Thermodynamics HW Solutions 272

Thermodynamics HW Solutions 272 - Chapter 3 Steady Heat...

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Chapter 3 Steady Heat Conduction 3-162 An ice chest made of 3-cm thick styrofoam is initially filled with 45 kg of ice at 0 ° C. The length of time it will take for the ice in the chest to melt completely is 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 one-dimensional. 3 Thermal conductivity is constant. 4 The inner surface temperature of the ice chest can be taken to be 0 ° C at all times. 5 Heat transfer from the base of the ice chest is negligible. Properties The thermal conductivity of styrofoam is given to be k = 0.033 W/m °C. The heat of fusion of water at 1 atm is h . if = 333 7 . kJ / kg Analysis Disregarding any heat loss through the bottom of the ice chest, the total thermal resistance and the heat transfer rate are determined to be C/W 6678 . 1 07508 . 0 5927
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This note was uploaded on 01/19/2012 for the course PHY 4803 taught by Professor Dr.danielarenas during the Fall '10 term at UNF.

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