Consider a diesel-fired steam power plant that produces 400 MW of electric power. The turbine inlet conditions of 5 MPa and 500°C and a condenser pressure of 25 kPa. The state of the water at the inlet of the pump is saturated liquid. The steam has quality of (x = 0.88) at the inlet of the condenser. Water from a nearby river is used to cool the condenser. To prevent thermal pollution, the cooling water is not allowed to experience more than 8°C as it flows through the condenser. The diesel has a heating value (energy released when the fuel is burned) of 40,100 kJ/kg. Assuming that 80 percent of this energy is transferred to the steam in the boiler and that the electric generator has an efficiency of 95 percent, determine (a) the overall plant efficiency (the ratio of net electric power output to the energy input as fuel), (b) the required rate of diesel supply and (c) the minimum mass flow rate of the cooling water from the river.

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