Subject: Re: What are ; Turgo and Pelton turbine wheel ????

From: [email-masked] (D.F.S.)
Date: 13 Apr 1995 21:42:40 GMT

Gaetan Mailloux ([email-masked]) wrote:

: What are the difference between a Turgo wheel and a Pelton wheel in a
: hydroelectric turbine, there's some use in 12 volt water turbine. And about
: the efficiency of each of these two kind of wheel, and which one are the
: best for low head water fall... etc...

The idea with an impulse turbine is to have the water exit the buckets in 
the exact oposite direction that it entered at at zero velocity.
this is not 100% possible but you can come pretty close.

In a turgo wheel the water exits to the far side of the wheel as the jet
in a pelton the jet hits the wheel straight on and splits in half
returning in the direction it came.

Turgo
      ^  bucket with a single bowl
     / \
  jet   Eexit dirction 

Pelton
      ^^   2 bowl bucket, the jet hits it in the exact center
      |||        Ascii is such a pain for this stuff
 out->|||<-out
       | 
      Jet

The turgo runs at a higher speed for a given diam and head than the pelton.
a turgo is a few percent more efficient then the pelton.

Neither is best for a low head application.
probably the best and cheapest turbine for a low head application is a
reaction type turbine called a cross flow turbine.

the university of oregon did some studies and built a bunch of these things.
the design they ended up with can be built from pipe and plate by anybody 
with a few basic metalworking tools and an interest in doing it.

The part of the study I saw that was included in another book had enough
information for anyone with no prior experience and elementary
math to figure the correct size and built one.
They claimed about 80% eff.
The eff. claim for the impulse turbines is in the mid 90% range.

Marc Christensen

---

From: Bretislav Beranek <[email-masked]>
Date: Fri, 14 Apr 1995 21:15:59 GMT

> Re: What are ; Turgo and Pelton turbine wheel ????
>

I doubt very much that you would be able to make cross flow turbine
in your garage and achieve 80% efficiency. There are two well known
companies in Europe,  manufacturing cross flow turbines. Companies
Cink (Czech Republic) and Ossberger (Germany) have installed
hundredth of cross flow turbines. Typical turbine output is around
0.5 MW, but 5 kW installation can also be economical.

Re: What are ; Turgo and Pelton turbine wheel ????                           R