Question

Let's suppose that you want to cook 1 lb of hot dogs using a parabolic trough concentrator on a clear June day in Los Angeles. The hot dogs would be skewered on a stiff piece of wire and aligned along the axis of the trough in the same position in which the absorber/receiver normally would be placed. The desired cooking time is 10 mins, with the resulting surface temperature of the hot dog about 450 F.
Find the length and width of the parabolic cylinder.

Answer 1

Important points to remember:

• The thermal energy stored in mater depends on its temperature and on the capacity of that matter to store thermal energy.
• Assume all sunlight incident on the mirror ends up absorbed.

Note:

From the given data Area of the parabolic surface can only be calculated. From that, if anyone of either length or width is provided then the other can be calculated.

Given data:

• The final temperature of hotdog(cooked):  
• Mass of hotdog: m =1lb=0.454Kg.
• Time taken to cook: t=10min.

Assumed data:

• The initial temperature of hotdog(room temperature):
• Incident beam intensity at the parabolic surface:
• Area of the surface=.
• Specific heat of hotdog: C==2.5Kj/Kg K.

Solution:

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