• Roger Penn

    Member
    October 13, 2022 at 12:09

    The leakage rate through the tank is very low. There may be other leaks in the system (valves, connections, etc.), but the tank itself is designed with extremely low leak rates (especially with hydrogen being such a small molecule that it tends to escape easily). No noticeable difference over a weekend, saw a calculation that showed it would take ~75 years to lose the hydrogen in a tank due to permeation. The more likely source of a loss of H2 is at the connection from the tank to the rest of the H2 delivery system (high pressure) where there have been detectable leaks.

    • Andreas Lubitz

      Member
      October 13, 2022 at 12:46

      Thank you Roger for sharing your experience. Would you be able to share the source for the figure of ~75 years? Is this for carbon fibre laminated tanks or steel or aluminum tanks?
      Do you have any exprience with existing systems (not just tanks) in vehicles? (not sationary applications)

  • Roger Penn

    Member
    November 15, 2022 at 16:12

    Hi Andreas,

    Estimate of ~75 years was for a Type IV tank. Past experience had H2 sensors near the tank system, but was mostly a risk of leak at the connection (boss) to the fuel delivery system, not because of permeation through the liner or carbon fiber.

  • Carl Whyman

    Member
    January 18, 2023 at 15:22

    I have not noticed any measurable loss in any of the Type 3 tanks that I use.

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