Calcuation tables?

[poleframer]

I notice there are a lot of questions about flow/pressure, etc. I have some of my own too. I've searched the site a little, are there any good calculators to plug info into, or good charts/tables to use?

Here's my hydro sitution. A little over 1500' of 2" polly pipe (old and has been spliced a few times, hav'nt counted the connectors). At the hydro I have 120 psi, runs at 110 psi flowing. The nozzle is a little under 5/16" (much bigger I have too much pressure loss) I think that would be about 25 gpm (?). I get 12 amps out of the alternator to the batteries. Does that seem right? should I be getting more?

Thanks, Russell

[willib]

12Amps 24/7 sounds very nice to me!

[AbyssUnderground]

Id certainly be very happy with that. I could run practically my whole bedroom from that. Its about 120watts at 12v :-)

[Nando]

You are getting 39.2 % efficiency for the site, the 5/16 gives you 1.23 liter/sec and 110 psi*0.3048 = 35.528 effective meters head

Available power is 1.23 * 35.528 * 9.81 = 429 watts

You seem to have an alternator so you may be using around 14 volts * 4 amps = 56 watts for the field

56 + 14 * 12 = 224 overall efficiency is 224/429 * 100 = 52.2 watts DARN GOOD for the system you have.

Your basic problem is the pipe 2 inches and 1500 feet.

If you have more available water volume and can change the pipe you may obtain around 35*9,81 = 343 watts for each additional liter/second you may add, then we need to calculate the efficiency if the generator is changed to a different one that does not use field current.

Are You planning to change the pipe ?. If so think in a larger diameter !!

Also if the length of piping at the beginning has low head, then for the first 20 meter= 65 feet head you use a larger diameter pipe for sewer service that are lower in price you may increase the available power.

I recently assisted a fellow to sell his battery banks and inverters and he changed the piping to a larger size to attain 4 KW constant power AC from the 450 watts he had, it seems that the "knowledgeable salesman" convinced him that was the right way = which seems the right way for him to make more money.

Nando

[Nando]

Heck I made a basic mistake

I DO NOT HAVE TIME TO CORRECT IT so do not pay attention to the message

I will try later when I return to fix the problem

Nando

[alancorey]

One very simplistic formula I've run across (in a book) is

((net feet of head) * (flow in GPM)) / 10 = watts

Net feet being what you've got left after friction losses in the pipe.  You can calculate that from your 110 PSI but I don't remember the feet/PSI conversion factor.

That's assuming "modern" efficiencies in the turbine and generator or something equally vague.

I've got about twice the flow and 1/5 the pressure in my situation and I'm hoping for 250 watts, which is about 20 amps at 12 volts.

Can you get a more accurate flow rate?  Maybe by sticking a container under where the water's coming off your pelton and timing how long to fill it?

Also we don't know what your battery voltage is so 12 amps doesn't tell us much.  12 amps at 48 volts is a lot better than 12 amps at 12 volts.

Nando can probably give you lots of information but he'll probably also chide you about lack of data in your post.  I don't know him, I've just read some of his posts.

  Alan

[poleframer]

My system is 2nd in line, my uphill neighbor runs a hydro,2" line up the hill from him. I get the water after him. The line is 2", too much line to change. My system is 12v.

For now, lets say the flow/pressure at the hydro is what it is. I figured the flow by a table I found, using pressure/size of nozzle. I would put the nozzle size at 9/23. Actually,for this discussion, I'm just curious if my hydro is putting out what it should under these conditions. I'll gladly add any info asked for, or pics.

I'd rather work with what I have, and understand it better, before I spend money on it.

Thanks, Russell

[poleframer]

Nando, is the miscalculation something about the 429 watts available? At that I should be running closer to 30 amps, or is my loss in nozzle size/friction loss? That is more like what my neighbor gets on his harris wheel. He just went to 24v, and rebuilt the alt., so I dont know what he's getting now. His line is over 150 psi, with more drop in less distance. my line goes out a ridge from his place, down steep, then out a ridge at my place.

Russell

[maker of toys]

I think Nando was noticing that his head number was a little off.

using your 110 psi, and assuming Nando calculated the flow across a 5/16" nozzle right:

 I get 110psi = 77 meters head (exact conversion 77.338..., rounding to 2 significant figures)

(77m) (9.(1.2 l/s)= approximately 910 watts available.

Using your 25gal/min number gives something like 1.6 l/sec, and about 1200 watts.

with 12A delivered at what I'm going to assume is 13.5 volts at the batteries, I get about 160 W delivered to your loads. . . . for a generator system efficiency of around 18% or 13%, depending on what flow number you use.

If you count the field current as part of your power extracted from the water (to try to get an handle on your wheel/nozzle/alternator effieciency) and take the voltage at the alternator output(nominally 14.5V, assuming from your pic a Delco with an un-tweaked  regulator)) then you're geting around 25% (or 19%) of what is available to you.  Make a voltage measurement at the gen and at the batteries to get a closer handle on what power you're actually getting.

A PMA might help with your efficiencies, especially if you can monkey the system RPM  to match your flow and nozzle better. . . you might find a sweeter spot with a higher flow, even given the lower head from pipe friction.  Nando will probably want you to characterize your flow options a bit better to figure the best flow vs head to design the wheel, nozzle and PMA for. . . .

using the formula (power = head * flow * specific gravity (9., you can work the numbers on a 4-function calculator right at the wheel house and figure that sweet spot for yourself.

(1 psi = 0.703 meters of head)

(rant on significant figures:  be wary of calculating a result to greater precision than your initial data:  it's easy to trick yourself into over-optimising a design based on poor understanding of the situation at hand.  By all means, calculate with as many figures as you wish, but keep in the back of your mind that no matter how many figures you get from the number-cruncher, you're still dealing with approximations.)

[Nando]

CORRECTING THE MESS I DID.

110 actual dynamic PSI is 110 / 1.42 = 77.46 meter head

Water velocity = squr-rt ( 2 * 77.46 * 9.81) = 38.98 m/s = 40 meter/sec.

Water volume = 3.14 * (0.5 * 0.0254 * 5/16)^2 * 40 = 1.98^-3 meter^3/sec = 1.98 liter/sec

GROSS Power watts = 40 M/s * 1.98 l/s * 9.81 = 0.777 Kilowatts with a perfect system

With 50 % efficiency then 0.3885 KWs = 388.5 watts are available

What CAN BE wrong here ?? : The PSI, the Nozzle diameter, some clogging of the Nozzle, different Nozzle diameter ( it would be good to take a water volume delivered to make sure that is as defined.

25 GPM is 1.57 l/s

CERTIFY THE NOZZLE DIAMETER, The PSI, The water volume

Your actual power says that there is a problem !!! You have 168 watts into the battery then around 60 or so watts for the field for 228 watts were are the other 388 - 228 = 160 watts

Nando

[poleframer]

Thanks, that's what I thought. I've put on different pressure gauges, but even topo maps show my neighbors place about 260'-280' elevation difference, so the pressure should be accurate. It briefly hits 140psi when I turn the valve off.

The batteries are within 15' of the hydro, 2ga wire. Amp gauge at the hydro. The nozzle is 9/32",I have 2 others, at 1/4" I have about 8 amps, at 7/16" I get 15 amps till the pressure drops to under 70psi.

The alternator was buildt by the guy who made the wheel, also makes PMAs, but I don't have the $700 he wants for one.

The readings I give are with a clean nozzle and inline screen (tried w/out screen too).

The pipe elbows twice around the box only because I wanted it to face me where I located it next to my shop. That could cause a loss of velocity I suppose. Could it need a bigger box? Seems like the water is falling into the barrel well enough. I think I'll put another nozzle in the box diagonal to the existing one, and a valve on each.I have another similar alt. (Delco) I can try as well, but I recently had this rebuilt and it should be good.

But there still has to be something wrong. This alt. should be putting out more under the conditions, shouldn't it?.

There is a rheostat to adjust (I've bypassed it for test) that works. I can turn it down and the pelton wheel screams, dial it up till it bogs and splashes hard.

Actually the 1/4" nozzle gives me plenty of power most of the year, and the water is fairly dependable thru the summer, much more problem in the winter with high water, and a lot of debris issues. I'm gone a lot in the summer and home a lot in the winter. ie; its 9:30 and I'm online, watching snow fall.

I'd sure like to get this thing up to 20-25 amps, and cut down on genny run-time.

I've been running the system for about 8 years now. Don't laff, I'm slow,and cheap, just put doors on the shop I've been building for 10 years.

Thanks again. Russell

[Nando]

My GOD another basic mistake and I thought that I was a perfect 10 Duh!!

GROSS ERROR AGAIN:

>>GROSS Power watts = 40 M/s * 1.98 l/s * 9.81 = 0.777 Kilowatts with a perfect system

GROSS Power watts = 77.46 M * 1.98 l/s * 9.81 = 1.5 Kilowatts with a perfect system

With 50 % efficiency then 0.750 watts of which around 80 to 100 watts for the field and 650 to 670 for the battery charging

The rest of the message stands. Hopefully without any more mistakes.

Let me say: for each liter/sec you can attain 760 GROSS watts and using the proper generator and being able to add more a few more liter/second, you may have enough energy without the need of batteries or inverters.

If the pipe has been repaired several times, how old is it ?.

Can you describe the slope of the site, specially at the intake section.

What is the water level of the overall stream ?.

adding also your water source coming from the other site.

We did a site where we tied 3 systems into one to take the advantage of the whole 3 heads which allowed to have enough energy for the three users to drop their batteries and inverters and have a lot of extra power.

Think in getting oil field piping that is high pressure and many times used and available at scrap cost.

Your system can be optimized dramatically if the proper processes are implemented.

Investigate costs versus batteries and inverters.

Nando

[Nando]

Russell:

Where are You located ?.

9/32 gives you around 1.2 KW GROSS power, still You are quite short power wise.

You can probably stop using the genny run time to Zero, except in emergencies if you spend around 3 to 500 dollars, calculate how much money you spend in genny fuel per year and then for 2, 3, 4, and 5 years and see how much you save by changing the generator, also think in going much higher voltage like 24 of 48 volts (this is best).

You need a permanent magnet brushless motor for sure, AND NOT A CAR ALTERNATOR TYPE.

Why type of inverter do you have ?. Pure sine wave or MSW (modified sine wave).

I see that you are a handyman -- You can rebuild the hydro ( new generator) and get at least a 100 % improvement.

Nando

[poleframer]

Hmm, that was interesting. I just checked flow at the pipe return to the creek, filled a 5 gal bucket in 15 sec. (there's probably a couple leaks here and there)

Back at the hydro I tried something, I turned the reostat down than rapidly all the way up a couple of times and the amperage went up to 18 amps !?!!(guess I never tried that before)

Heres some answers to your questions

The pipe is about 20 years old.I've put in a few new pieces here and there, but its all tight. You would get a kick out of the old tin breadbox hydro.

All my water comes from my neighbors hydro, from a concrete box there is a run of 300'-350' of 2" white PVC out a flat ridge with maybe 20'drop (our places are on the same ridge- imgine two big steps on a mountainside), then to 2" poly and most of the drop in the next 800', then out my flat(ish) ridge to my shop, with about 20' drop in 350'.What you discribe is what we are doing.

Moving to a 120v system is not going to happen. Financially. I've worked one one before, 6" plastic welded pipe (moving that pipe welder and a generator thru the mountains was fun), they ended up with 3 phase electricity. Also had a lot of money to spend.

I am mostly pleased with my system, and I think if I tune it up a little I should only have to run my welder/generator in the shop for welding, bigger tablesaw projects, and heavy air compressor use.

How will going to 2 different size nozzles work on the pelton? The smaller would take care of my home use fine (does now) then turn on a bigger one when I hang out in the shop.

That amp jump was interesting. Why would it do that?

Russell

[poleframer]

I'm in SW Oregon. Put a couple pics of the place in my files. Where are you? Russell

[SparWeb]

Nando,

Hope your confidence isn't shaken.  Many of us fall victim to the mistaken unit (even NASA screws it up, at times, so you're in good company).  I checked a nozzle chart (had to interpolate for 5/16" nozzles).  I got a flow rate of 32 gallons per minute (121 liter/min) and a head of 254 feet (77.3 meters), which agrees with your numbers.

[Nando]

Russell:

I am in Texas.

What is the Pelton hydraulic diameter in inches or millimeters ?.

The JUMP is called RAM Hammer and it is dangerous because it can Burst the pipe in several places.

It happens when a pipe like your is closed/opened rapidly allowing the water to go faster then doing a sudden stop -- the water mas cannot be stopped and a heavy weight against the valve and all the piping increasing the pressure -- you measured 140 PSI and the real pressure may have gone to about 200 + momentarily or even higher, it is a miracle you did not burst the pipe close to the turbine.

Let me put this way after reading this message, if you move the turbine to the site where the flat land starts ( 20 feet drop in 350 feet) You can have much higher power because you haver reduced the pipe length by 350 feet, though you will need a higher voltage generator with transformers to bring it down to the battery.

You run to say 120 volts AC, indeed would be better for you, BUT by just changing the generator for one brushless permanent magnet you gain the watts I indicated in a message previously, and if you move the turbine around 350 feet to attain another 25 to 35 % additional power. ( I will need to recalculate the gain)

Stay with 12 volts if you so want, but think how to reduce the genny usage and fuel expenses that can be quite high since you are in a remote area with the fuels additional costs for the delivery of it, PROPANE ?.

Your message seems to indicate to THROW the idea of reducing the genny usage to the side, instead of doing a deep analysis for its feasibility and practicability.

You may forget the idea of 2 Nozzles, You do not have the pressure due to the friction of the water in the pipe to get additional water and of course the additional power.

Your ONLY solution seems to be = Replace the generator for a Brushless DC generator.

Nando

[Nando]

Heck, I hate those mistakes, old age hits hard.

I am quite familiar with the metric system since I had to learn 4 systems Imperial ( the king had eight fingers), the metric, the Spanish and the Roman systems.

I have put aside the Spanish and the Roman, the later one completely useless.

I am doing the calculations on the fly while I write the message and this should be a no, a double no and a not, but laziness maybe the reason.

Nando

[LeissKG]

I know next to nil about turbines, but i have the impression that almost all advertisements for small turbines have more than one nozzle per wheel. Can there to much flow trough a nozzle? I seem to remember something like this, but that may be wishful thinking.

Klaus Leiss

[Nando]

Kalus:

The number of Nozzles in a turbine depend on several factors, the water volume, the diameter (size) of the turbine's spoons and the wanted power.

If the water available is greater than the nozzle can use for effective pressure on the spoons, then additional Nozzles are added to attain the necessary volume needed to harvest the projected power.

Some use full flow which is that the water volume hits all the spoons or blades surfaces at the same time, like the propeller of a boat that hits the water all around the blade surface to obtain the highest pressure to move the boat faster.

Nando

[poleframer]

Thanks for the posts, I'm not over egoed about my scene. The wheel is 7" OD, the cups are 2" wide x 1 1/2" deep.It wasnt turning off the water valve that produced the jump,I can turn the water off, do it often, my neighbor uphill cant- he will bust his pipe, it was adjusting the rheostat up and down that did it -it might need replacement, still showing 18 amps now.

I like the generator replacement idea. Part of the reason for putting it by the shop at the end of my ridge-flat(the yarder landing when the slope below me was logged) was the noise issue. I like it quiet when I sleep. Also I like to have the whole battery/power setup in my shop, nice and dry, near my tools and workbenches.

The water could be re-piped like you say, put the generator up by my house (shack ha)and run it at a higher volage wired to the batts at the shop. Or even put it in another location downhill(most of my property is below me) towards the return to the creek, and pick up some more head. I'd prefer to keep the power center in the shop,and the hydro not to far away- cuts down on walking back and forth all over the place-do enough of that anyway.

At this point my power center consists of a Trace 1512 wired to the cabin (300' away on 10/3), a Heart "Freedom 2500" wired to the shop (both 12v modified sw), a C35 charge control, 6 L16 batteries. I've split the batteries, 2 for the house, then the C35 in diversion to the 4 for the shop. Need to get another charge control for that set to a diversion load. pics are in my file.

Soooo, figure the water pipe isnt an issue (most of it's on my neighbors place, and I'd rather not make changes in that direction), what would I be into ($) for a PM generator (building one is a little out of my league), wire to send the juice to the batts ,and whatall to change to 12v at the batts? Or just to start by replacing the alterator? Anyone here have one to sell?

I'm a pay as I go kind of guy, if ya know what I mean. Got other situations that are yelling for cash as well.

Appriciate the input, Russell

[Nando]

Russell:

One of your problems is that the generator has 2100 RPM low RPM for the power the Hydro can generate You need around 1000 more RPM for higher output level.

How often do You change the alternator brushes ?.

Generator change would be better with a Brushless Permanent Magnet motor with 2000 RPM capabilities and at least 1200 watts for peak efficiency if the Pelton is Kept.

I see that you have additional head if the turbine is lowered, strange indeed, you need more power to reduce the genny time and fuel expenses but you want everything close -- which by principle is costing you "dearly financially".

I need to "reset" my logic.

Another factor for power increase, could be the home or the shop heating, so how much do you spend in heating fuel (propane, wood, etc ).

Of course, 12 volts for heating is very inefficient.

Pay as you go but better plan what to do to peak the power and spend accordingly.

I do not sell anything and the best for You would be a generator that produces high voltage and transformers to bring the voltage to battery level.

If you have situations "yelling" for cash, then think that you may need to do less "generally goofing off for the rest"

Nando

"You can take the horse to the water, but you can not force the horse to drink it"

[poleframer]

Doesn't take long to get cut down to size here.

[TomW]

poleframer;

Doesn't take long to get cut down to size here.

It is called "brutal honesty". Rather see your ego bruised a bit than see you toss a pile of cash / resources into an unworkable or poorly thought out system that becomes a money pit.

Cheers.

TomW

[Nando]

Unhappily what you are doing is what I have seen TOO MANY TIMES,

mind set to the wrong parameters,

wrong way of doing things,

wrong way to program what to do,

wrong way to do the proper investing to attain the best solution to the problem

and then given the excuse "that I am a tight wad".

Then asked for solutions but ONLY the way the mind is set, though it is the wrong path -- all the way.

Or say that there are other priorities that have to be fulfilled because the "cry for cash"

My father used to say:

If you want MONEY, Study a good high level career

If you want money - work

If you want to GOOF - work hard and long to have the money to GOOF OFF

If you want to live well, WORK HARD

If you want a girl friend, WORK Harder

If you want a vacation, WORK long and Hard

and I have many more of those " If You want -- sayings " he wisely kept saying,

He learned to read/write 5 languages by himself, I made the mistake to just learn 2 and comprehend some others.

Nando

[poleframer]

Hmmm, I should address some things said here

 "you are in a remote area with the fuels additional costs for the delivery of it"        

    Not as remote as you probably think, you make a LOT of assumptions in this thread.

"Your ONLY solution seems to be "

   Thats a pretty narrow minded way to think

"I see that you have additional head if the turbine is lowered, strange indeed, you need more power to reduce the genny time and fuel expenses but you want everything close"

   I think you WAY overestimate my gen. runtime.

"If you have situations "yelling" for cash, then think that you may need to do less "generally goofing off for the rest"

   I make a few lighthearted comments, and you peg me as a useless slacker?

   Geez- I start a thread about my little hydro, and that last post is where its gone in a couple days? What is this, some CULT??? -WE"ll SET YOU STRAIGHT HERE- LISTEN TO US!

You know alot about hydroelectric, thats what I came here for, not to stand under yer soapbox. You, friends, are WAY too uptight about my scene.

Russell

[Nando]

Russell:

I may be too "tight about your scene" but I would refer to what you initially said which indicated,by the way You wrote the message, that you were not expert in such a field and indirectly asking for assistance to understand it.

That is what you got.

I do not sell anything nor I am "forcing" to follow my suggestions, my path would be quite different, and I mean extremely different, if I were in your place and conditions.

What is happening here is what is common in these types of groups, unhappily.

REMOTE has very variable meaning levels from the point of view of many.

Only solution one the basis of what you based your questions -- indeed there are many solutions and ways to solve a problem or your problem.

GENNY runtime has not overestimated, you declared to reduce the run time, therefore you are complaining that is too much for You - no other since you did not extended or expressed the run time improvement.

"a few lighthearted comments" from YOU indicate a mental status strong enough that has to be expressed in public remarks, it is YOUR SIN, not mine.

I am not on a SOAP BOX, this group, where every one, most of the time, send messages, with photos showing what the have been doing, for the members to give opinions and possible solutions to such message, exactly what happened in your case, so happens I volunteered my experience for the messenger benefit and I am not looking for my " 5 minutes of glory".

My "5 minutes of glory" are quite different and never realized in this type of environment.

Nando

[alancorey]

One reason to use multiple nozzles is because most places have seasonal variations in the amount of water available.  You can run just 1 nozzle in the dry times (late summer where I live) and increase to running all of them in the wet times (spring, with snow melt runoff).  Turning nozzles on and off is easier than changing the size of a single nozzle, and might even be rigged so it could be done remotely and/or automatically.

  Alan