Steam enters a turbine steadily at 2 MPa, 400oC, 6 kg/s and exits at 0.3 MPa, 150oC.

Question:

Steam enters a turbine steadily at 2 MPa, 400oC, 6 kg/s and exits at 0.3 MPa, 150oC. Steam is losing heat to the surrounding air at 100 kPa and 25oC at a rate of 200 kW. Determine
(a) The actual power output (Wext),
(b) The maximum possible power output (Wext),
(c) The second law efficiency and
(d) The energy destroyed (I).