Fisher & Paykel Smart Drive

[Ronmar]

Has anyone heard of anybody using a tesla turbine for microhydro?  I have about 65gpm with about 80' of head to experiment with, and the tesla looks dead easy to fabricate...

[sailawayrb]

Has anyone heard of anybody using a tesla turbine for microhydro?  I have about 65gpm with about 80' of head to experiment with, and the tesla looks dead easy to fabricate...

Have not heard of anyone trying Tesla turbine for hydro, but I think it would work quite well...very efficient and there would be no blades to wear because of dirty water.

[vdubnut62]

I thought that the Tesla was primarily designed for high pressure steam use?
Might work for water, but a bunch of mods would be in order, I'm afraid.
Ron

[mobile_bob]

if i had the opportunity to work with hydro, i would go to a scrap yard and get an allison torque converter
and unbolt the body halves, remove the innards and use the stator element for my turbine, then
reassemble it after modifying for hydro input and outlet

or use the stator/turbine in the vertical position like the big boys and cold cast the intake and exhaust volutes

i have a feeling hydro would be a blast to work with,

sadly my property in kansas has no hydro possibility save for me pumping to a higher elevation and then recovering
the power on the down hill run, from what i can determine such systems are about 50% efficient, however

unlike batteries water doesn't wear out

bob g

[vdubnut62]

One of the old fluid drive turbines might  be better  Bob, they are probably what, 16 -18 inches? A downside might be the fin angle though, they are straight IIRC, the ones from the Allison, are they curved? Not sure that I remember what was used in the Allison app.
Been out of the torque converter business for going on 14 years now.  I'm just thinking out loud....
I don't remember many bolt together torque converters, the ones that bolted were all industrial units, the run of the mill automotive units were welded. I worked for Dacco Converters for 16 years, saw a LOT of the insides of darn near anything ever made in the converter line.
Ron

[mobile_bob]

i was thinking along the lines of the allison mt40 series, it was a bolt together unit, and the blades were curved
with the stator being cast with blades having a heavily cambered profile, which would make it very efficient
and harnessing power.

when you look at one, it looks very much like an early generation hydro impeller

allison made millions of the mt series transmissions and they have been around forever, at least back to the korean war era

bob g

[vdubnut62]

I'm not following you exactly, do you mean the cast aluminum center section with the one way sprag clutch (stator), or the pressed sheet metal back section that drives the tranny's input shaft? (turbine)
That's the way they were named when I worked on them back in the day, not saying that it was the correct terminology or anything,
just what we called 'em. I can't help it, I was born confused.
Ron

[mobile_bob]

iirc it was the center section, and i don't remember if they had a sprag or not

i just remember them being cast aluminum with beautifully shaped blades/vanes
that i later learned to be what is known as a heavily cambered profile which is very efficient at
converting flow to mechanical force.

i seem to remember one out of a converter that i cut apart that did not have a sprag, but rather a spline steel inserted hub

i kept it under my bench for years because it reminded me so much of a hydro impeller such is used by the big vertical units in the old days.

having no natural water asset i haven't really given hydro power much thought since.

but would sure love to have that resource to work with!

give me a 100ft of head down a 2" black plastic pipe, and i would be busy as a bee working on eeking out every last watt.

bob g

[vdubnut62]

 Okay Gotcha! You are looking at building a downshot turbine wheel! I am a little slow this evening, sorry.
I had a little different take, I was thinking more along the line of a dual pelton type setup using the turbine sections.
The round thing on the left is the turbine in question, they are made of pretty light stamped sheet metal sections with interlocking tabs.
The one on the right we called the hub, it's pretty close to 1/4 inch stamped steel for the body, pretty heavy. The smaller part in the center is the stator, and yes they do have a one way clutch in them, at least every one that I have seen.
The pic is pretty bad, but if you look closely, the fins form a sort of cup that would catch water nicely.
Mount 2 of them on a common shaft with the fins facing each other separated by a few inches, shoot  about a 3/4 inch stream of water in at both the bottom and top with a couple of wyes, I think they would work quite well.
Now that ya'll have given me an idea, I will have to give it a try, when I get time. So many ideas, so little time left from work, and family!
Ron

Let me try to post that again without the watermark!
Oh well not gonna work

[Chris]

I saw a youtube post about a guy experimenting making a Telsa turbine with CD disks. He got it working quite well, (poof of concept).

Chris

[mobile_bob]

i have seen the tesla turbine on youtube before too,

has anyone seen one powering a load?

its pretty interesting seeing one spool up and whine like a turbo, but quite another to have one
that can actually power a load with some efficiency

not saying they are inefficient, or efficient, i don't know
because i haven't seen one doing useful work.

bob g

[rl71459]

Bob

I have worked on the Allison with the assembled type converter. As I recall they were also made
with the more conventional weldup style also. I liked the assembled style as you could service
them as well as read possible upcoming failures by the finds that remain in the converter.
It was kind of like a centrifuge bowl... the bad news collects there.

Rob

[BruceM]

I did some more reading on the F&P smart drive as alternator.
Here's some info on the stock stator winding from thebackshed.com:

"From factory the Fisher & Paykel stator is wired into one large star winding, producing 3 phase AC when used as a alternator. If we were to use this standard stator on our windmill the output voltage would range from 0 to 400 volts unloaded, and up to 3-4 amps maximum loaded, not a very usable range for charging batteries, and very dangerous to work with.

The standard F&P Smartdrive stators have either a string of 14 or 12 coils (also called "poles") for each phase. 3 phases, means 42 or 36 coils total, depending on what model stator you have."

Plan A: If you can live with 3- step down transformers, the stator windings can be left in the "stock" configuration.  Three small variacs (100 watt) instead of transformers would let you dial in the output to suit your charge controller, so that other current limiting means would not be needed.  This has the advantage of not needing filtering of the output DC, and only adds one extra (small) wire for the long run to the battery bank.  

Plan B- rewire to single phase, about 120VAC. (Three strings in parallel.)  Filter output DC via choke and caps. A single 250watt Variac would then suffice.  

I wonder what the operating frequency will be???

PS-  In retrospect, the variac approach is problematic unless the output voltage is not too much lower than the input; as the output windings are shared with the input.  The variac must be rated for the lower output voltage current.  With a big step down, it's  inefficient due to excessive idle current.  If the windings were configured for about 120VAC, then the step down to 60 volts or so would make a variac work out pretty well.  For a bigger step down, transformers would have to be used.

[Jedon]

When you ask if I can live with step down transformers, do you mean a loss in power? Noise? Cost?
Tesla turbines and other interesting setups sound cool but I don't think I have enough experience to mess with stuff too far from the norm ( at first :-) )
I do have an even larger source of hydro but it's much less accessible and 2000ft away but it is a lot of flow, I would have about 25ft of head and thousands of gallons per minutes. I could power the whole area off it! Maybe in a few years I'll tackle that one.

[mobile_bob]

in a few years?

nothing like the present buddy!!



if there is anything i have learned in life, that is not to put of any project you are passionate about,
you just don't know how many years you will have the ability to tackle them.

bob g