{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

Thermodynamics HW Solutions 801

# Thermodynamics HW Solutions 801 - Chapter 10 Boiling and...

This preview shows page 1. Sign up to view the full content.

Chapter 10 Boiling and Condensation 10-20 Water is boiled at a saturation (or boiling) temperature of T sat = 120 ° C by a brass heating element whose temperature is not to exceed T s = 125 ° C. The highest rate of steam production is to be determined. Assumptions 1 Steady operating conditions exist. 2 Heat losses from the boiler are negligible. 3 The boiling regime is nucleate boiling since Δ TTT s = = = ° sat C 125 120 5 which is in the nucleate boiling range of 5 to 30 ° C for water. Properties The properties of water at the saturation temperature of 120 ° C are (Tables 10-1 and A-9) ρ σ l v l = = = = 9434 112 0 0550 144 . . . . kg / m kg / m N/m Pr 3 3 h fg l pl =⋅ ° 2203 10 0 232 10 4244 3 3 J/kg kg m / s C J / k g C μ . T s =125 ° C Water 120 ° C Heating element Also, 0.0060 and n = 1.0 for the boiling of water on a brass surface (Table 10-3). Note that we expressed the properties in units specified under Eq. 10-2 in connection with their definitions in order to avoid unit manipulations. C sf = Analysis Assuming nucleate boiling, the heat flux in this case can be determined from Rohsenow relation
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}

Ask a homework question - tutors are online