the replanting of lochaber hydro power station
DESCRIPTION
The Replanting of Lochaber Hydro Power Station. by Andrew Thick. Topics to be covered today. Scheme modelling; Operating capability of Lochaber; Turbine selection; Penstock works. Schematic of the Lochaber Scheme. Gravity Inflows. Surge Chamber. Gravity Inflows. Spill. Spill. - PowerPoint PPT PresentationTRANSCRIPT
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The Replanting of Lochaber Hydro Power Station
by Andrew Thick
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Topics to be covered today
• Scheme modelling;
• Operating capability of Lochaber;
• Turbine selection;
• Penstock works.
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Schematic of the Lochaber Scheme
Loch Laggan & reservoir
Loch Treig
SpillSpill
Gravity Inflows Gravity
Inflows
Power-house
Tailrace
Spill
Surge Chamber
LochLinnhe
Spey reservoir
Penstocks
tunneltunnel
tunnel
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Schematic of the Lochaber Scheme
Loch Laggan & reservoir
Loch Treig
SpillSpill
Gravity Inflows Gravity
Inflows
Power-house
Tailrace
Spill
Surge Chamber
LochLinnhe
Spey reservoir
Penstocks
tunneltunnel
tunnel
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Spey Dam
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Schematic of the Lochaber Scheme
Loch Laggan & reservoir
Loch Treig
SpillSpill
Gravity Inflows Gravity
Inflows
Power-house
Tailrace
Spill
Surge Chamber
LochLinnhe
Spey reservoir
Penstocks
tunneltunnel
tunnel
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Schematic of the Lochaber Scheme
Loch Laggan & reservoir
Loch Treig
SpillSpill
Gravity Inflows Gravity
Inflows
Power-house
Tailrace
Spill
Surge Chamber
LochLinnhe
Spey reservoir
Penstocks
tunneltunnel
tunnel
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Laggan Dam
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Schematic of the Lochaber Scheme
Loch Laggan & reservoir
Loch Treig
SpillSpill
Gravity Inflows Gravity
Inflows
Power-house
Tailrace
Spill
Surge Chamber
LochLinnhe
Spey reservoir
Penstocks
tunneltunnel
tunnel
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Schematic of the Lochaber Scheme
Loch Laggan & reservoir
Loch Treig
SpillSpill
Gravity Inflows Gravity
Inflows
Power-house
Tailrace
Spill
Surge Chamber
LochLinnhe
Spey reservoir
Penstocks
tunneltunnel
tunnel
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Schematic of the Lochaber Scheme
Loch Laggan & reservoir
Loch Treig
SpillSpill
Gravity Inflows Gravity
Inflows
Power-house
Tailrace
Spill
Surge Chamber
LochLinnhe
Spey reservoir
Penstocks
tunneltunnel
tunnel
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Loch Treig and Dam
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Schematic of the Lochaber Scheme
Loch Laggan & reservoir
Loch Treig
SpillSpill
Gravity Inflows Gravity
Inflows
Power-house
Tailrace
Spill
Surge Chamber
LochLinnhe
Spey reservoir
Penstocks
tunneltunnel
tunnel
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Schematic of the Lochaber Scheme
Loch Laggan & reservoir
Loch Treig
SpillSpill
Gravity Inflows Gravity
Inflows
Power-house
Tailrace
Spill
Surge Chamber
LochLinnhe
Spey reservoir
Penstocks
tunneltunnel
tunnel
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Schematic of the Lochaber Scheme
Loch Laggan & reservoir
Loch Treig
SpillSpill
Gravity Inflows Gravity
Inflows
Power-house
Tailrace
Spill
Surge Chamber
LochLinnhe
Spey reservoir
Penstocks
tunneltunnel
tunnel
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Penstocks, Powerhouse and Smelter
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Simplified Lochaber Scheme Model
QTspill
QP/H
QTin
Laggan
QTin
QTunnel
Treig
QLspillQLin
QLin
QLin
Qintakes
Qintakes
Gravity Intake Flows are combined with Reservoir Inflows
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Energy Modelling Results
Trial 1 2 3 4 5 6 7
Installed Cap. (MW) 65 80 60 70 80 90 100
Overall Efficiency (%) 75 87 87 87 87 87 87
Headloss Coeff. (k) 0.021 0.0172 0.0172 0.0172 0.0172 0.0172 0.0172
Operating rule Ext Ext Max E Max E Max E Max E Max E
Laggan Spill (mcm) 2,034 1,794 4,160 1,709 1,227 1,074 801
Treig Spill (mcm) 154 121 857 201 54 10 7
Ave. Energy (GWh/yr) 467 569 523 574 581 583 580
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Scheme Operating Capability Diagram
9.3 % Q90.7 % QAverage Operation
0 % Q100 % QNo Gravity Inflows
100 % Q0 % QMax. Gravity Inflows
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Operating Capability in terms of Loch Treig Level
Note: 90.7% of water from Loch Treig9.3% of water from gravity intakes
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Scheme Operating Capability Diagram
9.3 % Q90.7 % QAverage Operation
0 % Q100 % QNo Gravity Inflows
100 % Q0 % QMax. Gravity Inflows
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Operating Capability in terms of Surge Shaft Water Level
Penstock Limitation
Note: 90.7% of water from Loch Treig9.3% of water from gravity intakes
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Scheme Operating Capability Diagram
9.3 % Q90.7 % QAverage Operation
0 % Q100 % QNo Gravity Inflows
100 % Q0 % QMax. Gravity Inflows
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Note: All water from Loch Treig
Operating Capability in terms of Surge Shaft Water Level
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Scheme Operating Capability Diagram
9.3 % Q90.7 % QAverage Operation
0 % Q100 % QNo Gravity Inflows
100 % Q0 % QMax. Gravity Inflows
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Operating Capability in terms of Surge Shaft Water Level
Note: All water from gravity intakes
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Scheme Operating Capability Diagram
9.3 % Q90.7 % QAverage Operation
0 % Q100 % QNo Gravity Inflows
100 % Q0 % QMax. Gravity Inflows
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Example Operation exceeding Penstock Pressure Rise Limit
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Turbine Selection
The steps towards to turbine selection were:
• Analysis of historical data of scheme operation
• The number of generating units was selected – 5
• Analysis of operating data from scheme model
• Performance data from tendering suppliers was fed into the scheme model
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Scheme Operation Frequency Plot
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Turbine Selection
The steps towards to turbine selection were:
• Analysis of historical data of scheme operation
• The number of generating units was selected – 5
• Analysis of operating data from scheme model
• Performance data from tendering suppliers was fed into the scheme model
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Turbine Selection
The steps towards to turbine selection were:
• Analysis of historical data of scheme operation
• The number of generating units was selected – 5
• Analysis of operating data from scheme model
• Performance data from tendering suppliers was fed into the scheme model
34
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Turbine Selection
The steps towards to turbine selection were:
• Analysis of historical data of scheme operation
• The number of generating units was selected – 5
• Analysis of operating data from scheme model
• Performance data from tendering suppliers was fed into the scheme model
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Penstock works
Key aspects of the penstock works were:
• Need to undertake the works minimising shutdown of generation.
• Existing penstock system was very complex.
• In order to maintain double isolation, the penstocks needed to be dewatered sequentially.
• The works were complex with poor access.
• Decision with RTA to laser scan the penstock system and create a 3-D model.
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Multiple buspipesNumerous Valves
Bifurcations
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Penstock Area – difficult terrain!
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Penstock works
Key aspects of the penstock works were:
• Need to undertake the works minimising shutdown of generation.
• Existing penstock system was very complex.
• In order to maintain double isolation for the penstocks needed to be dewatered sequentially.
• The works were complex with poor access.
• Decision with RTA to laser scan the penstock system and create a 3-D model.
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Survey Point Cloud Data
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AutoCAD 3-D Model
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Project Summary
• The generating plant has been replaced to give 25+ years life extension.
• The water to wire efficiency has been improved from 75% to 90+%.
• Energy production increased from 460 GWh/yr to 600+ GWh/yr.
• The scheme’s capability is better understood and limitations identified.
• The scheme was completed ahead of schedule and is operating successfully with minimal disruption to Smelter operations during construction
Contact Details
Andrew Thick BEng CEng MIMechEURS Infrastructure and Environment UK LimitedInternational House, Dover PlaceAshfordKent TN23 1HUUnited KingdomTel: +44 (0) 1233 [email protected]
Thank you for your kind attention