Car Powered by Compressed Air 409
gripperzipper writes "CNN reports that a Korean company created a small car powered by compressed air. ENERGINE created its PHEV, or Pneumatic-Hybrid Electric Vehicle, which uses a two-stroke compressed air engine for start, acceleration, and uphill climbs. The car switches to an electric motor when its speed reaches 20-25 km/h (32-40 mi/h). Although major auto manufacturers have invested heavily in gasoline hybrids, it will be interesting to see if a market will open for this type of vehicle." Update: 04/04 17:18 GMT by T : Reader Tapsu spotted the incongruity here, writing "Interesting post, but the speed conversion has gone wrong way: "20-25 km/h
(32-40 mi/h)". ... Thus the correct speed range in miles would be
something like 12-15 mi/h."
Say goodbye to free air (Score:5, Interesting)
Re:Say goodbye to free air (Score:2)
Free air is what outside is, go and breathe it while it is... here
Re:Say goodbye to free air (Score:2, Informative)
Re:Say goodbye to free air (Score:5, Interesting)
Compressed air has great power density, but awful energy density. I.e., you can unload power incredibly quickly from it, but can't store much at all. Even batteries store far more energy in a given mass. This sounds like a big step in the wrong direction, honestly.
Re:Say goodbye to free air (Score:5, Interesting)
What is interesting about compressed air though, the energy you get out of it is NOT what you have put into it. The energy comes from the ambient temperature of the air. This means that if a compression technique could be found that is efficient enough then you could have a potential self filling energy tank.
Unfortunately, like you said, the air doesn't have *that* much energy. Still thought that concept was interesting though.
Re:Say goodbye to free air (Score:5, Informative)
e.g.
http://zebu.uoregon.edu/2001/ph162/l10.html [uoregon.edu]
The MDI aircar proposes 400 atmospheres. They don't have a production model with tanks to hold that though. Energy density is similar to recent (but not cutting edge) batteries.
The problem with compressed air is that it is basically still a heat engine whereas electric motors are not. Electric motors are 90%+ efficient and compressed air motors, well, 40% maybe.
Re:Say goodbye to free air (Score:4, Informative)
Where electric cars (including those that store energy in compressed air) have problems is energy density. The compressed air car could do a bit better there if it also had a resistively heated thermal mass to heat the air before expansion. The thermal mass would be recharged from the wallplug at the same time the air tanks are refilled. Low atomic number materials can store a great deal of thermal energy; LiH heated to a vapor pressure of 1 bar, for example, stores several megajoules per kilogram.
Re: (Score:3, Interesting)
Re:Say goodbye to free air (Score:3, Informative)
Typically, the tanks are some sort of high-tensile metal with 15-20 layers of kevlar wrapped around them. They can be shot with a bullet and not release their contents. So, safety considerations of the tank are less important than a thin metal tank full of a combustible material, such as gasoline.
Re:Say goodbye to free air (Score:3, Interesting)
Perhaps, but a thin metal tank of gasoline won't do anything without an outside force acting on it. A pressurized container can explode from fatigue or a flaw in the construction just sitting there. Commercial containers of pressurized materials (Oxygen, propane, whatever) have usage dates on them so this fatigue doesn't cause a rupture. This would probably be an issue with
Re:Say goodbye to free air (Score:4, Insightful)
Your local station's pump isn't nearly enough (Score:3, Informative)
That's higher than a SCUBA tank and it requires some heavy duty air compressor rigs to charge it.
I'd hate to be anywhere around that car in a crash or if it catches fire...
Re:Your local station's pump isn't nearly enough (Score:5, Informative)
Energy density on these things may not be that high, but they can release all of it in a fraction of second. On top of that, if it goes, it will send fragments of the tank like shrapnell all over the place. I wouldn't want to be sitting in the car where such a tank explodes. ;-)
Or more detailed: I wouldn't want to be sitting in any car where anything explodes (outside the confines of the explosion engine, of course
Re:Your local station's pump isn't nearly enough (Score:3, Insightful)
Re:Your local station's pump isn't nearly enough (Score:3, Informative)
The practical fact is, even if you did suddenly get an explosive rupture of a liquid hydrogen tank, it'd freeze everything nearby before suddenly heading straight up once it turned gaseous.
Secondly, in terms of molar volume, the amount of hydrogen in the tank would be so large as to actually displace all the oxygen from the immediate vicinity.
But the real thing is the buoyancy, as I say. Burning hydrogen makes a perfectly vertical flame. It's not like gas, which pools
Re:Your local station's pump isn't nearly enough (Score:3, Funny)
Re:Your local station's pump isn't nearly enough (Score:3, Informative)
No, it's not. Hydrogen-oxygen mixtures are explosive, though.
Besides, in the event of an accident, I'd rather have a gas flame that burns more or less localized than be drenched in burning liquid hydrocarbon (the vapors of which are no less dangerous than hydrogen). There are good arguments against using hydrogen as a fuel for vehicles, but safety isn't one of them.
Re:Say goodbye to free air (Score:3, Insightful)
The basic problem with this car is that it will require extra infrastructure. Not terribly expensive, but quite noisy. Compressing air to 300 bar is not a very quiet affair.
Conversion problems? (Score:3, Informative)
25 km/h = 15.625 mi/h, not 40 mi/h
Guess someone goofed up on the metric system once again :)
Re:Say goodbye to free air (Score:2)
Re:Say goodbye to free air (Score:5, Informative)
Re:Say goodbye to free air (Score:2)
So one could buy, say, a single packet of cigarette papers and fill up with all the compressed air you like?
Re:Say goodbye to free air (Score:2, Funny)
Still energy (Score:5, Insightful)
Re:Still energy (Score:5, Funny)
Re:Still energy (Score:5, Funny)
Re:Still energy (Score:4, Funny)
Re:Still energy (Score:5, Funny)
Re:Still energy (Score:5, Interesting)
Electric cars don't idle or break physical laws. (Score:5, Informative)
"Jake" brake. (Score:3, Informative)
The "air" in a Jake brake is exhaust and, as you say, is limited by the compression ratio of the engine (not to mention choking it). The system I saw ran off the drive shaft and engaged when you hit the brake so the engines compression ratio was not a limiting factor. The inertia of the bus was used to drive an air compressor that in tu
Re:Still energy (Score:2, Interesting)
Re:Still energy (Score:2, Informative)
Re:Still energy (Score:4, Insightful)
Centralizing the energy generation can take advantage of (a) economies of scale for better efficiency and (b) a varied portfolio of generating sources like hydro. For electric or fuel cell cars, this allows you to take advantage of the network effect of everyone already having electric wires as a means of transporting energy. I agree, compressed air is a bit silly b/c of its poor energy storage, but to knock it because of off-site production is simply wrong.
In this era of high oil prices, why are people so quick to complain about any alternative fuel?
Re:think long term (Score:2, Insightful)
Re:think long term (Score:2, Interesting)
Neocons (Score:4, Interesting)
Neocons are children who don't want their toys taken away, and won't clean their room because it isn't fun.
Thank you for recognizing that the distinction between the present domanant "neo-conservative" group think party in the US and true conservatives. True conservatives wouldn't have bought the toys in the first place (we're compulsive savers) and wouldn't have let the room get messy for fear of unspecified adverse consequences. True conservatives (I know, I am one) are more likely to avoid doing things because they are fun (on the principle that the more atractive the lure, the more likely it is to be bait).
--MarkusQ
Re:Neocons (Score:4, Insightful)
Re:think long term (Score:3, Insightful)
Neocons are children who don't want their toys taken away, and won't clean their room because it isn't fun.
That doesn't describe "neocons", that describes about 99% of the world's population. Which do you think is more effective - appealing to their self-interest, or pissing and whining about how they don't see things your way?
Re:Still energy (Score:5, Informative)
Beg pardon? Not to mention the fact that their torque curves are the stuff that give drag racers wet dreams.
The only disadvantage electric motors have over combustion engines of any kind is, well, that they run on electricity, which has to come from somewhere.
Which turns out to be rather inconvenient.
The compressed air booster is just one way of finding some sort of dodge around the whole battery issue, and I'm not convinced it's a good one. A true hybrid seems a better solution to me, although it lacks the politically correct advantage of hiding its energy use and emissions from public view.
Bear in mind that I'm actually quite fond of compressed gas engines and have actually built a few small ones, just for my personal enjoyment and edification, but I haven't, outside of the realm of entertainment, found any problem for which they are the solution.
KFG
Re:Still energy (Score:3, Insightful)
Beg pardon? Not to mention the fact that their torque curves are the stuff that give drag racers wet dreams.
Actually, you're nit-picking.. When he says electric-engines have little power, what he means is that the entire package provided to us in such a small form-factor as a car has too little power. It is more correct to say that the amount of electric power being provided by the battery-source is not sufficient to warrent a high-torque
Re:Still energy (Score:3, Interesting)
Guess why the fastest trains are all electric?
Many ships are moving to electric engines as well. This allows a shorter shaft as you can place the engine directly in the pod where the propeller is, reducing transmission losses. They are usually big enough that you can put your own electric power plant in them (fuel turbines will do fine) and still save space.
Some c
Re:Still energy (Score:3, Insightful)
That must explain why electic motors are the standard way of driving both high-speed passenger and high-mass freight trains.
If rapid depressurization is any indication... (Score:3, Funny)
New? (Score:5, Informative)
Re:New? (Score:2)
Re:New? (Score:2)
No, this is a hybrid that charges itself. RTFM, etc.
At some point I read that Ford was considering a hybrid pneumatic system for their heavy trucks. Braking would charge a cylinder which would later be used to drive acceleration, c
Re:New? (Score:3, Informative)
Re:New? (Score:5, Informative)
MDI car made by Guy Negre [slashdot.org]
No surprise it's italian, iirc he was working in Nice near the itlian border and the car lobby in france is too strong.
Re:New? (Score:5, Informative)
Technical details [theaircar.com]
Using a radio transmission system, each electrical component receives signals with a microcontroller. Thus only one cable is needed for the whole car. So, instead of wiring each component (headlights, dashboard lights, lights inside the car, etc), one cable connects all electrical parts in the car. The most obvious advantages are the ease of installation and repair and the removal of the approximately 22 kg of wires no longer necessary. Whats more, the entire system becomes an anti-theft alarm as soon as the key is removed from the car.
Perfect for us! (Score:5, Funny)
But I'm probably just repeating the first several dozen comments...
Wrong conversion (Score:5, Insightful)
The car swtiches to electric when it reaches 25 km/hr according to the Energine website which is actually more like 15 miles per hour [google.com].
Re:Wrong conversion (Score:2)
Re:Wrong conversion (Score:2, Funny)
Re:Wrong conversion (Score:3, Insightful)
32 km/h [google.com] = 19.88 mi/h
40 km/h [google.com] = 24.85 mi/h
Re:Wrong conversion (Score:3, Funny)
Don't Crash! (Score:5, Funny)
"Should you find yourself approaching the state of being in an accident, please yourself to duck so as to avoid looking at your previously attached body before the shrapnel took off your head." (Safety tips, Appendix A, P.232)
Nothing But Hot Air (Score:5, Interesting)
Re:Nothing But Hot Air (Score:2)
I'm not sure that anybody was claiming you could get an OverWeight Truck for neat cattle [ncl.ac.uk]. Perhaps you meant "aught for naught"?
Two sides to every story... (Score:3, Insightful)
Conversion Factors (Score:5, Funny)
Now we know why this car keeps crashing into Mars.
Compressed air... (Score:2)
futility in motion (Score:2, Interesting)
Adding an extra step for efficency loss makes sens (Score:2, Redundant)
Oh yea, this makes sense, because we all know you get more energy by first compressing air with a battery and then using it to power a motor than you would by powering the motor with the batter directly. Right. And it's not dangerous at all haveing a high pressure air tank sitting in a hot car that sits in the
Re:Adding an extra step for efficency loss makes s (Score:3, Funny)
It's not about energy, it's about power.
Shameless Joke (Score:2, Funny)
Flux capicitor optional? (Score:3, Funny)
Good for torque (Score:2)
As always: what's the power density? (Score:2)
Where's the savings? (Score:2)
And an air tank can't possibly hold enough air to power a compressed air motor for more than a few seconds.
MAYBE, if the air were liquefied, it might be feasible but still, the energy consumbed to liquefy the air would negate any possible savings that the vehicle would hope to achieve.
Sorry, I don't buy it..
Re:Where's the savings? (Score:3, Insightful)
It's not about the energy, it's about moving the pollution. As for the other points, we are talking about tanks bigger than soda bulb, so you can run motors - also the air may well be partially liquified - just like the CO2 bottles used in pubs to make beer foamy have some liquid in them.
I've seen a 50kg piston moved a fair way with a small portion of a bottle of compressed helium just like you would use to blow up balloons - it was the first stage of a shock tunne
Why bother? (Score:2)
"EV usually needs 30(A) of electrical current on driving and it consumpts 3~4 times more by starting or go up a hill."
Getting past 'All your base', they're doing all this to get past the high initial power requirements of a pure electric vehicle. IDK if the weight and complexity penalty is worth it, though.
French (Score:3, Informative)
http://www.gizmo.com.au/go/3523/ [gizmo.com.au]
slashdot, wake the fsck up.
Come on, READ the article. (Score:4, Informative)
Now, combine the compressed air engine with an hybrid car. You get an hybrid car with instant high torque when needed.
Re:Come on, READ the article. (Score:3, Interesting)
http://www.austinev.org/evalbum/035.html [austinev.org]
Ok, so it's not exactly a daily commuter, but still remarkably impressive.....
Old News (Score:3, Interesting)
It's even been tried in African [bbc.co.uk] (same company).
The company's own website seems to have gone. I would be suprised if this wasn't because the company has also gone out of business.
Why does it only get on Slashdot when it's an American company?
Same car, car, one year ago, in France (Score:2, Informative)
Site of the company in English: http://www.theaircar.com/Lucerne.html [theaircar.com]
compressed air car (Score:2)
see
http://www.theaircar.com [theaircar.com]
Units are the problem... (Score:3, Insightful)
The line should read:
The car switches to an electric motor when its speed reaches 20-25 mi/h (32-40 km/h).
It's probably already obsolete (Score:4, Interesting)
Hum: Mexico is on the system for years... (Score:3, Informative)
I can spot posts on the net at least from year 2000 about Mexico city running taxis and public buses on compressed air.
Am I missing the point ?
Z.
Already Been Done! (Score:5, Insightful)
100% compressed-air powered car already exists... (Score:3, Informative)
It doesn't use any fuel at all, only compressed air, and the features are good:
Weight: 750 kg
Maximum speed: 110 kmh
Mileage: 200 - 300 km
Maximum load: 500 Kg
Recharging time: 4 hours (Mains connector)
Recharging time: 3 minutes (Air station)
Re:100% compressed-air powered car already exists. (Score:3, Interesting)
So it's not totally green. Agreed. But it's a start in the right direction.
In my opinion midsized communal heating power stations are a good step forward to make that happen. They burn the fuel more efficiently and use the excess heat too. They come in ranges from 20 to 300 kW and cover most types of smaller to midsized bu
The Explosion Factor (Score:5, Informative)
The French air car article [gizmag.com] points out, "In the case of an accident with air tank breakage, there would be no explosion or shattering because the tanks are not metallic but made of glass fibre. The tanks would crack longitudinally, and the air would escape, causing a strong buzzing sound with no dangerous factor."
Well.
It's great to know that it's a carbon fiber tank so it won't turn into a screaming cloud of schrapnel [wahoo2001.com], but isn't there another issue at work here?
Now, I don't know exactly where on that tiny car the tank is, but I'd assume it's under the seat someplace.
The volume of that car is what...two cubic meters? What happens when you instantly put 90 cubic meters of air inside it? (Or under it?)
Have a look at this rather larger car [diveshop-pr.com] for an example. Look, ma! No fragmentation thanks to a steel tank, but all that air introduced to an enclosed space jiffy-pops a car like a cheap paper cup.
I'm more than willing to admit there's more to carbon-fiber tanks than I know. Maybe there's some property that prevents them from releasing all that energy in less than, say, 10 seconds, no matter how badly crushed. But I'm officially skeptical.
They say there's enough energy in a scuba tank to lift a hook-and-ladder fire truck 20 meters in the air. That's exactly the sort of energy I don't want released near me in a short timeframe. Gasoline is good in comparison because it doesn't tend to do this when the tank is ruptured.
Then again, a compressed air tank explosion might be just what I need to get ahead in today's Bay Area traffic. Up yours, Fastrak!
Re:The Explosion Factor (Score:3, Informative)
> Now, I don't know exactly where on that tiny car the tank is, but I'd assume it's under the seat someplace.
In the prototypes, it was apparently under the chassis [theaircar.com] (look at the third picture). I suppose the separation would prevent the air from entering the passengers' area.
> The volume of that car is what...two cubic meters? What happens when you instantly put 90 cubic meters of air inside it? (Or under it?)
Maybe the car will be lifted up a bit, but remember the tank is supposed to crack and l
Large trucks start with compressed air (Score:3, Informative)
Are you serious? I'll assume you are... (Score:5, Funny)
Re:Are you serious? I'll assume you are... (Score:2, Insightful)
Remember, life isn't like hollywood, not every car crash ends in a massive petrol explosion (or four... how many tanks do they keep in those cars?), but these compressed air tanks sound like shrapnel waiting to be flun
Re:Are you serious? I'll assume you are... (Score:5, Informative)
Err, no. A hole of any size equals a leak and a loss of pressure. I am not sure which science friction books (pun intended) you have been reading but I have suffered many leaks in high pressure air tanks and in only one case was it dangerous. That was when a friend dropped his tank on the side of the pool and the regulator valve broke off and the tank left the scene rapidly. The type of gas was irrelevant as any high pressure tank would have taken the same trip. Do you think we would be allowed to strap these things to our backs if they were as dangerous as you say?
Petrol vapour on the other hand is very explosive so even an empty petrol tank can explode.
Re:there are propane powered buses (Score:2)
No, they're not. (Score:5, Informative)
They are far safer in a fire, too. If there is an overpressure in the cylinder, the gas is slowly vented, where it burns. With a petrol tank, as the fuel heats up the pressure rises until the tank bursts (because they're either plastic or thin steel).
Re:No, they're not. (Score:3, Informative)
Re:there are propane powered buses (Score:4, Informative)
Take note too, that any major pressure loss on a propane tank will instantly drop the temperature of the remaining liquid in the tank (as it boils), resulting in less pressure - check a Pressure-Temperature chart for propane [glacierbay.com] sometime.
Compressed air at a few thousand PSI is a lot more trouble to deal with in an accident.
Re:Let's get this out of the way. (Score:3, Insightful)
Imagine what could be done with an advanced plastic tank that deforms in a severe vehicle crash or other incident, instead of shredding like a metal one. For an added safety measure, should a puncture occur, an inner membrane flows out of the hole(s)like a ballo
Re:Let's get this out of the way. (Score:3, Informative)
On the other hand petrol tank design and placement has received a lot of consideration and is no longer such a danger as it was 20 years ago.
Entertain the rest of us (Score:2)
(coming from a forum member)
Re:Rocket scientists wrote this one!!!! (Score:3, Interesting)
In my (unsucessful) haste to be the first to point this error out, I missed pointing out the cause of the problem. There are roughly 1.6 km/mile. To convert km/hr to m/h, divide, do not multiply km * 1.6 (20*1.6=32).
AirCON not Aircar (Score:5, Insightful)
If you read the website carefully, you'll note that the specifications he displays here http://www.theaircar.com/models.html [theaircar.com] for the various models (range, top speed, refuel rates, etc) are all based on theoretical measurements made by guessing how much improvement he can get from changing a number of things in his current design. The current design has been tested for a total of 7.2 km. He gets his 200-300km range by extrapolating based on his guesses. See http://www.theaircar.com/tests.html [theaircar.com] (scroll down to "Mileage comparison between the taxi in development and the final car") for the true specifications, and note that after the top row, they're all extrapolations. He's basically saying he should get x% increase from this change, and y% from that change, and that means the "improved" engine will get (x+y)% better performance.
His site hasn't changed in at least a year -- meaning those figures haven't been updates with actual test results, and I don't think they ever will be. It's real easy to guess how much improvement various changes may make. It's not so easy to get that improvement out of them.
Next, note that he's selling "licenses" to build factories to produce the car. This is his real goal: Grab some $$ from investors before they find out he has no real product. He's a lot like the guys selling free energy based on concepts that violate the laws of thermodynamics, but will have a working model "real soon now".
Go ahead and watch this guy -- it's entertainment at least, -- but don't give him any of your money until he can back up his specifications with real world tests.
Re:Not the first Aircar... (Score:3, Interesting)