Water Cooling Designs

[fullofhotair]

I had an idea of using the power piston diaphragm to also serve as a diaphragm water pump. The bottom is the power piston the top the water pump. Someone here turned me on to an even simpler solution. It was a U-tube of a guy tapping into the connection between the power piston and the displacer cylinder on a beta engine. He just used an air line like you would use on a fish aquarium. This ran a little water pump for the cooling water. He said he couldnt see it had any effect on the engines .I cant find the video or I would post it.

[Hawke]

Yep, saw that one too, :-) Ive got a diaphragm built for but didnt want to split the pressure on an engine just yet. I was thinking of a dual power cylinder motor off one larger volume displacer later. Im sure it takes "something" away, nothings free. Working on the crank here now.

[Hawke]

Full, you have PM messages here at the forum I sent.

[Hawke]

In working on what im calling the Super Cooler I figured I might go ahead and run it some while Im pondering the external cooling. Adjusting and tweaking still, I went ahead and put one tea lamp under it but no water coolant. I can say that while it took a while to heat up the bottom end got too hot to touch and the top seemed barely over room temperature. The displacer cylinder is doing better than I expected under current testing conditions. I had a 6 blade propeller on it which Ive removed temporarily to put on a flywheel. I was hoping to make the propeller serve as a flywheel as well. It lso has a pulley where I might be able to try running something later.

The Teaser:
The "accident" definitely has a huge effect but Im not sure it it should remain. Some dismantling will be in order if it has to be rectified from the original plan so Im holding off still. I really want to see what it does.

[fullofhotair]

http://youtu.be/LU4eynU6R-8
http://en.wikipedia.org/wiki/Heat_pipe
Hawke, Your teaser didnt work for you but here is something that might. It is called a heat pipe. It conducts heat 1000 times better than copper. It is almost a perfect insulator except at the condenser end. You could have one end in a candle flame and the condenser end inside the cylinder. You wouldnt have to heat up the bottom of the engine just pass the heat straight into the inside of the cylinder. It would almost be like a magnet to the heat in the candle flame because its is that good of a heat conductor. Actually 1000 times better than copper. They are extremely easy to build.One of the U-tubes gives instructions. For a stirling engine application you would water instead of acetone. Just boil a small bit of water in the tube ,then cap it and soldier.As the water condenses it forms a vacuum. You wouldnt need a long copper pipe like he used. He is using his heat pipe for a solar water heater. 2 or 3 inches would be enough.

[Hawke]

Crap! ...Waiting for some glue to dry, I finally watched this video, overlooked it several times as a generator is something Ive already done before. He referenced Popular Science magazine from around 1962. Well, Im pretty jealous. My only consolation is "my still unfinished one" Haha, is being built from household items with no machining.

https://www.youtube.com/watch?v=aNqPVEyAneQ
Impressive!
PS: the accident was I left a chunk of carbon steel inside the Stirling. I was using it for a spacer under the displacer cylinder. Hid by the heat chamber shroud I forgot to take it out before applying the silicone. I thought well it will heat up eventually and would be have folks scratching their head wondering how it ran for so long after flame removed, Hehe. Well the 1/2 inch thick steel never got hot enough with even double tea lamps. Ive removed it.

The engine does run on one tea lamp and ice to the tune of maybe 100-150 rpm. Not bad I guess for a non-machined stirling. Video later. Cooling system attempt after a little more fine tuning.

[Hawke]

Oh, I read the heatpipe info last night. Thank you Sir. Sounds interesting. So many ways to accomplish something! Youre right Full, about there being combinations not tried yet. That Peltier module is very interesting for cooling. $5 and runs on voltage a Stirling can deliver.

[fullofhotair]

Hawke,
That was really a nice engine you posted. Well thought out. Like something Ian SC might make. Doesn't the peltier effect work in reverse? If you have hot and cold it produces electricity.

[Hawke]

Dry run of the latest engine.
https://www.youtube.com/watch?v=OGa4HUYLZMQ

Had to make sure the engine would run first. It seems there's not enough power to run the pump yet but would drive the fan Im sure. Time for some tweaking of the crank and such. Im hearing a squeaking which I think is the displacer which would be a major undertaking to address. This is running on a single tea lamp only and some water in the top cooling chamber so high rpms were not expected. There is going to be a need for more power if I am to run the pump. Otherwise the cooling system may have to be with the next engine which I plan to have SS displacer cylinder and an upgraded displacer somehow.

Cooling is(or will be) via water pump thru a copper coil to top of displacer cylinder, then drain off into secondary cooling chamber below and then to aluminum holding tank. A fan is also to be run from a pulley off the crank.

[Hawke]

Still shots of the Cooling System

[fullofhotair]

Hawke,
You mentioned you might have displacer problems. What I eventually did was go to the beta design just for that reason. When you have a diaphragm as you power piston ,it is really easy to remove it to change displacers. Or just experiment.

[Hawke]

Got it going a little faster than the video but still slightly disappointing that the engine currently wont turn the fan even. Its consistent but slow enough I can count the pops of the diaphragm revealing 280 rpms. Not too bad at my skill level but if Im going to achieve my goal of using the self cooling systems there's going to have to be some major tweaking or a new build. The squeaking was the crank swivel joints which a little 3-n-1 cured.
Im pleased with the way the water pump works and if I blow across the cooling fins there's a definite rpm increase. I could gravity feed the water for this Stirling I suppose as ice really makes the temp difference so cooling is a weak point still. The Super Cooler design still alludes me. The long crank could be shortened, bearings added and balancing but I suspect the attainable power with the cylinder/displacer ratio to the diaphragm and stoke as it stands will limit power production negating the use of the entire Super Cooler idea.

Oh a vent tube was added to the heat chamber which does in fact make a noticeable increase in rpm's.

[theropod2]

snip...

Oh a vent tube was added to the heat chamber which does in fact make a noticeable increase in rpm's.

Could you show us that vent? Thanks,

R

[Hawke]

Sure theropod2. The vent is just what we've seen on other Stirlings. The tube coming out of the Heat Chamber does two things I can see.
1, It provides draft for the flame which increases efficiency of the flame.
2. Guides excess heat away from the cooling section of the cylinder.

I first simply held the vent tube up against the hole drilled in the heat chamber and noticed the slight increase in speed. If I could get the fan to run it would further move excess heat away from the cooling section along with cooling the copper coil and blow across the cooling fins of cool end of the cylinder. I vortex style vent tube would be another improvement. I was surprised at the effect on rpm of the vent so anything which increases the temperature difference has a positive effect on the engine, even an ever so slight modification ...at least in these made from scratch types.

[Hawke]

[tab=10]Quick run on a small alcohol burner. RPM over 200 and possibly around 260 but I dont know how much the steel wool displacer wrapped in aluminum will handle so I made it a short run to see the current RPM capacity on a hotter flame. Bearings(not oiled) added and cooling system not hooked up in this experiment. Ice was put in upper cooling chamber.
https://www.youtube.com/watch?v=5vg7TNnmmR4

[tab=10]Please share your experience on how long steel wool/aluminum displacer lasts under a alcohol burner ?

[tab=10]Time to dismantle my first engine and see what the steel wool looks like it it I suppose. It was given several red hot doses from a mirco torch. My next displacer will be stainless steel mesh wrapped around stainless steel wool inside a stainless cylinder Im thinking. I was wanting to do this build on a low heat and compensate with the cooling system making up the temp dif but one tea lamp is just not going to run the current cooling system.