Roadam Posted February 8, 2009 Report Posted February 8, 2009 I got a little problem... The house I live in was once a water mill. And because the wheels are long gone but the water still falls I thought it may be worthwhile to generate some electricity out of it. By the rule of thumb I would say that there is about 40 liters of flow but I am not very certain. Behind my house is a half pipe canal and I have seen some calculators that calculate the flow for the particular example. That is by using pipe diameter, height of the water and slope. I found a few snapshots of Mears calculator, but it doesnt help. Does someone know how to calculate it or owns one of those kind of calculators? Quote
Turtle Posted February 8, 2009 Report Posted February 8, 2009 Here's a starter page. Lacking the device that measures flow rate, you could throw in something that floats and time how fast it traverses a measured distance. Problem is the flow is not the same rate at all depths, but it would give you some idea. How streamflow is measured: USGS Water Science PS check out the story & link at my Blog. >> http://hypography.com/forums/blogs/turtle/slow-water-power-159/ Quote
Moontanman Posted February 8, 2009 Report Posted February 8, 2009 Sounds like a very interesting project Roadam, keep us informed as to how it goes. Not many people could generate their own electricity that way! Quote
Essay Posted February 8, 2009 Report Posted February 8, 2009 I googled: flume flow meter FLUMES -PARSHALL FLUME"A Parshall flume has a special shaped open channel flow section which may be installed in a ditch ,canal, or lateral to measure the flow rate."~ Turtle 1 Quote
Turtle Posted February 8, 2009 Report Posted February 8, 2009 I googled: flume flow meter FLUMES -PARSHALL FLUME"A Parshall flume has a special shaped open channel flow section which may be installed in a ditch ,canal, or lateral to measure the flow rate."~ :) Nicely done S A!! It's a new one on me. :hihi: Unfortunately the link your article gives to the Bureau of Reclamation to get the standards for flumes is a dead end, so I Googled Bureau of reclamations water measurement. :shrug:The Water Measurement Manual Post Script: Here's the whole article on a new scheme to generate power in low-flow water. >> http://www.physorg.com/news152115803.html... VIVACE, which mimics the way fish swim in currents, is to debut next year in the Detroit River, powering the light for a new wharf between Hart Plaza and the Renaissance Center. "Everybody is excited by this," said Mike Bernitsas, director of the Marine Renewable Energy Laboratory at the University of Michigan and inventor of the device. It's one of a handful of new techniques - the first in more than 100 years - to use water to create clean, renewable energy. Since late November, the device has been filmed by Canada's Discovery Channel and discussed in science blogs, journals and the British Sunday Telegraph. Unlike water-driven mills, turbines or dams, VIVACE doesn't require fast-moving water - most streams on the globe are slow-moving - and doesn't harm the environment. ... PS videos, lab tests, & details of the VIVACE system: >> http://www.vortexhydroenergy.com/ Quote
Roadam Posted February 9, 2009 Author Report Posted February 9, 2009 Believe it or not I have already been trough the water measurement manual. Did some homework :) Anyway, the weir method is something I could build but... I only just got the idea for where to put it. The reason I put this thread up is because I found this on the net: Mear's water flow calculator It has instructions and all but its too low resolution to just print it and use it :shrug: But it could be the easiest way to do it. As far as I read about these fumes, especially Parshall one has to be set and built to spec. So it aint that easy. I did actually measure the flow with the method you Turtle mentioned, and it seemed quite inaccurate. Though I think the flow is somewhere around 40 liters per second, it varies quite a bit. With about 3 meters of head I got, the energy of that flow is about 1.2 kilowatts. Because the flow varies and I would like to get everything I could, :hihi: I found a turbine that has about the same efficiency in the wide range of flows. That is Mitchaell-Banki turbine or crossflow turbine, so I think that all I have to do for starters is measure the annual flow in my site. Quote
Turtle Posted February 9, 2009 Report Posted February 9, 2009 Believe it or not I have already been trough the water measurement manual. Did some homework :) Anyway, the weir method is something I could build but... I only just got the idea for where to put it. I did actually measure the flow with the method you Turtle mentioned, and it seemed quite inaccurate. Though I think the flow is somewhere around 40 liters per second, it varies quite a bit. With about 3 meters of head I got, the energy of that flow is about 1.2 kilowatts. Because the flow varies and I would like to get everything I could, :) I found a turbine that has about the same efficiency in the wide range of flows. That is Mitchaell-Banki turbine or crossflow turbine, so I think that all I have to do for starters is measure the annual flow in my site. Sweet! Sorry for goin OT a bit with the low flow, since you already have a chute. :doh: So how 'bout this. Shove an empty 33 gallon waste can under the outflow & time how long it takes to fill? Rinse & repeat to get your variance. :) Got any photos of your setup? :) Sounds nostalgically bucolic. :) Keep us posted in any regard. :Alien: Quote
modest Posted February 9, 2009 Report Posted February 9, 2009 I think you're looking for Manning's Equation.[math]V = \frac{k}{n} R^{2/3} \cdot S^{1/2}[/math]where,V is the cross-sectional average velocity (ft/s, m/s)k is a conversion constant equal to 1.486 for U.S. customary units or 1.0 for [[sI units]]n is the Manning coefficient of roughness (independent of units)R is the hydraulic radius (ft, m)S is the slope of the water surface or the linear hydraulic head loss (ft/ft, m/m) Once you know V (the average velocity), you can multiply it by the cross sectional area to get flow (volume) per second. The three variables (n, R, and S) are explained in the wikipedia link above the equation. You can find R (the hydraulic radius) and S (slope) geometrically—that is to say, with a tape measure and access to the pipe. The variable n (the Manning coefficient) depends on what the pipe is made of and it can be referenced here:Manning's Roughness CoefficientOne thing that wikipedia doesn't seem to mention, but you need to know is that slope is vertical distance (rise) divided by horizontal distance (run). If you want me to crunch the numbers you could post the slope of the pipe, its diameter, how deep the water is at the center of the pipe, what the pipe is made of (just knowing plastic or metal would probably be sufficient), and... the shape of the pipe (i.e. circular or some other shape). By the way, your project sounds really fun. I'm crazy jealous. :) ~modest Quote
Roadam Posted February 9, 2009 Author Report Posted February 9, 2009 Thank you Modest, I think that this equation nails it. Once I have the equation, crunching numbers is way more easy. :) I will post a few pictures on my own album up here on Hypography. For anyone interested. So far this project is more or less in my head only. I hope it will get down to earth as there are almost no projects I ever completed. Quote
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