12V small hydroelectric turbine on a river

Renewable energies except solar electric or thermal (seeforums dedicated below): wind turbines, energy from the sea, hydraulic and hydroelectricity, biomass, biogas, deep geothermal energy ...
Boblamouche
I learn econologic
I learn econologic
posts: 17
Registration: 07/09/08, 11:29
Location: Ardeche

12V small hydroelectric turbine on a river




by Boblamouche » 07/09/08, 11:59

Hello,

I came across your forum after some research, and I thought that your opinion would be of great help to us.

With a friend, we would like to make a small hydroelectric turbine 12V (car alternator) providing approximately 1, even 2A or more if possible.
the turbine would power a buffer battery.
we want to power a light (a cabin more outside), and a car radio.

The constraints are as follows:

-Null budget (or almost, we only do recup ')
-In an ecological and beauty concern of the place, the alternator / turbine system must be removable (for the removed when we are not there for example)
- The water passage must be natural (natural dam) or a removable passage too.

Advantages:

- We are two and well motivated
- The flow of the river is quite substantial (I will try to put a photo if you want)
- We are handymen

We would like to know how we could take, if we need to multiply the movement, what type of turbine manufactured and with what materials ...
0 x
Christophe
Moderator
Moderator
posts: 79111
Registration: 10/02/03, 14:06
Location: Greenhouse planet
x 10972

Re: Small 12V hydroelectric turbine on a stream.




by Christophe » 07/09/08, 12:39

Boblamouche wrote:- The flow of the river is quite substantial (I will try to put a photo if you want)


This is where we should start: a flow without supply pressure

The hydraulic power of a flow Q with a pressure H (as Water height) is as follows:

P = Q * 1000 * H * 9.81

With Q = flow in m3 / s
H = height in m of water

Example: a stream of 100L / s and a fall of 1m will provide a potentially recoverable energy of:

P = 1 * 100 * 1 * 9.81 = 981 W on condition of capturing 100% of the flow and having machine efficiency of 100%

In reality: you can divide by 2 or 3 (paddle wheel efficiency + alternator +% of collectable flow).

Look at this: https://www.econologie.com/forums/construire ... t2820.html

ps: subject moved to self build
0 x
Boblamouche
I learn econologic
I learn econologic
posts: 17
Registration: 07/09/08, 11:29
Location: Ardeche




by Boblamouche » 07/09/08, 12:58

Goods.

I had already seen the subject. But the installation we want to do is much, much smaller, that's why I opened another subject.

otherwise to get an idea, here is the theater of operations:

Image

Flow level, it is variable during the seasons (logical) the photo above represents the "normal" flow in summer. Level drop, there is very little as you can see. We just wanted to harness the current of the river by building a natural slide to concentrate the flow to a specific location. Kind of a fall, right?

And, how do you know the flow of a river like this?

PS: thanks for moving the subject, I posted a little too quickly!
0 x
the middle
Econologue expert
Econologue expert
posts: 4075
Registration: 12/01/07, 08:18
x 4




by the middle » 07/09/08, 15:36

:? I wonder:
Make a small dam? .... is it legal? and the little fish, how will they pass?
Let's say the legal side I don't care, but the little fish? :D
0 x
Man is by nature a political animal (Aristotle)
Boblamouche
I learn econologic
I learn econologic
posts: 17
Registration: 07/09/08, 11:29
Location: Ardeche




by Boblamouche » 07/09/08, 15:49

It is not a concrete dam but in "dry" stones with the rocks recovered from the bed of the river ... nothing huge and permanent, which will leave at the first flood ...

In short, the fish will have no trouble passing : Cheesy:
0 x
Christophe
Moderator
Moderator
posts: 79111
Registration: 10/02/03, 14:06
Location: Greenhouse planet
x 10972




by Christophe » 07/09/08, 16:30

Look at these calculations: http://www.pfgtechnologie.be/Energie/Eo ... /index.htm

In your case it is absolutely necessary to know the average speed of the stream (I would say 5km / h max? What do the specialists think?).

Then you will be able to estimate what surface of "pressure" (or if you prefer contact with water) you will need by doing the following reasoning in reverse:

Data:

Reminder: (10 Newtons = approximately 1 Kg) (1N / m² = 1 Pascal)

a wind of 100 km / h (27.7m / s) over a surface of 1m² gives us a pressure of:

p = 1.293 x 27.7² / 2 = 496 N / m² or approximately 49.6 Kg on 1m²

one blade = 0.7 m²

F = px S = 496 x 0.7 = 347.3 Newtons (with K = 1)

Let's go back to our wind turbine:

Air density at sea level: 1.293 kg / m³
Surface of a blade = 1 x 0.7 = 0.7 m²
Penetration coefficient = around 0.3 ext. Circular side and 1.4 int circular side. The penetration coefficient or Cx is sometimes greater than 1 because it takes account of the depression on the back of the surface. Wind turbines with blades are more efficient for this reason, the driving force is due to 1/3 by pressure and 2/3 by depression.
Take a wind of 36 km / h or 10 m / s
Average circumferential speed of the blades = 1/2 or 5 m / s because of the wind speed, it is necessary to deduce that of the wind turbine.

F1 = 0.3 x 1.293 x 0.7 x 5² / 2 = 3.39 N
F2 = 1.4 x 1.293 x 0.7 x 5² / 2 = 15.84 N

P = C x W power = torque x angular speed

C = F x L torque = force x medium lever arm

= (15.84 - 3.39) x 0.35 = 4.36 Nm

V = 5m / s
W = v / R = 5 / 0.35 = 14.28 rad / s angular speed = speed / radius of rotation

P = C x W = 4.36 x 14,28 = 62.22 W for 36 km / h of wind
249 W for 72 km / h of wind
0 x
Christophe
Moderator
Moderator
posts: 79111
Registration: 10/02/03, 14:06
Location: Greenhouse planet
x 10972




by Christophe » 07/09/08, 16:55

Well I could not help but make an estimate.

I suppose:
- Current 5 km / h is V = 1,39 m / s
- Radius of the paddle wheel is R = m 0.2
- And that one motive dawn is permanently
- The friction is neglected in the air

Angular velocity:
W = V / R = W = 1,39 / 0,2 6,95 = Rad / s

Motive Pressure:
p = * 1000² 1,39 / 2 966 = N / m²

Drive power:

CdA = P * p * R * W

S = surface immersed in m² and Cx = coefficient of penetration of the blade, likened to a plate which is about 1 (after of what I read on the net).

Let P = p * CdA * R * W where S = P / (C * P * R * W)

In your case, say that you would need to drive 40W (considering performance and approximation).

One will find: S = 40 / (1 966 * * * 0.2 6,95) = 0,006 m² 300cm² be submerged by blade.

For theoretical 40W (20W practice with yields) with 5km / h of water flow, you should therefore build a paddlewheel 20 cm radius with 300cm² of driving surface. For example with blades 30 cm wide, ca would 10 cm immersed.

I have the good zamis? Rah you makes me want to try it now! We're lucky to have a stream bordering garden, cf. https://www.econologie.com/forums/belier-hyd ... t5268.html
Because nothing of mine has more potential than I thought !!


If I manage to make a 100W paddle wheel (not unrealizable from these calculations) 24 / 24h it would make a lot of energy over a year (at least enough to power 1 pc!) ... remains at make this energy "usable" ... and do something reliable!


Image
Last edited by Christophe the 08 / 04 / 09, 00: 56, 1 edited once.
1 x
Boblamouche
I learn econologic
I learn econologic
posts: 17
Registration: 07/09/08, 11:29
Location: Ardeche




by Boblamouche » 13/09/08, 22:44

excellent! Thank you for your answer! (and sorry to answer so late but I don't have internet access during the week at the moment)

I wanted to do some calculations but I didn't know where to start ...

Your estimate seems very realistic to me. But could we not increase the radius of the wheel, for example 30cm, in order to increase the torque and therefore the power?

If we manage to divert part of the stream, in order to concentrate the current in a chute, and behind create a small waterfall (by digging the river bed to position the wheel at the bottom) we could get increased speed.

There is also something that I don't quite understand:

of these two procedures, which do you recommend?

Image

or:

Image

the first process seems to me more efficient (I saw on a site a model of paddle wheel like its but in much larger) ...
0 x
User avatar
hic
Grand Econologue
Grand Econologue
posts: 995
Registration: 04/04/08, 19:50
x 5




by hic » 13/09/08, 23:08

Boblamouche wrote:excellent! Thank you for your answer! (and sorry to answer so late but I don't have internet access during the week at the moment)

I wanted to do some calculations but I didn't know where to start ...

Your estimate seems very realistic to me. But could we not increase the radius of the wheel, for example 30cm, in order to increase the torque and therefore the power?

the first process seems to me more efficient (I saw on a site a model of paddle wheel like its but in much larger) ...

Hi Boblamouche
To compensate for the lack of performance of a system
"over the water",
just multiply the number of wheels at will
to increase the overall power,
with minimal disruption to the environment
Goodbye
0 x
"Let food be thy medicine and thy medicine be thy food" Hippocrates
"Everything has a price has no value" Nietzche
Torture for Dummies
Forbid to express the idea that the field is acceleration (magnetic and gravitational)
And you get your patent mental torture option executioner successfully
User avatar
renaud67
I posted 500 messages!
I posted 500 messages!
posts: 638
Registration: 26/12/05, 11:44
Location: marseille
x 8




by renaud67 » 15/09/08, 09:58

Hello,
I already stuck this place there somewhere but failing to find it
http://www.moreau-fr.net/proto/turbine/index.html
voilà
good achievement ...
0 x
The absurdities of yesterday are the truths of today and tomorrow banalities.
(Alessandro Marandotti)

 


  • Similar topics
    Replies
    views
    Last message

Back to "hydraulic, wind, geothermal, marine energy, biogas ..."

Who is online ?

Users browsing this forum : No registered users and 213 guests