Download Volcanic ash filter testing experiments for EDF

Volcanic ash fall
impacts to diesel
generators – results
from the lab
George Williams and Thomas Wilson
Volcanic Ash Testing Lab, University of Canterbury
[email protected] [email protected]
Overview
1. Why is this important?
o Ash hazard in New Zealand
o Vulnerability of electricity supply to ash
o Case study from Argentina
2. What did we do?
o Test set up
o Test results
3. Implications
o Best-practice mitigation and preparedness measures
o International interest in further testing
• Cordon Caulle volcano erupting in 2011
• Clean and ash clogged filters from a hospital’s
HVAC system in Villa la Angostura, Argentina
NZ ash
sources
Tongariro
Last eruption 2012
Mayor Island
Last eruption ~7,000 a
Ruapehu
Last eruption 2007
Okataina
Last eruption 1886
Taranaki
Last eruption ~1854
Taupo
Last eruption ~1800 a
Volcanic ash impacts to electricity supplies
• Impact: Volcanic ash can cause outages on
both electrical distribution and transmission
networks.
High voltage flashover experiments
in the Volcanic Ash Testing
Laboratory at UC
New Zealand transmission network
Volcanic ash impacts to GenSets
Air Intake
Volcanic ash impacts to GenSets
Air Intake
Engine Air
Intake
Air flow
Radiator
Impacts to GenSets - Case study from Argentina
The 2011 eruption of Cordon Caulle, Argentina
Impacts to GenSets - Case study from Argentina
The 2011 eruption of Cordon Caulle, Argentina
Impacts to GenSets - Case study from Argentina
The 2011 eruption of Cordon Caulle, Argentina
Impacts to GenSets - Case study from Argentina
Towns receiving ash following the 2011 Cordon Caulle eruption
90 km from Cordon Caulle in the town of Bariloche, 45 mm of ash fell within 24 hours
Impacts to GenSets - Case study from Argentina
Bariloche
• Population: 113,000 (2010)
• Latitude: 41° S (the same as Wellington)
• Tourism town
Impacts to GenSets - Case study from Argentina
Electricity supply to Bariloche disrupted
• Transmission feed from national grid experienced
flashover during the ashfall causing disruption for ~10
days
Impacts to GenSets - Case study from Argentina
5MW emergency power generation facility
• Ash rapidly clogged air intakes within 12 hours leading to suffocation of generator
engines and overheating of radiators
• Lead to electricity disruption to key facilities (e.g. hospital, water supply, wastewater treatment facility)
Impacts to GenSets - Case study from Argentina
Newly built 20 MW generation farm
• Modern generator farm set up to provide power to the town
• Experienced ongoing issues related to ash ingress following intermittent ash falls
<1 mm and remobilised ash
Lessons from Argentina – potential mitigation strategies
• Deflection hoods installed GenSet air intakes.
• Large stocks of filters kept on site to allow for heightened filter replacement
frequency post-eruption.
Lessons from Argentina – potential mitigation strategies
Despite these mitigation measures, a fine layer of ash was still be found within the
GenSet’s casing
Overview
1. Why is this important?
o Vulnerability of electricity supply to ash
o Case study from Argentina
2. What did we do?
o Test set up
o Test results
3. Now what do we do next?
o Implications of testing
o Best-practice mitigation and preparedness measures
o International interest in further testing
• Cordon Caulle volcano erupting in 2011 (top)
• Clean and ash clogged filters from a hospital’s
HVAC system in Villa la Angostura, Argentina
What did we do? Filter performance testing
Experiments focussed on answering three key questions:
1. Determine ash concentration and
volume that will be ingested prior to
filtration
2. How effective are a range of standard
GenSet filters at filtering ash under
different ashfall scenarios?
3. Is there an optimal time to replace
filters and how often might this be?
Ash fall rates for Auckland
Basaltic ash
Rhyolitic ash
Experimental set up
Filter
Efficiency
1. Up to 90% of airborne ash
immediately outside a
GenSet can be ingested
into contact with the filters.
Irrespective of ash
concentration
2. All filters provide a tradeoff between % of ash
filtered and airflow rate
3. The percentage of ash
filtered varied between
different ash types despite
similar grainsizes being
used – particle mass
appears to be an important
ash characteristic
Operational
Lifetime of
Filters
1. Filters will clog rapidly even
when airborne ash fall
concentrations are relatively
low.
2. Slight changes in ash
concentration have a large
effect on the time it takes for
filters to become clogged.
Synthetic fibre filter pre and
post test
Take home messages
• The test results suggest GenSet operators should plan for replacing filters at much
higher frequency during ashfalls.
• Even exposure to relatively low ash concentrations may require hourly filter
replacement.
Facilities which rely on GenSets for emergency
power should:
1. have access to a large stock of filters
2. develop filter monitoring and replacement
procedures
3. ensure sufficient resources to effect the
procedure are available
(e.g. maintenance staff and additional
generators).
• When replacing GenSets, we recommend purchasing those that use high spec
filtration. Variety within GenSet filters implies that mitigation measures will need
to be determined on a case by case basis
Broader resilience considerations
• These results need to be taken with broader
resilience considerations in mind
• fuel supply
• staff making it to site: health concerns
Future work
Currently carrying out tests for a large European nuclear power plant operator
who are interested in investigating possible ash impacts to air-handling systems
following eruptions from distal volcanoes.
Investigate the feasibility of using cyclonic
filters versus conventional filters
Eruption scenarios for Auckland
Basaltic ash
Rhyolitic ash
Impacts to GenSets - Case study from Argentina
Ash travelled around the southern hemisphere having impacts on aviation in NZ
Ash grainsize distributions for Auckland