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goldhunter_2 Regular Member Joined: 10/03/2010 Location: United StatesPosts: 57
Posted: 01:10pm 25 Mar 2010
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Perry,
your right it would not increase power but rather multiple the torque. mechanical means such as a gear box or level & fulcrum allow you to do more then without
VK4AYQ,
yes your right that point has been beat to death in this thread I have a lathe and mill if I have any questions along the way I'll Pm you thanks for the offer
I don't normally consider that I have High winds all the time here but do have to rate the unit for 130mph witch basically means it has to survive on a test platform behind my boat for 30 minutes (with my boats engine at 2450rpm divided by 18.57mph wind per RPM equals 131 mph sustained wind speed )
on a another note have you ever seen the damaged caused form a wood or composite propeller exploding this is another reason I personally prefer the VAWT design for my use
turnymf,
its all personal preference in my opinion I am sure there are lots of mills that use direct drive and lots that use pulleys and belts to gear them just depends on each application specific requirements
turnymf Regular Member Joined: 04/10/2008 Location: AustraliaPosts: 84
Posted: 01:31pm 25 Mar 2010
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How big is this vawt your talking about?
What style?
Personaly I'm into vawts myself, as a hobby thou
If I had to produce power I'd go hawt
If you had a 130mph restiction, why not brake the mill in these conditions?
KarlJ Guru Joined: 19/05/2008 Location: AustraliaPosts: 1178
Posted: 03:41pm 25 Mar 2010
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indeed braking is the go as its a rare event.
BoB's offer is awesome...seriously consider itLuck favours the well prepared
Perry Senior Member Joined: 19/11/2009 Location: Posts: 190
Posted: 05:05pm 25 Mar 2010
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Why would you want to take a really slowly spinning VAWT and gear it down so it spins even slower just to increase torque? That makes the generator problem even worse.
Perry
goldhunter_2 Regular Member Joined: 10/03/2010 Location: United StatesPosts: 57
Posted: 07:13pm 25 Mar 2010
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gear up not down
Perry Senior Member Joined: 19/11/2009 Location: Posts: 190
Posted: 08:11pm 25 Mar 2010
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That makes better sense, you have been talking about using gearboxes for added torque in your previous posts.Wasn't sure if you knew that you needed more rpm and less torque.
PerryEdited by Perry 2010-03-27
goldhunter_2 Regular Member Joined: 10/03/2010 Location: United StatesPosts: 57
Posted: 08:13pm 25 Mar 2010
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yes
VK4AYQ Guru Joined: 02/12/2009 Location: AustraliaPosts: 2539
Posted: 10:11pm 25 Mar 2010
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Hi Goldie
On your comment regarding the failure of turbines on HSWT I am drawn to the conclusion that it is better to overbuild the propeller to stand the wind speed on smaller units, the sizes we play with rather than try to furl and use other methods to limit the speed as I have seen the effect of safety devices destroying the machine actually tearing it apart due to unplanned actions of the device.
A strong well balanced turbine blade on substantial bearings will survive a direct wind speed of 40 to 50 ms but if you start disturbing its flow pattern by crude furling devices the gyroscopic forces generated will tear the turbine and the tower to bits
On a VSWT the need for balance is much the same and in the size I am familiar with 12 to 14 ft diameter the speed needs to be limited at 150 rpm otherwise the centrifugal forces on the vanes become excessive as they cannot be as easily made in a state of equilibrium as a propeller type construction.
That is why I used the truck diff housing on larger units to utilize the brake drum to stop the mill and secure it in expected hi wind events and also for service. Once it is stopped it only presents a frontal area drag to the wind which is much less trouble to build for than all the factors of the rotational device.
With the brains of some of our electronic people on this forum I am sure they could help you with a automatic braking system tied to wind speed worked by air pressure or hydraulic actuation.
Your comment of testing behind a boat is a real worry as the dynamic forces introduced into a heavy rotating cylinder as a VSWT is from a structural point of view would be very hard to asses from structural point of view. A truck on a smooth road would be a better option.
All the best
BobFoolin Around
goldhunter_2 Regular Member Joined: 10/03/2010 Location: United StatesPosts: 57
Posted: 12:03am 26 Mar 2010
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VK4AYQ,
I guess that falls under personal preference , if for some reason I was not able to take down the mill in time and worst case scenario I would personally rather deal with a collapsed and destroyed mill then the dangers of shapenal form a exploding blades personally I wouldn't try to brake a mill under those winds would rather repair/replace it later ........ if it isn't down by then I figure its to late anyway
ok let me clear up the "boat" comment , I didn't mean dragging the mill behind the boat though a truck driving down a road may work for some I think the cops would give me a whole stack of tickets for driving 130mph for at least 30 minutes down the highway. Using what is available is a better choice or at least I think so. When I said test behind my boat I meant on a miniature height pole attached to the mill in a secured fixed point to the ground. We use the boats to produce consistent sustained wind and rain documenting the process before items can be signed off on. The boats used are basically the same as a portable wind machine (there are larger machines of stacked units to) in the engines ,props, gearing , distance form test item , measured wind speeds etc I think if it works good enough for some of the company's we test for including the Government so I guess it should be ok for me and the local code enforcement
again we normally have warning so I would still intend to take down the mill itself before such winds unless some unforeseen event happened but it still has to pass the wind rating to get the permits and I am not overly concerned with my fabrication or getting it signed off on
you wouldn't happen to have a source on larger 6.25"x 3.25" x 1.25" pie shaped magnets?
Perry Senior Member Joined: 19/11/2009 Location: Posts: 190
Posted: 02:15am 26 Mar 2010
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How could you put this on a truck for testing? It would be at least 20 ft wide and 20 ft tall. The truck would tip over like the Flintstones car when they put the ribs on it.
For testing at 130 mph you would have to provide 130 mph wind to the entire rotor. You would have to have an airboat at least as big as the turbine. How big is that sucker you have?
This talk of blades disintegrating is a little far fetched. Can't really compare an airplane prop spinning at thousands of rpms to a turbine rotor spinning at 100 rev's. HAWT blades do fail but not nearly as often as VAWT rotors, this is clearly documented in many test reports on the NREL site. The Windspire comes to mind. Either way it's not pertinent to your VAWT desire.
How do you plan to take this thing down? 10 kW sized turbines are heavy. Maybe a ton or more. Do you plan on keeping a crane on site for the purpose?
You should also check on how they want to have you prove a 130 mph survivability. This sounds high to me in the first place but I will take your word for it. The County doesn't have test equipment for it nor engineers to evaluate your method so they are probably looking for either a stamp from an accredited testing agency such as NREL or an analysis by a Professional Engineer that's willing to risk his stamp on it. There is no way an inspector would come out, watch you use an airboat to blow on a turbine 10 times it's size and say OK dude, looks good.
Not raining on your parade, just pointing out issues that will confront you and if you are serious about this you will see it as constructive.
Perry
goldhunter_2 Regular Member Joined: 10/03/2010 Location: United StatesPosts: 57
Posted: 03:11am 26 Mar 2010
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"For testing at 130 mph you would have to provide 130 mph wind to the entire rotor. You would have to have an airboat at least as big as the turbine."
some of the tents we test are about 20-25' tall
"Can't really compare an airplane prop spinning at thousands of rpms to a turbine rotor spinning at 100 rev's."
maybe maybe not but if for some unforeseen reason it was still up during a storm do you really think there going to only spin 100rpms . either way once you see wood & composite blades blow you just don't forget it and yes maybe it effects your judgment about them
"You should also check on how they want to have you prove a 130 mph survivability. This sounds high to me in the first place but I will take your word for it. The County doesn't have test equipment for it nor engineers to evaluate your method so they are probably looking for either a stamp from an accredited testing agency such as NREL or an analysis by a Professional Engineer that's willing to risk his stamp on it. There is no way an inspector would come out, watch you use an airboat to blow on a turbine 10 times it's size and say OK dude, looks good."
Actual yes they do have engineers here (unfortunately we are not out in the sticks). And yes as I said before it will be done by a "accredited testing agency" signed of by a "Professional Engineer" but do think we have a different idea on actual size of the application . like I said before we all have access to different resources doesn't make one way right and one wrong just done differently using whats available
"Not raining on your parade, just pointing out issues that will confront you and if you are serious about this you will see it as constructive."
no problem , I have given up for the most part any hopes of getting constructive info on the generators with the rare exceptions now and then
Perry Senior Member Joined: 19/11/2009 Location: Posts: 190
Posted: 03:56am 26 Mar 2010
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I think the info flow hasn't been that bad. You asked about alternators and myself and others have told you about the gens you proposed, how to build them, offered you plans and advice on ones they had built and I actually posted links to exactly what you had asked for. Not sure if you even looked at them. Heck, this forum is all about building and using alternators. If you can't find it here, where else would one look. Hundreds on this site and others built or own alternators, some the size you were interested in. You did have to eat some sh*t because some of the questions you asked are entry level questions that people get wrong all the time and you refuse to listen to the correct answers. Nothing to be ashamed of, I asked the same type of questions when I started, the difference is how one listens to the answers. Many, many experts on here.
OK, off my soap box in the interest of being constructive. For someone new in wind, I would recommend that you get to intimately know the formula for how much power a turbine will make. It works for HAWTs and VAWTs.
Power = 1/2 * rho * velocity^3 * Cp * Area
rho = density of air = 1.223 kg/m^3
velocity - windspeed in m/s
Cp = performance coefficient (.15 for a VAWT, .35 for a HAWT)
Area = cross sectional area presented to the wind. for a Vawt use the dia times the height in meters
This is the most important equation in wind power if you wish to make a mill. You know all the variables now just solve it for area and that will show you how big your VAWT rotor has to be.
I challenge you to perform this exercise, it will be sobering.
Perry
Bryan1 Guru Joined: 22/02/2006 Location: AustraliaPosts: 1344
Posted: 08:46am 26 Mar 2010
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Ok I have glanced the whole 10 page thread and not seen one member suggest an alternative way to reduce your power consumption. You say you basically run a full machineshop and everything else and want a VAWT to power everything . Anyway go and look and converting your machinery to VFD's single phase input 3 phase output to about 3hp ( in the Delta range)
I run my machineshop off the grid and use VFD's on several machines, currently I only have 5 of them and I won't be real happy until I have a dozen of them.
I haven't seen any quotes towards a SOLAR INPUT in this thread at all so how in the hell do you expect to keep your batteries charged when the wind isn't blowing and just remember MURHPY will pop his head up when you don't want him around.
OK so you want to build a 10kw VAWTon the roof of your house. Hope ya got good house insurance.
Just how much open land space do you have or is all the area taken up with garages for dolled up Veedub's (porches).
Well with a friday night post and a few ales under the belt one cannot wonder if this 10kw Yank has gone too far south......
Cheers Bryan
KarlJ Guru Joined: 19/05/2008 Location: AustraliaPosts: 1178
Posted: 10:12am 26 Mar 2010
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Bryan, there's some good stuff there particularly with knocking down the consumption and going for multiple input sources.
I'm inclined to agree 5KW turbine and a 5KW of solar would be a top solution that would probably yield better overall and certainly make the mill more manageable.
KarlLuck favours the well prepared
VK4AYQ Guru Joined: 02/12/2009 Location: AustraliaPosts: 2539
Posted: 10:19am 26 Mar 2010
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Hi Goldie
You have addressed my concern with the wind test, I was under the impression you where going to use the air boat and direct the airflow onto a small cross section of the Turbine and create asymmetric loading and strains different to the full exposure of the structure. I must ask if the 130 mph rule applies to your house as well as most structures would have to be heavily modified to survive that wind speed with a VAWT sitting on the roof,
are you able to make it retract down into the roof cavity by some means to reduce exposure, something like a scissor lift comes to mind.
On the magnets, good ones are hard to get in Australia or rather the cost including freight is prohibitive.
I used round bar magnets 2 inch diameter by 3 inches long that I picked up at a disposal sale several tones of them for scrap price specs not known but quite strong if they got together it was a hell of a job to separate them. Unfortunately none left as I used all of them on various projects.
The alternators I made from them where axial flux 12 magnets and 15 windings and the bigger one had 24 magnets and 30 windings with several types of coupling but basically load control was by bringing in more coils to increase loading, could also be set up as a three phase delta format if required.
With the new neo magnets I think you would have a lot more power out, the smaller generator put out a little over 10 kw at 125 rpm the larger one put out over 20 Kw at 100 rpm.
All the best
BobFoolin Around
goldhunter_2 Regular Member Joined: 10/03/2010 Location: United StatesPosts: 57
Posted: 01:19pm 26 Mar 2010
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VK4AYQ,
houses/buildings built after a certain date yes must be rated and even require other features before getting occupancy certificates but houses/building prior to that date are not required to meet this until such time as they need reconstruction. they also regulate building/structure heights in most areas . one of the earlier suggestions was to use a tower and I mentioned before I decide to go that route mainly for cost/time since I ran across a source.
you don't know what those 2"x3" round magnets came out of or where they already in a bin at the scarp yard when you got them?
Bryan1,
actual the idea was for the system to offset the major part of my power requirements operating at peak performance.
That is a good suggestion on the shop machines Thanks I'll have to look into that as posted power numbers where conservative as I said reduce power usage with out reducing equipment would be a good thing
yes have good insurance but actual earlier on it was suggested to use a tower type mount instead of roof top (still preferable but) witch I decide to go with because of cost/time factors since I found a source I could not pass up
Solar I think I did mention that I looked at solar first and would still be adding some solar pv panels to the system later but I only have around 6 hrs charge time and would require allot of panels for stand alone system . I do have solar heat for the pool and talked with someone about installing solar hot water heater panels the other day so I will make use of solar it just wasn't my main focus on this thread
Perry,
I do appreciate everyone who posted relevant information as I have mentioned more
then once and maybe it is wrong method but have found if I ask a questions or combine different questions into one as a person not knowing anything about anything NORMALLY I tend to get a more straight forward direct answer to my specific questions rather then disagreeable conversations over other components . I do think I tried to be civil and did ask,imply and what ever else could to just stay with the one subject so as not to have those disagreeable conversations but may have pissed off some in do so .
Karl
yes reducing power usage without reducing equipment would be a excellent idea especially compared to early on in this thread where it was suggested to just element power usage level
remember the 10kw mill was going to off set power usage and later I was adding the solar Pv panels but wanted to start with the wind for a higher power off set to begin with I could use your idea of two generators making them a little smaller and more manageable . really don't see handling this as a problem just swing the boom up there hook it up and swing out in the open to drop it down
VK4AYQ Guru Joined: 02/12/2009 Location: AustraliaPosts: 2539
Posted: 01:49pm 26 Mar 2010
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Hi Goldie
The magnets where at a military disposal auction with part numbers that meant nothing and sold as steel scrap it wasn't till I got them home that I realized they where magnets I thought they where steel pins originally.
I believe from a couple of searches I have done you can get neo 45 magnets that size in the states for around $55 each if you buy bulk lots, do a search lots come up.
All the best
BobFoolin Around
goldhunter_2 Regular Member Joined: 10/03/2010 Location: United StatesPosts: 57
Posted: 02:24pm 26 Mar 2010
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ok thanks
KarlJ Guru Joined: 19/05/2008 Location: AustraliaPosts: 1178
Posted: 11:06am 27 Mar 2010
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hmmm 6 hrs a day of solar is not that bad, a simplish tracker 2 axis will help and 1KW of panels is cheap(ish) next to the mill.
sus out energy efficient lighting too.
a 25% reduction in consumption is usually easy and 10/40 KW/day is 2KW of panels call it $14K so saving is far far cheaper than trying to make it.
I'm going through it myself, just bought a huge house and previous owner was spending $700+ every 2 months on power.
seems 20KW airconditioners drink heaps of juice!
solution for me may well be evaporative cooling at $3000. AS opposed to $10K in solar generation equip.
Glad your now looking at alternatives too.
LED lighting is now great with 3W CREE lights, group of 5 makes more light than a 50W downlight and can be had for less than $50 each.
Myself, i'm making my own light fittings with automotive HID lights 35W is as good as 150W of normal halogen lights but not dimmable. Make great outdoor floodlights though and they are now cheap as chips. even a pair of 55W HID's can be had for under $100AUD delivered and they are more like 220W (each).
stay posted, should have them running shortly.Luck favours the well prepared
wallablack Senior Member Joined: 10/08/2011 Location: AustraliaPosts: 164
Posted: 09:35pm 21 Nov 2011
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How do you have your stator wired?Foolproof systems do not take into account the ingenuity of fools.
Notice. New forum software under development. It's going to miss a few functions and look a bit ugly for a while, but I'm working on it full time now as the old forum was too unstable. Couple days, all good. If you notice any issues, please contact me.
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I have a lathe and mill if I have any questions along the way I'll Pm you thanks for the offer
