Optimizing gasoline energy output

[GJB]

Hi,

 

I have been tossing some crazy idea around

 

It came to me when I was using an acetylene torch.

You open the gas and you light it, this will give you a flame that will not even put a cup of water to boil.

Now you open the oxygen and you have a flame that will melt metal.

 

So here is my idea, but first I want to make sure that you understand that I do not want to increase the power output of any engine 50HP engine should still produce 50HP but with a lower gasoline consumption.

 

You already guessed that I want to put (some) oxygen in the mix.

At start up this oxygen is produced by electrolyses (energy taken from the battery)

The oxygen is then fed back in to the engine, while the hydrogen is fed into a second (a lot smaller) engine.

The smaller engine burns the hydrogen with the outside air, and produces electricity that is used for electrolyses of water.

I think (please correct me if I'm wrong) that the small engine could run at 30- or 40% efficiency.

 

Would this setup have a positif effect on the gasoline consumption of the engine?

 

Or is this a dream I should wake up from as soon as possible

 

Cheers

[Joatmon]

There is one detail you need to bring into your calculations. All the electricity you use for electrolysis will have to come from the car's alternator. The more electricity you use, the harder it will be to spin the alternator and so the more fuel the engine must burn to produce power to spin the alternator. I'm not at all good with maths, but I suspect that the overall effect may not be beneficial - I'll be interested to see what other, more qualified people, make of your idea.

[GJB]

Sure but on the other hand the small engine will produce oxygen for the big engine and also hydrogen for its own consumption.

 

I am hopeless with mathematics, but I gamble that the small engine could perhaps produce say 50% of it's own fuel.

 

Meanwhile maybe it would be perhaps possible to tweak the big engine in such a way that it gets a slightly bigger HP output to offset for the extra energy needed for the electricity production.

 

The whole question being: Is the gain of burning gasoline with some oxygen bigger than the extra electricity neede by this setup.

 

Just plain curious and absolutely clueless as to how to calculate this.

 

Cheers

[Joatmon]

I think you are asking a complicated question involving many variables - I can't put a sensible estimate to the end result, but you might like to follow the link which suggests adding oxygen to a practical engine is unlikely to be beneficial.

http://www.newton.dep.anl.gov/askasci/eng99/eng99567.htm

[John Cuthber]

There are a couple of points that need looking at. The first is the idea that a gas torch produces a lot more power when it's fed with oxygen.

It doesn't.

An acetylene torch without the O2 is dreadfully inefficient. But most of that problem is due to the fact that not enough air gets to the flame to allow all the fuel to burn- hence lots of soot.

A propane torch, designed to run with air, is a lot more efficient than an oxy acetylene torch without the oxygen. (even a candle is probably more efficient).

So it's not the fact that you use oxygen that makes a lot of difference: it's how the torch is designed to mix the gases to let them react well.

 

On the other hand, and oxy propane torch will burn hotter than an air propane torch- because it doesn't waste energy heating up nitrogen (which is pretty much just along for the ride).

In a similar way, a car running with oxygen rather than air could run hotter and more efficiently.

The problem would be providing enough oxygen.

Electrolysis is a non-starter. It takes a lot of electrical energy to split water.

However there are things like this

http://en.wikipedia.org/wiki/Gas_separation

which let you get fairly clean oxygen from air.

It might just be possible to design a system that uses this idea and is more efficient than a normal engine.

But I'm not betting on it.

[GJB]

I did not explain that :

1) my theoretical engine would be one designed for that fuel mix.

2) it would be a power generator running at optimum conditions all the time

 

Cheers

[John Cuthber]

Actually, it wouldn't be running at anything like optimal conditions all the time.

As you specify it, it generates (and wastes) large amounts of hydrogen. That makes it dead in the water as far a efficiency is concerned.

You seem to have missed the point. An oxy acetylene torch with the oxygen turned off burns very badly, but if you fed compressed air in through the oxygen inlet it would work just fine (albeit not as well as it does with oxygen.

Using oxygen isn't magic.

[GJB]

Thank you for your replies

 

Now I know I have to wake up from this dream

[Cap'n Refsmmat]

There's already an extensive amount of work that goes into ensuring the ideal combustion conditions for gasoline inside an engine. You can tell when an engine has too much gas and not enough oxygen -- black soot pours out of the exhaust, since some of the gasoline can't completely burn.

[John Cuthber]

True, but if it were running in pure oxygen you could (in principle) run in 5 times as much fuel and get 5 times the power.

Of course, the engine would melt, but that's another issue.

[Externet]

...want to increase the power output of any engine 50HP engine should still produce 50HP but with a lower gasoline consumption...

 

You can get into the complications of producing oxygen; but there is another way, by turning the gasoline to gas, or to atomize it into the tiniest droplets. That will lower the consumption. Water fog could be added too. I would explore this route:

 

 

The gadget is a piezoelectric atomizer, inexpensive :

http://www.mainlandmart.com/foggers.

 

I tried myself; I have the piezoelectric gadget, but did not produce gasoline fog; I suspect its built-in water level sensor has to be tricked into believing it is submerged in water, seems its level sensor does not work in gasoline.

[John Cuthber]

You can get into the complications of producing oxygen; but there is another way, by turning the gasoline to gas, or to atomize it into the tiniest droplets.

 

Do you mean use on of these?

http://en.wikipedia.org/wiki/Carburetor#History_and_development

[InigoMontoya]

Another potential problem: The more O2 you add to the mix, the more likely you are going to be seeing detonations inside the cylinder. Add in meaningful amounts of hydrogen and you're almost guaranteed to be detonating. So even if everything else worked as envisioned (it won't, but we'll say it will for the moment), you're going to have HUGE maintenance problems as your engine will be blowing itself apart over not very much time at all. True, you could built the engine heavier and more robust so that it could handle the detonations, but if you're shooting for lower fuel consumption you're not going to see it simply because everything just got more massive and harder to move.

[Externet]

No, John C. A polished/improved something like this :

 

youtube.com/watch?v=mmVfSGM71VI

[Joatmon]

Water injection is well known method of increasing power or decreasing fuel consumption for the same amount of fuel.

http://en.wikipedia....ction_(engines)

 

Sorry about the unreadable attachment (Which comes from the link and confirms fuel economy is possible)

Edited June 3, 2012 by Joatmon

[InigoMontoya]

Yes, water injection works.

 

On that note...

 

A few years ago I recall reading about somebody who built a 6-cycle engine that was a hybrid between a normal IC engine and a steam engine (I'll see if I can find a link). It was very cool. Basically it was a normal internal combustion engine for the first 4 cycles. Then, after the normal exhaust stroke water was injected. The next two strokes were a power stroke using water boiled using residual heat from the previous 4 strokes, and a second exhaust stroke. A good indicator of how well the engine was using energy was the fact that it didn't require a cooling system; the 2 steam-related cycles not only generated power but removed enough heat from the system to eliminate the need for additional cooling.

 

 

edit to add... a link

Edited June 3, 2012 by InigoMontoya

[John Cuthber]

No, John C. A polished/improved something like this :

 

youtube.com/watch?v=mmVfSGM71VI

What do you think a carburettor does?

[Externet]

A carburetor sprays fuel from venturi nozzles, on much larger droplets. That is one of the reasons they are obsolete and have been replaced by injectors, to obtain finer mist.

Fog of around a micron diameter droplets is supposed to be the size obtained from ~2MHz piezoelectric devices. Worth researching of new technology.

 

There is much research on the automobile industry to improve the efficiency of gasoline as Cap'n states, this fog one could yield something useable some day. For sure they have looked into it.

 

The water fog addition could help to avoid detonation of poor octane cheaper gasolines.

[John Cuthber]

The big reason carburettors are obsolete is that they give very poor control of the amount of fuel added.

While the combustion of fuel is far from perfect and finer drop size will help, even my dad's clapped out old lawnmower could get the reaction so fast that it pinked.

 

Of course it's an excellent idea to think of ways to improve efficiency- that six stroke system sounds fascinating.

The original idea in this thread was to run an engine with oxygen rather than air.

The energy requirement for extracting oxygen from air isn't that great but I don't know if the efficiently gain would be worth it, but it's probably worth looking into.

It would require a substantially different engine design and it would be in trouble if the oxygen concentrator failed.

[dragonstar57]

wouldn't this only increase efficiency if there was already gasoline not burning in the combustion?

[John Cuthber]

It would let you run more fuel into the engine (though pre ignition would probably be a problem so this would be more worthwhile for Diesel engines).

It would also save the energy of heating up nitrogen though, since the hot nitrogen expands and helps push the pistons I'm not sure how much that would help.

It would raise the combustion temperature which would improve thermodynamic efficiency as long as the engine could cope.

[dragonstar57]

why not inject microscopic amounts of lox prior just prior to the fuel?

the lox is a stronger oxidant and would allow for some wicked horse power

[PaulS1950]

Using oxygen in a gasoline engine instead of air will decrease the efficiency of the engine while causing heat at dangerous levels.

The engine is designed to run at a specific temperature (or in a specific range of temperatures). The engine pulls in about 14 - 15 pounds of air for every pound of fuel. In that air is the correct amount of oxygen to burn the fuel, around 70% nitrogen and some other gasses and water vapor which do nothing for the combustion process but they do aid in the production of usable power. They cool the flame as they heat up, expanding over 200% which helps to prolong the push of the burning fuel adding power to the engine. If you remove the extra gasses and water vapor then you would have to redesign the engine with better cooling and to take advantage of the shorter pressure impulses that make less power.

 

A cheep shortcut to better mileage is to use the lowest octane gas you can get and use a water injector to prevent detonation. The water absorbs the heat and turns to super heated steam which raises cylinder pressures over a longer period of time. You have turned your engine into an internal combustion steam engine. The drawback to this shortcut is that it can cause corrosion because of the steam/nitrogen mix in the exhaust products. Over the short term it will clean out the carbon that has built up in your engine but soon after that it will become an electrolyte that carries galvanic charges to the dis-similiar metals used in your engine.

 

It is better to use the lowest octane gas that doesn't cause detonation and leave the water for drinking.

 

Paul

[dragonstar57]

Using oxygen in a gasoline engine instead of air will decrease the efficiency of the engine while causing heat at dangerous levels.

The engine is designed to run at a specific temperature (or in a specific range of temperatures). The engine pulls in about 14 - 15 pounds of air for every pound of fuel. In that air is the correct amount of oxygen to burn the fuel, around 70% nitrogen and some other gasses and water vapor which do nothing for the combustion process but they do aid in the production of usable power. They cool the flame as they heat up, expanding over 200% which helps to prolong the push of the burning fuel adding power to the engine. If you remove the extra gasses and water vapor then you would have to redesign the engine with better cooling and to take advantage of the shorter pressure impulses that make less power.

 

A cheep shortcut to better mileage is to use the lowest octane gas you can get and use a water injector to prevent detonation. The water absorbs the heat and turns to super heated steam which raises cylinder pressures over a longer period of time. You have turned your engine into an internal combustion steam engine. The drawback to this shortcut is that it can cause corrosion because of the steam/nitrogen mix in the exhaust products. Over the short term it will clean out the carbon that has built up in your engine but soon after that it will become an electrolyte that carries galvanic charges to the dis-similiar metals used in your engine.

 

It is better to use the lowest octane gas that doesn't cause detonation and leave the water for drinking.

 

Paul

doesn't the lower octane cause less complete combustion?