Ashell-and-tube heat exchanger is used for the heating of oil from 20°c to 30°c ; the oil flow rate is 12 kg/s (cp = 2.2 kj/kg* k). the heat exchanger has one shell pass and two tube passes. hot water (cpw = 4.18 kj/kg* k) enters the shell at 75°c and leaves the shell at 55°c. the overall heat-transfer coefficient based on the outside surface of the tubes is estimated to be 1080 w/m2 * k. determine:
a. the corrected logarithmic-mean temperature difference.
b. the required surface area in the exchanger.