/standarization_of_civil_engineerin

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

ÉCO L E PO LY T EC H N IQ U E FÉ D ÉRA LE D E L AUSAN N E

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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