2. (14 pts) A process stream carrying 1 kg/s of saturated steam at 1 bar must be condensed to saturated liquid. This will be achieved by contacting the process stream

with water from a nearby river in a heat exchanger. The cooling water enters the heat exchanger at 25 °C, and must not be heated more than 10 °C before discharging due to environmental regulations. If the overall heat transfer coefficient in the heat exchanger is 37o w/m²K , find: (a) (4 pts) The amount of cooling water required (in kg/s). b) (6 pts) The total contact area required (in m2) for counter current flow. ts) Does the answer in part (b) change if the heat exchanger operates in co current flow? Explain why.

Fig: 1

Fig: 2

Fig: 3

Fig: 4