Icebreaker fuel tank size

Discussion in 'Boat Design' started by Brynjaminjones, Mar 16, 2015.

  1. Brynjaminjones
    Joined: Mar 2014
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    Location: Cornwall/Plymouth, England

    Brynjaminjones Junior Member

    Hi all,
    I've not been on this forum much before, so I hope you don't mind me jumping straight on in with a question.

    I'm in my final year of a marine engineering/naval architecture degree, and we've been tasked with designing an icebreaker.
    We're nearing the end now, but I've got to figure out how big the fuel tanks need to be.

    This ship needs a range of 24,000 nautical miles, and max. power is roughly 46,000kW.
    With these figures the fuel requirement seems astronomical, so I'm wondering if you guys could guide me in the right direction as to what the accepted way to calculate the fuel requirement is?
     
  2. TANSL
    Joined: Sep 2011
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    TANSL Senior Member

    24000 nm is enough to go around the earth without refueling. I do not think any ship, even as a theoretical exercise, can have that autonomy.
    Beyond that, the procedure is to relate all fuel-burning equipment (perhaps main engines are the least consuming), ask the manufacturer of the equipment consumption data, and adding. Many of these equipments will be consuming even is the boat is stationary.
     
  3. Brynjaminjones
    Joined: Mar 2014
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    Brynjaminjones Junior Member

    Thank you, I've got all of the manufacturer's fuel consumption information, but have discovered that at cruising speed the required power is actually only 9300kW, which gives us a much more feasible fuel requirement.
     
  4. gonzo
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    gonzo Senior Member

    Is your consumption about 2400 l/hr?
     
  5. Brynjaminjones
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    Brynjaminjones Junior Member

    I've got it about 1650 l/hr at the moment
     
  6. gonzo
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    gonzo Senior Member

    What is the consumption per Kw?
     
  7. TANSL
    Joined: Sep 2011
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    TANSL Senior Member

    A modern engine can consume something like 240 gr / kw-h (I know the motor catalog give a lower figure) but that's only part of the total consumption of the ship. Talk about what consumption per kw no sense because you have to take into account the hours of operation.
    The hours of operation of the main engine, for example, are not the same as the air conditioner equipment.
    To calculate the autonomy not only to count the main engine consumption but must take into account the power system is working (very variable in an icebreaker), and several other things.
     
  8. gonzo
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    gonzo Senior Member

    Thus my estimate of about 2400 l/hr
     

  9. TANSL
    Joined: Sep 2011
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    TANSL Senior Member

    Maybe you're right, Gonzo, I do not care. What I mean is that, with this data, he has only one part of the data needed to calculate the volume of the tanks.
     
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