Water at an average temperature of 107掳C and an average velocity of 3.5 m/s flows through a 5-m-long stainless steel tube (k = 14.2 W/m 路 掳C) in a boiler. The inner and outer diameters of the tube are Di =1.0 cm and Do = 1.4 cm, respectively. If the convection heat transfer coefficient at the outer surface of the tube where boiling is taking place is ho= 8400 W/m2 路 掳C, determine the overall heat transfer coefficient Ui of this boiler based on the inner surface area of the tube. Take 蠀=0,268 x 10-6 m2/s, k=0,682 W/m.K, Pr=1,58 for water at 107 潞C. Neglect fouling resistance at the inner and outer part of the tube.
a) 3500 W/m^2.C
b) 5887 kW/m^2.C
c) 5887 W/m^2.C
d) 3501 kW/m^2.C
e) 5887 kW