Heat rise in a closed system
Heat rise in a closed system
(OP)
I have 10 electrical components that carries a total of 350 watts inside a sealed .075" thk. steel box of 24"Hx30"Wx8"Deep. What would be the inside temp inside the box before heat starting to dissipate outside the box through convection with outside ambient temp of 50 degrees Centigrade.





RE: Heat rise in a closed system
Zeroth Law of Thermodynamic
RE: Heat rise in a closed system
You are speaking of unsteady state heat transfer. If it is a sealed box full of liquid, as thermcool insinuates, and depending on the original liquid nature and temperature, thermal expansion of the liquid may rupture the box before any heat starts to dissipate.
If it is air, because of its low thermal conductivity, the electrical elements, being by definition constant heat flux system components, may heat up markedly and be damaged as a result, until the inner steel wall reaches a temperature just above 50oC by conduction and radiation (assuming no air convection currents inside the box). The tabulated thermal conductivity for air being about 0.024 W/(m*oC).
I hope you can estimate the final steel box wall temperature when reaching steady state or equilibrium heat transfer considering external convection and radiation as well.
RE: Heat rise in a closed system
RE: Heat rise in a closed system
To chicopee, why have you selected about 50oF ?
RE: Heat rise in a closed system
RE: Heat rise in a closed system
But the outside air was given at 50oC !
RE: Heat rise in a closed system
RE: Heat rise in a closed system
TTFN