Are FCVs safe? What if they catch fire?

Discussion in 'Fuel Cell Vehicles' started by GrumpyCabbie, Feb 5, 2015.

  1. GrumpyCabbie

    GrumpyCabbie Senior Member

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    I ask this question seriously.

    Are FCVs safe? With the introduction of more and more fuel cell vehicles into the market, even in small numbers, I ask what happens to the 10,000 psi tank in the event of a fire?

    It's all well saying it should hold until the fire is extinguished, but some cars can burn for hours such as stolen vehicles dumped miles from anywhere or even a lit vehicle in a riot. What happens to that 10,000 psi tank? It'll be straining away already holding a full supply of hydrogen let alone when the car is white hot after some miscreant has set it on fire.

    So how does the hydrogen tank stop itself from blowing up? Does it vent? What are the dangers? Will it have to be left completely alone for two or three days to cool down? Will it just split and go bang? If it does go pop will it just affect the immediate area like a petrol car or will it take out all the windows for half a mile?

    If your new Mirai or Hyundai FCV had been parked in the middle of this;
    [​IMG]
    Would the image be the same or would there be a large crater with all the windows of that building blow out?

    Or is this one for MythBusters?
     
  2. catgic

    catgic Mastr & Commandr Hybrid Guru

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  3. GrumpyCabbie

    GrumpyCabbie Senior Member

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    That was a canvas ballon not a 10,000 psi pressure vessel. How would a FCV car react in a white hot fire? I can't imagine it would just slowly burn like the Hindenburg, but more an explosion.

    I'm only guessing. Does anyone knowledgeable in such matters know what would happen in a white hot fire?
     
  4. catgic

    catgic Mastr & Commandr Hybrid Guru

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    GrumpyCabbie - Hydrogen and Fuel Cell Safety
     
  5. bisco

    bisco cookie crumbler

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    the article contains no relevant information. but i have to think some serious testing has been done. i hope.:eek: if i were going to set a fuel cell on fire to watch what happened, i think it would be in on a pacific atoll.
     
  6. wjtracy

    wjtracy Senior Member

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    Here are the 2 experiments you want to do:
    (1) Fill a balloon with H2 (or methane), light it with a spark...small fire.
    (2) Fill a balloon with H2 (or methane) and say 80% air, light it with a spark...you get a extremely powerful explosion known as a "detonation".

    H2 is not to be taken lightly on safety, but to suggest it is enormously more hazardous than a tank full of gaso or nat gas already is, is probably not warranted. Here at the DC auto show, Toyota was on the radio touting FCV as a safe way to power your house in elec loss emergency. They said you could keep the FCV in your garage with the garage door closed (no fumes, CO).

    H2 has a couple diffferences to be aware of...of course rapidly rises in air. Fairly easy to catch fire via spark etc. Fairly wide explosive limits in air. But my understanding the H2 fuel tanks are very expensive due to all the engineering, so we must assume the engineering has been taken very seriously. Maybe if we gave regular gaso cars the same safety level, we could not afford them either!
     
  7. The Electric Me

    The Electric Me Go Speed Go!

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    I also have to believe that automakers have tested and taken into account the greatest risks of fire or ignition in relationship to how the tank would react.

    And my exhaustive years of research and training coming from marathon spans of watching numerous "Myth Buster" episodes has taught me that usually the reality is that things you think would be "easy" to make explode....are actually very difficult, and vice versa, sometimes you find out that powdered Non-Dairy Creamer creates a devastating fire ball.

    Are Fuel Cell Vehicles Safe? Or is "This vehicle safe?" Has got to be a fundamental question any automaker hoping to introduce a fuel cell vehicle to the public market must answer.

    For an automaker the answer can not be "It's as safe as Non-Dairy Creamer".
     
  8. GregP507

    GregP507 Senior Member

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    Any vehicle can catch fire, but it won't be certified as roadworthy if it's unsafe.
     
  9. GrumpyCabbie

    GrumpyCabbie Senior Member

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    It's not if the vehicle will catch fire - some do. It's what happens when some oick sets fire to your vehicle or if your vehicle catches fire due to some other outside source - as can happen.

    Rather than assuming a car has safety features to stop a fire in the first place I'm pondering on what happens when it is on fire. I've seen a petrol car on fire and they burn rather nicely and maybe pop a little when the tank goes. I've also seen news reports of lpg cylinders on fire and they're a whole different matter.

    What happens to a 10,000 psi tank in a white hot car fire that's been burning for twenty minutes? It's all well saying the tank will hold for 30 minutes or 60 minutes, but there are times when such fires go on for longer;


    [​IMG]

    This ferry burnt after a fire occured in the car deck. Would it still be afloat if one of those cars had been a FCV?

    Nobody is answering, so my money is on the tank giving way after 60 minutes of heat and leaving a large crater in the ground, or in the case of that ferry, a large hole in it's side :)
     
  10. The Electric Me

    The Electric Me Go Speed Go!

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    Well I'll concede that I can't know exactly what might happen to a fuel cell vehicle under any hypothetical heat/fire scenario. I mean, I haven't designed the tank nor do I have access to a testing facility.

    But I think what you are alluding to with your query is the concept or question..will fuel cell vehicles be "safe"?

    Without putting my money down on any bet, I have to think that standards are being met, and will be met that makes the vehicle safe in the vast majority of potential situations it is likely to encounter, including fire and impact. To NOT meet these standards would be devastating to the whole industry and fuel cell vehicles as a whole.

    If ferrys start sinking like stones, and parking lots suddenly cratered as a result of Fuel Cell Vehicles...I'll be glad I didn't bet you.
     
  11. GrumpyCabbie

    GrumpyCabbie Senior Member

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    I just think it's an unanswered question. What happens to a 10,000 psi hydrogen tank in a fire?

    Maybe the insurance industry will be the deciding factor. If they're happy then no issues getting cover. If they're not, expect problems. They'll be the ones paying out for either minor or significant damage.
     
  12. GregP507

    GregP507 Senior Member

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    I believe most fuel caps nowadays are plastic, therefore a fire would melt it off before enough pressure could build up in the fuel tank to cause an explosion.
     
  13. wjtracy

    wjtracy Senior Member

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    I tried to answer the question. The full H2 tank could be a fire, but not really a big explosion. That ship might not have caught fire. If however somehow there was an H2 leak that became mixed with air, say in a room with no ventilation, that could be an extraordinarily powerful explosion if it ignited. It the same as natural gas. I believe there is some question if nat gas vehicles should park in parking garages. TWA Flight 800 was thought be detonation of air/fuel vapor mix in the tank vapor space...same idea.
     
    #13 wjtracy, Feb 5, 2015
    Last edited: Feb 5, 2015
    GrumpyCabbie likes this.
  14. bisco

    bisco cookie crumbler

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    insurance industry won't help. they don't care if a few people get blown to smithereens, it's a numbers game.
     
  15. GrumpyCabbie

    GrumpyCabbie Senior Member

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    You have liability coverage on your policies?

    How much do they pay out for third party property damage? Here it's a minimum of £20m ($30m) liability coverage for non commercial policies. I guess if your insurer has a limit of £500k, then they won't care if the car takes out a neighbourhood. If it's £20m, they might.
     
  16. GrumpyCabbie

    GrumpyCabbie Senior Member

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    Sounds similar to the lpg vehicles we have at the moment. They're banned from many underground carparks/lots, tunnels, ferries, probably for the reasons you've given.

    So the concern isn't the 10,000 psi tank going pop but more a leak in a confined space. Would the gas smell? Will they add a smell to the gas so people would be aware of it? Or could you get the lift down to your works underground carpark at the end of the day, turn the key and take out the building?
     
  17. usbseawolf2000

    usbseawolf2000 HSD PhD

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  18. GrumpyCabbie

    GrumpyCabbie Senior Member

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    Hmmm comparing real world against a controlled fire isn't totally fair. The following is a lpg car that had an small, undetected leak.

    [​IMG]


    Maybe MythBusters should set fire to one for their next show?
     
  19. GregP507

    GregP507 Senior Member

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    Does anyone doubt that if gasoline were introduced nowadays, it wouldn't stand a chance of being certified?
     
  20. wjtracy

    wjtracy Senior Member

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    No natural smell...nat gas sometimes they add mercaptans for smell. But combustible gas meters can detect. Probably we see more combination gas detectors (CO, Combustibles. CO2, O2) in homes and businesses. Needed anyway for nat gas. Engineering controls such as ventilation.

    They say H2 is little more easy to catch on fire...if you have a leak it will be more prone to ignite. Also the flame can be hard to see in daylight, as shown in USB's photos above (at night you can see it better).
     
    #20 wjtracy, Feb 6, 2015
    Last edited: Feb 6, 2015