Luigi Papetti
Transcript of Luigi Papetti
Luigi Papetti
Rehabilitation of SHP low head plants
Guidelines and case studies
STUDIO FROSIO
Via P. F. Calvi, 9 - 25123 Brescia
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Rehabilitation Low Head
•low head = 1,5 ÷ 30 m
•very low head = 1,5 ÷ 3 m
Restoration of the integrity
of the main parts of the
plant, with restoration or
even improvement of the
global performance of the
plant in terms of energy
output and reliability of
operation
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Mind map……
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Fields of action
TQHE = =many options =no options (by now)
H=some options Q=some options
T=many options
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TQHE =
Improvement of weir operation safety
•Hg = 8,85 m
•Qmax = 22 m3/s
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Improvement of sediment management
Desilting gate too small
TQHE =
•Hg = 12,87 m
•Qmax = 75 m3/s
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Improvement of sediment management
21 m wider desilting span
TQHE =
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Improvement of sediment management
Submerged longitudinal wall to concentrate flow lines
TQHE =
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Improvement of floating debris management TQHE =
•Hg = 10,50 m
•Qmax = 60 m3/s
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Units: improvement of efficiency TQHE =
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Units: improvement of efficiency
Old open flume Francis
TQHE =
•Hg = 10,50 m
•Qmax = 60 m3/s
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Units: improvement of efficiency
New permanent magnet vertical bulb unitsavg > 87%
TQHE =
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Units: improvement of efficiency
New permanent magnet vertical bulb units avg > 87%Old units (1922): avg < 70% (estimated)
Rendement pales bloquées de 0° à 13,2°
0,800
0,850
0,900
0,950
1,000
100 200 300 400 500 600 700 800 900 1000 1100 1200 1300 1400 1500 1600
puissance (kW)
rendem
ent
8,00
9,00
10,00
11,00
12,00
Rendement total chute nette m
TQHE =
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Units: improvement of efficiency – new draft tube
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Headrace channel: hydraulic performance improvement
Trapezoid cross section
Rectangular cross section
TQHE =
•Hg = 7,97 m
•Qmax = 16 m3/s
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Headrace channel: improvement of operation safety
Open channel
Steel Penstock
TQHE =
•Hg = 27,30 m
•Qmax = 5,0 m3/s
17STUDIO FROSIO
Tasks: New Kaplan unit, new powerhouse, complete and reliable automation, new
tailrace canal, weir crest raise, rehabilitation and upgrade of supply canal, new fish
passage, reliable discharge of environmental flow rate.
Critical constraints: inclusion in a productive area, excavations in narrow places, new by-
pass facilities, old plant in operation during most of the working time
Project costs (2006): 4,628,000 €
Intensive cost: 2,755 €/kW; 0.51 €/kWh
Old plant Rehabilitated plant %
Owner Elettra 2000 S.p.A.
Commissioning year 1903 2005 2005
Maximum flow rate 10.0 m3/s 15.0 m3/s +50%
Medium flow rate 7.5 m3/s 11.12 m3/s +48%
Net head 9.50 m 12.96 m +14%
Units 5 Francis 1 Kaplan =
Rated capacity 1,500 kVA 2,100 kVA +40%
Operating hours 6,550 MWh 8,500 +30%
Energy production 4,680 MWh 9,000 MWh +92%
Units replacement: upgrading TQHE =
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Units replacement: upgrading TQHE =
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Units replacement: restoring initial efficiency TQHE =
•Hg = 15,0 m
•Qmax = 12 m3/s
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Units replacement: restoring initial efficiency TQHE =
•Hg = 10,0 m
•Qmax = 1,1 m3/s
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Units replacement: improving safety of operation
•Hg = 10,5 m
•Qmax = 3 x 4,3 m3/s TQHE =
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Hydraulic works replacement: improving safety of operationTQHE =
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Units replacement: improving safety of operation
TQHE =
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FINAL REMARKS
Don’t search for higher units efficiency at any cost
Overall optimisation (electromechanical AND hydraulic/civil) rather than exasperated solutions referred to one aspect only
Prefer solutions without civil works below downstream water level
Look for the solution with minimum risk of uncertainties even if it’s not the theoretically best possible
Deep analysis of possible hydraulic improvement where often wide margins are available
1% less efficiency is quickly paid back by a safer and simple operation
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THE END