This preview shows page 1. Sign up to view the full content.
Chapter 15
Steady Heat Conduction
381
A 3m diameter spherical tank filled with liquid nitrogen at 1 atm and 196
°
C is exposed to
convection and radiation with the surrounding air and surfaces. The rate of evaporation of liquid nitrogen
in the tank as a result of the heat gain from the surroundings for the cases of no insulation, 5cm thick
fiberglass insulation, and 2cm thick superinsulation are to be determined.
Assumptions
1
Heat transfer is steady since the specified thermal conditions at the boundaries do not
change with time.
2
Heat transfer is onedimensional since there is thermal symmetry about the midpoint.
3
The combined heat transfer coefficient is constant and uniform over the entire surface.
4
The temperature
of the thinshelled spherical tank is said to be nearly equal to the temperature of the nitrogen inside, and
thus thermal resistance of the tank and the internal convection resistance are negligible.
This is the end of the preview. Sign up
to
access the rest of the document.
 Fall '10
 Dr.DanielArenas
 Thermodynamics, Convection, Mass, Heat, Radiation

Click to edit the document details