1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Electric cable in a Vertical Tube: Estimate the Conductor Temperature

  1. Sep 9, 2010 #1
    Hello,

    I have an electric cable in a vertical steel Tube. I estimated the temperature that will reach the JTube exposed to sun radiation.

    I came with these equations

    QCable+ Qsun - Qradiated = mc( Tfinal - TAmbient)

    where QRadiated= k.A.(Tfinal^4-TAmbient^4), QSun=234 [W/m^2] * A
    A=Area of the Tube
    K=Radiation constant= 4E-8
    m=Mass of the tube
    c=473 for steel

    I finally find for a day the maximum Temp that will reach the Tube ( Resolved a quartic Equation with Tfinal as an unknown knowing that Tambient=34 for instance )

    However I want to know what temperature will reach the conductor ( after a day =86400 Secs)

    What I thought was

    For each t ( from 0 to 86400 secs)

    QCable = mc( Tfinal - TAmbient) - Qsun + Qradiated

    For each t, I know the right side. I Find QCable and then Divide it by the Thermal Mass to find the Temperature :/

    However I find extremely large Results so I think it might be wrong ( it shouldnt be bigger that 90 Degrees)

    Hope someone will be able to help me because I am really losing Hope...

    Thank you very much Guys

    Steve
     
  2. jcsd
  3. Sep 10, 2010 #2
    Ooooooook I found it :)
     
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook