An ideal Rankine steam cycle modified with two closed feedwater heaters and one open feedwater heater is shown below. The power cycle receives 100 kg/s of steam at the high pressure inlet to the turbine. The feedwater heater exit states for the boiler feedwater and the condensed steam are the normally assumed ideal states. Use the data provided in the tables given below to
(a) Sketch the T-s diagram for the ideal cycle.
(b) Determine the fraction of mass y extracted for the open feedwater heater.
(c) If, in addition to your result from part (b), the fraction of mass entering the high pressure turbine at state 7 extracted for the closed feedwater heater operating at 140 kPa is z = 0.0655, and at 1910 kPa the extraction fraction is w = 0.0830, determine the cooling water temperature rise in the condenser, in °C, when the cooling water flow rate is 4200 kg/s. Assume cp 5 4.18 kJ/kg·K for cooling water.
(d) Determine the rate of heat rejected in the condenser and the thermal efficiency of the plant.

Process states and selected data State P kPa T,C h, kJ/kg s, kJ/kg:K 20 620 620 620 5000 5000 5000 1910 620 140 20 4 3900 3515 3154 2799 2478 7.514 7.514 7.514 7.514 7.514 700 9 10 Saturation data P kPa Tsat C V, m2/kg h kJ/kg s kJ/kg K 20 60.1 0.00102 251 140 109.3 0.00105 458 676 1910 210.1 0.00117 898 5000 263.9 0.00129 1154 7.907 7.246 6.748 6.356 5.973 620 160.1 0.00110 Turbine turb Cooling water Boiler ity Condens Cooling water out I D Steam trap Steam trap FIGURE P10-106