Chapter 10 Boiling and Condensation10-49 Saturated steam at a saturation temperature of Tsat= 55°C condenses on the outer surface of a vertical tube which is maintained at 45°C. The required tube length to condense steam at a rate of 10 kg/h is to be determined. Assumptions1Steady operating conditions exist.2The tube is isothermal. 3 The vertical tube can be treated as a vertical plate. 4 The density of vapor is much smaller than the density of liquid, ρvl<<. PropertiesThe properties of water at the saturation temperature of 55°C are hfg= 2371×103J/kg and ρv= 0.1045 kg/m3. The properties of liquid water at the film temperature of TTTfs=+=()/sat2(55 + 45)/2 = 50°C are (Table A-9), μνμlllllpllk==×⋅==×=⋅°°−−98810547 100554 1041810644336../..kg / mkg / m sm/sC J/kgCW/m C2AnalysisThe modified latent heat of vaporization is hhCfgfgpls*.()=+−×⋅°−°×0682371 10451033satJ / kg + 0.68 4181 J / kg C(55) C = 2399J / kgSteam55°C CondensateLtube= ?D= 3 cm45°CThe Reynolds number is determined from its definition to be
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