Standardization of civil engineering works of small hydropower plants (development of an optimisation tool)
Dr Erik Bollaert Porto 19.10.2004
ÉC OLE P OLY TEC H NIQU E FÉDÉRALE DE LAUS ANNE
SE.
SECTIONS 1- Purpose 2- Scope of work 3- Typical small hydro 4- Sand trap design 5- Results of sand trap 6- POPEHYE tool
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PURPOSE Purpose Scope of work Typical small hydro Sand trap design Results of sand trap
ØStandardization of main structures of a small hydropower plant as a function of the design parameters (discharge, head, …) with focus on high head power plants ØDevelopment of parameterised, design drawings of the main structures and construction cost functions ØImplementation of the standardized structures in a general applicable optimisation tool for the layout of the hydropower plant: POPEHYE tool ÉCO L E PO LY T EC H N IQ U E FÉ D ÉRA LE D E L AUSAN N E
SCOPE OF WORK Purpose Scope of work Typical small hydro Sand trap design Results of sand trap
Design criteria for civil engineering works and structural and hydraulic design of: üIntake (Tyrolian weir, side intake) üDesilting basin and rock trap üFree surface flow canals (open air and buried) üForebay and transition to pressure flow üPenstock with fixed points (anchor blocks)
ÉCO L E PO LY T EC H N IQ U E FÉ D ÉRA LE D E L AUSAN N E
SCOPE OF WORK Purpose Scope of work Typical small hydro Sand trap design Results of sand trap
Standardization of structures as a function of the design parameters üStandardized geometries (concrete dimensions, constructions details, steel dimensions, …) üParameterised design drawings with excavation concrete volume, formwork surface and reinforcement üConstruction cost functions (based on design parameters and unit prizes)
ÉCO L E PO LY T EC H N IQ U E FÉ D ÉRA LE D E L AUSAN N E
SCOPE OF WORK Purpose Scope of work Typical small hydro Sand trap design Results of sand trap
Implementation of optimisation tool
üReview and generalisation of existing optimisation tool POPEHYE üImplementation of standardized structures and cost functions in optimisation strategies üDerivation of general rules for optimisation strategies
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TYPICAL SMALL HYDRO
T Y .
Purpose Scope of work Typical small hydro Sand trap design Results of sand trap
Sand trap Intake
Forebay Weir
k stoc Pen
Network
Small hydro Turbine & Generator
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SAND TRAP DESIGN Purpose Scope of work Typical small hydro Sand trap design Results of sand trap
Purpose q To separate the undesired sediment carried by the flow from the water.
Conventional type q Longitudinal settling tank : It consists of one or more chambers of sufficient length to allow the sediment particles to settle down.
Sand traps with continuous flushing (system DUFOUR) ÉCO L E PO LY T EC H N IQ U E FÉ D ÉRA LE D E L AUSAN N E
SAND TRAP DESIGN Purpose Scope of work Typical small hydro Sand trap design Results of sand trap
Design Criteria (Scheuerlein) o
Identification of the maximum grain size which has to be excluded. The range of design grain size lays between 0.1 mm and 1 mm.
o
Uniform approach flow conditions to the basin which is particularly important when several parallel basins are to be used.
o
Uniform flow conditions in the basin itself to facilitate the settling process.
o
Sufficient length to allow all particles of design grain size to settle down.
o
Installation of a device to clear the basin when necessary.
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SAND TRAP DESIGN Purpose Scope of work Typical small hydro Sand trap design Results of sand trap
Main part of sand trap : Desanding chamber Ø For proper design, the dimensions of this chamber must correspond to the settling characteristics of the design grain size: ω = ω 0 - ∆ω= ω0 - 0.04 Vmc (CAMP formula for the settling velocity in a sand trap) ω = Settling velocity of sand in flowing water (m/s) Vmc = 0.44 * (dsc)0.5 Critical mean flow velocity (m/s) dsc = Design grain size (mm) ω0 = Settling velocity of sand in quiescent water (m/s) = d sc *g/η *(ρs-ρ)/18 ρs = Specific mass of the particle ρ = Specific mass of the fluid η = dynamic viscosity of fluid For application the next fiqure shows ω, ω0 and Vmc as functions of dsc. ÉCO L E PO LY T EC H N IQ U E FÉ D ÉRA LE D E L AUSAN N E
SAND TRAP DESIGN Purpose Scope of work Typical small hydro Sand trap design Results of sand trap
Vmc 1 : Critical mean flow velocity (Vmc) 2 : Settling velocity of sand in quiescent water (ω0) 3 : Settling velocity of sand in flowing water (ω)
ω0
ω
ÉCO L E PO LY T EC H N IQ U E FÉ D ÉRA LE D E L AUSAN N E
SAND TRAP DESIGN Purpose Scope of work Typical small hydro Sand trap design Results of sand trap
Design of Desanding chamber: Length L, width B and depth H of the chamber must fullfil the following conditions: L>= Vmc/ω *H B= Q/(Vmc*H) Q= design flow (m3/s) B=H/1.25 B<= L/8 Recommendations: § Extension of the calculated basin length by 10% to 20% in order to compensate for excessive turbulence in approach flow. §
Decision upon having two or more basins instead of one in order to be more flexible to react upon undesired effects without taking the plant out of operation (particularly important with respect to flushing) ÉCO L E PO LY T EC H N IQ U E FÉ D ÉRA LE D E L AUSAN N E
RESULTS OF SAND TRAP Purpose
6
Scope of work Typical small hydro Sand trap design Results of sand trap
B
5
Geometry of sediment trap
4 Width [m]
Width (B) and Height (H) of sediment trap for different discharges (0.5 to 5.0 m3/s).
3
2
B_d=0.1 B_d=0.2
1
B_d=0.5 B_d=1.0
8
0
H
7
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
3
Discharge (m /s)
Height [m]
6 5
Different design grain sizes from 0.1 to 1.0 mm have been considered.
4 3 H_d=0.1 2
H_d=0.2 H_d=0.5
1
H_d=1.0 0 0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
3
Discharge (m /s) ÉCO L E PO LY T EC H N IQ U E FÉ D ÉRA LE D E L AUSAN N E
RESULTS OF SAND TRAP Purpose
Geometry of sediment trap Different design grain sizes (d=0.1, 0.2, 0.5, 1.0 mm) have been considered.
Length (L) of sediment trap for different discharges (0.5 to 5.0 m3/s). 60
L 50
40
Lenght [m]
Scope of work Typical small hydro Sand trap design Results of sand trap
30 L_d=0.1
20
L_d=0.2 L_d=0.5
10
L_d=1.0 0 0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
Discharge (m 3/s) ÉCO L E PO LY T EC H N IQ U E FÉ D ÉRA LE D E L AUSAN N E
RESULTS OF SAND TRAP Purpose
Volume of concrete [m3] Different design grain sizes (d=0.1, 0.2, 0.5, 1.0 mm) have been considered.
Volume of concrete is estimated for different designs based on discharges (0.5 to 5.0 m3/s). 1400
Vcon
1200
Concrete volume [m 3]
Scope of work Typical small hydro Sand trap design Results of sand trap
Con_d=0.1
1000
Con_d=0.2 Con_d=0.5
800
Con_d=1.0 600 400 200 0 0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
Discharge (m3/s)
ÉCO L E PO LY T EC H N IQ U E FÉ D ÉRA LE D E L AUSAN N E
RESULTS OF SAND TRAP Purpose
Weight of steel bars [kg] Different design grain sizes (d=0.1, 0.2, 0.5, 1.0 mm) have been considered.
Reinforcement in concrete has been estimated for different discharges (0.5 to 5.0 m3/s). 180,000 160,000
Wst
St_d=0.1 St_d=0.2
140,000
St_d=0.5 Steel weight [kg]
Scope of work Typical small hydro Sand trap design Results of sand trap
120,000
St_d=1.0
100,000 80,000 60,000 40,000 20,000 0 0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
3
Discharge (m /s) ÉCO L E PO LY T EC H N IQ U E FÉ D ÉRA LE D E L AUSAN N E
RESULTS OF SAND TRAP Purpose
Excavation volume [m3] Different design grain sizes (d=0.1, 0.2, 0.5, 1.0 mm) have been considered.
Excavation volume is estimated for different discharges (0.5 to 5.0 m3/s). 2,500
Exc
Exc_d=0.1 Exc_d=0.2
2,000 Excavation volume [m3]
Scope of work Typical small hydro Sand trap design Results of sand trap
Exc_d=0.5 Exc_d=1.0
1,500
1,000
500
0 0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
3
Discharge (m /s) ÉCO L E PO LY T EC H N IQ U E FÉ D ÉRA LE D E L AUSAN N E
RESULTS OF SAND TRAP Purpose 400,000
Scope of work Typical small hydro Sand trap design Results of sand trap
Concrete cost [CHF]
Con
PrCon_d=0.1
350,000
PrCon_d=0.2 PrCon_d=0.5
Concrete cost is estimated for different discharges (0.5 to 5.0 m3/s) and different grain size diameters (d=0.1, 0.2, 0.5, 1.0 mm)
Concrete cost [CHF]
300,000
PrCon_d=1.0 250,000 200,000 150,000 100,000 50,000
500,000
0 0.5
1.0
1.5
2.0
2.5
Prst_d=0.2
400,000
3.0
3.5
4.0
4.5
5.0
3
Discharge (m /s)
Prst_d=0.5
350,000 Steel cost [CHF]
St.
Prst_d=0.1
450,000
Prst_d=1.0
300,000
Steel cost [CHF]
250,000
Reinforcement cost of concrete is estimated for different discharges (0.5 to 5.0 m3/s) and different grain size diameters (d=0.1, 0.2, 0.5, 1.0 mm)
200,000 150,000 100,000 50,000 0 0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
3
Discharge (m /s) ÉCO L E PO LY T EC H N IQ U E FÉ D ÉRA LE D E L AUSAN N E
RESULTS OF SAND TRAP Purpose 30,000
200,000
Gate
Pg_d=0.1 Pg_d=0.2
25,000
Sit_d=0.2
160,000 Site equipement cost [CHF]
Pg_d=0.5
20,000
15,000
10,000
Site
Sit_d=0.1
180,000
Pg_d=1.0 Gate cost [CHF]
Sit_d=0.5
140,000
Sit_d=1.0
120,000 100,000 80,000 60,000 40,000
5,000
20,000 0
0 0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
0.5
1.0
1.5
2.0
3
2.5
3.0
3.5
4.0
4.5
5.0
3
Discharge (m /s)
Discharge (m /s)
90,000 Prexc_d=0.1 80,000
Excavation, gate and site equipment cost [CHF] For different discharges (0.5 to 5.0 m3/s) and different grain size diameters (d=0.1, 0.2, 0.5, 1.0 mm)
Exc
Prexc_d=0.2 Prexc_d=0.5
70,000 Excavation cost [CHF]
Scope of work Typical small hydro Sand trap design Results of sand trap
Prexc_d=1.0 60,000 50,000 40,000 30,000 20,000 10,000 0 0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
3
Discharge (m /s)
ÉCO L E PO LY T EC H N IQ U E FÉ D ÉRA LE D E L AUSAN N E
RESULTS OF SAND TRAP Purpose
Total cost [CHF]
1,200,000 tot_d=0.1
üConcrete
tot_d=0.2
1,000,000
tot_d=0.5
üReinforcement üExcavation üGate üSite equipment
tot_d=1.0 Total cost [CHF]
Scope of work Typical small hydro Sand trap design Results of sand trap
800,000
600,000
400,000
ü…. 200,000
For different discharges (0.5 to 5.0 m3/s) and different design grain sizes (d=0.1 to 1.0 mm)
0 0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
5.0
Discharge (m3/s)
ÉCO L E PO LY T EC H N IQ U E FÉ D ÉRA LE D E L AUSAN N E
POPEHYE Dimensioning and optimisation of small hydropower plants Objectives of POPEHYE - Facilitate feasibility studies of inexplored sites - Encourage studies with different possible solutions - Contribute to optimisation of chosen solution
ÉCO L E PO LY T EC H N IQ U E FÉ D ÉRA LE D E L AUSAN N E
POPEHYE Computational phases Hydrologic analysis of catchment area
Economical optimisation of equipped discharge
Predimensioning of main structural elements STANDARDIZATION
Surge tank Discharge Intake
Trap
Canal
Penstock
Power house
Forebay
ÉCO L E PO LY T EC H N IQ U E FÉ D ÉRA LE D E L AUSAN N E
POPEHYE Main structural elements Intake
Forebay
Penstock
Desilting basin
Surge tank
Pressurized canal
Free surface canal
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FURTHER DEVELOPMENTS …
Detailed design of all structural elements Construction drawings Economic optimisation Compilation of software in Visual Basic Language choice Etc…
ÉCO L E PO LY T EC H N IQ U E FÉ D ÉRA LE D E L AUSAN N E
Thanks for your attention!
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