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Water water everywhere

  1. May 13, 2010 #1
    I have alot of ideas. Water is an amazing substance and there is no way we could live with out it.

    but with all these ideas i search on the web everywhere can cannot find the answers i desire.

    so heres your questions. have fun answering them.

    1. with pressure and heat combined at what cc compression and F degree does water turn to steam instantly?

    2. whats the expansion ratio of water turning to steam in volume?

    3. hydrogen alone has been considered "unpredictable" during ignition, what about a stiometric(sp?) mixture? is it always stable?

    4. why can hydrogen and oxygen exist together as gases but when ignited turn into water? is it like the same thing as nuclear fusion only on a very smaller scale?

    i have many more questions but the main reason for all these questions is because i want to make a "super" engine. something that will produce an insane amount of power, electricity, thrust, ect.. without any disasterous outcomes (or else i would be using tritium and uranium =p)

    anywho. final conclusion. i want to go really really fast. fly. without paying a cent for gas because water is renewable. i've experimented with magnetism as well but i dont understand all the aspects about that as well.
     
  2. jcsd
  3. May 13, 2010 #2

    russ_watters

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    Staff: Mentor

    Welcome to PF.

    1. What is "cc compression"? A certain fraction of water will flash to steam if the water is discharged to atmosphere from a certain pressure. Here's a graph: http://www.engineeringtoolbox.com/docs/documents/262/flash-steam-diagram.png

    2. It's the ratio of specific volumes in a steam table: http://www.efunda.com/materials/water/steamtable_sat.cfm

    3. A stoichiometric mixture is ready to explode with the smallest spark.

    4. It almost seems like you think steam is a stoichiometric mixture of separate gases. It isn't. Steam is still H2O. And no, burning hydrogen and oxygen isn't like fusion. Hydrogen just burns and water is the waste product of that combustion, that's all. Similarly, burning carbon yields CO2:
    H2 + .5O2 => H2O + Energy
    C + O2 => CO2 + Energy

    For your final conclusion, I think you misunderstand something: water isn't a fuel, it is a waste product of combustion. It's the ash that's left over after you burn hydrogen and oxygen.
     
  4. May 13, 2010 #3
    yea but to make hydrogen you gotta get is from water ash right? anywho do you know anything that will make a crap ton of power? like the idea of using deuterium alone in nuclear fusion and yielding up to 70 megawatts of electricity tickles me to death, too bad we cant reach the temperature required to do so. any ideas that wont radioactively corrupt me or constantly eat away at my wallet?
     
  5. May 13, 2010 #4

    russ_watters

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    Right, but since it is already burned, you have to unburn it - which requires putting in exactly the same amount of energy as you get back when you burn it. So hydrogen isn't really a fuel source, but an energy carrier like a battery.
    A bunch of ways, yes...
    Sorry, no. If it were easy, everyone would already be doing it.
     
  6. May 14, 2010 #5
    If you desperately want to do a fuel in the 'good life' way, it has to be biodiesel. It's about the only thing the man on the street can do cost effectively. Or use compressed biogas if you have a lot of cows near you and don't mind collecting their digestive excretions.

    As Russ said neither water nor hydrogen are fuels. They can be used as energy carriers, ie you can 'charge' them up by putting energy into them to extract energy later. Unfortunately there is no cheap way of doing this.
     
  7. May 16, 2010 #6
    omg. i was trying to making hydrogen today... i was using a 760w wire plugged into my house outlet. i put the pos an neg in the water and steady sparks started appearing off the surface. like a tiny little flame on each wire. i accidently sneezed and suddenly i heard a loud BOOM and when i opened my eyes all i saw was white and purple light. as the light faded i looked down and saw water everywhere and glass fragments everywhere.

    did i seriously just make water explode? i'm not trying to sound stupid, but for real what the flip just happened?
     
  8. May 16, 2010 #7
    and no i dont really care for "green fuel" i'm getting a pretty good vibe that magnetism is the way to go with all this. i would use nuclear but fer real theres way too much prep and clean up for a reactor to be portable.
     
  9. May 16, 2010 #8
    How would magnetism help?
     
  10. May 16, 2010 #9
    You didn't get the reference :). The Good Life was a sitcom in the 70s, about some people who have the goal of becoming self sufficient, who live next door to some snooty posh people. Doing things in a good life kind of way, means self sufficiency.

    Magnets, aren't magic. They don't produce power, they don't even transmit it that well. I'm sorry but this is one of my pet peeves, people think magnets somehow don't follow the basic laws of physics we apply to everything else becuase they have no physical connection. I'm not having a go at you, it just really winds me up, I don't even know why.


    I'm talking purely from a cost benefit, 'grow your own diesel' it's te only cost effective way to make your own fuel.
     
  11. May 16, 2010 #10
    Jesus, this above is really the reason why people who shouldn't know what they are doing should really NOT attempt things without finding the consequences first.

    1- you either created a short as water is conductive that caused heating of the water causing cold glass to break. - This is pretty unlikely as 760W is less than the element in a kettle. However as you just jammed electricity into a galss of water you create sparks.

    2- you DID indeed create hydrogen. And this is a perfect example as to how dangerous sticking an electrde in water is. The sparks of electricity combusted the H2 causing the water to go everywhere and shards of glass to shower the room. This is the most likely option.


    You really neeed to be more careful. Acutally think about what could happen beofre you do it. Would you wave a lighter around a vapoursised petrol air mixture? You are making a gas what will readily combust with air, and people can and havedied doing this.
     
  12. May 16, 2010 #11
    magnets dnt produce power indeed. but they could emit thrust=] i took an electromagnet i made and connected it to a 4in. iron boat motor propeller using an aluminum pipe as a bearing. there are no bearings or oil but when i plugged in the juice the magnet made sometime of polarity (idk N or S) and the propeller rotated, i dont know an exact measurement but it was a little over a second for every rotation. so i'm thinkin, with more electromagnetic force this could produce more thrust. i think a tesla coil could come in handy for something like this=]
     
  13. May 16, 2010 #12
    ...i'm sorry it was fun..=[ but back to the hydrogen. if that little amount of hydrogen made a glass cup explode that means it creates pressure right? petrol engines are just one big vaccuum machine with a spark plug and gas to put pressure on the cylinder to move. so wouldnt hydrogen do the same thing as gasoline?
     
  14. May 16, 2010 #13
    idk the biodiesel involves lye and other harmful chemicals, plus it takes 3-4 days to produce it which would only be about 8 gallons at a time unless i use my garage as a diesel factory. plus dont you need vegetable oil or animal oil? isnt that expensive in amount? plus the whole seperating the glycerin from the diesel sounds dangerous if its not fully extracted. idk its a great idea if it were mass produced by companies. deff be a smarter choice than scarring the earth.
     
  15. May 17, 2010 #14

    russ_watters

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    Staff: Mentor

    Yes, you can make an internal combustion engine run on hydrogen.
     
  16. May 17, 2010 #15
    There are basically 'home brew' kits you can just buy. It's simply the cheapest way to make your own fuel. It's expensive, but less so that getting something to produce, store and then run on hydrogen. As you can't just stick H2 in a standard engine, it will detonate and kill the engine if done unmodified. Not only that it doesn't provide the same lubrication as petrol so you get problems like valve seat recession meaning frequent rebuilds. Homegrown biodiesel can go straight in without any enigne modification, or the most you have to do is use different seals.

    Frankly the cheapest way to run your car is to buy fuel from the pump. Unless you went into big time production (and I mean a full sized refinery) it's simply more expensive to do things small scale. Trying to make your own fuel to same money, really is spending a pound to save a penny. It's a false economy.

    But for gods sake, next time you want to produce H2, use a heavily insulated wire above the water surface, you basically want nothing that will create a spark. Also use a vent to take the H2 away, or at least do it in a very well ventilated area and don't use a glass jar.
     
  17. May 18, 2010 #16
    House outlets do not have negative and positive wires they are connected to ac not dc. In the fire service this type of behavior is known as job security.:wink:
     
  18. May 18, 2010 #17
    Please do not do that again.
     
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