A Rankine cycle steam power plant design

  

A Rankine cycle steam power plant is to be designed to produce 300 megawatts of net power. The plant has a reheater and a single open feedwater heater. The reheater is located at the high pressure turbine exhaust. The extraction point for the open heater is at the exhaust of the intermediate pressure turbine. The layout of the plant is shown in the attached figure. You are to find the cycle efficiency, the quality at the low pressure turbine exhaust, and the required steam flow into the high pressure turbine for two different extraction pressures for the open heater.

You may assume that the pressure losses through the boiler, reheater, condenser and any connecting piping are small and can be neglected, and that the turbines, pumps, connecting piping, and open heater are well insulated. Changes in potential and kinetic energy are negligible. You should also assume that the discharge pressure of the condensate pump and the suction pressure of the boiler feed pump (exit of the open heater) are equal to the exit pressure of the intermediate pressure turbine. 

State points 8a, 9, and10 all have the same thermodynamic properties (pressure, enthalpy, entropy, etc.) but have different steam flows.

SPECIFICATION TABLE

Cycle Rankine-reheat-regenerative

HPT Inlet Steam Pressure 1500 psia

HPT Inlet Steam Temperature 1000 F 

Number of Reheaters One

HP Turbine Exhaust Pressure  1000 psia

Reheater Outlet Temperature 1000 F

Pressure for Open Heater  use 600 psia first, then use 300

Condenser Pressure 1 psia 

HP Turbine Efficiency 85%

IP Turbine Efficiency 87%

LP Turbine Efficiency 89%

Boiler Feed Pump Efficiency 80%

Condensate Pump Efficiency 60%