A nuclear power plant generates 3000 MW of heat energy from nuclear reactions in the reactor's core. This energy is used to boil water and produce high-pressure steam at 320?C. The steam spins a turbine, which produces 1100MW of electric power, then the steam is condensed and the water is cooled to 25?C before starting the cycle again.
Cooling water from a river flows through the condenser (the low-temperature heat exchanger) at the rate of 1.2×108L/h (?30 million gallons per hour). If the river water enters the condenser at 18?C, what is its exit temperature?