Pumped Storage

[itsmoked]

Can large typical pumped storage systems keep the turbine(wheel) moving in the same direction but just reverse gates or the blades or do they always stop the machine then reverse it?

 

[Deke1]

Pumpd storage plants require that the unit be shut down and restarted in the opposite direction; the larger ones sometimes use a pony motor and liquid rheostat to bring them up to speed in the pump direction.

Deke1

 

[jtkirb]

deke1 is correct (can't comment on the pony motor).

I live about 40 minuts from the Ludington, MI pumped storage facility on Lake Michigan. Cool site.

JTK

 

[jtkirb]

straight from the company's mouth:

http://www.consumersenergy.com/apps/pdf/Ludington.pdf#search='ludington pumped storage'

 

[itsmoked]

Just what I thought then I started thinking about Kaplan turbines and it seemed like you could actually control the blade angle and reverse them like a variable pitch boat propeller.

 

[jraef]

Well if you think about it, with enough pipe and a few check valves you could reverse just the water flow and have the turbine spin the same way, but why not just reverse the turbine? What is the problem you are trying to solve?

Eng-Tips: Help for your job, not for your homework Read faq731-376

 

[MikeHalloran]

A long time ago, I stood on a Kaplan turbine blade that was being hardfaced. I think an axial section would show the blades overlapping each other quite a bit. I suspect that you'd have to make the root chord a lot shorter in order to get the blade to swing past vertical, and you'd lose some efficiency to that.

At which point the blade twist would be all wrong, and you'd be fighting the curvature of the volute, too.



Mike Halloran
Pembroke Pines, FL, USA

 

[itsmoked]

Thanks guys. Not a problem. A teacher asked me about pumped storage for a lesson. Which I explained in detail. But then was asked if piping was used or if the pump ran backwards. I said backwards but then started wondering if that was always the case.

Stopping and restarting backwards twice a day sounded electrically and mechanically abusive.

 

[itsmoked]

I hear you Mike! The few Kaplans I saw looked like that would be a problem.

 

[ScottyUK]

ItSmoked,

You might be interested in First Hydro's Dinorwig pumped storage station at Dinorwig, North Wales.

http://www.fhc.co.uk/gallery/gallery.htm

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I don't suffer from insanity. I enjoy it...

 

[itsmoked]

ScottyUK; Nice site except I wish they'd labeled the pictures.