Repeat Problem 8.1 but assume that a fouling factor of 0.00018 m2 K/W has developed on the inside of the tube during operation.
Problem 8.1
In a heat exchanger, as shown in the accompanying figure, air flows over brass tubes of 1.8-cm 1D and 2.1-cm OD containing steam. The convection heat transfer coefficients on the air and steam sides of the tubes are 70 W/m2 K and 210 W/m2 K, respectively. Calculate the overall heat transfer coefficient for the heat exchanger
(a) based on the inner tube area and
(b) based on the outer tube area.
