Dual Hull Design. Expertise Needed

Discussion in 'Powerboats' started by FreelanceBuild2, Jan 16, 2012.

  1. daiquiri
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    daiquiri Engineering and Design

    FreelanceBuild2, this is the basics of engineering: the energy to produce the hydrogen from water has to come from somewhere, some primary energy source. Hence, hydrogen is not a fuel - it is just a carrier, a mean of transportation of the energy from this primary source to the engine. The engine then converts the energy trapped in the hydrogen into a mechanical energy necessary to propel a vehicle or a vessel.

    The point is, to produce the hydrogen you will waste (dissipate) around 20-50% of the energy contained in your primary energy source, because of the conversion efficiency. It is not avoidable. So, for every 100% of the energy contained within hydrogen, you will have to spend from 130% to 200% of the energy contained in your primary energy source (solar energy, hydrocarbons or whatever). Read here for more info on that regard: http://en.wikipedia.org/wiki/Hydrogen_economy#Efficiency_as_an_automotive_fuel

    At this point, the question the others are probably (and me for sure) trying to ask you is: why do you want to waste all that energy for producing hydrogen? Why not using the energy from the primary source to directly feed the engine, thus increasing the energy efficiency up to two times?

    Cheers
     
  2. FreelanceBuild2
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    FreelanceBuild2 Junior Member

    well Gorden came home and i asked some questions and i have to change a few things. first thing id like to say is that we would filter the salt out of the water and then also the semi alternators would be to power the electronics and everything else not to power the fuel cells. all you need for that is a normal 12 volt battery and a normal alternator to charge the battery. and the reason the back seat is needed for converting a car engine is because of the fuel cell. for example a v6 engine would need to have a fuel cell the size of a coffee table to completely power the engine without other means of fuel. like gasoline.
     
  3. Richard Woods
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    Richard Woods Woods Designs

    I don't know how much salt water you will need per hour, but a watermaker uses a lot of power in itself. Getting the salt out of salt water isn't easy

    I assume you will try your small prototype project on a fresh water lake or river??

    Don't do too many (complicated) experiments at one time

    Richard Woods of Woods Designs

    www.sailingcatamarans.com
     
  4. FreelanceBuild2
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    FreelanceBuild2 Junior Member

    yes freshwater experiments first. and i guess if the power consumption needed to to separate the salt from the water is too much then it wont be completely free to go around the world and also you'd need space to store freshwater that wouldn't be needed if you could still separate the two and still power the engine. ive seen first hand that a hydrogen fuel cell can completely power a vehicle. the battery charges the cell which creates the hydrogen fuel mixture which runs the engine which runs the alternator which charges the battery. the jeep that was converted didnt need any other power source. power cells have come a long way since 2004. if the jeep can do it i dont see why the boat cant.
     
  5. FreelanceBuild2
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    FreelanceBuild2 Junior Member

    for the jeep with the fuel cell the size of a coffee table to run continuous for a week would only need enough water for one full fuel cell.
     
  6. DCockey
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    DCockey Senior Member

    Sounds like another one of those free energy from water ideas which have been discussed numerous times before here. You might want to do a search on the archives (Search button above) for threads on hydrogen and fuel cells.
     
  7. lumberjack_jeff
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    lumberjack_jeff Sawdust sweeper

    A hydrogen fuel cell oxidizes hydrogen (converts it to water) without burning, releasing the latent energy as electricity directly without the intermediate step of generating heat.

    You CAN NOT however, extract enough electricity from the fuel cell to electrolyze enough water to keep the fuel cell supplied with hydrogen and oxygen and especially not if you insert the inefficiency of converting the power to mechanical energy and back to electrical energy (through mechanically-driven alternator) first.

    If by "fuel cell" you mean a HHO, Oxyhydrogen or Brown's Gas generator, then the same law of thermodynamics bites again. It takes more energy to split the water molecules than you recover by recombining them (by burning).

    There's no free lunch.

    There are two possibilities here. Either you're explaining the idea poorly or your friend should get a refund on the cost of his "advanced engineering" degree.

    I'm all for experimentation, even experiments designed to prove what I've already learned from books. But it helps to read the books first.
     
  8. Richard Woods
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    Richard Woods Woods Designs

    Energy cannot be created or destroyed

    My understanding is that electric cars aren't any more efficient than ICE cars. However they are cheaper to run because power stations get charged so little (relatively) for their fuel

    Richard Woods of Woods Designs

    www.sailingcatamarans.com
     
  9. CatBuilder

    CatBuilder Previous Member

    Perpetual motion aside, I have one word to contribute:

    Trawler!

    You need a lot of weight carrying ability. A catamaran isn't going to cut it. Get a regular used trawler. On the plus side, you can hunt for one with an old engine that's about to go or a blown engine and find yourself a deal.
     
  10. FreelanceBuild2
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    FreelanceBuild2 Junior Member

    OK so mabie hes got it all wrong. what would be better? ive been doing some reading since i last got on. is there another way to separate the water by another power source other than gasoline, (which would be redundant)? i know that solar panels are very expensive so right now that is out of the question. any thoughts? wind? in all likeliness im thinking that this isnt going to happen.
     
  11. lumberjack_jeff
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    lumberjack_jeff Sawdust sweeper

    A sailboat is a wonderfully elegant way to harness the power of the elements. It is very possible to use the wind for propulsion, to generate electricity, and to make drinking water via windmill, solar panels and tow-behind generator.
    A well designed system may be able to generate and store enough energy to run a motor for docking.
    Call it an almost-free lunch.
     
  12. redreuben
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    redreuben redreuben

    The OP asked about hull design not a critique of his engine, that is for he and his partner to resolve. :D
    RR
     
  13. Mr Efficiency
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    Mr Efficiency Senior Member

    The obvious response, I think.
     
  14. FreelanceBuild2
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    FreelanceBuild2 Junior Member

    well does anyone have an example of a boat that has a wind turbine that doesn't look like its out of place, weird? because ill already have a sail on it in case of engine failure so i guess ill just use that as a primary source of propulsion. I don't want to just throw the hydrogen idea out the door but if running an electric engine instead is smarter and more efficient then that's what ill do
     

  15. FreelanceBuild2
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    FreelanceBuild2 Junior Member

    the hydrogen engine is just to get us out there. the dream is the boat. and before we build the boat we would get the money for the project by sponsorship from the engine designs and a working prototype. but even if the engine doesn't work i still have a backup plan to get the money. it only takes a lot longer to get there.
     
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