BR

Compressed Air Car from France
« on: April 27, 2009, 09:45:50 PM »
http://www.mdi.lu/english/miniflowair.php

Hey Guys,

I've been reading about this.  I guess it will be available here in the US next year or so.  I was wondering if any of the Europeans here have had any experience with this, or any more info.  I'm really interested to know what kind of maintenance these guys require.  It seems like a really cool technology.

Here is the link to the US company that is claiming to be bringing this technology over.
http://zeropollutionmotors.us/?page_id=46

take care
Gil



SSLtech

Re: Compressed Air Car from France
« Reply #1 on: April 27, 2009, 09:53:12 PM »
He's (Guy Negro) been promising this for a long time.

I'm skeptical... not that it CAN'T be done, but that it probably won't.

There's no way I can conceive that he could scale up to export to the US next year when he's not filling the streets of France with them right now...

The company site is a Luxembourg domain, they spend most of the video focusing on stuff like styling details (and bad ones, at that!) and providing NO information... but I can't find any record of them having completed any crash-testing... which would be kinda necessary in order to export to the US as a public-road-going vehicle...

I'll believe it when I see it.

Keith
« Last Edit: April 27, 2009, 10:00:38 PM by SSLtech »
"A waist is a terrible thing to mind"
Quote from: PRR
Ah, but that was 1999; we don't party like that any more.

JohnRoberts

Re: Compressed Air Car from France
« Reply #2 on: April 27, 2009, 10:13:57 PM »
+1  not new, but dubious for car replacement.

The compressed air gas tank, must hold the rough equivalent of the expanded gasoline after it is burned.....

Sounds more like a bomb than a vehicle.

JR
It's nice to be nice....

SSLtech

Re: Compressed Air Car from France
« Reply #3 on: April 28, 2009, 03:38:56 PM »
Sounds more like a bomb than a vehicle.

No kidding...

If you had enough compressed air for stopping a car many times over a (modest)  250-mile range, and held that in a tank, the tank has to be able to survive you hitting an immovable object at 40MPH...

Is anyone else thinking "pinto-on-a-much-grander-scale"?

 :D

Keith
"A waist is a terrible thing to mind"
Quote from: PRR
Ah, but that was 1999; we don't party like that any more.

tv

Re: Compressed Air Car from France
« Reply #4 on: April 28, 2009, 04:43:44 PM »
ONE POINT THAT WAS NOT EXPLICITLY LAYED OUT BUT IMPLIED NEVERTHELESS (or am I just being exceptionally lucid?):

a). You need a PROPER FEMALE on the passenger seat. In case you run out of fuel, she'll give you a couple of extra miles!!

8)
If you sprinkle when you tinkle, please be neat and wipe the seat.

owel

Re: Compressed Air Car from France
« Reply #5 on: April 28, 2009, 04:45:41 PM »
Here's what a 350 psi water tank explosion looks like.
http://www.youtube.com/watch?v=JmJoyuUJj2Q

I can't imagine what a 4500 psi will do... then imagine you're in the car when that tank failure occurs.

... besides, it's an ugly car.  

PRR

Re: Compressed Air Car from France
« Reply #6 on: April 29, 2009, 03:31:40 AM »
Compressed-air "engines" are old. Some torpedoes used them. In rail-yard switching service, they offer instant start and zero standby loss (compared to steam), plus lack of smoke in your eyes when run backward. They have been used in mines.

Note that all of these are fairly heavy-weight systems. Iron wheel/rail locomotives need massive weight to get useful traction. And rail-yard and mine safety expectations are lower than most of us accept in casual life (though air-engines can be safer than some alternative rail-engines).

And I do not know of any current use of air-motors on vehicles. Diesels killed air-engines in switch-yards: far greater range and faster re-filling, with negligible start-up and standby losses. Mines mostly went electric, battery or trolley.

A particular point: air-motors can often be built from steam-engine part-bins. Same/similar initial pressures (same pistons and cranks), optimum valve timing just a little different. 1800-1930, this was universal technology. 140 pages in Marks Handbook 1930. 3 pages in Marks 1965, and that mostly to help you estimate a Diesel or electric replacement for an existing steam engine. Piston-steam is 99.44% dead. (They just re-launched a steam paddlewheel on the Delaware, but it is clearly a folly and will surely get an explosion engine when the novelty wears off.)

> tank, must hold the rough equivalent of the expanded gasoline after it is burned.....

For energy, yes. You want a normal car with a normal range, you need over a million BTU of stored energy. Enough to feed the fire under my house-heater all day and all night. If I re-rigged my heater to output a day's supply of heat in a second, the house would vanish.

I'm not sure about weight/volume being comparable. Of course you can compress very dense, on paper, but life with refillable HIGH-pressure air is dangerous. And not light.

The funny thing about gasoline is a very thin cheap tank usually holds it, and when it does leak it does not always catch fire. The inevitable EXPLOSION seen in every Hollywood car-chase is rare in real life (though a quick-burning fire can be devastating). As I understand air-storage, a small crack usually leads to total release in all direction at somewhat super-sonic speed. And this stored energy does not need mixing and ignition, it is ready to BOOM. Even little 2-gallon 100PSI air-tanks are industry regulated, and some cheaper types are not legal in my state (I used to smuggle them over the line).

That's before we get to the fact that new car companies do not happen in Europe or North America. Car companies started in the early 1900s or failed. Tucker was under-capitalized, but Kaiser had ship-loads of money, spent a bunch, quit. Ferrari and Lamborgini are too small to matter (and are they not FIAT now? 1899!). BMC and AMC don't count because they had old roots, and died anyway. VW snuck in mid-1900s for exceptional reasons. Japan is on a different track but Toyota, Mitsubishi (Nissan), and Mazda are very old and Honda was a strong man who snuck in via motorbikes and farm engines, then let Japanese bankers hedge-play him against the other car makers. So the three classic markets have not birthed a new car company in 50 years. Korea, India, and China are stirring strong, but have favored tried-and-trusted technology rather than crazy ideas.

OK, I looked at the link. There was a guy promoting crammed-air utility delivery vehicles; this is cute but not necessarily bound to succeed.

It does keep some graphic artists busy. The only actual photo I noticed could be cobbled-up from golf-cart and bicycle bits; most of the site is renderings.

None of those vehicles is ready for general US use.

And the business plan is "commercializing turnkey factories".... which means someone else invests money for a "franchise", like a hamburger chain. Worked for McDonalds, Coke, Pepsi... except they were not franchising "turnkey" factories, and do not have so many special parts as a car. In an utterly free market, this would be a tough sell or a bad deal. However they note that Vehicle Import Taxes skew the economics.

> what kind of maintenance these guys require.

The air-system: next thing to zero maintenance. BUT if you must break any part of the high-pressure system, you better know JUST how to reconnect it. We have very high pressure systems in cars (brakes, power steering) but liquid systems do not BOOM the same as gas or vapor systems. A mistake is not a an oil-spot in the driveway.

If you want to drive out of sight of your refilling compressor, then you also have a plain old spark-engine with all its joys and pains.
« Last Edit: April 29, 2009, 03:38:54 AM by PRR »

PRR

Re: Compressed Air Car from France
« Reply #7 on: April 29, 2009, 03:39:32 AM »
> a 350 psi water tank explosion

That's different. If it is 'solid' water below boiling, no air-space, the failure is quite mild. Boilers were routinely tested by filling solid with water and raising the pressure, even to a repairable crack. For steam, or water ready to turn to steam, you have an expansion different from air; I believe the air-engine needs higher pressure to give similar force to expanding steam. But as you say, 4500 psi is higher. Higher than any utility steam system.
« Last Edit: April 29, 2009, 03:41:09 AM by PRR »

SSLtech

Re: Compressed Air Car from France
« Reply #8 on: April 29, 2009, 08:18:47 AM »
Ferrari = Fiat, Lamborghini = VW... but high-volume companies like Safeway can always buy out small-volume specialists like Fortnum & Mason, so what appears as cart-before-horse to many consumers is actually perfectly normal, of course. -But indeed, all of the established car volume production capacity is in OLD hands, and new companies just DON'T get that capability.

They attract non-thinkers by talking about the air as if it was the energy. -I lost track of how many times they mentioned that "Air is free". The ENERGY to compres the air is NOT free, and the air doesn't make the car move as anything other than a medium for the ENERGY.

Then they mention about how the engine which is driving the car can simultaneously be used to compress more air, to drive the car, which in turn compresses more air, which in turn drives the car, which in turn compresses...

Yeah. -Sadly some viewers get excited about that aspect... (well, air's free after all!) but it will NEVER work. In addition they mention that the expanding air can be used to chill the car (free air-conditioning!) but skip over the fact that -in 'filling' the car, compressing all that air in a short fill-up will likely  HEAT the air tanks to a couple of hundred degrees... "Your car's all filled up and ready sir... if you can just wait a few hours until it cools to a survivable temperature!" ;)

Keith
« Last Edit: April 29, 2009, 08:20:55 AM by SSLtech »
"A waist is a terrible thing to mind"
Quote from: PRR
Ah, but that was 1999; we don't party like that any more.

JohnRoberts

Re: Compressed Air Car from France
« Reply #9 on: April 29, 2009, 10:52:10 AM »
Yup that air is free thinking just highlights how little people think through grand concepts. While one would expect the people developing the actual technology should understand. I get similarly irritated by the Hydrogen power crowd, it's "only water", and even the electric car crowd, "requires no gasoline", just plug it onto your outlet. Until we start building a bunch of nuclear power plants, we probably won't have enough electricity on our current path.

I like electric cars for one pretty useful thing that the compressed air car promises (regenerative braking), but electric cars can do in practice (charge batteries when braking). it might be interesting to hear a more thoughtful analysis of our energy needs, usage, and engineering trade-offs. This is just my short list.

For transportation if we break down the components of energy usage, we have

1) accelerating and slowing the mass of the vehicle which is many x the mass of occupants.

2) lifting mass of vehicle and occupants over hills.

3) tire sidewall flexing with rotation

4) wind resistance

5) simple bearing friction.

While items 1 and 2 consume massive amounts of energy, and is proportional with the mass of the vehicles, in principle these could be mostly recovered. We already recover most potential energy by coasting down hills, but most of the kinetic energy from velocity gets scrubbed off by wind resistance and braking which turns it to heat. Electric regenerative braking could be significant here.

3) Tires are a tough nut to crack.. This is also proportional with mass of the vehicle.  The soft flexible side walls are not just a comfort issue. Running extremely high tire pressures to reduce losses and improve gas mileage significantly impact traction and steering safety.  I could imagine variable tire pressure that pumps up the tires for straight line highway driving, then deflates them for local secondary road use.

4) wind resistance is another tough one. We can look at this two ways, design uber sleek low cd vehicles, or make square boxy cars that couple well together and draft each other on the highway. Wind resistance has a square term in it, so it's negligible at slow speeds but significant at reasonable highways speeds. This is largely proportional to frontal area, with a lesser drag issue related to length. So long skinny is slicker that short fat.  Personal choice may depend on ratio of highway to secondary road driving (and speeds) one does.

5) Bearing friction is proportional to mass but modest so of lesser concern.

I see electronics being helpful in A) regenerative braking, b) smart tire inflation, c) auto pilot highway drafting.

While the mass of vehicles (and heavy battery packs) will be somewhat mitigated by regenerative braking, I still favor energy delivery via the road surface or some indirect method to draw power as needed rather than carry.  Of course the spread out nature of most of the US makes gasoline still desirable for it portability and energy density.

----------

The next major nut is building energy usage (some 40% of total)... kind of like regenerative braking it is remarkable how much energy we throw away because of ineffective insulation. The human body actually throws off heat, so with perfect insulation we could literally heat ourself if our homes didn't conduct so much heat to the cooler outdoors, in the summer cooling needs would be much lower if we kept the outside heat out.

Of course this requires special consideration for air exchange to keep air clean and fresh, but this will pay off much larger dividends than finding cheaper energy. I see no reason why every residential rooftop shouldn't have solar shingles to collect the modest energy needs of an efficient home. (I wonder how much all those black roofs contribute to global temperatures. It does make a difference in cities).

Sorry if this is an oversimplification... but we need to look at energy use from a zero based budget approach, not taking current practice as some distillation of mass wisdom. While what we are doing is mature, it is not efficient.   

JR
It's nice to be nice....


owel

Re: Compressed Air Car from France
« Reply #10 on: April 29, 2009, 11:36:52 AM »
Quote
I see no reason why every residential rooftop shouldn't have solar shingles to collect the modest energy needs of an efficient home.

Again, it all boils down to about money.

I thought about installing solar panels on my home a few years ago and did research. The amount of $$$ investment required, upkeep, maintenance, my consumption, the "solar quality" in my state/location/house orientation, the amount of power I could only generate, the number of batteries I need to have, the floor space area needed for the equipment and batteries, VS. the  amount I currently pay to the electric company and my projected ROI (10+ years to break even)....

it didn't make financial sense to install solar panels.

When solar panel efficiencies go up, costs go drastically down, batteries become better and related equipment costs go down... then maybe.  Right now, it's more of a "feel-good" accessory for a house.  Crunch the numbers and solar energy is still not attractive.


Energy:
The public majority doesn't understand that you can't create energy from nothing. You're just converting one form of energy to another.  (But they all know who got kicked off the island, who's dancing with who, and who got eliminated.)


Quote
Then they mention about how the engine which is driving the car can simultaneously be used to compress more air, to drive the car, which in turn compresses more air, which in turn drives the car, which in turn compresses...

So now they're hawking a perpetual motion machine.


JohnRoberts

Re: Compressed Air Car from France
« Reply #11 on: April 29, 2009, 01:09:04 PM »
My suggestion about solar panels was long term in future thinking...

Today I feel adding insulation and sealing leaky doors/windows is compelling for cost/benefit. Just "need" less energy no matter where it comes from.

We will then need to deal with "tight house" syndrome.

JR
It's nice to be nice....

PRR

Re: Compressed Air Car from France
« Reply #12 on: April 29, 2009, 01:38:27 PM »
> they mentioned that "Air is free".

Water is free. Fetching water may cost.

Industrial Revolution started on water power. Once you have mechanical weavers, a water wheel is much more power than a bunch of laborers. And "free".

Well, the water does no work, the fall of water does work. The first mill on a stream could take water far uphill and dump it far downhill. When the inevitable neighbors (especially other mills) complained, water-drop rights were established. Your intake and outlet elevations were regulated. Compliance was enforced by your neighbors, nominally through courts, but sometimes dams and flues got the midnight axe.

> .... the engine which is driving the car can ...compress more air, to drive the car, which in turn compresses more air, which in turn drives the car, which in turn compresses... ... it will NEVER work.

When all available fall-of-water was tapped, but mills needed more power, they turned to steam engines. But steam engines were mostly adapted to pumping, not shafting; anyway "water is free" (and fall-of-water was already invested). So there were several installations where a steam pump picked up water from the tail-race and pumped it back up over the dam, while the wheel continued to drive the mill. Not a complete perpetual-motion loop, no. And wildly inefficient (but thermodynamic efficiency was not yet defined). And such a scheme can be used for storage: New Jersey and South Africa store electricity in ponds to even-out the day/night cycle of electric consumption.

> expanding air can be used to chill the car (free air-conditioning!) but skip over the fact that -in 'filling' the car, compressing all that air in a short fill-up will likely  HEAT the air tanks to a couple of hundred degrees...

Filling should be done like any non-toy air compressor. Massive fins (even water-sinking) between compressor and storage tank. And vehicle filling is intermittent, while compression is probably cheapest if done slow and steady. So the local Esso-Air station would have a compressor running all night to bring tanks up to 5,000psi, then drop to 4,400psi in the morning rush, catch-up mid-day, droop again in the evening.... most air to vehicle tank will be several hours old and cooled simply by storage, on top of probably massive initial cooling to protect station lines and tanks and to maximize tank fill.

Expanding air will chill. We don't want to just waste it. IIRC, the better air-motors were "compound", high and low pressure cylinders. Expanding 300:1 can't be done well in a single cylinder. But also: expand half-way, say 17:1, and the air is COLD. Go a lot further, and it freezes. So there was an "inter-cooler" between HP and LP cylinders, actually to re-warm the air to recover pressure and avoid ice-up. So there is coolth to waste. But maximum at max power, and passenger cars do not run max-power most of the time. And OTOH, in winter this coolth is a problem, possibly requiring massive "radiators" for best efficiency.

> the compressed air car promises (regenerative braking), but electric cars can do in practice

This requires "downshifting", same as "engine braking". You want to pump energy from road to storage, different "gear" than running energy from storage to road. Electric motors have a number of tricks, from series/parallel windings to switcher-technology, to exchange voltage/current and force electric either way. Engine tricks are different, and perhaps not so elegant.

In general, for me, regen braking is useless. I run highway speed non-stop. All the energy I put into momentum when starting is scrubbed-away by air-drag (bearing losses are near-zero, and tire loss is small compared to highway air-drag). The most I could recover is the last minute before my exit. And I usually use very little dissipative-braking for that: I know I am getting off, I slack-off and spend my momentum to carry me off the ramp. There is a hard 25MPH-zero stop at the bottom, and that's the zone where regen braking needs impractical gear-up, usually resorts to friction to take the last few bits of momentum off. But I may be anomalous: I replace brake pads not for wear-out but because calipers suck and either stick or wear-off one corner of the pads. I see many drivers wear brakes harder than I do, and some of them stupidly excessively. A spurt-brake-spurt-brake driver could get considerable benefit from regen.


 

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