatigue crack growth rate in each material regardless of the circumstances investigated in this study including hydrogen gas at 45MPa pressure. Those results indicate that fatigue properties are not affected by gaseous hydrogen at around room temperature in both AA6061-T6 aluminum alloy and 316L type of stainless steel, and that both materials can fully be employed to the liner of the 35MPa on-board hydrogen fuel tanks from the viewpoints of fatigue properties.

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