Exhaust Heat Recovery - Steam Power

[jdgFirefly]

Originally Posted by LeakyIdeas

drip a small amount of water into a tube at 500F it expands to about 1600times it's volume,

heat a small rc motor to 500-600F and small amount of water is injected a few degrees ATDC, it will expand 1600 times and force piston down

The first option sounds like a flash boiler, not a bad idea.

The RC motor is an interesting idea. Put a bunch of RC motors in the exhaust, and with there cooling fins they would quickly heat up. I could see the limiting factor being the rate of heat transfer into the water, which only has the surface area of the combustion chamber to transfer the heat, and not much time to do it.

[Christ]

Originally Posted by Dr. Jerryrigger

I seem to recall water to steam expiation is 1:1075, but that is likely not factoring in a large temp change. Anyway, that doesn't really matter at all...

If we are just trying to drive the alternator, then this drip boiler seems like it would really be quite sufficient. I feel like it would need a rather beefy fly wheel, which might have some trouble getting started, but popping the hood and giving it a spin start is not big deal.
Dose anyone have access to CNC machines? I'm willing to draw up a turbine/fly wheel. It seems like it would be best to just make the turbine directly connect to the alternator shaft, and be really heavy, though a easy to alter weight may be good....

You might extract more energy from a flywheel if you can change it's angular momentum.

In other words, if you start with a small diameter flywheel, and make it expand as it speeds up, then extract it's energy after it's at maximum speed/diameter, you get more angular momentum. You can put less energy into it and get more out than you normally would. It just brings the energy input/output closer to equilibrium, is all.

You'd have to make it so that it only contracts once the usable energy is used up, though, so as not to lose the momentum developed prematurely.

Does this make sense? Just something I thought of.

[Dr. Jerryrigger]

Originally Posted by Christ

You might extract more energy from a flywheel if you can change it's angular momentum.

In other words, if you start with a small diameter flywheel, and make it expand as it speeds up, then extract it's energy after it's at maximum speed/diameter, you get more angular momentum. You can put less energy into it and get more out than you normally would. It just brings the energy input/output closer to equilibrium, is all.

You'd have to make it so that it only contracts once the usable energy is used up, though, so as not to lose the momentum developed prematurely.

Does this make sense? Just something I thought of.

I like it! and it's essay to find a pre-fab, A syntactical clutch form a chain saw would do just that (may need some little adjustments)

[Frank Lee]

Originally Posted by Dr. Jerryrigger

A syntactical clutch form a chain saw would do just that (may need some little adjustments)

Say what?

[Dr. Jerryrigger]

I guess I shouldn't be posing at 2:45AM, what I was trying to write is: Centrifugal Clutch

I don't know how that happened, but based on how hard it is for me to get this post out (and I'm sure there is some ridiculous typos in it too) I can see I should sleep, and post another day.

[Daox]

Well, it looks like my ignorance has caused some issues and possible mis-information and at the very least just bad testing.

I was reading this site this morning:

Using an Alternator in Renewable Energy Projects

There is a section on how to hook up an alternator and it is not the same procedure I used. I simply connected the field wire to the battery and ran it. That means the field is on FULL strength. Also, you're supposed to put some sort of resistor (and a switch) in that line which also wasn't done. This also increases the field strength, to what point I don't know.

Also, I did not hook up the regulator wire to the battery, so the regulator could not regulate the power to the field coil again letting it just go full blast.

SO, what does this all mean? Well, it means I need to retest with things properly hooked up. My one question is, my connector has 3 wires. So, I effectively have 5 connections to make:

1) ground (case) to battery -
2) positive post to battery +
3) field to battery +
4) regulator to battery +
5) ???


Here is a diagram off the linked site, but it only shows four connections. Any ideas on what the 5th does? A ground for the regulator perhaps, or just something car related (warning light or something)?

[Patrick]

Originally Posted by Christ

You might extract more energy from a flywheel if you can change it's angular momentum.

In other words, if you start with a small diameter flywheel, and make it expand as it speeds up, then extract it's energy after it's at maximum speed/diameter, you get more angular momentum. You can put less energy into it and get more out than you normally would. It just brings the energy input/output closer to equilibrium, is all.

You'd have to make it so that it only contracts once the usable energy is used up, though, so as not to lose the momentum developed prematurely.

Does this make sense? Just something I thought of.

Umm, no. You will get the same amount of energy out that you put in, less any friction losses. Angular momentum is conserved.

"The conservation of angular momentum explains the angular acceleration of an ice skater as she brings her arms and legs close to the vertical axis of rotation. By bringing part of mass of her body closer to the axis she decreases her body's moment of inertia. Because angular momentum is constant in the absence of external torques, the angular velocity (rotational speed) of the skater has to increase."

Angular momentum - Wikipedia, the free encyclopedia

You might lose even more than a regular flywheel due friction in the mechanism.

[LeakyIdeas]

Wouldn't it depend on your source of input? if you have for example a limited rpm range and low torque, by increasing the size of the flywheel you are storing more energy per rev, and when it's small you can get it up to speed, which in this case may be needed as i think it wouldn't have the torque to get a large flywheel started... kind of like having a gear box built into the flywheel.

but we don't have any movement yet so it'll be "a nice problem to have" :-)

[Dr. Jerryrigger]

I think this is a situation where we need fewer egg-heads thinking out the details, and more action (no offense anyone, I'm just as guilty).
With this project, like many, I think it would be best to start at the beginning. We need a holding tank, simple enough, right? Then some one-way valve or pump. Then a boiler, this is where it starts to gets complicated, so lets get the first things down first.
Once we get steam blowing, we can figure out what we can do with it and how to do it best.

[Frank Lee]

That's the spirit! Figuring stuff out never amounts to anything anyway.