Heat loss through shell to atmosphere
Heat loss through shell to atmosphere
(OP)
anyone know a quick equation or rule of thumb to figure out how much heat can be loss through a shell and tube heat exchanger shell side fluid to the atmosphere?





RE: Heat loss through shell to atmosphere
Without getting too complicated with internal flows, etc, as a quick indicator, I'd treat it like a length of equivalent sized pipe and use a heat trace calculator program to approximate the heat loss.
rmw
RE: Heat loss through shell to atmosphere
or 20 btu/hr-ft2 on a windy day.
Of course Q = U * Area * Delta T
RE: Heat loss through shell to atmosphere
For example, 3 BTU/hr-ft^2 might be the result of using a 5 W/m^2-K heat transfer coefficient with only a 2°C temperature difference.
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RE: Heat loss through shell to atmosphere
Check this old post:
http://www
RE: Heat loss through shell to atmosphere
RE: Heat loss through shell to atmosphere
You'll have some sort of conductive thermal resistance to the surface that's in contact with air. The resistance induces a temperature drop reflected in the surface temperature. That surface temperature is what you use for both the radiative and convective losses. You'll need to know the emissivity of the surface. The solution to the heat balance between heat getting to the surface from the interior of the exchanger and the heat leaving the surface through radiation and convection will give you the final surface temperature. That temperature, when applied to the heat balance expressions, will give you the heat lost.
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RE: Heat loss through shell to atmosphere
For example, 3 BTU/hr-ft^2 might be the result of using a 5 W/m^2-K heat transfer coefficient with only a 2°C temperature difference"
If you read further down his post ,Chance17 does have the correct equation that includes the delta T and his result is a very good "Rule of Thumb" that the OOP needs.
RE: Heat loss through shell to atmosphere
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