Energy Saving Innovations in Arctic Engineering Design

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Energy Saving Innovations in Arctic Engineering
Design

• CDR Michael MarcAurele, P.E.
• LT Chris T. Fehrman, E.I.T.
• Alaska Native Tribal Health Consortium
• USPHS Symposium June 1st, 2009

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Huslia Water Treatment Plant
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Huslia Water Treatment Plant
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Huslia Water Treatment Plant
COMPLICATED SYSTEMS
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Huslia Residence
SERVING BASIC NEEDS
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THE 1 Challenge in Arctic Climates

• Keeping Systems Thawed

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The 1 Challenge of Arctic Climates

• Freeze prevention methods for water and sewer
  systems include
• Designing highly insulated systems
• Designing redundancy and controls
• Circulating distribution loops
• Continuously heating water and glycol lines
• These systems are expensive
• Both to Construct and to Operate

Material Costs
Material Costs
Electricity Costs
Fuel Oil Costs
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Operational Costs Are Passed on to the Consumer

• Electricity Diesel Generators (88 Rural AK)
• Heating Individual boilers burning oil
• Price increases in recent years expected to
  continue
• Price Trend Further removed communities pay a
  higher premium per gallon

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80 barrel
May 2008 120 barrel (50 Increase)
www.iser.uaa.alaska.edu
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(No Transcript)
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Rural - Urban Comparison
State of Alaska, 2000 Census Data
(http//www.dced.state.ak.us/dca/)
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Cost Burdens Lead to Facility Failures

• Frozen Lift Station in Kiana
• Community could not afford to repair a leak in
  the glycol heat trace in the force main, causing
  lift station to freeze
• Sewage back-up discharged into a stream that
  feeds the drinking water source for a community
  downstream

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Overdesign/Misuse of Backup Systems Burdens
Homeowners

• Homes in Akiak run electric heat tape on
  residential lines continuously on their service
  lines to prevent freezing
• March 2009 Site Visit revealed
• Potable water in circ loops sent out from the WTP
  at 45 deg F returned at 48 deg
• WTP heat exchanger was not transferring any heat
  to the line customers were paying for service
  and supplying the heat as well!

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Energy Saving ApproachesEmployed by ANTHC

• 1 Waste Heat Utilization
• 2 Optimization of Arctic Pipe
• 3 Utilization of more efficient mechanical
  systems
• 4 Selection of appropriate designs

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1 - Waste Heat Utilization
Akiak Water Treatment Plant Upgrades, August 2007
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Heat Transfer Observations - 12/07 Q 108
gpm T,in 160 deg F T,out 164 deg F _at_ 7.70
per gallon, Diesel Fuel 13.73/hr 50- 70,000
/ year Potential Savings
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2 - Optimizing Arctic Pipe
Conditions 60 deg F Glycol, Static Water, -50
deg F Ambient
2006 STANDARD
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PROPOSED CONFIGURATION
Conditions 60 deg F Glycol, Static Water, -50
deg F Ambient
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NEW STANDARD
Conditions 60 deg F Glycol, Static Water, -50
deg F Ambient
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SIDE BY SIDE COMPARISON
Heat Flux (Btu/hr-lf) 13.5 Reduction -2.6
Heat Flux (Btu/hr-lf) 14.1 Reduction -2.0
Operational Heating Cost Savings 2 BTU/hr-lf
(Relative to Original Design) Example 5000
Sewage FM Above Ground Heating Oil 7.70/gal,
190.5 freeze days/year Savings 3,520 per year
(12.4)
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3 Mechanical Systems

• Heat Recovery Ventilators prevent cold arctic air
  from directly entering the building

Heat Recovery Ventilator Layout
Plan
Elevation
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• Multiple Stage Boilers perform with better
  overall efficiency than Single Load Boiler

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• Automatic Outdoor Reset Controls regulate the
  supply water temperature based on the outdoor
  temperature increase system efficiency
• Preheat Oil Day Tanks and Tiger Loops ensure warm
  fuel oil and optimum nozzle performance

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4 Selection of Appropriate Designs

• Example Vacuum Sewer Systems vs. Low Pressure
  Sewer Systems (LPSS)
• Historical solution in flat land applications

• System leaks are
• Common
• Difficult to locate
• Cause pumps run continuously
• Poor function leads to freezing

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• Low Pressure Sewer System Option
• Residential grinder pumps
• If an individual unit fails, the entire system is
  not burdened with additional operational costs

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Looking Forward

• Optimization of systems
• Deployment of remote sensing devices need to
  collect baseline data (drive by)
• Temperature/Acoustic Sensors
• Target system operation closer to 32 deg F
• Utilize more efficient circulation pumps
• OM Development
• Efficiency Evaluations
• Active preventive maintenance

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Mike MarcAurele, [phone],
mmarcaur_at_anthc.org
QUESTIONS?