|
  |
 waterheel efficency |
waterhead
Gast/Guest+
Registration Date: 01.03.2009
Posts: 7
Herkunft / Country: Northern Ireland
 |
|
Overshot waterwheels are always streets ahead of undershot as far as efficency is concerned,but I presume the undershot is in the stream as it were. What if I had an undershot and introduced the water at the bottom of my 5.4 meter fall? Surely I would have a faster wheel and therefore not the same loses through gearing etc. to my generator
|
|
03.07.2009 15:31 |
|
|
Simon 
Administrator
Registration Date: 02.04.2007
Posts: 110
Herkunft / Country: Germany
|
|
Do you have a sketch of your idea?
__________________
Kleinstwasserkraft Klopp
www.kleinstwasserkraft.de
PowerPal Distributor for Germany, Austria and Italy
EXMORK Distributor for Germany, Austria and Switzerland
Micro-Hydropower research partner of the University of Siegen -fwu-
|
|
|
18.09.2009 02:36 |
|
|
waterhead
Gast/Guest+
Registration Date: 01.03.2009
Posts: 7
Herkunft / Country: Northern Ireland
Thread Starter 
|
|
Thanks Simon for your reply.
Perhaps I haven't made myself very clear, in that I mean water to be jetted to the bottom of a suitably designed waterwheel, in effect a rather large Pelton wheel. I am trying to think of something which would be relatively cheap to make as turbine prices seem to rise with each mention of renewable energy.
Best Regards,
Waterhead.
Ps The idea hasn't reached the sketch stage yet!
|
|
|
18.09.2009 22:58 |
|
|
Simon
Administrator
Registration Date: 02.04.2007
Posts: 110
Herkunft / Country: Germany
|
|
Ah okay! I know what you mean.
Hmm... It seems to be a waterwheel that only uses the strike of the velocity of the free falling water....
Certainly, the construction is easy and maybe cheap. But if you will do a sketch, you will see, that the constuction is not so easy as it seems: Problem is, that you have normally a quadratically, free falling water jet and you want to hit with full crossection of this jet the wheel. Now the wheel is a circle, and you have two options:
1. Your wheel has only several buckets => water jet touches every bucket just for a fraction of the circumfence optimal => low efficiency
2. Your wheel has much buckets and so the jet will hit more than one bucket full => not the maximum possible deflection => low efficieny
But I wonder if you have a location for a overshot wheel and can build DIY waterwheel, why don´t you build a overshot one. If you build selfly, the price difference beween overshot and undershot is not much!
Regards
Simon
__________________
Kleinstwasserkraft Klopp
www.kleinstwasserkraft.de
PowerPal Distributor for Germany, Austria and Italy
EXMORK Distributor for Germany, Austria and Switzerland
Micro-Hydropower research partner of the University of Siegen -fwu-
|
|
|
18.09.2009 23:35 |
|
|
waterhead
Gast/Guest+
Registration Date: 01.03.2009
Posts: 7
Herkunft / Country: Northern Ireland
Thread Starter
|
|
Simon,
Thank you for your reply to my query.
The reason I was thinking of a backshot wheel was because this river can rise maybe 1.5meters in a flood.
I have been pondering what to do with my site for quite a while now,there was not a waterwheel or turbine at this particular point at any time,they were there in former years in a different part of the dam,which is not a dam anymore,I purchased the functional part many years ago. I have long thought a modern waterwheel would be the job,but since I want to export to the grid I want to utilise as much power as possible,and I have been leaning toward the crossflow, Kaplan turbine,options . At my site it is not just a case of installing X Y or Z ,I have to build a wall to divide my dam from the much larger section,I have a weir already,so I think this will be quite an expensive operation.
Best Regards,
Waterhead.
|
|
|
19.09.2009 11:42 |
|
|
|
|
|
|
|
