Examples of Results in 2008
In the Winter Sciece Camp 2008, we made concentrator type, box type and panel type solar cookers. I would like to introduce you some interesting results and facts clarified through the analyses. These knowledge are new to me and I enjoyed them a lot. Do not try to mimic the successful ones but try a new improvement. I'm not expecting an old success but new findings by you!
Study the last year's findings.
A Concentrator type with a pseudo parabolic reflector. It employs the same plan as Educooker004 but twice as large. The concentration is 80%.
If you make four reflector parts of the Educooker004 leaving the corner of the sheet and assemble them, the shape of the reflector becomes square as shown above. The concentration increases a little. But the cooker made by the students did not show a good result. We found that the pot was placed a little forward and it causes a big difference between the results.
There are box type solar cookers with plural booster mirrors to raise the concentrations and robustness. But this one shown in the above figure did now perform well because they put the pot at a wrong position. If you put the pot in the center, its concentration will be as low as 14%.
Very similar box type solar cooker with the previous one. It also has two booster mirrors. The obvious difference is the position of the pot. In this case where they put the pot in the rear of the inner box, the concentration is more than 30% and the stew was cooked perfectly.
This box type cooker has only one booster mirror, but by arranging the shape of the inner box and making the wall of the inner box reflective, the concentration was improved to 35%. The two small mirrors attached to the main booster mirror does not contribute to any improvements because they are parallel to the sunlight.
The above figures show the concentration of the Educooker003 as a criterion of comparison because the panel type solar cookers fabricated by the students have almost the same sizes. The Educooker003 can concentrate 47 % of the sunlight received by its body on the pot.
This one has a shape very similar to a screen with three rectangular panels. It is too tall and the lights hitting the upper potion of the panels cannot be directed to the pot. This height of the cooker is not necessary when the sun elevation is as low as that of this season. But in summer, it may contribute to the concentration.
Combined panel and trough shape. The idea is not so bad, but the curvature and the size of the trough is too inadequate.
Take good measures against the wind！
Asikaga is in very windy district. Especially in winter season, the strong wind coming from the Mt. Akagi is called "Karakkaze". We are preparing enough double layer cardboards and bricks. Do not give your nice food to the Karakkaze!
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