7-A well-insulated turbine operating at steady state is sketched in the figure. Steam enters at 3 MPa, 400C, with a volumetric flow rate (V = AC) of 85 m'/min. Some steam is extracted from the turbine at a pressure of 0.5 MPa and a temperature of 180C. The rest expands to a pressure of 6 kPa. The total power developed by the turbine is 11,400 kW. Kinetic and potential energy effects can be neglected. Determine: (a) The mass flow rate of the steam at each of the P, MPa two exits, in kg/h. (b) The diameter, in m, of the duct through which steam is extracted, if the velocity there is 20 m/s. Power out Turbiae P=3MPa T= 400C (AV), - 85 m'/min P: =0.5 MPa T = 180C V= 20 m/s P3=6 kPa X= 90% State 1 0.5 0.006 T, C u, kJ/kg Density, kg/m 10.1 400 180 2930 2610 2200 2.47 0.0468 Useful I data: Y = C/C 1.4 Gas Molar mass- M-, kg/k mol Air 28.97 32 1.4 en Butane (CH10) Nitrogen (N2) Methane (CH) 58 1.1 28 1.4 16 1.32 Universal gas constant = 8.314 kJ / kmol. K 1 bar = 100 kPa For liquid waterh = 4.18 *t, kJ/kg where t in C Water density 1000 kg/m %3D