commissioning mcnary fishway hydro project · history & lessons learned mcnary northshore...
TRANSCRIPT
4/8/2017
21th Annual TECHNICAL SEMINAR
Machines, Maintenance, and Management:
Keeping Hydro Facilities Up and Running
History & Lessons Learned McNary Northshore Fishway
Hydro Project
• McNary project history
• McNary re-powering project aka Runner install (part 1)
• Powerhouse crane failure & repair
• Rewind Project
• Runner install (part 2)
• Commissioning
• Lessons learned
• On September 30, 1991, the Federal Energy Regulatory Commission (FERC)
issued a 50-year license to North Wasco County Peoples Utility District
(NWCPUD) to construct, operate and maintain a hydroelectric project at the
McNary Dam.
• Originally, BPA entered into a power purchase agreement with NWCPUD in 1993.
• BPA withdrew from the agreement in 1994.
• Klickitat PUD then joined with NWCPUD to develop the McNary Project.
• The PUD’s entered into an Ownership Agreement in August of 1995
• The McNary North shore hydroelectric project was completed and started
production on October 17th 1997.
• The total cost of the project was $29 million.
Brief Project History
Project Design7
• The project uses attraction water from the north shore fish ladder on the McNary Dam for power generation.
– Attraction water flow is diverted through penstocks, runs through the turbine and is then routed back to the entrance of the fish ladder to attract migrating fish and lamprey.
• The intake structure at McNary is located at the bottom of the dam and draws water from about 80 ft below the surface of the dam forebay.
• The generator at McNary produces approximately 10 MW of power, which is split equally between NWPCUD and KPUD.
– Over a year, this amounts to approximately 80,000 MWh of energy – enough power to provide electricity to about 8,000 homes
McNary Re-powering Project Runner Install - Part 1
4/8/2017
• Review repair history of turbine blade cracks
• Review welding procedures from past blade repairs.
• Evaluate failure risk and cost associated with a blade failure
• Recommend remedial protection measures, e.g. vibration
monitoring, startup/shutdown timing, other, that may mitigate
damage if a blade failure occurs.
• Make recommendations for repair or replacement of turbine
runner or other in-water equipment.
4/8/2017
• 10 MW vertical unit commissioned in 1997
• Orenco supplied Hangzhou turbine & generator,
manufactured in China
• History of propeller runner blade cracking
• Runner casting quality poor with dimensional problems
• Initial McMillen Jacobs site visit on June 17, 2014
• Annual outages with weld repairs
Project Information
Recommendations
4/8/2017
• Contract for additional engineering, including developing
contract documents
• Perform generator detailed inspection early 2015
• Bid and award new runner contract
• Bid and award runner install site work contract
Action: Owners direct McMillen to develop runner procurement
bid documents and runner installation bid documents.
Runner Procurement
4/8/2017
• Bid documents prepared and issued to bidders
• Bids evaluated and recommendation for award February 2015
• Weir – American Hydro awarded contract effective March 31,
2015
• Runner to be delivered within 311 days
Runner Installation Contract
4/8/2017
• Bid documents prepared and issued to bidders
• Bids evaluated and recommendation for award August
2015
• HCMS awarded contract effective September 9, 2015
• Runner to be installed by February 5, 2016
• Outage begins October 2015
November 18, 2015 - Crane Failure
4/8/2017
• During the last lift of major equipment from the turbine pit, a
defective weld in the powerhouse crane failed.
• The old runner, shaft, bearings, brackets and head-covers
dropped 18”.
• Parts of the crane fell into the powerhouse damaging the
stator and concrete.
• Nobody was injured!
Crane Failure Damage
4/8/2017
• The crane failure damaged several major components of
the project:
• Generator stator windings and core
• Turbine bearing bracket that supports the runner and
shaft
• Lower guide bearing support bracket
• And the crane itself was no longer serviceable for the
runner installation work
Other Component Defects4/8/2017
• Stator winding defects
• Loose wedges and missing side/depth packing
• Caused excessive wear, winding damage and reduced life expectancy
• Lack of strand transpositions or internal transpositions resulting in higher losses
• Tin/lead solder results in higher losses and increased outage risk
• Other (PD evidence, inadequate end winding clearances)
• Wicket gates, bearing surface degradation, runout measurements too high
• Multiple inner and outer head cover defective welds
• Upper and lower bearing bracket defective welds
• Possible defective rotor welds investigated – need rewelding
Project Timeline
4/8/2017
• Late 2015: HCMS Stabilized the Project
• Early 2016: Disassembly of Plant Components
• Feb-Aug 2016: Off-site Component Repairs
• May-June 2016: Crane Repair and Installation
• April 2016: Boards Authorized Stator Rewind
• May-July 2016: Stator Rewind
• June-October 2016: Reassembly of Plant
• Nov 2016 – Feb 2017: Commissioning
Generator Rewind
4/8/2017
• Based on inspections during repair of damage to stator core
laminations a rewind was recommended
• Developed rewind bid documents and issued bid documents
• Evaluated bids and awarded a contract for stripping coils and
installing new to National Electric Coil (NEC)
• After coils were manufactured HCMS took short break while
installed new windings
Runner Install – Part 24/8/2017
• While rewind was underway 300 ton mobile crane used to service work
• Meanwhile powerhouse crane components are repaired/replaced
• HCMS weld repairs rotor spider following EME fracture mechanics analysis
• HCMS begins reassembly of unit in July 2016 following rewind
• Other work included: headcover line bored for wicket gate bushings, discharge
ring machined, wicket gate stems repaired, bracket weld repairs, etc.
• Unit alignment complete in November 2016
• Unit water up attempted mid-November 2016, but leakage from wicket gate
cartridges causes delay
• Corp of Engineers ladder outage (December 2016 through January 2017) delays
commissioning to February 2017.
• Commissioning begins February 7 and is complete February 12, 2017
4/8/2017
0.0
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40 45 50 55 60 65 70 75 80 85 90 95 100
Tu
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Servo %
Turbine Power vs. Servo %
4/8/2017
Commissioning Conclusions
• Runner met guaranteed output
• Load rejection unit speed rise and pressure rise acceptable
• Generator temperature rise acceptable
• Bearing temperatures acceptable
• Vibration levels below maximum allowable
Lessons learned
4/8/2017
• Purchasing Chinese equipment is risky – extreme vetting is
needed
• Weld repair of CA6NM castings very difficult
• Crane load testing isn’t the final word
• Need a good team to recover from an extreme situation
• Be prepared to respond to changed conditions based on
disassembly inspections
• Watch out for bad paint system specifications
Acknowledgements
4/8/2017
• NWCPUD and KPUD staff
• HCMS
• American Hydro
• National Electric Coil
Congratulations to Bob Guidinger on his retirement!