the future of car engines?

[vorticon]

i still think that 6 stroke design that was posted about 6 months back is very, very promising - if they can get it working with regular tap water.

[Vulcan]

Is this gonna be like the biofuels where we have to switch farms from food production to fuel production and we have fuel but no food?

Once you put a value on air we're all screwed.

[scottydawg]

One thing's clear, we're going to have to figure SOMETHING out.

That First Law of Thermodynamics is a b*tch, ain't it?

[Angus]

Originally posted by mora
I'm sure you  realize that hydrogen is just a very inefficient battery. Doesn't matter in Iceland though, as you have an abudancy of free energy. The only advantage a hydrogen car has over an electric car is the lower charging time.

AFAIK. Hydrogen production, even from fossile fuels, is as effective in energy economy, as using it directly in a combustion engine.
The pollution is also better to harness.

And as for this:
"Is this gonna be like the biofuels where we have to switch farms from food production to fuel production and we have fuel but no food?

Once you put a value on air we're all screwed"

Well, we had civilization for some 7000 years now. The way we live now, even if it stops where it is, won't even work for 200 years ahead. One day or another the party has to stop.
The fun part is that most of the energy we are using is not just cars, and secondly, mostly for waste. You'd be surprized how much energy gets wasted on dumpings,..,.,......

[Hornet33]

I can see how this could work. The carbon fiber storage tanks is a smart way to go. Range is going to be the big problem. Now if they were able to say hook up a small compressor that was linked to the drive wheel, on longer drives where the wheel was turing at a fast rate the compressor would allow the car to recharge the tanks by itself, or at least extend the range before having to fill the air tanks again. All you would need is a clutchable drive belt for the compressor to engage or disengage.

[Chairboy]

Originally posted by Hornet33
I can see how this could work. The carbon fiber storage tanks is a smart way to go. Range is going to be the big problem. Now if they were able to say hook up a small compressor that was linked to the drive wheel, on longer drives where the wheel was turing at a fast rate the compressor would allow the car to recharge the tanks by itself, or at least extend the range before having to fill the air tanks again. All you would need is a clutchable drive belt for the compressor to engage or disengage.

No, all you would need to do is violate the laws of thermodynamics.

It wouldn't work, and it would decrease your range.

[Maverick]

Chairboy......SSSHHHHHHH!!

You are disturbing the birth of the perpetual motion machine!

[stantond]

Originally posted by Chairboy
I think your assertion that the electric car is more efficient than any other is a bit off.  Chemical batteries have very low efficiencies, a significant portion of the power is lost to heat.  It's possible that flywheel or compressed air would be more efficient than electric, but it depends on the systems in between.

Pure electric=not very efficient.
Internal combustion=not very efficient

The risk of explosion with the tanks is pretty darn low, these prototypes use carbon fiber wound tanks that are much more likely to simply leak than explode.

The basic lead acid battery is about 75-85% efficient.  An electric motor is 90+% efficient.  Energy from heat has a Carnot efficiency of about 35%.   If gasoline or diesel fuel is used, then something burned must be turned into electricity, converted into mechanical motion by an electric motor, then the energy from the electric motor stored in either a spring, compressed air, or kinetic energy (i.e. flywheel).  Applying the second law of thermodynamics means spring, compressed air, or KE storage, along with any coupling and transmission efficiencies would have to be greater than 70% to equal the efficiency of an electric powered car using lead acid batteries.  Lead acid battery technology is over 100 years old and more efficient batteries now exist.

Any of the above energy storage types can be used independent of petroleum oil and can use coal, solar, or nuclear energy.  However, if using petroleum oil, directly burning oil at 30+% efficency is at or near Carnot efficiency.  So, for a thermal energy source such as petroleum oil, the internal combustion engine (i.e. the otto cycle or diesel cycle) is a very efficient use of the oil energy.  Without oil, all energy needs to be converted to electrical energy for transmission.  Converting elecrical energy back to mechanical energy for storage has a cost in efficiency.

The carbon fiber high pressure cylinders are composites, which are lighter weight than fiberglass but still prone to the same types of failures.  Carbon fibers aren't a 'magic bullet' and still use an epoxy binder much like fiberglass.   Work has been done to embed strain sensors for health monitoring in these tanks but it is still under development.  Someday (I doubt in my lifetime) high pressure composite tank rupturing may not be a consideration.  Depending on the cost, compressed air cars may become more practical then.  However, compressing air to be later expanded for mechanical work will never be as efficient as electrical energy converted to mechanical energy.


Regards,

Malta

[mora]

Originally posted by Angus
AFAIK. Hydrogen production, even from fossile fuels, is as effective in energy economy, as using it directly in a combustion engine.
The pollution is also better to harness.

I believe burning hydrogen in an internal combustion engine isn't any more effective than burning up  hydrocarbons. Perhaps you could build a working adiabatic(sp?) internal combustion engine running on hydrogen, but I doubt it would happen.

 You have to take into account the losses in transportation and converting eletricity into hydrogen. The fuel cells aren't 100% efficient either. The hydrogen also needs to be cooled to keep it in a liquid form. All in all I believe the efficiency of all this would be way below a lithium battery. The only advantage would be the charging time, which would be minutes with hydrogen, and an hour with a lithium battery. Me thinks that electric cars have a better future.

[mora]

Originally posted by Angus
AFAIK. Hydrogen production, even from fossile fuels, is as effective in energy economy, as using it directly in a combustion engine.
The pollution is also better to harness.

I believe burning hydrogen in an internal combustion engine isn't any more effective than burning up  hydrocarbons. Perhaps you could build a working adiabatic(sp?) internal combustion engine running on hydrogen, but I doubt it would happen.

 You have to take into account the losses in transportation and converting eletricity into hydrogen. The fuel cells aren't 100% efficient either. The hydrogen also needs to be cooled to keep it in a liquid form. All in all I believe the efficiency of all this would be way below a lithium battery(or other types of advanced batteries in the future). The only advantage would be the charging time, which would be minutes with hydrogen, and an hour with a lithium battery.

[Excel1]

Originally posted by Vulcan
Is this gonna be like the biofuels where we have to switch farms from food production to fuel production and we have fuel but no food?

Growing fuel is helpful and there is some money in it for some farmers, but to do it on a large scale is just a greenies pipe dream. There's not enough arable land on the planet to make it worth while growing enough fuel in bulk to offset the costs of lower food production.

Originally posted by Vulcan Once you put a value on air we're all screwed.

Speaking at a domestic level, we are well down the path to screwedom as it is. The profitability is being taxed right out of farming by local and central govt  i.e. increased production costs, which is hurting our ability to compete in trade.

If things don’t change soon and we are hit with the inevitable "global warming taxes" imo they will either deliver a killer blow or spark a revolt. I'm betting on the latter.

[Angus]

Originally posted by mora
I believe burning hydrogen in an internal combustion engine isn't any more effective than burning up  hydrocarbons. Perhaps you could build a working adiabatic(sp?) internal combustion engine running on hydrogen, but I doubt it would happen.

 You have to take into account the losses in transportation and converting eletricity into hydrogen. The fuel cells aren't 100% efficient either. The hydrogen also needs to be cooled to keep it in a liquid form. All in all I believe the efficiency of all this would be way below a lithium battery(or other types of advanced batteries in the future). The only advantage would be the charging time, which would be minutes with hydrogen, and an hour with a lithium battery.

I took my data from news and websites a long time ago and I don't have it handy except in the back of my head. But I recall it was roughly the same output by making Hydrogen and then use it for propulsion (it's not done by combustion) as taking the fuel for a combustion engine. The magic is that only a little part of the fuel we burn in a car engine is effective for propulsion, while electicity generated even by burning fossil fuels is done in a plant which is far more effective than Ms.Daisy driving her car.
So, there are all these ideas around about how to store the energy to get a max output from the engine, such as air, electricity etc, or move to Hydrogen.
But the downside of Hydrogen is there as well. It's bulky, and the engine is bulky. You can use it on a bus, but we're far away from making it practical for personal vehicles.
The trick there would rather be methanol, but again, then you're back into combustion....
My 2 cents is that the solution will not be a single one.

[Ghosth]

Need to go back to steam, rebuild the steam or Stirling engine to current standards. Steam engine can be setup to burn virtually any fuel, biomass, etc.
Its just a matter of setting up the firebox and adjusting the fuel/air rate. You could drive to the office on last weeks newspapers. Or throw in a couple of oak logs, or fill a wood pellet hopper for that long trip.

Look at todays modern wood pellet/corn stoves for heating.
It would be very easy to design a steam engine with similar features & safeguards. Multi fuel capability is also easy. You could burn straight vegetable oil without having to refine it or convert it to biodiesel.

Steam Electric hybrid has LOADS of potential, but will it happen in our lifetime?
Don't bet on it, big business is not going to let anything happen that can seriously impact their revenues.

As for Hydrogen, its really only efficient if we use renewable resources to make the power. Solar, wind, tidal all have potential depending on where you live.

[Viking]

Steam engines are incredibly energy-inefficient.

[Chairboy]

Viking, do you include the Sterling cycle in that assessment?