Exhaust Heat Recovery - Steam Power

[Daox]

Winding copper tubing around a horizontal exhaust pipe won't work very well. As the water heats up it will turn to steam. As it turns to steam it will want to rise. Since your loops are all horizontal the steam gets trapped at the top of each winding. If you wind the tubing around a vertical pipe you are fine, but there aren't many vertical pipes to wind around.

[Daox]

Originally Posted by Patrick

Air tool vanes are a plastic composite. They are cooled by the expansion of the compressed air and you have to add lubricating oil periodically or they will seize up. The tools also run at very high rpms, so some sort of gearbox would probably be needed.

I'll have to take apart the die grinder I have to see what materials are in it. I'll post pics when I do.

You are correct though, most grinder's rpm is way higher than what an alternator will handle. I suspect once you put the loaded alternator on the grinder you'll drop those rpms to a reasonable level though. Hopefully no reduction is needed. To be honest, I'm more worried about getting enough pressure to keep up with the grinder at this point.

[jdgFirefly]

Originally Posted by Patrick

Air tool vanes are a plastic composite. They are cooled by the expansion of the compressed air and you have to add lubricating oil periodically or they will seize up. The tools also run at very high rpms, so some sort of gearbox would probably be needed.

I agree with you, I'm likely mistaken about the vanes being graphite, that would be to brittle. They did look like and feel vary similar though.

If heat is going to be a problem then you may need to fab some vanes for this idea to work.

Here is some diagrams of closed systems, I'm sure you have seen these before. The Rankine cycle and the vapor compression cycle just to show the similarity in the components.

Basically you need a condenser and a pump to make it a closed loop system.
With a closed loop system you may be able to use a refrigerant which would be good because I think they usually have lubricant in the solution.

[bandit86]

I didnt read any except page one, but i toyed with this idea for a long time

My idea was to run a water pipe in the exhaust manifold and use it to heat up lots of water, say 20 gallons, to pressurise it. then you would need a steam engine to either run the drivetrain or charge a battery bank on a hybrid.

I would like to take a small 3 ylinder engine and get a custom camshaft job done. that would allow the engine to run as a steam engine

[Daox]

Well, I tried the die grinder powering the alternator tonight. It was quick and easy to do. I just put a 10mm socket adapter in the die grinder. The alternator has a 10mm hex on the end of it.





I tested at 50, 75 and max (120ish) psi. Here is the result at max psi.

http://www.youtube.com/watch?v=WdAnBLx3yug

[RobertSmalls]

You get a for going out and testing a hypothesis, but I can't hear the video.

I see 12.48V with the die grinder on, but what was the resting voltage of the battery?

[Patrick]

And what was the amperage?

[rbrowning]

cyclone waste heat engine at: Cyclone Power Technologies - How It Works
uses it's own combustion heat source but could use your exhaust to supply the heat for their engine that would drive your alternator, A/C, etc.

[Daox]

Well, apparently youtube isn't liking my video file. I've uploaded it a few times now and I just don't get sound.

Anyway, the die grinder could not spin the alternator fast enough with the field coil powered up. As you can see, the voltage slowly drops on the battery as the video progresses. So, we need something capable of flowing more air or higher pressure, or both.

[Schelter]

What about marine exhaust manifolds, don't they have water jackets? Not that they ever used your engine in a boat but....a little work can adapt a cheap steam maker