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Optimization of Tekniikka elämää palvelemaan (TEP) ry's box-type solar cooker : Insulation Improvement
Ayalew, Michael (2015)
Ayalew, Michael
Metropolia Ammattikorkeakoulu
2015
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Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:amk-2015052810876
https://urn.fi/URN:NBN:fi:amk-2015052810876
Tiivistelmä
The purpose of this thesis was to evaluate the cooking performance of an existing, field tested box-type solar cooker by studying computer plotted rates of temperature change in the cooking chamber and to suggest improvement ideas. The solar cooker was originally designed by Maria Telkes, a Hungarian-American scientist and inventor who worked on solar technologies, and its design was modified by Kari Silfverberg, an architect doing volunteer work for a Finnish non-governmental association called Technology For Life, Finland (Tekniikka elämää palvelemaan or TEP in short), which distributes free solar cookers to countries in the developing world.
Thermal simulations in Solidworks software, researches on different types of solar cookers and the results of actual performance tests on kari Silvferberg’s box-type solar cooker and its modified version named Metropolia 1 made in Metropolia’s Environmental Engineering Laboratory were used to devise design modifications for the different parts of the solar cooker that can improve the cooking performance. An improved version of the conventional box-type solar cooker incorporating the design modifications was made and experimentally investigated for its insulation. The results obtained suggest that the improved version has a better insulation than TEP ry’s box-type solar cooker.
The experimental and thermal simulation results showed that, the insulation of TEP ry’s box-type solar cooker can be improved by adding an additional insulation layer of polyurethane to its existing stone wool insulation and by using double-paned glazing in place of the existing single pane glazing. Thermal simulations in SolidWorks software and computer plots of the temperature versus time for the inside of a solar cooker that is heated to 100°C and left at room temperature for 5 hours were made for the TEP and Metropolia version-1 solar cookers and compared. It was observed from these plots and thermal simulations that the rate of temperature change for Metropolia 1 was lesser, which suggests that the design of Metropolia 1 can be taken as one improvement option to that of the TEP solar cooker.
Thermal simulations in Solidworks software, researches on different types of solar cookers and the results of actual performance tests on kari Silvferberg’s box-type solar cooker and its modified version named Metropolia 1 made in Metropolia’s Environmental Engineering Laboratory were used to devise design modifications for the different parts of the solar cooker that can improve the cooking performance. An improved version of the conventional box-type solar cooker incorporating the design modifications was made and experimentally investigated for its insulation. The results obtained suggest that the improved version has a better insulation than TEP ry’s box-type solar cooker.
The experimental and thermal simulation results showed that, the insulation of TEP ry’s box-type solar cooker can be improved by adding an additional insulation layer of polyurethane to its existing stone wool insulation and by using double-paned glazing in place of the existing single pane glazing. Thermal simulations in SolidWorks software and computer plots of the temperature versus time for the inside of a solar cooker that is heated to 100°C and left at room temperature for 5 hours were made for the TEP and Metropolia version-1 solar cookers and compared. It was observed from these plots and thermal simulations that the rate of temperature change for Metropolia 1 was lesser, which suggests that the design of Metropolia 1 can be taken as one improvement option to that of the TEP solar cooker.