In a power plant operating on a Rankine cycle with superheat (Fig. 9.12), steam at 4.0 MPa

Question:

In a power plant operating on a Rankine cycle with superheat (Fig. 9.12), steam at 4.0 MPa and 700 K enters the turbine; the pressure is 3.5 kPa in the condenser. Modifying your EES program from Problem 9.26, vary the boiler pressure across the range from 400 kPa to 4.0 MPa for a Rankine cycle with superheat, with steam at 700 K entering the turbine. Plot the cycle efficiency as a function of the boiler pressure. Use at least five values of the boiler pressure to generate a smooth plot.

Problem 9.26

Consider a 50-MW Rankine-cycle steam power plant. The steam enters the turbine at 1000 F and 1200 psia and leaves at 1 psia with a quality of 0.90. Water leaves the condenser at 80 F and 1 psia. The power supplied to the pump may be neglected. Determine the thermal efficiency for the power plant and the mass flow rate (Mlb_m/h_r) of steam in the boiler.

Fig. 9.12