Superheated water vapor enters a valve at 2 MPa and 3508C and exists at a pressure of 0.4 MPa. The expansion is a throttling process. Determine the exergy destruction per unit of mass flowing, in...

Superheated water vapor enters a valve at 2 MPa and 3508C and exists at a pressure of 0.4 MPa. The expansion is a throttling process. Determine the exergy destruction per unit of mass flowing, in kJ/kg. Let T0 = 278C and p0 = 0.1 MPa.

Water vapor at 6.0 MPa and 440°C enters an insulated turbine operating at steady state and expands to saturated vapor at 0.2 MPa. The effects of motion and gravity can be neglected. Determine the work developed and the exergy destruction, each in kJ per kg of water vapor passing through the turbine. Let T0 5 30°C, p0 5 0.1 MPa.

Air enters an insulated turbine operating at steady state at 10 bar, 600 K, and 170 m/s. At the exit the conditions are 1 bar, 350 K, and 20 m/s. There is no significant change in elevation. Determine the work developed and the exergy destruction, each in kJ per kg of air flowing. Let T0 5 303 K, p0 5 2 bar.