(Solved): 7.4 The objective of this problem is to design an oil cooler with sea water. The decision was made ...

7.4 The objective of this problem is to design an oil cooler with sea water. The decision was made to use a hairpin heat exchanger. Length of hairpin $=3\mathrm{m}$ Annulus nominal diameter $=2$ in. Nominal diameter of inner tube (schedule 40 ) $=3/4$ in . Fin height, $H=0.00127\mathrm{m}$ Fin thickness, $\delta =0.9\mathrm{mm}$ Number of fins/tubes $=18$ Material throughout $=$ carbon steel Thermal conductivity, $k=52\mathrm{W}/\mathrm{m}\cdot \mathrm{K}$ Number of tubes inside annulus $=3$ Select the proper fouling factors. Calculate the following: a. The velocities in the tube and in the annulus b. The overall heat transfer coefficient for a clean and fouled heat exchanger