Thermodynamics HW Solutions 860

# Thermodynamics HW Solutions 860 - Chapter 10 Boiling and...

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Chapter 10 Boiling and Condensation 10-83 Steam at a saturation temperature of T sat = 100 ° C condenses on a suspended silver sphere which is initially at 30 ° C. The time needed for the temperature of the sphere to rise to 50 ° C and the amount of steam condenses during this process are to be determined. Assumptions 1 The temperature of the sphere changes uniformly and thus the lumped system analysis is applicable. 2 The average condensation heat transfer coefficient evaluated for the average temperature can be used for the entire process. 3 Constant properties at room temperature can be used for the silver ball. Properties The properties of water at the saturation temperature of 100 ° C are h fg = 2257 × 10 3 J/kg and ρ v = 0.60 kg/m 3 . The properties of the silver ball at room temperature and the properties of liquid water at the average film temperature of TT T fs a v e = + = () , sat 2 / (100 + 40)/2 = 70 ° C are (Tables A-3 and A-9), Silver Ball: ρ α = =⋅ ° ° 10 500 174 10 235 429 3 6 , k g / m m/ s C J / k g C W/m C 2 p l k
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## This note was uploaded on 01/24/2012 for the course PHY 4803 taught by Professor Dr.danielarenas during the Fall '10 term at UNF.

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