EPA Solar Oven Project #05301

EPA Solar Oven Project #05301

Critical Design ReviewMay 13, 2005

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Team Solar Oven

Team Lead: Emma Fulton ISE

Team Members: Josh Bates ME

Otman El Allam ISE

Natasha Privorotskaya ME

Jon Steiner ME

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Agenda Project Mission Statement Needs Assessment and Requirements Materials Selection Testing Methodology Types of Solar Ovens Concept Development/Selection Three Generations and Their Performances Environmental Assessment Questions

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Project Mission Statement Design, test, and build a low-cost solar

oven for use in Latin American countries using locally available resources, mass production methods, and labor

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Needs Assessment: Scope Limitations Design must be ultra low cost Design should only incorporate locally available

resources, production methods, and labor Design should be mass-producible Design must be durable Design must be able to cook food and pasteurize water Design must be benchmarked against three

commercially available units Thermal analysis must be conducted on prototypes

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Ranking of AttributesOrder of Weights

ATTRIBUTE Points Awarded

1 Low cost 70

2 Reaches Temperature Quickly 10

3 Able to Pausterize Water and Measure Completion of Pasteurization

10

4 Easy to use 2

5 Durable (Weather Resistant) 1

6 Capable of cooking large meals 1

7 Easy to clean 1

8 High packing density (stackable) 1

9 Light weight 1

10 Easy to Store/ Portable 1

11 Made of eco-friendly materials 1

Points AwardedLow cost

Reaches Temperature Quickly

Able to Pausterize Water andMeasure Completion ofPasteurization

Easy to use

Durable (Weather Resistant)

Capable of cooking large meals

Easy to clean

High packing density(stackable)

Light weight

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House of Quality- Part 1

1 Low Cost 70 9 9 52 Reaches Temperature Quickly 10 5 9

3 Able to Pausterize Water and Measure Completion

10 9 9

4 Easy to Use 2 95 Durable 1 96 Capable of cooking large meals 1 1 97 Easy to clean 1 5 1 98 High packing density 1 99 Light-Weight 1 9

10 Easy to Store / Portable 1 9 511 Made of eco-friendly materials 1 9

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House of Quality: Low Cost Solar Oven

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Materials Selection* Main Construction Material Reflector Material Cover Material

* CES Selector 4.5

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Main Construction Material

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Main Construction Material

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Wood Selection

Type of Wood

Price (USD/lb)

Density (lb/in3)

Thermal Expansion (µstrain/ºF)

Particle Board 0.291 0.0217 6.945MDF 0.374 0.0271 6.945Plywood 0.624 0.0271 3.889

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Reflector and Cover Material Offset printing plates chosen for reflector

Cost Reuse of waste material

Acrylic chosen for cover material Durability

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Testing Methodology Determine angle of reflectors

Square One software Laser Testing

Mimic sun’s energy Create indoor setup Calibrated solar cell

Test prototypes outside Thermocouples

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Three Main Types of Solar Ovens

Types Advantages DisadvantagesMost commonEasy to useEasy to buildRetains heat longerEasy to build Not sturdy during windy weatherCheapest to build Easy to damageHeats up very quickly Requires direct sunlightSturdy Dangerous to use

Inconvenient (frequent adjustment)

Longer to heat up food

Parabolic

Panel

Box

Box Panel Parabolic

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Concept Development

Homemade ~$10

Commercial: $120-$220

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Generation I: Four Reflector Box

$33.64 (Materials)

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Generation I: Single Reflector Box

$15.38 (Materials)

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Generation I: Pyramid Reflector Box

$19.65 (Materials)

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Generation I Performance

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Generation II-A Trip to Venezuela

Fabricated 2 units Single-paned acrylic Double-paned acrylic

Tested outdoors Performance

Reached water pasteurization temperatures 65C (149F)

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Expert Input Dr. Nandwani

International Expert on Solar Cooking Materials and Designs

Utilize glass not acrylic Suggested suitable insulation materials Optimal thicknesses

Generation II-B Retrofitted Generation II-A unit

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Generation II-B Performance

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Generation III Thermal analysis

Optimal insulation thickness

Increased capacity for larger families

Cost: $32.33

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Generation III Performance

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How did we do? One fourth the price of the cheapest

commercial unit: $29.33 (materials + labor) vs. $121.94

Full price, $32.33, includes a WAPI ($3) A device to tell if water has been pasteurized

Reaches cooking and water pasteurization temperatures

Uses 36% reuse materials

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HOQ- How Did We Do?

%~in2 in2 in3 in3 USD y/n sec °C/min y/n min y/n y/n lb0 323 4659 207.8 184.26 y 25.8 0.71 n 78 n y 19.3

35.6 270 4557 279.1 32.33 y 24 0.48 y 95 y n 38.5y n y y y y y n y n y n y0 210 4202 159.5 210.85 1350 30.7 n/a n n/a n y 210 434 3787 209 121.94 0 21.7 0.71 n 78 n y 110 324 5990 255 220.00 935 25 n/a n n/a n y 26

Meet Criteria (y/n)

SOS SportSun Cook Solar Oven

Benchmark Values

Objective Measures

Global Sun Oven

Actual Values for Generation III

Measurement Units

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House of Quality: Low Cost Solar Oven

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Recommended Future Work Slant oven so more direct sunlight hits pot(s) Research optimal number of glass panes Explore sealants for weatherproofing Replace the main construction material,

MDF, with a less dense material with similar or better thermal properties to reduce weight

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SOS Solar Cooker vs. RIT Solar Cooker Life Cycle Impact(Characterization)

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SOS Solar Cooker vs. Generation III

81%

67%

84%

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Benefits of Solar OvensIf 1,000 solar ovens are used year-round by

families of six, this would save approximately…

FIREWOOD 17,000 Tons CO2 6,300 Tons CO 300 Tons FUEL 9 Million Lbs

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Thanks and Questions Thanks to:

Dr. Carrano Dr. Thorn Dr. Mozrall Mr. Wellin Dr. Raffaelle Dr. Nandwani Carlos Plaz Chris Wood

Questions?

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Backup Materials Feasibility Assessment Indoor Test Cell

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Feasibility Assessment:How Many Prototypes to Build

# of Units T1 T2 E1 S1 S2 S3 S4 R1 R2 SUMBuild 1 Unit 0 0 3 3 1 3 3 3 3 19Build 2 Units 1 1 3 3 1 3 3 2 3 20Build 3 Units 2 2 3 3 2 3 3 1 3 22Build 4 Units 3 3 2 2 3 3 2 0 2 20

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Feasibility Assessment:How Many Prototypes to Build

0

1

2

3T1

T2

E1

S1

S2S3

S4

R1

R2

Build 1 UnitBuild 2 UnitsBuild 3 UnitsBuild 4 Units

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Indoor Test CellIndoor Test Cell

0.00E+00

5.00E+02

1.00E+03

1.50E+03

2.00E+03

2.50E+03

3.00E+03

3.50E+03

4.00E+03

300 400 500 600 700 800 900 1000 1100

Wavelength (nm)

Inte

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(a.u

.)