heat and mass coulson

Question 1

A heat exchanger is required to cool 20 kg/s of water from 360 to 340 K by means of 25 kg/s
water entering at 300 K. If the overall coefficient of heat transfer is constant at 2 kW/m2 K,
calculate the surface area required in
(a) a countercurrent concentric tube exchanger, and
(b) a cocurrent flow concentric tube exchanger.

Answer 1

(a) Counterflow
A= 19:95m^2

(b) Cocurrent flow
A= 21:27m^2