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-   -   NEWS: 100MPG air-powered car to be in America by 2009 (https://ecomodder.com/forum/showthread.php/news-100mpg-air-powered-car-america-2009-a-1143.html)

NoCO2 02-22-2008 11:57 AM

NEWS: 100MPG air-powered car to be in America by 2009
 
http://www.popularmechanics.com/auto...html?series=19

Quote:

Originally Posted by popularmechanics.com
'Company officials want to make the first air-powered car to hit U.S. roads a $17,800, 75-hp equivalent, six-seat modified version of MDI’s CityCAT'...'that, thanks to an even more radical engine, is said to travel as far as 1000 miles at up to 96 mph with each tiny fill-up.'


bestmapman 02-22-2008 12:03 PM

This will be great if it comes true.

Gone4 02-22-2008 12:28 PM

The MPG estimates will probably be way off. As it is, the numbers they throw around seem to be coming from the assumption that you compressed air into the tank for free before you started your drive. Regardless, a technology that boosts efficiency without the environmentally detrimental effects that battery production tends to incur, is an excellent thing.

NoCO2 02-22-2008 12:43 PM

I'm just impressed more by the fact that someone is actually, at least, trying to make air powered cars work. I have always liked the idea of being able to pull my fuel right out of the air I'm driving through. Even if they make it something like a hybrid where it cruises on gas and accelerates up the 35mph (like the article stated they were planning). Using a compressor hooked up to the engine to refill the air tank once at speed would be just as efficient as any hybrid is today without the worry of replacing batteries, etc.

basjoos 02-22-2008 02:40 PM

I wonder how they are getting around compressed air's inherent inefficiencies. A lot of heat is produced when air is compressed. On large compressors, this heat is usually removed with a heat exchanger at the output of the compressor, allowing them to store a greater quantity of room temperature compressed air rather then a lesser quantity of heated air. Then when the compressed air is expanded to room pressure, its temperature drops precipitouosly. That air heater they use at speeds over 35mph looks like a method to try to compensate for expansion cooling of their compressed air to increase their range. And if you talk to anyone in industry who runs a compressed air system, compressed air is not cheap to produce and can be one of a plant's larger electrical expenses.

Ryland 02-22-2008 03:42 PM

I suspect that the main reason they are adding the gas engine to these cars is that air powered cars in cold climets don't really work! every design that I have seen for an air powered car has a radiator to warm the air befor it goes to the air motor, and that a commen problem in humid enviroments is that radiator freezing up.
I did read an interesting artical a while back about a liquid nitrogen hybrid electric, were the nitrogen cooled the wires, and motor bringing making them better conductors of electricity, and that in turn made the nitrogen boil/expand so that it could turn a turbine that ran a generator that powered the car...

My dad works at a university and has said that their air compressers are alwas being repaired, and have huge motors on them that draw tons of power, and that is just to compress air to 1/10 of the presure that an air powered car would need.

wumpus 02-23-2008 08:18 PM

quick question
 
Anyone know the expected lifespan of an off the shelf turbo charger if run semi- continuously? This would give you an off the shelf compressor and power source. Generally turbines are as highly efficient as you can get, but there really isn't any need to do so with turbos (it's waste anyway), so I don't know how much it would help.

There have been other suggestions with diesel and otto engines (requiring magic valves), but this could presumably use off the shelf parts.

trebuchet03 02-23-2008 09:28 PM

I know it's nit picky... but air is not the fuel for this car... Air is just the energy storage medium - the battery. The fuel will be whatever ultimately drives the compressor (gas, coal, hydro, etc.)... I hope it has regenerative braking :)

Also, NoCO2 - the 100mpg was just speculation by the article writer....

I am curious as to how they're keeping it from freezing. As the whole system does generate heat, I imagine that with proper controls that problem would be minimized. I'm also curious as to what pressures they're dealing with.

WaxyChicken 02-23-2008 09:30 PM

Looks familure... Tato Nano anyone?

basjoos 02-24-2008 12:17 PM

I wonder how the efficiency of a series pneumatic hybrid would compare with that of a series electric hybrid. A series electric hybrid is of course a small IC engine driving a generator, feeding a battery, which powers an electric motor. A series pneumatic hybrid would be an small IC engine driving an air compressor, feeding a pressure tank (insulated to retain the heat of the compressed air), which powers an air motor. If the tank was well insulated, then the air motor's exhaust temperature should be close to the temperature of the air before it was compressed, thus almost eliminating one major cause of pneumatic system inefficiency. So you would have the weight of the compressed air tanks versus the weight of the batteries. Also the energy conversion efficiencies of the electric generator, electric motor, batteries, and voltage controller circuitry versus the efficiencies of the compressor, air motor, and heat loss from the air tanks and air lines.

trebuchet03 02-24-2008 12:25 PM

Quote:

Originally Posted by basjoos (Post 11245)
I wonder how the efficiency of a series pneumatic hybrid would compare with that of a series electric hybrid. A series electric hybrid is of course a small IC engine driving a generator, feeding a battery, which powers an electric motor. A series pneumatic hybrid would be an small IC engine driving an air compressor, feeding a pressure tank (insulated to retain the heat of the compressed air), which powers an air motor. If the tank was well insulated, then the air motor's exhaust temperature should be close to the temperature of the air before it was compressed, thus almost eliminating one major cause of pneumatic system inefficiency. So you would have the weight of the compressed air tanks versus the weight of the batteries. Also the energy conversion efficiencies of the electric generator, electric motor, batteries, and voltage controller circuitry versus the efficiencies of the compressor, air motor, and heat loss from the air tanks and air lines.

In theory, the air powered variant wouldn't have battery wear. But I'm not sure how their tanks fatigue. On the same coin - the tanks are storing an incredible amount of energy that, in theory, could be quite dangerous in an accident compared to a non lithium battery...

Ryland 02-25-2008 12:33 AM

They often talk about these cars having a huge air tank presurized to a simaler presure of a scuba tank, about 3,000psi, and that is alot of energy, not something you would want to get in an accedent with, or have built by the lowest bidder.
Also, if you are compressing air, yes your air tank is going to heat up and that is a bad thing as it will then hold less air, and as it cools down you will loose that presure, I've used a number of compressers for air tools that have cooling fins on the air lines coming from the compresser so that air going in to the tank is as cool as possible, the compresser is going to work more efficently that way, even if you were to store that heat, then as the air passes thru the air motor and cools it will condense and drop in presure, that is why if you can have a radiator that warms that cooling air, you will go farther on a tank of air, but that only works in warm places like India... where cars like this are being used.

Xringer 06-14-2008 10:00 AM

That's fer sure Ryland. When I take my 106 cubic foot 4350 PSI scuba tank to get it filled,
I made darn sure it's tied down to the cargo clips. I would hate to have that thing rocketing around inside my car.
http://i46.photobucket.com/albums/f147/Xringer/B012.jpg

I think driving around in an HPA car would a bit more dangerous than using regular fuels.

I once saw a kid using way too much pressure while filling his bike tires in a gas station.
I yelled at him to stop, but he kept filling it. When that little tire exploded,
it wrapped a section of tire around his face at about mach 1..
He wasn't seriously injured, but the abrasions & tire marks were on his face
for days afterwards.

My point? Even low pressure air (under 400 PSI) can be pretty dangerous.

Jigsaw 06-14-2008 12:54 PM

With all due respect,
Aren't you guys missing the forest for the trees?

It runs on air. AIR. Even if it got 20 miles to the fillup (with 3 dollars worth of electrcity) This technology provides a clean, and inexpensive alternative to fossil fuel.

It's like you guys are sitting on the fence waiting for the "water car" or something, except in the mean time the Europeans and Indians are using and perfecting the future.

I admire many of your advances on plain old ICE engines and 90's car bodies, but don't detract from the brillance of this advancment with safety concerns. Of all people, the community here should appreciate the virtue of not giving up on potential so easily.

Xringer 06-14-2008 01:47 PM

I know how much power can be stored in compressed air. I've used compressed air all my life. (Even drive nails & take off my lug nuts with it). :)

But, it would take a LOT of 3,000 PSI scuba tanks to get the kind of results you get
with one gallon of gas. One problem is the HPA tanks would all have to be made from
carbon fiber (which isn't real cheap). Or, the car would be way too heavy.
And if you wanted to maintain a smallish size, those tanks would need to hold a lot more than 3,000 PSI (200 bar).
More dangerous pressures and your home compressor would be VERY expensive.
Just check out the prices of a little home compressor to fill a 300 bar scuba tank..

My guess.. A car designed from the wheels up to be a plug-in EV would be < 1/2 the price of an air powered car with the same range and load capabilities.
When you added in the cost of compressor hardware, the air car becomes something that no one would buy.

Go Google up the all the news on the Indian air car. A lot of it is very old news. They were going to start full production a few years ago.
Why didn't they? My guess is, they just can't get the range they need,
at the price point they need.

Heck we could be driving EVs made out of carbon fiber and covered with
high output solar cells, but what would be the MSRP? :eek:

Cheers,
Rich

Ryland 06-14-2008 02:35 PM

Quote:

Originally Posted by Jigsaw (Post 34759)
With all due respect,
Aren't you guys missing the forest for the trees?

I sometimes think that the people who support ideas like air powered cars are the ones missing the point, air is just the storage medium, it is not energy and so far it seems to be a pretty poor way to store energy,
when compressing air there are so many issues and losses, things like lead acid batteries start to look really good n comparison.

Jigsaw 06-15-2008 01:57 AM

As a former 3 wheel City-El EV owner, I know what limits lead acid have, so until Li-on or lipos are alot cheaper and available to the masses, this advance appears closer to the ultimate goal.

http://www.youtube.com/watch?v=QmqpG...eature=related

Xringer 06-15-2008 07:26 AM

That rotatory motor looks really nice. That might be the way to go. :)

mattW 06-15-2008 09:15 AM

I did a lot of research for a blog about air cars, the most interesting things I learnt were:
  • The air tanks at 300 Bar (4350psi) hold about the same amount of energy as gallon of gas.
  • In terms of efficiency "According to the efcf, the cars can have a theoretical compression efficiency of 46% and a tank to wheel efficiency of up to 84%, the report concludes that given 100MJ of energy a hydrogen FCEV could travel 42km, an air car 46 and a Li-ion BEV an impressive 133km."
  • Because of the huge pressure you have the same chicken and egg fill up infrastructure scenario as hydrogen to get longer than the 125km range of the tanks.
Check out the blog for the sources. I'd rather get triple the efficiency and range in an EV, but the potential cost for a mass produced one is nice, and the air tank versus battery replacement is a plus, but A well looked after battery pack (i.e. properly engineered production car) is going to last a long time, LiFePo4 batterys are looking in the 2000-3000 cycle range so I don't think battery replacement will be too big of an issue.

Cool technology but EVs are better :eek::D:p

NoCO2 06-15-2008 09:34 AM

I really like the air powered rotary motor. Looks like it's going to be super efficient and the fact that it's as small as it is means less weight and greater flexibility for auto manufacturers for designing cars since 1/3 of the car doesn't have to contain the engine alone.

Xringer 06-15-2008 03:03 PM

Quote:

Originally Posted by mattW (Post 34948)
[*]The air tanks at 300 Bar (4350psi) hold about the same amount of energy as gallon of gas.

How much gas would be equal to my 106 cubic foot 300 BAR scuba tank?
Off the top of my head, only a few onces.?.

theunchosen 12-06-2008 01:32 PM

It has been said above but is worth pointing out again.

They are using a battery, or in ZPM's case, they are using a gas engine to heat the air. Compressing air fights against the process the whole way. It heats up allowing fewer cubic feet to be stored, it cools as it expands which has to be overcome in order to feed the expansion in the engine.

If you are going to have a battery. . .why don't you just use it to power an electric motor instead of run a heater than runs an air engine? you still lose the 5% in conversion and you lose the %'s associated with heating air and carnot ideals.

I have a PADI scuba license. . .I would much rather haul around a single gallon of gas than a 4,000 PSI tank. 3,000 PSI tanks are heavy enough and more PSI means more materials. 80 Cubic foot tanks weigh 40-50 lbs, they tank they are talking about holds slightly more air but is much heavier. 40 lbs compared to 6 lbs(gasoline).

Even if the motor weighs absolutely nothing to replace my 10 gallon tank you would end up adding weight(over 400 lbs for just the air compared to 60 lbs and 300 lbs of motor).

If you are going to use a KWH for propulsion in a car use it for an E-motor, instead of something complicated.


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