Author Topic: 1.4 Megawatt Hydro  (Read 1695 times)

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dbcollen

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1.4 Megawatt Hydro
« on: February 24, 2008, 09:00:45 PM »
I had the opportunity to work at a 1.4 meg hydro plant last summer with my friend Mark who runs the plant.


First the specs


The hydro has 2 diversions, on two seperate creeks, they join in a settling tank, then start thier 2.1 mile journey down the penstock. the penstock begins at 24 inch diameter, necks down to 20 inches, and finally to 18 inches for the bottom .75 mile.



  1. ft total head.
  2. 7 Cu Ft/Sec  flow.


The alternator is a 8 pole 900 rpm 3000HP 4160 volt 3 phase induction motor made by Cato Engineering. it is inseresting that it only has 8 RPM of slip, at full power it runs at 908 rpm.





That is me standing in front of the generator.




That is the Pelton runner in front of the alternator.


The reason the runner had to be replaced is, there was a grid failure and the deflectors failed to drop into place in front of the nozzles. The nozzles take 3 minutes to close. The resulting overspeeed cracked the runner through the keyway. The cracked runner was run for the rest of the season at reduced power while a new one was cast. The new runner was cast from the wrong alloy, and subsequently work hardened and was shedding entire cups under load after a few months, so the original runner was welded and re-ground and put back into service while a 3rd runner was cast from the right alloy. These pictures are of us replacing the welded runner with the final new one.

 


Here is my hand inside one of the cups for scale





We had to pound the coupler on to the 5 inch shaft with this white oak log hung from the ceiling, the new shaft was a few thousandths larger than the old one.

It took 3.5 hours to get it all the way on. Heating the coupler didn't help at all.


Dustin

« Last Edit: February 24, 2008, 09:00:45 PM by (unknown) »

dbcollen

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Re: 1.4 Megawatt Hydro
« Reply #1 on: February 24, 2008, 02:04:52 PM »



Here is a picture of the view in the tailrace, you can see the 3 inch nozzle with its pintle closed pointing at the runner.


There are two of those nozzles.


Dustin

« Last Edit: February 24, 2008, 02:04:52 PM by dbcollen »

dbcollen

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Re: 1.4 Megawatt Hydro
« Reply #2 on: February 24, 2008, 03:08:32 PM »
Why does scoop always screw up nombers in posts?


That is supposed to read 1084 ft head, 14.7cfs


Dustin

« Last Edit: February 24, 2008, 03:08:32 PM by dbcollen »

marv

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Re: 1.4 Megawatt Hydro
« Reply #3 on: February 24, 2008, 03:34:21 PM »
Nice pics Dustin thanks! Must of been a interesting summer.


Marv.

« Last Edit: February 24, 2008, 03:34:21 PM by marv »

TomW

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Re: 1.4 Megawatt Hydro
« Reply #4 on: February 24, 2008, 04:47:09 PM »
db;


You can:


Either set the drop down between "post" and "preview" to "plain text".


Or put any character in front of the numbers like # -  + * etc not the greater / less than symbols they are special html parts.


Other than numerical first character:


-1

-2

-3

-3

-4


Otherwise the retarded software assumes its a "list"


Just the 2 easiest ways I know of.


TomW

« Last Edit: February 24, 2008, 04:47:09 PM by TomW »

oztules

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Re: 1.4 Megawatt Hydro
« Reply #5 on: February 24, 2008, 06:29:17 PM »
Or even just a space in front of the number like this

 234

 333

 4567

 3434


........looks better than a non useful char in from of the number


.....oztules

« Last Edit: February 24, 2008, 06:29:17 PM by oztules »
Flinders Island Australia

oztules

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Re: 1.4 Megawatt Hydro
« Reply #6 on: February 24, 2008, 06:32:49 PM »
sigh...

.......looks better than a non useful char in from of the number


should be .....looks better than a non useful character in front of the number.


.......oztules

« Last Edit: February 24, 2008, 06:32:49 PM by oztules »
Flinders Island Australia

TomW

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Re: 1.4 Megawatt Hydro
« Reply #7 on: February 24, 2008, 07:03:27 PM »
oz;


Thanks. Thats lots better than a unnecessary character. Space being a character technically.


Didn't know that trick worked.


TomW

« Last Edit: February 24, 2008, 07:03:27 PM by TomW »

12AX7

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Re: 1.4 Megawatt Hydro
« Reply #8 on: February 25, 2008, 10:04:07 PM »
Very nice!


That's a hair more than most diyer would need.


does it run year round? supplies power for how many?


A dead blow that large, the bearings can take it?


I'd like to see the puller used to take the coupler off!


Is the frequency an issue?


I'd like to see more pics...  


Thanks!

« Last Edit: February 25, 2008, 10:04:07 PM by 12AX7 »

dbcollen

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Re: 1.4 Megawatt Hydro
« Reply #9 on: February 26, 2008, 06:43:02 PM »
Here is the puller I made.






The plant runs about 8 months a year.


The other end of the shaft was up against the concrete wall, the bearings took no load.


It is an inductive plant, so the grid sets the frequency to 60hz.


An interesting thing, because it is an inductive plant, to come online we slowly crack one nozzle, the machine accelerates, and when it hits 900 rpm the contactors close and it is connected to the grid, no matter how hard the water pushes the runner it will not go above 908 RPM.


Before we go online we have to call the bridgeville substation and have them engage the trip doublers ( an extra set of fuses in parallel ) because the inrush current to the generator can blow the fuses to the whole local grid.


Dustin

« Last Edit: February 26, 2008, 06:43:02 PM by dbcollen »

jonas302

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Re: 1.4 Megawatt Hydro
« Reply #10 on: February 26, 2008, 07:08:36 PM »
 Great pics looks like a good time hard on the back I bet
« Last Edit: February 26, 2008, 07:08:36 PM by jonas302 »

dbcollen

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Re: 1.4 Megawatt Hydro
« Reply #11 on: February 27, 2008, 09:03:19 AM »
Here is a short video of Mark pounding the coupler on, there is also 4, 2 ton come-alongs pulling the coupler on. We got only a few thousandths of an inch per hit, and it has about 8 inches of engagement


http://www.otherpower.com/images/scimages/5756/100_4121.MOV


Dustin

« Last Edit: February 27, 2008, 09:03:19 AM by dbcollen »