Standardization of civil engineering works of small hydropower plants (development of an optimisation tool) Settling basin Channel Forebay
Intake
Penstock
M. Andaroodi Lausanne 30.06.2005
ÉC OLE PO LY TEC H NIQU E FÉ DÉRALE D E LAUSAN NE
SECTIONS • Purpose • Scope of work • Intake • Settling basin • Next steps
ÉC OLE PO LY TEC H NIQU E FÉ DÉRALE D E LAUSAN NE
PURPOSE Purpose Scope of work Intake Settling basin Next steps
¾ Standardization of main structures of SHP as a function of design parameters (e.g. Q) with focus on high head power plants ¾ Development of typical design drawings for the main hydraulic structures ¾ Implementation of the standardized structures in a general applicable optimization tool for the layout of the hydropower plant
ÉC OLE PO LY TEC H NIQU E FÉ DÉRALE D E LAUSAN NE
SCOPE OF WORK Purpose Standardization of civil engineering works of small hydropower plants
Scope of work Intake Settling basin
Design criteria for the main components of SHP
Next steps
Intake
Settling basin
Canal
Forebay basin
Penstock
Standardization as a function of design parameters
Civil works: Standardization of geometry: Dimension of structures Construction details
Sample design drawings Concrete volume Formwork surface Reinforcement Estimation of excavation
Construction cost functions
ÉC OLE PO LY TEC H NIQU E FÉ DÉRALE D E LAUSAN NE
SCOPE OF WORK Purpose Scope of work Intake Settling basin Next steps
Existing optimization tool ''POPEHYE'' :
Implementation of standardized structures and costs in optimization strategies
Review and generalization Preparation of an english version
Derivation of general rules for optimization tools
Final results Design charts, tables and drawings Recommendations
Settling Basin Intake Canal
Forebay
Weir + Fishway
stoc Pen
Outl et C
han nel
k
Line Power
Table of Command Power House Residual Discharge Turbine & Generator
POPEHYE Main component of a small hydropower plant ÉC OLE PO LY TEC H NIQU E FÉ DÉRALE D E LAUSAN NE
INTAKE Purpose Scope of work Intake Settling basin Next steps
Purpose Divert water into a waterway leading to the power plant
Conventional type Bottom intake : It consists of a canal built in streambed and covered by a trashrack with a downward sloping profile. Drop intake, Tyrolian type Sluiceway Intake
Trashrack
Tyrolian Intake
ÉC OLE PO LY TEC H NIQU E FÉ DÉRALE D E LAUSAN NE
INTAKE Purpose Scope of work Intake Settling basin Next steps
Design critera Tyrolian intake : Dimensions are based on the following formula: Qe =
2 ⋅c ⋅ μ⋅ B b ⋅ L ⋅ 2⋅g⋅h 3
b
Flow
écoulem ent fluvial
L : intake length over the grids (m) B : intake width (m) Q : design flow (m3/s) β : grid slope hcr : critical depth (m) h : water depth in start point of grid (m) μ : discharge coefficient (grill shape) c : grid coefficient (a/b, β)
6.00
L
hcr h
3.00
3.00
3.00
a
grille
grill
β
1.00
Qe μ = 0 62
Assumptions
1.00
Grid, a/b=0.5
0 65
1.0
2.0
Q=0.5 m3/s , a/b=0.5
a : 2 to 4 cm a/b : 1/3 , 1/2 , 2/3 β : 30 to 45o
1.9
S1
0.8
S2
S1 S2<S1
Recommendations: Extension of the calculated length by 20% for more security because of possible partial grid obstruction
1.65
9Intake position 9Stepped side walls ÉC OLE PO LY TEC H NIQU E FÉ DÉRALE D E LAUSAN NE
INTAKE Purpose Scope of work
Geometry of tyrolian intake
Intake Next steps
Width and Length of intake for different design discharges (0.25 to 3.0 m3/s).
a/b=0.5 , β=35o (grid slope: 70%)
Tyrolian Intake , a/b=0.50 , β =35o 4.5
Width
4.0
L=2.6m B=1.9m
Width and Lenght [m]
Settling basin
Lenght
3.5 3.0 2.5 2.0 1.5 1.0 0.0
0.5
1.0
1.5
2.0
2.5
3.0
Discharge [m 3/s]
Q=1.0 m3/s ÉC OLE PO LY TEC H NIQU E FÉ DÉRALE D E LAUSAN NE
INTAKE Purpose
Civil works
Scope of work
Sluiceway
Intake
9Concrete, Reinforcement
Settling basin
9Form work, Excavation
Next steps
Intake
Structures: Intake+Sluiceway+Side walls+Spillway
350
0
300
2,000
450
0
400 100
250
6,000
150
8,000
100
10,000
300
3
2
200
250 300 200
Form work 400
150 Excavation
100
500
12,000
50
Form work [m ]
200
Excavation [m ]
4,000 Reinforcement [kg]
3
Concrete volume [m ]
350
50 14,000
0 5
10
15
20
25
30
600
0 5
10
River width [m] Con_rock
Con_aluv.
15
20
25
30
River width [m]
Reinf_rock
Reinf_aluv.
Exc_rock
Exc_aluv.
Form_rock
Form_aluv.
Q=0.5 m3/s , a/b=0.5 , β=35o , m=1 ÉC OLE PO LY TEC H NIQU E FÉ DÉRALE D E LAUSAN NE
SETTLING BASIN Purpose Scope of work Intake Settling basin Next steps
Purpose Separate the undesired sediment carried by the flow from the water.
Conventional type Longitudinal settling basin : It consists of one or more chambers of sufficient length to allow the sediment particles to settle down. Canal
Grids
Settling chamber
Weir
Settling basin Büchi type Transition section Flushing part and Diposition of sediments
Flushing gate
9 It has to be drained almost completely whenever it is flushed out. This may cause disturbance to power production.
ÉC OLE PO LY TEC H NIQU E FÉ DÉRALE D E LAUSAN NE
SETTLING BASIN Purpose Scope of work
Conventional type
Metallic plate
Intake Settling basin, Bieri type
Settling basin Next steps Canal
Grids
Hydraulic system
Settling basin
Flushing device (Metal plates)
Flushing channel
Weir
Flushing gate
9 The Bieri Settling basin ensures energy production even during the flushing procedure. 9 The sediments which settle in the settling basin are flushed vertically through the opening into the flushing channel and back to the river. The flushing water volume is therefore kept to a minimum. 9 Sensors permit fully automatic operation.
ÉC OLE PO LY TEC H NIQU E FÉ DÉRALE D E LAUSAN NE
SETTLING BASIN Purpose Scope of work
Design of Settling basin:
Intake
Length L, width B and depth H of the basin must fulfill the following conditions:
Settling basin Next steps
L≥
Q vD ⋅B
Grids grille tranquilisatrices
VT < Vcr B<= 2h (typically 1.25 to 1.50h) B<= L/8 B : basin width (m) canal Channel Q : design flow (m3/s) d’amenée (section VD : settling velocity (m/s) rectangulaire) VT : mean flow velocity (m/s) Vcr : critical flow velocity in basin (m/s)
Flushingde device (Metal plates) dispositif dessablage, purgeur
h
t → JS
→ retour rivière Back àtolariver
Flushing channel chenal de purge L dessableur Settling basin
transition
vanne de purge Flushing gate
Js=3%
Settling velocity Design grain size : 0.2 to 0.3 mm Empirical formula of Zanke is used for Settling velocity
Recommendations:
B
h t
4 5
a
Extension of the calculated basin length by 10% to 20% in b order to compensate the excessive turbulence in approach flow. Decision upon having two or more basins instead of one for high discharges
dispositif de dessablage, Flushing device purgeur chenal de purge Flushing channel
ÉC OLE PO LY TEC H NIQU E FÉ DÉRALE D E LAUSAN NE
SETTLING BASIN Purpose Scope of work
Geometry of sediment trap
Intake
Width and Height of settling basin for different design discharges (0.25 to 3.0 m3/s).
Settling basin Next steps
Design grain size as 0.2 and 0.3 mm has been considered.
4.5
5.0
d=0.3mm
d=0.2mm
H=2.3m
4.0 width and Heightof settling basin [m]
B=2.9m
width and Heightof settling basin [m]
4.5 4.0 3.5 3.0 2.5 Width Height
2.0
3.5 3.0
B=2.65m
2.5 Width
H=2.15m
2.0
Height
1.5
1.5
1.0
1.0 0.0
0.5
1.0
1.5
2.0 3
Discharge (m /s)
Q=1.0 m3/s
2.5
3.0
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3
Discharge (m /s)
Q=1.0 m3/s ÉC OLE PO LY TEC H NIQU E FÉ DÉRALE D E LAUSAN NE
SETTLING BASIN Purpose Scope of work
Geometry of sediment trap
Intake Next steps
Design grain size as 0.2 and 0.3 mm has been considered.
Length of settling basin for different design discharges (0.25 to 3.0 m3/s). 55
L 50 45
L=35m L=24m
Lenght of settling basin [m]
Settling basin
40 35 30 25
d=0.3 mm
20
d=0.2 mm 15 10 0.0
0.5
1.0
1.5
2.0
2.5
3.0
3
Discharge (m /s)
Q=1.0 m3/s ÉC OLE PO LY TEC H NIQU E FÉ DÉRALE D E LAUSAN NE
SETTLING BASIN Purpose
Next steps
Weight of steel bars [kg]
Volume of concrete is estimated for different design discharges (0.25 to 3.0 m3/s).
Reinforcement of concrete has been estimated for different discharges (0.25 to 3.0 m3/s).
400
0
Con. St. Power (St.) Power (Con.)
350 300
2,000 4,000
1.2903
St = 3433.5Q
250
6,000
2
R = 0.9998 200
8,000
d=0.3mm 150
10,000
100
12,000
Con = 85.836Q
50
Reinforcement [kg]
Settling basin
3
Intake
Volume of concrete [m3]
Concrete volume [m ]
Scope of work
1.2903
14,000
2
R = 0.9998
0
16,000
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3
Discharge [m /s] ÉC OLE PO LY TEC H NIQU E FÉ DÉRALE D E LAUSAN NE
SETTLING BASIN Purpose
Form work surface of concrete is estimated for different discharges (0.25 to 3.0 m3/s).
2100
0 0.8807
Form = 500.56Q 2
R = 0.9998
1800
200
1500
400 2
Next steps
Excavation volume is estimated for different discharges (0.25 to 3.0 m3/s).
Form work [m ]
Settling basin
Form work surface [m2]
3
Intake
Excavation volume [m3]
Excavation [m ]
Scope of work
1200
600 Exc. Form.
900 600
Power (Form.)
Exc = 466.1Q1.3473 R2 = 0.9999
Power (Exc.) 1000
d=0.3mm
300
800
1200
0
1400
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3
Discharge [m /s] ÉC OLE PO LY TEC H NIQU E FÉ DÉRALE D E LAUSAN NE
SETTLING BASIN Purpose Scope of work Settling basin Next steps
Total cost [CHF]
1,000,000
9Concrete
900,000
9Reinforcement
800,000
9Form work
700,000
9Excavation 9Study of SHP 9Site installation
Total cost [CHF]
Intake
1.2652
Cost = 242400Q 2
R = 0.9999
600,000 500,000 400,000
Total cost
300,000
POPEHYE Power (Total cost)
200,000 2
For different discharges (0.25 to 3.0 m3/s) and design grain size (d=0.3 mm)
POPEHYE : 5000F/m
100,000 0 0.0
0.5
1.0
1.5
2.0
2.5
3.0
3
Discharge (m /s)
Concrete Reinrforcement 3 Kg m CHF 250 2.5
Excavation 3 m 250
Form work 2 m 50
Study Installation % % 10 30 ÉC OLE PO LY TEC H NIQU E FÉ DÉRALE D E LAUSAN NE
NEXT STEPS Purpose Scope of work Intake Settling basin Next steps
Forebay and Penstock Validation of the work concepts by engineering companies Typical maps for a series of discharges Construction details Optimization process and upgrade of POPEHYE
ÉC OLE PO LY TEC H NIQU E FÉ DÉRALE D E LAUSAN NE
Thanks for your attention!
ÉC OLE PO LY TEC H NIQU E FÉ DÉRALE D E LAUSAN NE