Small scale water turbine generator

[itsmoked]

YouSlube Turbine vid

This is surprising to me as I've always seen the turbine at the very last millimeter of the penstock. Is this a normal install? Is nothing (major) being lost in translation here or should the turbine actually be at the end?

I'm trying to equate the 500 watts being generated with 'could you pump that much water from the after bay back up to the reservoir with that same 500W'? Seems like you'd need more than a horsepower to move that much making me think there's a huge efficiency hit going on. ??

Keith Cress
kcress -

http://www.flaminsystems.com

 

[LittleInch]

Difficult to say but the amount of shite being talked is unreal.

It seems to based on the fact that the differential head is being driven by the near vacuum conditions downstream the turbine.

Lots of inefficiencies going on.

Also I wouldn't want to be living downstream of that dam!!

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[FacEngrPE]

With the driving head being vacuum the maximum available DP is about 32 ft. Any more vacuum than that and the water boils. The water likely will boil (cavitation) in low pressure regions of the turbine with this arrangement long before 32 ft of vacuum, resulting in both impeller erosion, and lower efficiency.
Might still be OK for a small turbine, depends on the owners idea of fit to task, and acceptable service life.

I would use the above comment as good advice if I was looking at living near this dam. Too many get less attention than they need.

 

[LittleInch]

The amount of bubbles seemingly continuous at the exit tells you that there is some serious cavitation going on here.

The whole setup looks about as professional as the dam.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[itsmoked]

I agree all around.


Good point about easy cavitation Fac.

Little; That dam looks hideous. It looks like it would fail if any one of those beams failed. The beams look like rotting 4x4s.

The dam is holding back probably 15tons. Some soggy 4x4s. Crazy.

I also was wondering about the constant bubbles and thinking cavitation.

A bunch of sharp 90's in the flow is wasteful too.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[waross]

500 Watts, he made it himself and he's having fun.
Apart from that:
Warning:- Don't scale this up at home.
Thanks for sharing, Keith.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[John2025]

energy.gov has a formula for residential size hydro: Watts = Head(ft) * GPM / 10
So 500 watts at 15ft gives 333 GPM. His system looks pretty goofy( using the ground wire on UF as a current carrying conductor, venturi effect suction, etc) but it seems like he's actually doing pretty well.

 

[LittleInch]

We have no idea about GPM that he's getting through.

Could be much more than 330.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[John2025]

True enough, flow is really hard to estimate by eye, at least for me.

 

[1503-44]

Its the impulse turbines (Pelton wheel momentum driven type) that are placed in the free water jets the end of tha pipe, just above tailrace elevation. This must be a reaction, or combined, Francis type turbine. It is driven by pressure drop across the turbine, similar to a reversed pump. The draft pipe below the turbine minimizes the pressure at the turbine outlet, which should also have flow controller valve somewhere on that pipe to keep that pressure above vapor pressure to avoid cavitating the turbine. Cavitation ocurring just downstream somewhere in the pipe isn't so worrisome.

I like tennis ball vortex breaker. And thats not a bad looking dam when compared to many I have seen without those angle iron backstays.

 

[LittleInch]

42

"which should also have flow controller valve somewhere on that pipe to keep that pressure above vapor pressure to avoid cavitating the turbine."

Did you watch the video?

That guy doesn't understand the word cavitation. He thinks the "vacuum" you get is a good thing and I would be surprised if he doesn't try to use it to vacuum his house!

My guess is that the turbine will disintegrate after a few months operation.

I think he would get a bigger pressure drop if this was a bit further down the pipe where the height drop might not be pulling vacuum / cavitation and end up with more power for less water flow.

That dam is still a small disaster waiting to happen.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[btrueblood]

Not clear where the turbine is actually located, there could be a long shaft down to near the bottom of the vertical 6-foot (or so) section, where the actual turbine wheel is located. Still losing a couple more feet of possible head, but the location appears to me to be chosen where the electrical generator (alternator?) can be kept dry or undamaged by storm flow...maybe.

 

[1503-44]

Watched it. I dont think they understand much more than the tennis ball vortex breaker.

Yes he would have a greater inlet head/pressure and be able to generate more power, if the turbine was placed at a lower elevation, but we don't want him to melt his wires and blow up his house either.

 

[MikeHalloran]

He's got plenty of positive head at the turbine, which is placed about halfway down the drop at the dam, so I'd expect pretty good efficiency.

The tennis ball vortex breaker is very clever.

I'm not real thrilled about feeding the house panel through an outlet with a cheater cord, but I think he mentioned some sort of interlock that will shut down the inverter when the grid power is off; I'm not real sure that will actually work, and I can't imagine how it would be code-compliant, but maybe there's some magic in the inverter that I don't understand.

At least the output is small enough that the rig might go undetected by the power company for a while, but I wouldn't want to be his insurer.



Mike Halloran
Corinth, NY, USA

 

[LittleInch]

The turbine is right at the top not half way down.

Have I watched a different video?



Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[MikeHalloran]

No, you're right; I got confused and thought the siphon had more vertical drop than it does.
Mea culpa.



Mike Halloran
Corinth, NY, USA

 

[itsmoked]

42; Thanks for that info.

Mike; Those are common grid tie inverters. People all over the world stick a panel or two somewhere including in a house window. They hook the panel(s)(up to two as 500W tends to be the maximum) to the inverter and a plug a cord into the closest wall outlet. The inverter does its due diligence and will not feed into a dead outlet, it must see a functioning voltage for about 30 seconds before injection starts. Then they usually do a pretty good job of MPPT (Maximum Power Point Tracking). The down side is the last two wires out to the power outlet are undersized and can cook. Mine did. Luckily I keep most non-UL stuff outside in a metal enclosure.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[waross]

500 Watts at 120 Volts = 4.17 Amps.
The minimum size power wiring an North America is #14 AWG protected by a 15 Amp breaker.
Only the cheater extension cord may be undersized.
Some grid tie inverters monitor the incoming line current and curtail production to avoid a back-feed.
That doesn't always work.
We had a thread some time back concerning the issues with trying to use a 220 Volt European grid tie inverter in the US on a 120/240 Volt system.

Bill
--------------------
"Why not the best?"
Jimmy Carter

 

[itsmoked]

It was the DC current in from the panels.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[waross]

Yup.
It smoked alright. grin

Bill
--------------------
"Why not the best?"
Jimmy Carter