To control an isentropic steam turbine, a throttle valve is placed in the steam line leading to the turbine inlet Steam at 6 MPa and 600 deg C is supplied to the throttle inlet, and the turbine exhaust pressure is set at 40 kPa What is the effect on the stream exergy at the turbine inlet when the t...

A throttle valve is placed in the steam line supplying the turbine inlet in order ...

To control an isentropic steam turbine, a throttle valve is placed in the steam line leading to

Question:

To control an isentropic steam turbine, a throttle valve is placed in the steam line leading to the turbine inlet. Steam at 6 MPa and 600°C is supplied to the throttle inlet, and the turbine exhaust pressure is set at 40 kPa. What is the effect on the stream exergy at the turbine inlet when the throttle valve is partially closed such that the pressure at the turbine inlet is 2 MPa. Compare the second-law efficiency of this system when the valve is partially open to when it is fully open. Take T0 = 25°C.