Temperature rise due to thermal load?
Temperature rise due to thermal load?
(OP)
I have aluminum and fiberglass enclosures approx this size 12.2"x10.2"x6.25" (WxHxD) respectively. These enclosures will be installed outside and the solar load on them will be 1120W/m2. Consider the ambient temperature to be +55 deg C. So can someone tell me how to calculate the additional rise in temperature just due to the solar load?
Thanks!
Thanks!
RE: Temperature rise due to thermal load?
Given the additional information, you simply equate the incoming solar and internal heat load with the exiting radiated and convected heat. There will be a single surface temperature that satisfies the equality.
IF you do not have an HT text, you should get one; this one is free for downloading: http://web.mit.edu/lienhard/www/ahtt.html
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RE: Temperature rise due to thermal load?
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RE: Temperature rise due to thermal load?
where Q = Solar Load, A = area exposed to solar load, K = thermal conductivity of aluminum, delta T = temperature difference between ambient and inside of enclosure, L = thickness of aluminum enclosure
Basically I am saying that the solar load is a heat source inside the enclosure and now want to know the rise in ambient temperature due to it?
RE: Temperature rise due to thermal load?
This method doesn't offer a direct solution, you have to start with a guess temperature and iterate the procedure until it converges.
RE: Temperature rise due to thermal load?
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RE: Temperature rise due to thermal load?
RE: Temperature rise due to thermal load?
solar_load*absorptiivity*area1 = area2*htc*(Tbox-Tair)+ area3*emissivility*Planck*(Tbox^4 - Tamb^4)
Tamb is the emissive temperature of the environment
Tair is the air temperature
Solve for Tbox, which can be done manually, or through a solver routine such as the one inside of Excel.
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RE: Temperature rise due to thermal load?
absorptivity of what? aluminum?
area 1 = ?
area 2 = ?
area 3 = ?
htc = ?
planck = ?
what's the difference between Tamb and Tair?
What's Tbox4?
Can you plug the numbers that I have already provided in your equation so I know what is what?
Thanks!
RE: Temperature rise due to thermal load?
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RE: Temperature rise due to thermal load?
Thanks!
RE: Temperature rise due to thermal load?
TTFN
FAQ731-376: Eng-Tips.com Forum Policies
Chinese prisoner wins Nobel Peace Prize