A.    Water enters a counterflow double-pipe heat exchanger at 15ºC flowing at the rate of 1700 kg/h. It is heated by oil (cp = 2000 J/kgK) flowing at the rate of 550 kg/h from an inlet temperature of 94°C. For an area of 1 m2 and an overall heat transfer coefficient of 1075 W/m2K, determine the total heat transfer and the outlet temperatures of water and oil. (cp of water = 4186 J/kgK).


B.    A simple counterflow heat exchanger operates under the following conditions: Fluid A: inlet and outlet temperatures 80°C and 40°C, Fluid B: inlet and outlet temperatures 20°C and 40°C. The exchanger is cleaned, causing an increase in the overall heat transfer coefficient by 10% and inlet temperature of fluid B is changed to 30°C. What will be the new outlet temperatures of fluid A and of fluid B. Assume that the capacity rates remain unaltered.