Chapter 10 Boiling and Condensation10-54 Saturated steam at a pressure of 4.25 kPa and thus at a saturation temperature of Tsat= 30°C (Table A-9) condenses on the outer surfaces of 100 horizontal tubes arranged in a 10×10 square array maintained at 20°C by circulating cooling water. The rate of heat transfer to the cooling water and the rate of condensation of steam on the tubes are to be determined. Assumptions1Steady operating conditions exist.2The tubes are isothermal. PropertiesThe properties of water at the saturation temperature of 30°C are hfg= 2431×103J/kg and ρv= 0.030 kg/m3. The properties of liquid water at the film temperature of 30 + 20)/2 = 25°C are (Table A-9), TTTfs=+()/sat2(=ρμνμlllllpllk==×⋅==×=⋅°°−−997 00891 100894 1041800607336../..kg / mkg / m sm/sC J/kgCW/m C2Analysis(a) The modified latent heat of vaporization is n= 100 tubes20°C L= 8 mP= 4.25 kPaCooling water Saturated steam hhCfgfgpls*.()−×⋅°−°×0682431 1020)1033satJ / kg + 0.68 4180 J / kg C(30C = 2,459J / kgThe heat transfer coefficient for condensation on a single horizontal tube is
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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.