ƒ

H.V. Pre – conference workshop

ƒ

27

th

July. 2010

ƒ

Shogo Nakamura

(Voith Fuji Hydro, K.K.)

Development of
Vertical Bulb Turbines

1.

Renovation plan in Agano and Tadami river

2.

Kaminojiri No.2  (Vertical bulb turbine)

3.

Intake stricture development

4.

E & M development

5.

Toyomi S & B proje

Presentation Contents

page 3

page 4 - 7

page 8 - 10

page 11 - 17

page 18 - 24

BOD Presentation – OU xxx – Autumn 2008.ppt  | 2

1. Renewable plan in Agano and Tadami rivers

1963

27MW  2 units

VK

Agekawa

1973

55MW  1 unit

VK

Kanose No.2

1928

8MW  6 units

VF

Kanose

1975

57MW  1 unit

VK

Toyomi No.2

1929

10MW  6 units

VF

Toyomi

2001

14MW  1 unit

VB

Kaminojiri No.2

1958

17MW  3 units

VF

Kaminojiri

1993

25 MW  1 unit

HB

Yamazato No.2

1933

15MW 3 units

VF

Yamazato

1984

39MW  1 unit

HB

Shingo No.2

1939

13MW  4 units

VF

Shingo

1953

19MW  3 units

VF

Katakado

1953

25MW  3 units

VF

Yanaizu

1954

26MW  3 units

VF

Honna

Inst. Year

Capacity MW

Type

1. Renewable plan in Agano and Tadami rivers

Tokyo

Sendai

Niigarta

Lake 
Inawashiro

Tadami

Agano

Kaminojiri

2. KAMINOJIRI No.2 / VERTICAL BULB   - Plan view 

Existing units

Vertical bulb
14MW

2. KAMINOJIRI No.2 / VERTICAL BULB   - Elevation view

Vertical bulb

Existing Kaminojiri

Kaminojiri No.2

2.  Kaminojiri No.2   - Comparison of Power House size

Vertical Bulb

Horizontal Bulb

Vertical Kaplan

11.

5m

φ8.5m

13

ｍ

φ8

.3

m

φ4

.4

m

Total plant cost is 
reduced by 14 %

Power house floor 
is reduced by 30 %

Overhaul duration 
is reduced by 33 % 

3.  Intake structure development

Entrained air bubbles induce vibration and power swing

Air taking

Air taking

Intake 

Intake 

flow

flow

Casing

3. Intake structure development

Anti vortex stabilizer was developed by hydraulic
scaled model

Stabilizer

Stabilizer

Intake 

Intake 

flow

flow

3. Intake structure development

Intake

Anti vortex stabilizer

(Before setting)

Anti vortex stabilizer
(set position) 

4. E & M development

Basic concept

1.

Minimum plant cost

2.

Minimum maintenance cost

3.

Maximum reliability

Direct heat 

dissipation (stator)

Location of access 
shaft

Fin cooling

Minimum Plant Cost

Water lubricated 

bearing

Twin bearing 

structure

Experiences in bulb 

machines

5 bladed runner

Maximum Reliability

Direct heat 

dissipation (bearing)

Experiences in 

Kaminojiri No.2

Minimum 

Maintenance

Improved bulb 

bracket

PTFE thrust bearing

4. E & M development

Basic concept

4. E & M development  (Runner)

Bend-draft tube has negative 
effect on turbine efficiency

Runner diameter was 
selected to attain optimum 
turbine efficiency

HB

VB

HB

VB

4. E & M development

Minimum maintenance cost

Direct heat dissipation 
(Generator stator)

Ventilation air cooling 
through  fins 

Direct heat dissipation 
(thrust bearing)

River water

Bearing

4. E & M development

Maximum reliability

①Strain (stress)

End and center of bulb bracket rib
Inner casing

②Vibration mode and natural frequency

Strain gauges were attached at the locations 
specified from simulation and strain was 
measured during water filling stage.

Field test at Kaminojiri No.2

③BB rib end

②BB rib center

①Inner casing

Access shaft

4. E & M development

Maximum reliability

Stress simulation and comparison

G.V.

Bulb Bracket

Inner Casing

BB rib end

BB rib center

Inner casing pressure

Error(%)

FEM

Meas.

BB rib end (Z)

-9.5

-9.57

+0.7

BB rib center (Z)

12.1

9.51

-27

Inner casing (X)

-1.94

-1.78

-9

Watered（GV open）

Meas. (kgf/mm2)

4. E & M development

Maximum reliability

Rotor

Stator

Runner

Access

Shaft

Exciter

Bulb bracket

Guide vane

Temperature simulation 
and comparison

River water; 
12.2

℃

Stator temp.

Calc.; 88.2

℃

Meas.; 76.7

℃

Error; -18%

Bearing temp.

Calc.; 49.1

℃

Meas.; 44.9

℃

Error; -8.5%

5. Toyomi

S & B project 

(6 x 10 MW Vertical Francis → 2 x 30 MW Vertical bulb)

Streamlines and Pressure 
distribution around Wicket Gates

Strength 
analyses

Leakage flow from runner gap
( for design of runner hub contour)

Pressure distribution on runner
( for prediction of cavitation )

5. Toyomi S & B project

Model 
acceptance 
test                          
2009 Jan.

5. Toyomi S & B project

Vortex takes 

air bubble

Intake vortex problem

Influence of the intake 
vortex for the turbine 

１．Unit Vibration

２．Noise

３．Power swing

5. Toyomi S & B project

-10

-8

-6

-4

-2

0

2

4

0

10

20

30

40

50

t [sec]

Cp=

2

⊿

p/

ρVi

n

2

 [-]

上流側水車
下流側水車

Flow speed and Vector plot 

Pressure Fluctuation

Vortex Method is unsteady calculation. Therefore, it is good 
method to solve the unsteady intake vortex problem.

CFD - 3D Vortex Method is applied for the optimization 

Intake optimization

5. Toyomi S & B project

After CFD tuning by
prototype test

Before CFD tuning by

prototype test

•Inflow condition     (River flow CFD)

•Fine mesh

Intake optimization

5. Toyomi S & B project

Intake optimization

-10

-8

-6

-4

-2

0

2

4

0

10

20

30

40

50

t [sec]

Cp=2

⊿

p/

ρVi

n

2

 [-]

上流側水車
下流側水車

No vortex on water surface

Small pressure fluctuation

Final design

Anti vortex stabilizer

5. Toyomi S & B project

Existing Toyomi power house under scrapped