Please answer with all steps correctly. https://www.mediafire.com/?nsu3026np43r7

Question

Please answer with all steps correctly.
https://www.mediafire.com/?nsu3026np43r70w
https://www.mediafire.com/?nsu3026np43r70w
https://www.mediafire.com/?nsu3026np43r70w
These 3 links are supportive files.

2. Convection and radiation. /10 points/ Hot water pipes in a home typically move water at a temperature of roughly 110 F 43 C. We want to compare heat loss due to convection to heat loss due to radiation. The heat transfer coefficient inside the thin copper pipe is 250 WIm -C, while the outer h 14 WIm2-C. For this estimate we will treat the pipe as a blackbody, and ignore any back-radiation from the room, which has a temperature of 20 C. State any assumptions or approximations you make, and find the ratio convective heat loss radiation loss? 97 b) 8.7 c) 14 d)71 e) 0.54

Explanation / Answer

Heat transfer coefficient  is the proportionality constant between the heat flux and the temperature difference, T

    h = q / T

Where,

Q=amount of heat transferred (heat flux), W/m2 ,T=difference in temperature between the solid surface and surrounding fluid area

For radiation heat flux,

Q(radiation)=h* T =14 W/m2.C(43-20)C=322W/m2

For, convection,

Q(radiation)<Q(convection)

Tf=Ts+Tbulk/2=20+43/2=31.5    Tf=film temperature, Ts=surface temperature , Tbulk=bulk temperature

Q(convection)=h* T =250W/m2.C(43-31.5)C=2875 W/m2

Ratio=2875/322=8.9

Related Questions

Navigate

• Browse (All)
• Browse P
• Subjects

---