Here’s site of a new car that is to be demonstrated in London in September.
http://www.theaircar.com/
Might the same idea work for yard switchers?
How does the air get compressed? I didn’t see where it said anything about that. The way I see it compressed air is just a means of transmitting power from the source (whatever that is) to the load (the vehicle). I must ask why would this be an improvement? You are just going to add the inefficiencies of converting energy into compressed air and back to mechanical propultion. You are still going to need a means of compressing the air.
That’s not all that new of an idea;some of the ‘old’ steam switchers that
ran on compressed steam,could also run on compressed air.
I hope this idea works, could be a good inner city commuter car. If its a viable car I wouldnt mind on for the daily grind, but…
Range and power are going to be the Achilles Heal of this car.
OK I like the idea, and I like the cool micro-car look of the little bugger but I have serious reservations about just how far can a tank of compressed air carry you? It would have to compressed at a very high pressure to maintain consistant air pressure over several miles. I really wonder how big the tank would need to be?
The website claims that the cars milage is “comparable with other pollution free vehicles” …thats techno-speak for it gets the same milage as electric cars, namely 50 miles max. OK for short jaunts around town but not much more, thats why they have the dual-power option listed, even they know its air only range is severly limited.
Also I really wonder just how much power this car would have going up a hill? Air pressure would again, have to be very high to provide enough pressure in the cylinders to pu***he car up a hill. Even a small gas engine would have a significant advantage over air pressure alone.
I hope the makers of this look into a hybrid sysytem where the gas motor can assist the air system.
One serious advantage over electric cars, re-filling the air tank would only take a few minutes, like filling a gas tank and unlike hydrogen, high pressure air lines could be retro-fitted to any existing gas station…
…or you just drop a quarter and use the tire filler! LOL!
Pnuematic or fireless locomotives have been around for over a hundred years, they consisted of a BIG tank and a standard locomotive chassis. These engines were common in industries and jobsites where a fire lite open flame locomotive would be downright dangerous if not dam-near suicidal. Explosives factories, chemical plants, flour mills, oil refineries, etc, all used fireless lokies. They, were VERY reliable and often last well into the diesel age for the very same reasons, even diesel or electric lokies both have sparks or flame sources that made them just as dangerous in these locations. The downside has always been that the pressure only lasts for so long and they would frequently need to be recharged with either steam or just plain air under high pressure and they were never ment to be big haulers or pushers. Sure they could be used for switching, but I suspect that a Green Goat hybrid’s electric traction motors would give it a huge advantage over any pnuematic system.
It’s all a function of energy storage. Compressed air, batteries, flywheels, liquid fuels, solid fuels, etc. Among energy storage alternatives, compressed air is probaly the WORST for energy storage per unit volume. It IS good though for being able to deliver a LOT of energy very quickly.
Battery and flywheel systems are better. Hybrid cars use a small engine to keep their batteries of flywheels charged for the heavy uses. It’s the battereis that do the real work, allowing the small engine to charge everything back up again.
I’ve heard of an attempt to build a battery powered locomotive. It required pulling an unpowered calf behind it loaded with batteries, and couldn’t go very far.
Lets face it, hauling tons and tons of freight around, even in a yard, simply requires a LOT of energy.
Mark in Utah
about a century ago – give or take a few years (no, I don’t have my reference here!) New York tried compressed air driven streetcars. Electricity was still pretty scary stuff back then, and horses have an aversion to steam engines…
It didn’t work very well. The problem was storing enough compressed air to have a range of more than a few blocks – and I do mean a few blocks. However, as vsmith notes, the same principle works very well in industry, where the distances are short and compressed air is easy to get hold of.
http://www.goldminetours.com/index.html
If you scroll down you will see a air powerd locomotive. Fireless locomotives…either steam or air were great at factorys were they could be recharged by hoses connected to boilers or compressors already makeing a*** load of air or steam to run the stuff in the factory.
The LSRM’s trolley runs on compressed air.
There are possibilities for breakthroughs in batteries, and alreayd NiCad is a big improvement over the lead acid type and makes Hybrids practical. But compressed air is still compressed air, just like 100 years ago! Same with fireless steam.
Fireless steam will last longer between recharges than compressed air since the water in the boiler will gradually flash over to steam as the steam pressure decreases. Nevertheless, both methods are tied to their outside source of air or steam as sure as an electric locomotive is tied to catenary.
Considering that the average Self Contained Breathing Apparatus bottle (like firefighters and divers use) has between 45 and 87 cubic feet of air compressed in it, at pressures ranging from 2200 psi to 4500 psi, and that I can exhaust a 2200 psi bottle in about 15-20 minutes just breathing, things don’t bode well for using compressed air for any large-scale applications. We’re very possibly back to pulling a “tender”, although “regenerative braking” might help keep the pressure up. On the other hand, a high capacity compressor, running like the Green Goats only pumping air instead of charging batteries, might make the idea a little more practical. It does imply that there would have to be a fair amount of idle time in the work cycle.
Cobrn35: Why isn’t the LSRM’s trolley running now?,or did we just hit there on an off day?
I still think a Green Goats electric traction motors would have a huge pulling advantage over a compressed air piston system any day. I seriously doubt the car mentioned in the article above could go more than a few blocks before having to be recharged.
Compressed air locomotives were fairly common in mines at one time. Exhausting the air inside the mine was actually a benefit. But as several have already said, the range was very low.
Very early in the development of the diesel locomotive several people tried pneumatic drives where the diesel engine drove a large compressor. The compressed air was then used in a steam locomotive type running gear. The system worked, but was very inefficient.
I rode behind a compressed-air powered passenger train in about 1975. It was a small amusement park train on a circular track at the Texas State Fair grounds. Had a “steam” type locomotive with cylinders, pistons, etc. and a tender that looked a bit like a Vanderbilt-- or like a big cylindrical propane tank on wheels. Went round and round a couple minutes and when it ran out of air, that was the end of the ride. While passengers were loaded, the tender tank was recharged with air.
My pictures were slides I think, to which I do not have instant access for posting. I can’t scan without going to the photo store.
For a commuter or rapid transit train, might something like this involve recharging the tanks at each station stop?
We use Scott 50’s with a 4.5 -30 minute bottle. [:)] 18 minutes.
You lose effeiceny when you compress are because you generate heat as well…so you will never get same or greater horsepower from compressed air unlike with batterys.
What about using a wind generator? With a wind generator (take out electrical generator, put in an air pump), compressed air could be created without any energy conversion (fossil fuel to electricity, electricity to compressed air).
Compressed air would probably work better if the drive line was based upon a turbine type of system rather than the steam locomotive or automotive piston system. These latter systems require large volumes of air for single or perhaps two or three uses befor exhaust. The multiple stages of the steam turbines used in ocean shipping use the steam or air over and over before it is exhausted at near atmospheric pressures. Downsizing these turbines would be possible but will the turbine power curve and duty cycle work in automotive applications?
Saw a compressed steam locomotive this weekend at the Heart of Dixie rail museum in Calera, Alabama. They told me it was used for industrial switching. It’s a huge “Thermos” mounted over steam running gear with a giant valve on the side where the steam was put into the “boiler”. Like most museums, it’s waiting for a lot of love and, I suspect, more than one bruised knuckle.
Erik