Slide 1

							                                                                                                                                                  OPTIMIZATION OF SOLAR OVENS
                                                                                                                                                                                                                IN TANZANIA
Problem Statement                                                                                                                                                                                                                                                                                                            Final Design Recommendation
The goal of the Solar Circle project is to design and                                                                                                                                                                                                                                                                        Side-by-Side model, black inner box
manufacture a solar oven that can be produced in Tanzania
                                                                                                                                                                                                                                                                                                                               • Outer box
primarily with domestic materials at a reasonable cost. The
                                                                                                                                                                                                                                                                                                                                     Linear Low Density Polyethylene
oven must be easily manufactured and aesthetically pleasing
                                                                                                                                                                                                                                                                                                                                     558 mm wide, 558 mm long , 241 mm tall
to the people of Tanzania and perform to an acceptable
standard.                                                                                                                                                                                                                                                                                                                      •   Inner box
                                                                                                                                                                         Group Members: Allison Lewis, Stacie Proctor,                                                                                                               Aluminum Lithograph
Project Background                                                                                                                                                          Gerard Westover, and Matthew Winkley                                                                                                                     420 mm wide, 420 mm long,153 mm tall
Solar Circle Organization                                                                                                                                                      Project Sponsor: Ms. Judy Martin                                                                                                                •   Insulation
  • Based in Okemos, Michigan                                                                                                                                                Faculty Advisor: Dr. Craig Somerton                                                                                                                     Kapok
  • Non-profit organization producing affordable solar ovens for                                                                                                                                                                                                                                                                     Thickness: 64 mm
                                                                                                                                                                 Testing                                                                                                                                                       •   Seal
  people of Tanzania                                                                                                                                             Prototype built prior to trip to Tanzania to familiarize team with
Tanzania                                                                                                                                                                                                                                                                                                                             Shoe Rubber
                                                                                                                                                                 manufacturing methods                                                                                                                                               12.7 mm wide, 445 mm long, 8 mm tall
  • Located in East Africa on Indian Ocean between
  Mozambique and Kenya                                                                                                                                                                                                                                                                                                         •   Collectors
                                                                                                                                                                 Prototypes built and tested in Tanzania to allow for two pots                                                                                                       Anodized Aluminum Alloy
  • Wood and wood charcoal used for cooking                                                                                                                        • Stacked design, reflective inner box
     • Contributes to high rates of deforestation                                                                                                                                                                                                                                                                                   • East, West, and North Facing Collectors
                                                                                                                                                                   • Stacked design, black inner box                                                                                                                                    Permanent
     • Smoke inhalation can result in respiratory disease                                                                                                          • Side-by-Side design, reflective inner box
  • Average annual income less than $500 per year                                                                                                                                                                                                                                                                                       60˚ from horizontal
                                                                                                                                                                   • Side-by-Side design, black inner box                                                                                                                           • South Facing Collector
Modeling and Research                                                                                                                                                                                                                                                                                                                   Adjustable
Matlab model and research were used to optimize the                                                                                                                                                                  Air Temperature Comparison- March 12th                                                                             50˚ from horizontal October through March
following components:
                                                                                                                                                                                                                                    -One Pot-
                                                                                                                                                                                                                                                                                                                                        60˚ from horizontal April through September
                                                                                                                                                                                                                                                                                                                               •
                                                                                                                                                                                                                                                                                                  1400

    • Inner and outer box material and dimensions                                                                                                                                               250
                                                                                                                                                                                                                                                                                                  1200
                                                                                                                                                                                                                                                                                                                                   Weight
    • Insulation thickness                                                                                                                                                                                                                                                                                                           12.5 kg (27.5 lbs)
    • Seal design and material
                                                                                                                                                                                                                                                                                                  1000




                                                                                                                                                                                                                                                                                                         Solar Flux (W/m2)
                                                                                                                                                                            Temperature (' F)




                                                                                                                                                                                                200



    • Collector material
                                                                                                                                                                                                                                                                                                  800




    • Number and shape of the solar collectors
                                                                                                                                                                                                150                                                                                               600




    • Collector tilt angles                                                                                                                                                                     100
                                                                                                                                                                                                                                                                                                  400



                                                                                                                                                                                                                                                                                                  200



                                                                                                                                                                                                50                                                                                                0
                                                                                                                                                                                                      0   20    40         60     80    100    120   140     160   180    200   220   240   260

                                                                  Solar Radiaton vs. Month                                                                                                                                                      Time (min)
                                                         - North, East, and West Facing Collectors -                                                                                             Side-by-Side Reflective        Stacked Reflective   Side-by-Side Black     Stacked Black   Solar Flux

                             650


                             600


                             550                                                                                                                                 Testing Conclusions
       Solar Radiation (W)




                             500
                                                                                                                                                                   • Solar flux is inconsistent due to varying conditions
                             450
                                                                                                                                                                   • Painted, black, inner box maintained a more consistent interior
                             400


                             350
                                                                                                                                                                   air temperature
                             300
                                                                                                                                                                   • Side-by-Side designs out-performed Stacked designs
                             250                                                                                                                                   • The Side-by-Side, black inner box design reached a maximum
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                                                                  N,E,W = 55
                                                                                            Month
                                                                                    N,E,W = 60         N,E,W = 65          N,E,W= 70
                                                                                                                                                                   • Height of oven was reduced after measuring pots in Tanzania


Optimization Example
Tilt Angle: North, East, and West Facing Collectors
   • 55˚ optimal April through October, ineffective otherwise
   • 60˚ most consistent for entire year