Comressed air powered car conversion

[Hondo]

I see on you tube that there is a company (I think in France) that is manufacturing a new car that runs on compressed air. Just wanted to know if anyone in this forum has toyed with the idea of converting an ICE powered car over to compressed air. It looks very promising as the high pressure tanks would cost less than batteries and would never wear out. Plus, if you had large "refueling" tanks, you could re-fill the on board tanks in about 5 min.

[MetroMPG]

I don't know if anyone has toyed with the idea, but I've never seen a thread on the subject of doing a conversion.

[doviatt]

Those air powered piston engines in the Air-Hogs pump-up air planes are pretty cool. Wonder if it is similar? Wonder what kind of range you could get with a large reservoir?

[DonR]

The air hogs engine is exactly the same.

CO2 engines have been around for quite a while. People build very small ones to put into model planes.

Basically they are a 2-stroke engine with the porting optimized for the application. I believe the French man. is using a "multi stage" engine. Air runs through the first set of cylinders, then the "exhaust" is run into another set of cylinders designed to operate on the reduced pressure... I don't know how many stages it has, but it helps extract as much energy as possible.

You can run your weed eater by putting a compressed air into the spark plug hole 7 pulling the starting cord to get it to go the right direction. I would try it without the carb on it though.

Don

[Hondo]

I've been doing a little research, and in the 30s they used to use air powered locomotives in the mines to pull the stuff out. It was great at the time because it eliminated problems of safety and fumes the ICE had, and it pumped fresh air into the mine with it's exhaust. The french company claims 100km per fill up, thats a lot better than the 25 miles I get out of my electric Fiero, and I have to wait 6 hours to charge the batteries back up.

[rmay635703]

Originally Posted by Hondo

I've been doing a little research, and in the 30s they used to use air powered locomotives in the mines to pull the stuff out. It was great at the time because it eliminated problems of safety and fumes the ICE had, and it pumped fresh air into the mine with it's exhaust. The french company claims 100km per fill up, thats a lot better than the 25 miles I get out of my electric Fiero, and I have to wait 6 hours to charge the batteries back up.

There was a guy on newradio 550 last november that was sarcastically interviewed that had put fittings on each cylinder of his V8 dodge magnum a sizable air tank and some other mods to make his own hybrid.

He said he could drive 20 miles at 25mph on only air and would stop at gas stations to fill, if he needed to go faster he just had to shut off the valves and he could run on gas, I have been trying to figure out WHO he was for some time, maybe someone else from the central WI area remembers, it seems he was from out of state.

We need to the folks like him to get into the diy movement so the more timid can replicate

[captainslug]

Originally Posted by Hondo

The french company claims 100km per fill up

Which is complete BS.MDI has been drumming for investors for a few years and has yet to deliver any finished products.

Filling a 680 liter 3000psi tank (one of the 5-foot tall ones) from even the most powerful hydraulic compressors you can use at home will take you between 10 and 45 minutes. But one of those tanks is not likely to get you a useful amount of range, so you will need to double or triple that amount of time.

And that method of energy storage is only 60% efficient. A good deal of the compressor output is converted to heat, which sinks out of the tank over time. So you're using 40% more electricity and you're still probably getting less range. Which is just as affected by temperature as SLA batteries.

[MazdaMatt]

I used to work at a paintball field. We had large compressed air tanks (16"dia x 5'h) and typical co2 tanks (8"dia x 5.5'h). When things went wrong, it was very valuable to have had some training. I wouldn't want Joe Commuter to have that same compressed air setup in his garage filling up his car.

Incidentally, our big compressor had 3-stage compression... probably the same way that the french co is using staged decompression.

When we moved to a new facility we had to drain nearly-full air tanks. There were 3 of them. The amount of energy stored is pretty significant because they made a hell of a ruckus for 10 minutes when they were emptying. Not taking care would have blown eardrums, if not air embolisms. They were 3kpsi.

This discussion inevitably turns to efficiency. I know that a 68cu air cylinder filled to 5000psi in half a minute gets HOT. That isn't coming from the compressor, but from the source tanks that were at room temp. I'm pretty sure that is an indication that the process is rather lossy, but i'm no compressor engineer.

[Hondo]

Quote:
When we moved to a new facility we had to drain nearly-full air tanks. There were 3 of them. The amount of energy stored is pretty significant because they made a hell of a ruckus for 10 minutes when they were emptying. Not taking care would have blown eardrums, if not air embolisms. They were 3kpsi.

More than an equivelant amount of gasoline?

[MazdaMatt]

Depends on what you mean by equivalent amount. If you mean volume... that much gas could have exploded a city block. If you mean environmental effect, economic cost or energy consumed in the making... I have no idea, but it COULD be comparable (unlike volume).