4. A steam power plant operates between a boiler pressure of 42 bar and a condenser...

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4. A steam power plant operates between a boiler pressure of 42 bar and a condenser pressure of 0.035 bar according to a Rankine cycle with reheat. At the boiler exit, the steady-flow of steam at 4 kg/s is superheated to 500C, whereas the water is saturated at the condenser exit. Both high-pressure and low-pressure turbine expansion processes are assumed to be isentropic. At the high-pressure turbine exit, the steam at this intermediate pressure is just dry saturated, which is then reheated at constant pressure back to 500C. Show the cycle on a t-s diagram and then determine: (a) The re-heater pressure. (b) Thermal efficiency of the cycle. (c) Specific steam consumption of the cycle. [Ans: (a) 2.3 bar; (b) 0.41; (c) 2.14 kg/kW.h] 4. A steam power plant operates between a boiler pressure of 42 bar and a condenser pressure of 0.035 bar according to a Rankine cycle with reheat. At the boiler exit, the steady-flow of steam at 4 kg/s is superheated to 500C, whereas the water is saturated at the condenser exit. Both high-pressure and low-pressure turbine expansion processes are assumed to be isentropic. At the high-pressure turbine exit, the steam at this intermediate pressure is just dry saturated, which is then reheated at constant pressure back to 500C. Show the cycle on a t-s diagram and then determine: (a) The re-heater pressure. (b) Thermal efficiency of the cycle. (c) Specific steam consumption of the cycle. [Ans: (a) 2.3 bar; (b) 0.41; (c) 2.14 kg/kW.h]