Trying to build a miniature binary geothermal plant for education

[chemisthypnos]

I am trying to build a miniature (it should fit on a desk) binary geothermal power plant for educational purposes. I obviously do not expect to drill into the ground with this power plant, but I hope to be able to demonstrate new design principles with it.
I have many questions as to how to do this. What size of piping do I use? How do I know what size turbine is appropriate for this use? How do I get vaporizing water to spin a turbine? etc...
In the end, I aim to place a part of this miniature plant on a hot plate to simulate subterranean heat, watch in real time as the water is vaporized to spin a turbine, use heat exchangers to have the same hot water vaporize a volatile fluid to spin another turbine, have the volatile fluid recondensed via evaporative cooling, and then have the original hot water returned to a reservoir.
I think that this will prove to be a great educational tool, but I need help in doing calculations for it and other design implementations.

 

[berkeman]

Sounds like a fun and educational project.

What are you going to use for your cool reservoir?

 

[chemisthypnos]

I am thinking of simply constructing a hyperbolic water cooling tower (at least I know how to do that). The rest of the design - I am much less certain of as I am a chemist by education, but I think that this would be really great if this could be built.

 

[256bits]

Reminds me of the put-put ( pop-pop ) boat which works ( like a geyser ) by heating the water in the chamber to steam which then exits the tube due to the increase in volume. Water then flows back into the chamber and the cycle starts again. Placing the tube(s) vertical and one could conceive and jerry rig some kind of geyser as long as you have some way of water to flow back into the chamber.
Just a thought.
https://en.wikipedia.org/wiki/Pop_pop_boat

 

[anorlunda]

Wow. The ambition is staggering. You must have great mechanical skills to machine those things on such a small scale.

But no matter the skills, some things don't scale down well. The hyperbolic cooling tower is one such thing. I don't believe that a small one could generate the air currents necessary to make it really cool.

That pop pop boat suggested by @256bits is no joke. It would be much easier and faster to build and the students might find the physics easier to understand than turbines and cooling towers. You might consider something simpler like that as a pilot project.

 

[chemisthypnos]

We do have a sizable machine shop that could be used to create such a device. I suppose that the pop boats would probably be an easier demonstration of the principles, though. I never knew that these even existed! They are simple but amazing. Thank you all.