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Surface Temperature from Solar Radiation
2

Surface Temperature from Solar Radiation

Surface Temperature from Solar Radiation

(OP)
I am investigating heat loss through a insulated chamber during specified ambient temperature and solar radiation.  I can calculate the diffuse and direct solar radiation using published TMY2 data (from NREL).

I am wondering if it is possible to calculate the surface temperature of a specified surface as a result of solar radiation and ambient temperature conditions.  I have poured through heat transfer texts and ASHRAE books but have not found a solution.  Does anyone know if this is possible?

RE: Surface Temperature from Solar Radiation

Why wouldn't it doable?  It's just another heat flow balance problem:

Input: solar
Output: emission, convection, conduction

TTFN

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RE: Surface Temperature from Solar Radiation

Surface temperatures on solar panels with no heat removal approaches 600F.

RE: Surface Temperature from Solar Radiation

(OP)
I am aware of empirical data available for various surfaces, but I cannot find data for black ABS plastic that is horizontal.  It would be possible to measure this directly, but I am trying to avoid this because I need temperatures from the hottest day of the year, and I need to do analysis ASAP.

I am aware that the input is solar and the output is emission,  convection and conduction, but with that I want to know what temperature this will bring a black ABS surface up to, given a known solar flux and emissivity, absorptivity, and reflectivity of a surface.  I don't need to know the heat transfer associated with this situation, I simply wish to calculate surface temperature.

RE: Surface Temperature from Solar Radiation

"I don't need to know the heat transfer associated with this situation, I simply wish to calculate surface temperature."

??  It's one and the same.  If you want to calculate the temperature, then you do the heat transfer problem.  If you can't, or won't, then you need to hire someone that will.  If you want to do the analysis, then crack open your HT textbook.

TTFN

FAQ731-376: Eng-Tips.com Forum Policies

RE: Surface Temperature from Solar Radiation

In order to get that temperature, you have to write the heat transfer equation across the irradiated wall of the enclosure
assuming inside temperature, Ti , outside surface temperature, Tw and ambient temperature, T0 and, average background temperature Tb for radiation you can write the net heat transferred to the surface must be zero, or

U*(Ti-Tw)+alpha*I -e*sigma(Tw^4-Tb^4)-hc(Tw-T0)=0
U conductance between inside Temperature and outer surface
e emissivity
hc convective coefficient
Now solve for Tw

 

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