Francis Turbine
description
Transcript of Francis Turbine
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Examples Losses in Francis turbines NPSH Main dimensions
Francis turbines
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X blade runnerTraditional runner
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SVARTISEN
P = 350 MWH = 543 mQ* = 71,5 m3/SD0 = 4,86 mD1 = 4,31mD2 = 2,35 mB0 = 0,28 mn = 333 rpm
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P = 169 MWH = 72 mQ = 265 m3/sD0 = 6,68 mD1e = 5,71mD1i = 2,35 mB0 = 1,4 mn = 112,5 rpm
La Grande, Canada
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Outletdraft tube
Outletrunner
Inletrunner
Outletguide vane
Inletguide vane
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Hydraulic efficiency
n
uuh Hg
ucuc
= 2211
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=3
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z2chgz
2chg
lossesz2chgz
2chg
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Losses in Francis Turbines
Draft tube
Output Energy
Head [m]
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Losses in Francis TurbinesH
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Output Energy
Output [%]
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Friction losses between runner and covers
Friction losses
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Gap losses
Gap losses
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Gap losses
Friction losses in the spiral casingand stay vanes
Guide vane losses
Friction losses
Runner losses
Draft tube losses
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Relative path
Absolute path with the runner installed
Absolute path withoutthe runner installed
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Velocity triangles
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Net Positive Suction Head, NPSH
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gcz
gchhz
gch b ++++=++ 222
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2'22 hhh b +=
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3 2zz
gc
hHs ++=
g2czHhz
g2ch
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2sb2
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2 ++=++
JJHh
g2ch sb
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2 +=+
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NPSH
vasb hJgcHhh >
= 2
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NPSHs2b HhhNPSH =
NB:HS has a negative value in this figure.
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AsvabR NPSHHhhNPSH =