IET Presentation 19 th May Generation Engineering, Energy Wholesale 1

Transcription

1 IET Presentation 19 th May 2010 Generation Engineering, Energy Wholesale 1

2 Presentation Agenda Introduction Background and technical details Plant problems and solutions Lessons learned using Hydro Pumped Storage 2

3 John Strettle, Production Manager Cruachan Power Station Started work in the Electricity Supply Industry in 1985 Spent 4 years at Torness Nuclear Power Station Based at Cruachan since 1989 when I joined NoSHEB Circa 1989 I manage, Operational and Maintenance work, planning and direction. 3

4 ScottishPower History Started life in 1955 as SSEB Then in 1990 became ScottishPower In 2007 became Iberdrola 4 th Largest Utility Company in the World 4

5 Plant ScottishPower Generation Assets Installed Capacity (MW) Fuel Age Longannet (LCPD opt-in) 2,304 Coal 40 CHP Hydro Pumped Cockenzie (LCPD opt-out) 1,152 Coal 43 Coal CCGT Damhead Creek 800 CCGT 10 Cruachan Longannet Rye House 715 CCGT 17 Lanark Cockenzie Galloway Brighton 400 CCGT 10 Sappi Ravenshead Pearsons Cruachan (pump storage) 440 Hydro 45 Galloway Scheme Lanark Scheme Hydro Hydro 73* 83 NHHT Basingstoke Brighton Rye House Damhead Creek Well balanced generation mix of 6GW - * Approximation, plants range from opening years 5 5

6 Background to the building of Cruachan An upper reservoir high above but close to the lower reservoir Good rock, cheaper the work Large Loch, Close to industrial belt Requirement for flexible plant 6

7 Cruachan History Built by North of Scotland Hydro- Electric Board (NoSHEB) Transferred to South of Scotland Electricity Board (SSEB) Balance of assets for the Scottish Generators

8 Cruachan Technical details Cruachan PS is situated 18miles East of Oban Located underground, 1Km tunnel Man made machine hall, 229,000 cubic metres of rock extracted Operating head of the pump/turbines of 365m 8

9 Cruachan Technical details Reversible pump-turbine technology 1 of only 4 such stations in the UK 440MW capacity 2 120MW and 2 100MW Four modes of operation 9

10 Highly flexible and available plant Rest to full load in 3 minutes Spin Gen to full load in 30 seconds Approximately 10,000 mode changes a year Reservoir capacity of 7GWh Provides Black Start capability to National Grid 10

11 Cruachan running regime, in the early days. Early years fraught with technical difficulties Poor reliability and availability Intense maintenance regime Maintenance team of 30 in 1989 now 12 in

12 Changes to plant and equipment. Problems areas identified Alternative Engineering designs tried Examples: Shaft seal, Guide vanes. Low availability and high maintenance in the early years 12

13 Changes to Shaft seal design Types fitted and problems Reliability, difficult to fit and leakage Recent experiences to date Low wear rate low maintenance 13 13

14 Changes to Guide vane arrangement Purpose of Guide Vanes Problems New design Guide vane connection improvements to the regulating ring 14 14

15 Changes to Suction cone measuring device Sequence requirements Suction Cone fully watered up Suction Cone water level high History and issues Suction Cone Water level indicator Open Air Admission valve Close Air Admission valve Recent experiences Hours in spin mode increasing 15 15

16 Changes to Super Grid Transformers Previous failure details Super grid replacement considerations Reduced installation time Super Grid Transformer replacement 16

17 Changes to Generator Rotor brush maintenance Problems with main rotor brush gear High level of carbon dust Potential for electrical flash over Maintenance interval extended by use of harder brushes 17 17

18 Changes to guide bearing maintenance High maintenance requirements Solution, Non intrusive techniques Outcome, less maintenance Reduction in guide bearing maintenance 18 18

19 Changes to Penstock maintenance arrangements Previously involved draining the penstock Now inspected, using ROV, while watered up Less stressful and reduced time Time saved on Penstock internal inspections 19 19

20 Conclusions Looked at Cruachan s experiences Examined some of the solutions Current market place demands Cruachan a success story 20

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