(12 points) a heat exchanger is designed to cool 120 kg/min of water vapor at 2 bar and 400 oc to a saturated liquid at 100 kpa. the cooling water is taken from a local river at an inlet at 5 oc. after passing through a condenser, the temperature of the cooling water is not allowed to exceed 20 oc as regulated by the environmental codes. please determine the minimum mass flow rate of cooling water.