Advanced Technology Solar Telescope ENCLOSURE

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Advanced TechnologySolar Telescope ENCLOSURE
Performance
LeEllen Phelps
January 2006
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Enclosure Systems Design ReviewTopics of
Discussion

• Overview Charge to Committee (Mark Warner)
• 6 Major Parts of SDR
• SRD Flow Down Error Budgets (Rob Hubbard)
• Specifications (LeEllen Phelps)
• Reference Designs (LeEllen)
• Lunch
• Performance Analyses (LeEllen)
• Contracting Approach (Mark)
• Risk Areas (LeEllen)
• Plans for Future Work (LeEllen)
• AOB
• Executive Session (closed session for committee
  members)
• Feedback from Committee (All Hands)
• --------------------------------------------------
  --------------------------------------------------
  ----
• Dinner

Overview Charge to Committee
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Enclosure PerformanceEnclosure Thermal Control
Overview

• Function Suppress seeing

Air Scavenging System
Carousel Cooling System Lower Enclosure Cooling
Seeing is caused by temperature differences
If a surface is the same temperature as the
surrounding air, that surface introduces no seeing
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Enclosure Performance Enclosure Thermal Control
Overview

• Interior Seeing
• Fluent
• Shell Seeing
• MuSES
• M3
• Site data
• Energy Conservation
• AMEL

Enclosure Performance
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Enclosure PerformancePassive Ventilation

• Overview
• Requirements and Goals
• Configuration for analyses
• CFD Results
• Phases 2, 3 at Fluent Inc. (Phase 1 was an old
  design)
• Validation via CosmosFloWorks

Enclosure Performance
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Requirements and Goals
Enclosure PerformancePassive Ventilation

• Minimum of 20 enclosure volumes per hour
  passive air flushing
• For wind speeds greater than 2 m/s from any
  azimuth direction
• No stagnant dead zones inside enclosure
• Ability to throttle down interior air flow as
  outside wind speed increases (max interior air
  velocity 5 m/s)
• No direct sunlight to enter enclosure
• System should fully seal out weather during
  non-operational periods (e.g., overnight, rainy
  periods)
• Low-risk, high-reliability system
• COTS-type equipment
• Equipment easily serviced, replaced

Enclosure Performance
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Enclosure PerformancePassive Ventilation

• 3 sunshades on each side of enclosure
• Keep sunlight from entering enclosure
• Keep ice, snow, rain from reaching vent gates
• Help catch and direct wind into enclosure

• 3 vent gate sizes
• 6m x 2m
• 5m x 2m
• 3m x 2m

Enclosure Performance
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CFD Results Fluent, Phase 2
Enclosure PerformancePassive Ventilation

• Three wind directions East, South, and South
  East
• One wind speed 5 m/s (11.2 MPH)
• Shutter angle 45-degrees elevation
• Results meet requirements and goals
• 36-240 enclosure volumes/hour (requirement 20)
• Minimal flow up side of enclosure
• Minimal recirculation inside enclosure
• Mostly single-pass recirculation
• Good air flow through dome centerline (i.e.,
  telescope location)
• 30-40 of outside wind speed from floor to ceiling

Enclosure Performance
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Velocity Vectors
Enclosure PerformancePassive Ventilation
Enclosure Performance
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CFD Results Fluent, Phase 3
Enclosure PerformancePassive Ventilation

• Additional Runs
• North flow cases (with rear vent/access door)
• Shutter angle effects (15 deg from horizon,
  zenith)
• E, S, N, SE flow cases
• Telescope obstruction effect
• One wind speed 5 m/s (11.2 MPH)
• Results consistent with Phase 2 results
• 35-220 enclosure volumes/hour (requirement 20)
• Flow mostly thru flow, with some single-pass
  recirculation
• TMA causes a minor flow disruption
• Primarily at base of TMA, below mirror
• Some slowing of flow downstream of TMA
• Minor reduction (3-5) of total throughput
  through enclosure
• Good flow/flushing across optical path of TMA

Enclosure Performance
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Enclosure PerformancePassive Ventilation
Flow path lines through Enclosure with Telescope
Mount Assembly (TMA) as flow obstruction
Enclosure Performance
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Velocity Contours with TMA
Enclosure PerformancePassive Ventilation
Enclosure Performance
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Enclosure PerformancePassive Ventilation
Enclosure Performance
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Enclosure PerformancePassive Ventilation
Enclosure Performance
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Enclosure PerformancePassive Ventilation
Enclosure Performance
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CFD Results Validation
Enclosure PerformancePassive Ventilation

• Water, air tunnel testing too expensive for
  current DD phase budget
• CosmosFloWorks CFD package used to check
  Fluents results
• Different solver, analytical method
• Good agreement for results
• Total throughput within 5 for all flow
  direction cases
• Individual vent gate throughput 3-8
• Interior velocities _at_ specific points 7
• Also used to check Site performance

Enclosure Performance
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Enclosure PerformanceShell Seeing Overview

• Overview
• MuSES
• for performance analyses
• for design development
• Other tools
• for Lower Enclosure
• for optimization
• Results
• M3 designs
• Value Engineering

Enclosure Performance
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MuSES Modeling Validation at Gemini North
Enclosure Performance Skin Thermal Control
Development
Validation
Enclosure Performance
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MuSES Analyses forSkin Thermal Control
Development
Oblique skin panels air cooled, h 5 W/m2-K
Shutter air cooled, optional water cooling on
lower end hair 8 W/m2-K hH2O 100 W/m2-K
Option use fins on skin underside to increase
effective area
Enclosure support wall water cooled if
presenthH2O 100 W/m2-K
Sun-facing skin panels air or water cooled hair
5 W/m2-K hH2O 100 W/m2-K
Enclosure Performance
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Enclosure PerformanceShell Seeing

• Enclosure Heat Loads
• Heat load on the Enclosure was developed using
  MuSES analyses
• Heat load for each part was established (W/m2)
• These loads were the basis for the M3 designs

Enclosure Performance
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Enclosure PerformanceShell Seeing

• Lower Enclosure
• Absorbed solar load figure was developed using
  MuSES analyses
• Air volume for each part was established (cfm)
• These loads were the basis for the M3 designs

Velocity provided by fans
Loads influenced by surrounding ground treatment
Enclosure Performance
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Enclosure PerformanceThermal Systems Optimization
Ground Treatments
Enclosure Performance
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Enclosure PerformanceThermal Systems Optimization
Enclosure Performance
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Enclosure PerformanceThermal Systems Optimization

• Look at MuSES model with no cooling
• Minimize irradiated surface area
• Optimize for times of excellent seeing

Enclosure Performance
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Enclosure PerformanceShell Seeing
Overall, excellent seeing occurs first thing in
the morning
Excellent seeing with no wind and low wind
conditions occurs only rarely outside of morning
hours
Enclosure Performance
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Enclosure PerformanceShell Seeing

• Reduced plate coil coverage
• Reduced Lower Enclosure Cooling System

Enclosure Performance
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Enclosure PerformanceEnergy Conservation

• EnergyolutionsSM for Business
• Maui Electric Co., Ltd. capacity deferment
  program
• Funds energy studies to explore energy-efficient
  options in new construction
• Recommended Energy Conservation Measures (ECMs)
  eligible for rebate program
• AMEL Technologies, Inc.
• Melek Yalcintas, Ph.D., P.E., LEED-AP

Enclosure Performance
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Enclosure PerformanceEnergy Conservation

• Review the current baseline and determine the
  most energy efficient design options for
• Enclosure and SO facilities envelope design
• Temperature control strategies and chiller plant
  configuration
• Lighting systems
• Motor and motor control systems
• Other applicable mechanical and electrical
  equipment
• Determine the estimated construction costs,
  associated energy savings, simple payback, return
  on investment (ROI) for each recommended Energy
  Conservation Measures (ECMs).

Enclosure Performance
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Enclosure PerformanceEnergy Conservation

• Determine the estimated construction costs,
  associated energy savings, simple payback, return
  on investment (ROI) for each recommended Energy
  Conservation Measures (ECMs).

MECO Energy Solutions
Enclosure Performance
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Enclosure PerformanceEnergy Conservation
Enclosure Performance
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Enclosure PerformanceEnergy Conservation

• Recommended ECMs
• Chiller Plant Option 4 Low temperature chiller
  operation with ice storage system.
• VFDs on upper enclosure pump and lower enclosure
  fan motors.
• VFDs or similar technologies for upper enclosure
  and telescope system rotating equipment.
• Thermal control system for upper enclosure
  integrated wind speed as a control variable.
• Upper enclosure early morning thermal controls by
  active ventilation.
• Reflective treatment of the enclosure surrounding
  with 35 meter diameter white concrete ground
  treatment with vertical shield.
• NEMA premium efficiency motors, T8 fluorescent
  lighting and occupancy sensors where applicable.

Enclosure Performance
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