Question

Steam enters an adiabatic turbine steadily at 3 MPa and 400°C and leaves at 50 kPa and 100°C. If the power output of the turbine is 2 MW, determine the isentropic efficiency of the turbine and plot the actual and isentropicprocess on a T-s diagram. Steam at 7 MPa and 450°C is throttled in a valve to a pressure of 3 MPa during a steady-flow process. Determine the entropy generated during this process and check if the increase of entropy principle is satisfied. Steam enters a compressor operating at steady state at 250°F, 14.7 psia and exits at 400°F and 160 psia. The work input is claimed to be 120 Btuper Ibm of steam flowing through the compressor. Heat transfer between the compressor and its surroundings occurs at an average outer surface temperature of 70°F. Neglecting the kinetic and potential energy changes between inlet and exit, is it possible that the compressor operates as claimed? (Justify your answer quantitatively.)

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