Author Topic: Smart Drive Oil Barrel Undershot Waterwheel  (Read 4831 times)

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george65

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Re: Smart Drive Oil Barrel Undershot Waterwheel
« Reply #54 on: September 13, 2017, 03:47:38 PM »


I am thinking a very low weir (300mm) higher up and long run (300m) of large bore (300-500) mm pipe - just have to find the pipe!

I know Pipe size is exponential rather than linear for flow but perhaps you may find like I have in the past that using multiple smaller pipes does in fact work out cheaper than using one large one.

90mm here seems to be about the best value and most widely used so even maybe  4-5 runs of that or even 150mm could work out better than something harder and more expensive like 500mm.

Have you ever worked with large PVC Pipe? I have and it's a bitch.  Firstly its heavy as hell due to the wall thickness. I was using pressure pipe which you'd probably want as well and it had at least a 5mm wall thickness. This makes it heavy. 2ndly, if you have to cut it, it's a big job more than one would realise.  9" grinders are the order of the day with that, not much else is big or fast enough. 3rd, Not that you would have to put in the bends and fittings I did, but even putting on an elbow on that big stuff is a multiple man job that requires an amount of planning.  And check the prices of those fittings as well. Yeeesh!
And as for the cement..... Was going through 4L tins of the stuff like it was going out of style.

I think you will find that size pipe is anything BUT cheap and for the length you need..... Also just see if you can look at some to get a feel for handling it.
You are pretty much going to need machinery just to move the lengths round of that big stuff.

MattM

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Re: Smart Drive Oil Barrel Undershot Waterwheel
« Reply #55 on: September 13, 2017, 06:54:40 PM »
A dam doesn't need to block the main flow.  You just need a bypass at a higher level.  The bypass is essentially a non-invasive stream flow, so eels won't be cut off.

But why use round pipe to mismatch your rectangular bucket surface facing the water?  Marine-grade plywood should hold up a few seasons.  Build your bypass out of wood.
« Last Edit: September 13, 2017, 08:09:16 PM by MattM »

bmannz

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Re: Smart Drive Oil Barrel Undershot Waterwheel
« Reply #56 on: September 17, 2017, 03:34:22 AM »
Hey boys, thanks for the comments,

George, the large plastic pipe sounds like a PITA, I have also considered large bore concrete and steel, I spent a bit of time on the eco innovation / powerspout calculators playing around with different pipe configurations and an open trough is the best for me but a trough is going to create its own issues

I have access to an endless supply of 60L and 200L drums and was wondering about creating my own pipe, funnily enough my barrel man at Ruakaka is selling exactly this at the moment - not load bearing worth a damn but set it deep enough and your all good. My run will be around 300m so trade me (NZ eBay) is my friend right now!

Matt, during my research phase, I came to the understanding that a dam is a structure where the water usually goes underneath in a pipe and a weir is a structure where the water goes over the top

Remembering that my flow is super variable (dry to 47 cumecs) and basically no head, I am thinking a low weir is the only way to satisfy all 4 points above, any sort of dam will be either empty or overflowing - or perhaps I misunderstood your post?

as for shape mismatch, a ply section will fix that, I've seen a few examples online of how they look.

Fully off grid thanks to 2.1kw of Jinko panels into 6KW of Outback FP2 and 1.5kw Wind Turbine on 8m tower all into 390AH of Synergy AGM batteries with a MATE3 HMI

bmannz

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Re: Smart Drive Oil Barrel Undershot Waterwheel
« Reply #57 on: September 17, 2017, 03:39:30 AM »
This is how the lay shaft turned out:

10786-0

The lowest ratio I could get was 50:1, but even that was to high and the wheel is currently stalled so I'm going to change the small end from a 9 or 10 tooth to a sprocket carrier and aim for 25:1 overall



Fully off grid thanks to 2.1kw of Jinko panels into 6KW of Outback FP2 and 1.5kw Wind Turbine on 8m tower all into 390AH of Synergy AGM batteries with a MATE3 HMI

MattM

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Re: Smart Drive Oil Barrel Undershot Waterwheel
« Reply #58 on: September 17, 2017, 08:10:19 PM »
I was thinking you had a more substantial flow to draw energy from.  You have only one flow, not really a diversion off a stream.  With so little flow and so little elevation delta, it might make sense to run two gennies.  Maybe switch from your F&P in high water and run a scooter motor at low flow.  The F&P probably has the mass to spin only with the highest flow.

I have the same problem with my crick.  No mass or drop most of the year.  I'm not going to try to generate that one or two days a year the rain from hell gives it flood stage.

george65

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Re: Smart Drive Oil Barrel Undershot Waterwheel
« Reply #59 on: September 17, 2017, 08:25:38 PM »

Don't know if it's at all applicable here re a dam, But, I was looking at a property a couple of years back that had a small stream running through it. Was told it ran all year but was pretty much only a small flow till it rained then it was a gusher.

Always wanting to do a MH setup, I thought about building a dam that open and closed as the flow I was seeing was pretty much useless. Not much chance of elevation but plenty of room to back the water up.
My idea was to have a dam with an automated gate.  The gate would close till the water built up to sufficient level and then would trip a float switch which would open the gate and the water would flow in sufficent volume to be put to useful generation.  Could easily control it with an arduino and some float switches to open and close. When the water was flowing as in after or during rain, the thing would run constantly. When the flow got too low, it would shut down and save up the water till there was the set level and off it would go again.  Seems to me that short runs even just once or twice a day would in the end yeild more power than the piddly flow that was normal and still be able to run hard and handle the much better flow with rain.

You may be able to back the water up a little at least to do this.  May be the easiest way to get some work out of what you have while still allowing for when there is a lot better flow.

bmannz

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Re: Smart Drive Oil Barrel Undershot Waterwheel
« Reply #60 on: September 18, 2017, 04:15:30 AM »
Thanks again for the good suggestions,

Matt, I had thought of putting two smart drives on the system at lower ratios and kicking in the second one electrically when the RPM gets up using the Hall effect sensor to trigger.  I haven't heard about the scooter motor, do you think they will have less cogging force than the F&P? is that scooter as in electric bike motors?

George, I read some calcs on pump storage early on and the storage area required to do anything approaching useful is going to make the upstream neighbour a bit pissy & we don't want that!

Planning on surveying the whole drain in the next few weeks so will know then exactly what fall I have and where, one funny thing is the place i surveyed with Emma using the garden hose method showed great fall (at least for my site) of 1.3m but the bottom of the creek was 1m under water so left me with only 300mm fall!

In retrospect, I'd probably have been better there with a breastshot and 300mm than an undershot where I am at the moment - oh well, live and learn and that's all part of the fun!

Thanks again guys, much appreciated!

Fully off grid thanks to 2.1kw of Jinko panels into 6KW of Outback FP2 and 1.5kw Wind Turbine on 8m tower all into 390AH of Synergy AGM batteries with a MATE3 HMI

MattM

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Re: Smart Drive Oil Barrel Undershot Waterwheel
« Reply #61 on: September 18, 2017, 05:22:04 AM »
I have taken apart a few scooters and the motors are usually between  750W to 1000W at 24V.  Not a ton of amperage, but they reach 16V without a ton of resistance or clogging.  The other easy to find motors are the 24V and 48V treadmill motors.  Even less amperage, but might be the voltage you want.

bmannz

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Re: Smart Drive Oil Barrel Undershot Waterwheel
« Reply #62 on: September 19, 2017, 12:56:39 PM »
Thanks Matt, I'm 48v so will put the word out for treadmill motors & check them out
Fully off grid thanks to 2.1kw of Jinko panels into 6KW of Outback FP2 and 1.5kw Wind Turbine on 8m tower all into 390AH of Synergy AGM batteries with a MATE3 HMI