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10-22-2008, 10:38 AM
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#21
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Registered Member
Join Date: Oct 2008
Posts: 10
Country: United States
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I have a question as I do not completely know the answer.
Gasoline is a hydrocarbon only containing hydrogen and carbon and a few additives, when the combustion takes place, does any of the energy come from the the atoms of carbon reuniting with oxygen or nitrogen?
It seems to me that when 1 gallon weighing 6 pounds and has 5 pounds of its weight in carbon that only hydrogen combing with oxygen is the only energy supplied.
Is this why the efficiency of gasoline combusting is so low, and if i'm adding more hydrogen and oxygen to the combustion wouldn't this add to a greater efficiency in that combustion?
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10-22-2008, 11:09 AM
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#22
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Registered Member
Join Date: Apr 2008
Posts: 1,831
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holycow,
a big problem with all of these claims of HHO is that they site that hydrogen can be used as a fuel which is correct and has worked very well. honda actually has a hydrogen fuel cell vehicle.
the problem is that they are not putting in hydrogen. they are putting in hydrogen and oxygen. I have heard (I don't know for a fact) that the hydrogen in the mixture is not enough to burn the oxygen that is also in the mixture thus this adds oxygen to the end product making the computer think that your car is running lean. I am not that big into HHO so I don't know for sure (just wanted to reitterate that).
the concept that a lot of HHO guys work on is that hydrogen burns at a different rate than gasoline so you can run the mixture leaner without detonation or the problems associated with it.
here comes the bravery question:
are you willing to trust what other say and lean out the mixture on your car?
I want my car to run for a long time with no problems. that is why I am not even willing to try HHO on my car. there is the lack of gas logs from people that claim they are getting significant gains as well.
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10-22-2008, 11:46 AM
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#23
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Registered Member
Join Date: Apr 2008
Posts: 6,624
Country: United States
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Quote:
Originally Posted by Aquatron
Is this why the efficiency of gasoline combusting is so low, and if i'm adding more hydrogen and oxygen to the combustion wouldn't this add to a greater efficiency in that combustion?
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Is the efficiency of gasoline combustion low? I thought the lost efficiency was in harnessing that energy -- in the thermal and mechanical reactions, not the chemical reaction.
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10-22-2008, 11:55 AM
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#24
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Registered Member
Join Date: Apr 2008
Posts: 6,624
Country: United States
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Quote:
Originally Posted by BEEF
I have heard (I don't know for a fact) that the hydrogen in the mixture is not enough to burn the oxygen that is also in the mixture thus this adds oxygen to the end product making the computer think that your car is running lean. I am not that big into HHO so I don't know for sure (just wanted to reitterate that).
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I think that is a proposed explanation for why HHO isn't producing results when people try it. I don't think it's true. Just think about it...you do the opposite of burning when you split H 2O into HHO; so once you burn it, you're recombining it and releasing that energy which you stored in it. When you recombine it, the hydrogen atoms have to recombine with the oxygen atoms to form H 2O molecules again, thereby using up the oxygen that was brought in along with the hydrogen.
...or is it that in combustion chamber conditions, the hydrogen doesn't combine with oxygen the same, and you don't get water, instead getting HO and an extra H, or maybe something like H 3O 2 and an extra O for every two molecules made?
Or is my basic (VERY basic) chemistry knowledge failing me and splitting water isn't the opposite of burning hydrogen, and therefore burning hydrogen doesn't produce water? We are always told that burning hydrogen results in water, hence why a hydrogen (not HHO) car doesn't pollute (though, of course, whatever source of energy was used to make the hydrogen could pollute).
It's times like these that I wish I had paid attention to what was being taught in chemistry class.
(Now you say: Why, what was being taught? Then I say: I don't know, I didn't pay attention.)
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10-22-2008, 12:15 PM
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#25
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Registered Member
Join Date: Apr 2008
Posts: 1,831
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holycow,
that is a good question about what it actually combines to. I haven't heard of people having water coming out of their tailpipe or steam for that matter but maybe that is understood amongst the HHO crowd. that one I am not sure about.
also, I thought the inefficiency in the ICE (internal combustion engine) was a mixture of the thermal energy lost and the losses in transferring a linear motion to a rotary motion...and all the gearing with the transmission and differential.
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10-22-2008, 01:01 PM
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#26
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Registered Member
Join Date: Apr 2008
Posts: 6,624
Country: United States
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Well, how would they know if it's recombining to water? AFAIK, most HHO users use at most a few ounces of water per day...and it's hard to tell if there's any steam or water coming out of your tailpipe anyway, unless it's so much that it's leaving a cloud of steam (as it does on a cold morning anyway).
Regarding ineffiencies: Indeed, those inefficiencies are there, but again...none of those are combustion inefficiency.
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10-22-2008, 01:38 PM
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#27
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Registered Member
Join Date: Apr 2008
Posts: 1,831
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maybe the heat if you really wanted to stretch it.
and you are right, if water was coming out of the tailpipe it would be a very small amount so I'm not sure on that one.
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10-22-2008, 02:10 PM
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#28
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Join Date: Nov 2007
Posts: 1,111
Country: United States
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To me, combustion inefficiencies would come from things like having to spark the cylinder 30 degrees BTDC to burn the fuel on time as opposed to all of it instantly burning at 5-10 degrees ATDC (more like a diesel).
I imagine that if combustion efficiencies were improved that you would have more knock after HHO installation.
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10-22-2008, 02:30 PM
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#29
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Registered Member
Join Date: Jan 2006
Posts: 2,444
Country: United States
Location: Tiverton, RI
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Ok Aquatron - that solar panel is maybe going to keep up a little with your usage depending upon how many amps you use to make the HHO. If you do a lot of down hill with "no gas pedal" on your trip I would recommend switching in the deep cycle battery to the alternator and get some of that free energy converted to electricity and charge that 120ah battery when you are engine braking down the hills.
Depending upon where you inject the HHO will determine if the air flow sensor counts the extra gas coming in but you basically have a perfect combustion mixture being added to the air and fuel and I don't think the ECU will know what is going on other than the fuel will burn a little better because the HHO is going to ignite the droplets of gasoline better. Output of HHO is heat and water - output of gasoline which is composed of hydrocarbons hydrogen oxygen and carbon molecules combining with the oxygen and some of the nitrogen in the incoming air making CO2 CO and H2O along with NO2 and NO. By adding ethanol they/we add some oxygen and hydrogen molecules reducing the carbon content of the fuel a little thus reducing the CO and CO2 output.
Burning the gasoline in the engine is NOT releasing all of its energy - because not all of the gasoline is burned. Most of it is in newer engines at light loads and yes there is a lot of energy lost to heat into the cylinder walls and as friction.
I think if the efficiency of HHO (making and burning) was high enough I could probably get my engine to idle on 900-1000 watts of electric power into the HHO generator and then run the engine completely on HHO. It would make more sense to add an electric motor to the engine and turn the engine over with the electric motor than to produce HHO if it is not too efficient. Adding the electric motor is a lot more work and more cost however and doesn't increase the burn efficiency of the gasoline.
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10-22-2008, 02:42 PM
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#30
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Registered Member
Join Date: Feb 2008
Posts: 1,652
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Combustion efficiency, 99% of all the fuel is burned period, a little bit gets past the rings and a few molecules are "allowed" into the cat to keep it happy.
All the energy in the gasoline is released, but 70-85% of that is in heat and noise. What is normally taken to be meant as the thermodynamic efficiency of an IC motor running gasoline is the proportion of that energy that it converts into kinetic energy that can be used, in the first instance this is pressure, which is converted to linear motion by the piston and rotary motion by the crankshaft.
So there is no hidden energy, you get all of it out of the gas, but what you want is more of that energy shoving you down the road, and less of it leaking wastefully out of your tailpipe and cooling system.
Now the rate at which gasoline can change it's energy into pressure is relatively slow, this means that to get peak cylinder pressure at top dead center, you actually need to light the mixture before top dead center. aka ignition timing advance. BUT the only pressure that is useful is the pressure at TDC and afterward, the rest of the motor has to work against the pressure generated before TDC, and the time it takes to complete the burn means heat is lost to the cylinder head that could have gone into making pressure.
So, anything that could be used to speed the burn up, should be good. H2 has a flame front speed 10x faster than that of gasoline. If you can get enough H2 in there to light off the mixture more rapidly, you can reduce spark advance, moving ignition timing closer to TDC and save the wasted work against the combustion pressure generated before TDC. Additionally, by lighting the gas mixture "everywhere at once" you cut the heat loss to the cylinder head during the propogation phase of the reaction, meaning the amount of heat the gas puts into the motor is less, allowing a little less gas to make the same pressure.
The hydrogen itself contributes to cylinder pressure, it appears the theoretical thermodynamic efficiency of H2 is double that of a gasoline air mixture, but the best that has been achieved in H2 IC motors is only 50% due to mechanical limitations. However, it is fairly likely in small proportions that the H2 actually achieves it's theoretical efficiency, because the gas mixture is something of a buffer to it. How does this work?
Imagine inflating a balloon with a firecracker... Now if you have your standard balloon completely deflated and have a firecracker that will produce exactly the volume of gas required to inflate it... you may be dissappointed. The violence of the reaction would likely unevenly stretch and rip the balloon, or attempt to stretch it too fast, or it may melt the rubber. This is similar to the mechanical limits encountered in trying to make an H2 motor better than 50% efficient. If however we were to have a balloon that was 3/4 inflated, and use a firecracker that will produce the last quarter of gas required to inflate it, we might be more likely to meet with success, as the reaction would be cushioned somewhat by the air already in the balloon, the violence damped. This may be true for any hydrogen assist technology, HHO, plasmatron, bottled H2, any combined H2 and gasoline mixture, the mere presence of "buffering" gases allowing the maximum amount of energy to be captured from the H2. This means that any given BTU amount of H2 up to a saturation point we don't know, but could be inferred at 33% from MITs publications on their plasmatron work, is worth at least double, more likely triple the same BTU amount of gasoline in producing pressure = KINETIC ENERGY.
Additional effects of HHO supplementation are the fact that it takes up a lot of room in the chamber, this reduces pumping loss, increases dynamic compression at smaller throttle openings and lower rpms, and increases the efficiency point of the motor, causing it to be running in a better BSFC range. Theoretical efficiency of a gasoline motor might sound good at 30 odd percent, but practically, at part throttle, you've got an effective CR of next to nothing. You only need 25HP out of a motor capable of 150, so your motor is 6x too large, the volume hydrogen displaces makes it effectively "smaller", you get your 25HP at maybe 80% of theoretical efficiency instead of maybe 30%.
These effects are in addition to the observation by MIT and Arvin Merritor that hydrogen supplementation can shift the lean misfire point from about 17:1 to 25:1
However... you do have to fight your oh so clever ECU, because it does exactly the opposite things you want it to do. For instance, timing advance is often mostly determined from the coolant temp sensor. IF you turn your HHO on, when your engine is nice and hot and advance is pulled right back... you start cooling the motor off, because you're getting more push for less heat, so the ECU advances the timing.... completely the opposite of what is good when you're putting HHO in there.
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I remember The RoadWarrior..To understand who he was, you have to go back to another time..the world was powered by the black fuel & the desert sprouted great cities..Gone now, swept away..two mighty warrior tribes went to war & touched off a blaze which engulfed them all. Without fuel, they were nothing..thundering machines sputtered & stopped..Only those mobile enough to scavenge, brutal enough to pillage would survive. The gangs took over the highways, ready to wage war for a tank of juice
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