Water cooled stator?

[gizmoguy]

Hi all,

I am about to cast the stator for my backyard water project.  I am concerned about the daily, and rapid increase in flow that I get from  the water treatment facility's back flush up the way.  It lasts for about 4 hours and almost doubles the speed and depth of the creek.

I don't want the stator to burn out from overspeed and was wondering if it is possible to cast something like silicone or plastic tubing into the stator to help it cool.  The alternator is below the turbine in height and gravity would keep the water flowing through without trouble.  In the winter I could shut off the water inlet to prevent freezing damage and hope that the cold air would compensate for the cooling needs.

Is it worth the effort?  I can't find anywhere on this site where it has been done yet.

What do you guys do when there is no furling system?

Thanks,

Gizmoguy

[wooferhound]

Here are some discussions about getting rid of Stator heat . . .

http://www.fieldlines.com/story/2008/2/23/183038/106

http://www.fieldlines.com/story/2007/10/31/31530/655

http://www.fieldlines.com/story/2005/5/16/204225/364

http://www.fieldlines.com/story/2007/9/15/154035/292

[Stonebrain]

Unlike windpower,where you can't control windspeed,with hydro normally you control waterflow,which make a furling system superflu.

To avoid overheating,you have to match waterflow/pressure ,impeller and alternator.

cheers,

stonebrain

[Ungrounded Lightning Rod]

Second that.

Hydro power is far less "wild" than wind - and you can easily "furl" with a spillway (or equivalent plumbing) to prevent excessive head even if your water source has extreme level changes.  So it's simple to build and operate your stator in an condition where heating is low enough to be handled with convection and rotor-swept forced air cooling alone.  So you don't need additional cooling - let alone anything as extreme as water cooling.

[RA]

If you decide to cool stator use not water but transformer oil. or silicon oil.

[gizmoguy]

Thanks guys.  I might not have picked the best way to extract energy from my creek by building a PMA, I will have to figure out how to make a very steady water supply.  Thanks for the advice.

[NukeManSoon]

Why couldn't you dunk a soldered up stator assembly in wax prior to casting the stator. then after casting heat it up to melt the wax and run hot water through it to flush out the melted wax. One of a few problems I see is having the coils securely fastened in the casting. If you you use a few patches of resin alternating around the coil attached to some fiberglass cloth making sure not to block off cooling flow completely. then just melted the wax offm of that prior to casting the stator then they would be relatively well fastened inside. this would be the best way considering the first area to be danaged due to heat is the insulation around the wire. just an idea, but this would still be a bitch and their would still be a little air gap for flux to try and get through. I wonder if they make microbore enameled magnet wire? This would be good with a centrifugal pump coupled to the rotor asssembly because Heat transfer= Mass flow rate *Specific heat capacity * Differential temp. Therefore faster the rotor, the more heat produced by Resistive losses, but the increased flow rate counteracts this. You may not even need to furl haha.