Post on 30-Sep-2014
transcript
Kaplan turbine
Jebba, Nigeria
*Q = 376 m3/s
*H = 27,6 m
*P = 96 MW
D0 = 8,5 m
De = 7,1 m
Di = 3,1 m
B0 = 2,8 m
Machicura, CHILE
*Q = 144 m3/s
*H = 36,7 m
*P = 48 MW
D0 = 7,2 m
De = 4,2 m
Di = 1,9 m
B0 = 1,3 m
Outlet
draft tube
Outlet
runner
Inlet
runner
Outlet
guide vane Inlet
guide vane
Flow rate Q
Runner blade angle
f = constant
Hydraulic efficiency
Hill chart
c1
v1
u1
c2 v2
u2
Hg
cucu 2u21u1h
Pressure distribution and
torque
Lift
Drag
Torque
Arm
L
D
c
LChord
4
a
FLift
FDrag
v
AVCF
AVCF
DD
LL
2
2
2
1
2
1
Blade profile data
L
D
C
C
Angle of attack
Angle of attack
Average relative
velocity
d
v
Pressure distribution and
torque
Pressure side
Suction side
Cord length, l 0,24 · l
Single profile
Cascade
The pressure at the outlet is lower for a cascade than
for a single profile. The cavitation performance will
therefore be reduced in a cascade.
Radial distribution of the
blade profile
CL =Lift coefficient for a cascade
CL1 =Lift coefficient for a single profile
The ratio t/l influences the lift coefficient in a
cascade. The cord length for a blade will therefore
increase when the radius becomes increase
Radial distribution of the
blade profile
Flow in the axial plane
The figure shows blades with two different design of
the blade in radial direction. This is because it will
influence the secondary flow in the radial direction
Main dimension of a
Kaplan turbine
n
o Q
1.5
Cml =0.12 + 0.18 0
Cm
l
2.0
0
0
0.5
(tilnærmet)
1.0
2.5 3.0
m1
n
m1
22
n
c
4QD
c4
dDQ
Diameter of the runner
Height of the guide vanes
and runner diameter
0.4
0.3
300 400
ns
B /D0
d/D
d/D
, B
/D0
500 700600 800 900
0.5
0.6
0.7
45
n
sH
Pnn
Gap between hub and ring
and the runner blades
Gap between the
blade and hub
Gap between the
blade and ring
Spalteåpning x =1000s/D
Vir
kn
ingsg
rad
0
0.80
0.85
0.90
1
s = x 10 d-3
2 3 4 5 6
Eff
icie
ncy
Gap
Runaway speed
kavitasjonskoeffisient
Rusn
ingst
all/
norm
alt
urt
all
Voit h
Cavitation coefficient
Runaw
ay s
pee
d
H
H10 S
The figure shows different runaway speed at
different runner blade openings. The runaway speed
is dependent of the cavitation as shown in the figure
Hill chart
Example
• Find the dimensions D, d and Bo
• Given data:
93,178,674,0Qn
o
sm7,171682,92Hg2
srad1,13
60
2125
60
2n
1m74,0
sm7,17
srad1,13
Hg2
2
3
nm78,6
sm7,17
sm120
Hg2
Speed number:
Diameter, D:
467,018,012,01 o
mc
mc
QD
m
n 3,4467,0
478,64
1
Diameter, d:
59016
22826125
4545
m
Hprpm
H
Pnn
n
s
0.4
0.3
300 400
ns
B /D0
d/D
d/D
, B
/D0
500 700600 800 900
0.5
0.6
0.7
m9,145,0Dd45,0D
d
Height, B:
0.4
0.3
300 400
ns
B /D0
d/D
d/D
, B
/D0
500 700600 800 900
0.5
0.6
0.7
m76,141,0DB41,0D
BO
O
Number of vanes, z:
95,0t
l
5z
Num
ber
of
bla
des
z