Question

Please I just want the method of solving part E, no need for solving A-D parts as I already solved them but stuck at part E

A shell and tube heat exchanger with one shell pass and two tube passes is used to heat 8.82 kg/s of fluid from 15.6 °C to 60 °C by using saturated steam at 150 kPa. The steam is condensing on the outside of the tubes with no = 15 kW/m².K. There are 50 tubes with an outside diameter of 1.91 cm and a wall thickness of 0.211 cm. If the fouling coefficient on the inside of the tubes is 5678 W/m2.K, determine: A. The length of heat exchanger per one pass B. The pressure drop through the tubes C. The pumping power required when the pump efficiency is 60% D. Pumping cost per year if the energy cost is $0.1 kW.h E. The wall temperature at each end of the exchanger if the wall thickness of the tube is neglected For turbulent flow, the friction factor is given as: vin -1.8 log los [ + (9)"] The properties of the fluid are given as: p=790 kg/m”, K = 0.182 W/m.K, p = 12 x 104 Ns/m?, Cp = 2470 J/kg.K, Pr = 16.29.

Answer 1

n Se heat exchanger ora E). Assuming the length per pass be L as calculated you in part. A. This is an example of constant flux heltw - T2) Ts steam Y tw heat Y Tz fluid he effective transfer coefficient of fluid inside the tube considering fouling coeff of inside of the tube ㅗ R; q=mper (Ta-Ti) hi A = Do. Lx nanoq passe, where + h. tuus Tw= / q + Tz Ahe plug in the values of q, A, he & Į to the wall temperature at the outlet. get