Dry Ice in Intake?

[cfg83]

Christ -

Originally Posted by Christ

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BTW - the O2 sensor will not mistake CO2 for O2, it's a different compound, that creates a different signal. The O2 sensor is trained to see a certain amount of O2 after a burn cycle (little or none is preferred), so you're giving the O2 sensor exactly what it wants, by displacing oxygen intake. It will read that there is substantially less air than the "normal" volume, and start pulling fuel until it gets a bottom line.

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Okay. I was thinking that the O2 in CO2 would separate during combustion, but you are saying that won't happen. That makes sense since that's already one of the emissions of combustion.

CarloSW2

[blueflame]

A wet sponge?

One of those mounted infront of an incar air vent was my idea for a swamp cooler a/c system.

If you got hurt playing football they gave you a wet sponge.

[Christ]

Originally Posted by cfg83

Christ -



Okay. I was thinking that the O2 in CO2 would separate during combustion, but you are saying that won't happen. That makes sense since that's already one of the emissions of combustion.

CarloSW2

Carlos - let me say this - I'm no chemist, by any means, so I won't say that it absolutely CAN'T happen...

I will say that afaik, it shouldn't happen, b/c in order for the compounds to separate, the O2 would have to have something to bond to during the combustion process, and since most of the O2 at that point (running lean) will just be extra compounds that have no "match" so to speak - that shouldn't happen.

[pasadena_commut]

Originally Posted by pasadena_commut

Nitrogen could be used instead.

Or, come to think of it, oxygen. This wouldn't save fuel as a retrofit in an existing motor. However, it could let a car with a very small motor produce bursts of energy, for acceleration or climbing hills, somewhat similar to a turbocharger. The atmosphere is 20% oxygen so adding 10% by volume pure oxygen to that would raise the oxygen level by nearly 50% (that is, to nearly 30%), which would let the motor burn 50% more fuel per cycle without changing the compression. (Ignoring for the moment complications such as the tendency for this high oxygen mix to ignite earlier.) Carrying around a tank of strong oxidizer would be a safety concern though, and the tank would have to be as far away from the gas as possible. If the oxygen tank ruptured in a crash, assuming the pressure related damage was contained by design, there would be a brief period of severe fire and explosion danger while the local oxygen levels are high, but this would dissipate quickly. It wouldn't be like a ruptured fuel tank, which leaves flamable liquid on the ground for a long time. Of course if both the oxygen and fuel tanks rupture at once, and there is any heat or sparks, it would be more boom than burn.

In theory a car could also be fitted with equipment to concentrate oxygen directly from the atmosphere while it drives. Depending on the amount of energy this takes, it might end up energetically favorable if the normally aspirated motor was enough for 95% of driving, and it used that time to top off a small oxygen tank. No idea which separation technology would be used though, because commercial oxygen separation is cryogenic and the equipment is very large - that technology is not likely to miniaturize well. In any case, the waste product of the separation is just the other normal atmospheric gases, so releasing them back into the air should not count as pollution. Hmm, carried to an extreme, where the car runs entirely on separated oxygen, there could be some substantial pollution related benefits - no Nitrogen to form NOx and on a lean burn the extra oxygen would convert any CO all the way to CO2. That could allow the elimination of the catalytic converter(s), which would recover some of the weight of the oxygen separating equipment. Or go whole hog and carry equivalent tanks of both fuel and oxidizer, both of which to be filled at the "gas" station. That would be one heck of a dangerous gas station though!

[some_other_dave]

If you put the CO2 into the intake "upstream" of the intake air measuring device (MAF, MAP sensor, carb venturi) then the fuel system will see the CO2 as air. It will add fuel to go with that air--which will result in a rich mixture. It may very well be richer than the O2 sensor downstream can cope with. So you'd need to add the CO2 "downstream" of the air meter. That will be very difficult with a MAP-based injection system (such as older Hondas have), because pretty much the whole manifold from the intake valves to the throttle plate is the air meter... Easier with an air-flow based system, which I think most cars today use.

The drop in intake temperature will also cause a richer mixture, as the fuel system will "see" colder intake air, which is denser and needs more fuel. (BTW, cold air intakes generally hurt fuel efficiency unless the "regular" intake temps are very high indeed. Though there are exceptions, as always!)

The CO2 is very unlikely to be dissociated in the combustion process. It is one of the products of combustion, after all.

Another idea would be to find a nice warm source of CO2 and add that into the intake, down stream of the air metering devide. You could probably tap it from the exhaust, in fact. Perhaps you could call it "Exhaust Gas Recirculation"?

...Sounds like the OP has found a nifty complex way to re-invent EGR, only in a less controlled fashion.

-soD

[superchow]

I have read a very interesting article on Autospeed.com about exhaust gas recirculation (linky). The tweaking process is what seems daunting to me. The author gets bonus points for control of the system, but I am looking for the "swamp cooler" approach. BTW: Wet sponge in air filter box = Brilliant!

I became suspicious why my idea of this crude leaning of the air hadn't been tried before. Just think how the car manufacturer's could have cheated during the EPA testing procedures... Then again, they were also gunning for cleaner emissions, which this would not necessarily accomplish.

No, this is an unabashed attempt at "cheating" to get better mileage, emissions be damned. And trying this in my econobox once is still more environmentally friendly than driving a Suburb-Hum-hoe every day. Heck, I commute by bus most days - even during these cheap gas price days.

At least the wet sponge may solve my lackluster low end torque during hot days. That's what I call lateral thinking. Thanks to all who chimed in.

[blueflame]

You could design a water reservoir that drips constantly on to the sponge.

Like an inverted caged pet feeder.

Make 2 and use one for a swamp cooler air con, I'd love to know if it really works. Dryer climates benefit more from swamp coolers than tropical humid or wet places.

Removing the crankcase fumes from going back in the engine via air intake, and fixing a mini pod filter MAY also cool the engine considerably. Some motors dont like it though...

[cfg83]

blueflame -

Originally Posted by blueflame

You could design a water reservoir that drips constantly on to the sponge.

Like an inverted caged pet feeder.

Make 2 and use one for a swamp cooler air con, I'd love to know if it really works. Dryer climates benefit more from swamp coolers than tropical humid or wet places.

Removing the crankcase fumes from going back in the engine via air intake, and fixing a mini pod filter MAY also cool the engine considerably. Some motors dont like it though...

Ha ha, now all we need is the hamster making electricity running in his wheel !!!!!!!! If I used the wet sponge method, I'd make a cool "WSpower" decal to make someone think I had a performance mod in my car.

CarloSW2

[blueflame]

140hp- really cram those little guys under the hood

[Lazarus]

Originally Posted by blueflame

You could design a water reservoir that drips constantly on to the sponge.

Like an inverted caged pet feeder.

Make 2 and use one for a swamp cooler air con, I'd love to know if it really works. Dryer climates benefit more from swamp coolers than tropical humid or wet places.

Removing the crankcase fumes from going back in the engine via air intake, and fixing a mini pod filter MAY also cool the engine considerably. Some motors dont like it though...

I find that it works very well. Just need instrumentation to verify the IAT and timing. Unless the commute is long you don't need elaborate setup(Keep it simple. KIS) it will work for about an hour on 100+ days. As always your mileage may very.