Why don't they make compressed-air steam engine autos, trucks and etc?

Question

This combines the ideas of the compressed air-car, multi-stage steam engine efficiency and regenerative braking. Electric power companies use steam engines to generate electricity because it is much more efficient. The efficiency of internal combustion engines has a mechanical efficiency of about 20%. Using a small steam engine, is more efficient, cleaner and simpler than an internal combustion engine however nobody wants to wait for the steam to heat up. Two 43 liter tanks of compressed-air would provide 15-20 miles while the boiler heats up. This solves the drawbacks of straight steam power. When the steam pressure becomes adequate the engine would automatically switch from air to steam pressure. During braking the engine would work backwards as a compressor forcing air back into the air cylinder tanks. The water in the boiler would keep from freezing by automatically heating the water with the fuel when the temperature was too low. SUV Results: 73.8 MPG @ 15 gal. water.

So far, this engine design appears to be a viable improvement. You should watch the Mythbusters episode "Air Cylinder of Death." This episode proved that a scuba tank doesn't explode so much as they take off like a rocket. Gas cylinders just have to be installed correctly. Boilers are also safe since the tubes are enclosed in an unsealed housing, a burst tube would simply let steam go out the exhaust. No chance of explosion.

The fuel used to heat the boiler could be heated by gasoline, oil, propane, natural gas, ethanol, diesel, alcohol or even hydrogen. The air to fuel mixture just needs to be adjusted to the optimum stoichiometric reaction.

Along with your opposing answer provide a possible improvement.

Answer 1

That would work and it would only take minutes to achieve full operating pressure. There are other drawbacks to using a steam engine as direct power to the wheels. If about to be hit by a truck, you push the throttle full on the steam pressure drops, and although the boiler flames up it takes a bit to get back to full pressure. The auto hesitates and the truck hits you. You can't "gun it" with a steam engine.

Water freezes and in cold weather you would have to constantly burn fuel when parked to keep the engine warm. The compressed air would not keep it warm.

For an air-steam car you would have to burn fuel from start to stop, since the compressed air is used only to allow the steam pressure to build up. A steam-electric hybrid would actually be a plug-in electric car with batteries charged from the grid plus an onboard steam-powered generator. Since most driving is within 30 miles of home the car would be an EV most of the time, using no fuel, just cheap electricity. The problem with an EV is, to get more distance you need more batteries or more expensive batteries and then when you arrive it takes 6-12 hrs to recharge. By having a generator built-in the batteries could be kept charged and you could drive the distance then simply refuel in about 5 minutes.

AC, heat, power steering, power brakes and all the other accessories on an EV have to be powered by electricity, which drains the batteries and reduces the distance an EV can travel before recharging. By having an onboard generator you wouldn't have to worry about the distance being affected by heat or cold and you could have all the power accessories.

An electric motor can be accelerated suddenly, you can "gun it". The batteries solve the problem of the steam engine system freezing by using electric heat strips and insulation. The steam engine/generator would start automatically any time the batteries were low, even when parked in freezing weather, thus making enough electricity to prevent freezing. If parked at home the car would be plugged into the grid and the heat strips would keep it from freezing as the batteries were charging.

I think the steam-electric hybrid would use even less fuel for the miles driven since 80-90% of driving would be done as an EV, near home, using only electricity. Your idea is good, but it doesn't solve many of the problems that a steam-electric hybrid would.

E-mail beesidemeusa@yahoo,co.uk to discuss more.

Answer 2

Internal Combustion engines are compressed air engines, igniting the fuel causes the air that is taken into the cylinders to expand in turn causing the piston to go down.
Diesel engines in over the road trucks use compression brakes which shut off the fuel to a few of the cylinders and keep the ex aughts valves from opening and create a braking action.
Power companies use the steam to turn turbines which are connected to generators.

Answer 3

the inherent dangers of using compressed air are enormous, without proper care they will be lethal, I have used quite a few very large diesel engines that use a combination of starting methods, One engine used the following
A koffman starter using a cartridge
compressed ether
high pressure air,
battery start
and lastly hand crank.
As for the steam engine it went out with the Stanley Steamer, you have just got to see a steam engine blow for something spectacular. It is not however clean, some method of heating the water is required which could prove its downfall. Still a very interesting hypothesis. You probably wont believe this but myself and a colleague built an engine that ran off water using generated high voltage to 'crack ' the water into oxygen and hydrogen, this was in 1972 and we had the engine running for about 4 hours, the 'losses' were enormous but with modern technology it could be made to work again

Answer 4

Just what kind of fuel do you intend to use to heat the water into steam? Many electric power companies burn coal to make the steam to drive their steam turbine generators. It may be efficient on a large scale, but not on the smaller scale of an automobile. Coal is a very dirty form of fuel that creates soot and sulfuric acid as a by-product of burning. If you think the greenhouse gasses from automobiles are bad now, just think what they would be like if all the millions of cars on the road today were coal fired.

Answer 5

there are cars being built today with steam engines, just not by the big auto makers. there is also a couple of air powered cars in prototype, and soon to be built in France. there are drawbacks to both though, for example with the steam car you have to boil water, which means you need a boiler, to contain the steam pressure. boilers do come apart rather violently. as for the air car, it also needs high pressure tanks to contain the air. you also need to re-pressurize the air tanks, and since they are also under pressure, they also tend to come apart rather violently. you would also have to have the tanks or the boiler re-certified every so often, and replaced on a regular basis.

Answer 6

They stopped making steam powered cars one hundred years ago. And they still burn fuel!

Answer 7

WHERE WOULD THE TANK BE MOUNTED ????????????