Chapter 6, Problem 6.73P

5.29 From a constant temperature reser- voir (in the surroundings) at 3000°F, there are transferred 2000 Btu of heat to a Carnot engine. The engine receives the heat at 440°F and discharges at the sink temperature of 80°F. (s) Are the heat transfers reversible? Compute the change of entropy of the engine system accompanying the heat added process and the heat rejection process. (b) What is the net change of entropy of the universe in one cycle? of the engine in one cycle? (c) When all the Carnot work produced has been used, what is AS, for the universe? (d) If the input to the engine is 2000 Btu of paddle work (other events remaining as first des- cribed), what is AS, for the universe? Ans. (a) 2.222, -2.222 Btu/°R, (b) 1.644 Btu/°R, 0, (c) 3.124, (d) 2.222 Btu/°R.

A  well insulated steam turbine receives steam at temperature T1 = 540 °C and pressure p1= 30 bar. Steam exits the turbine at p2 = 0.7 bar and T2 = 160 °C.  The mass flow rate of the steam at the inlet is 4kg/s. a) Calculate the power generated by the turbine b) Calculate  the rate of entropy production, in kW/K, of the turbine process.  c) Calculate the isentropic efficiency of the steam turbine. You can assume that Potential energy change and kinetic energy change can be neglected. The turbine can be modelled as a control volume at steady state.

PLEASE ANSWER WITH COMPLETE SOLUTION AND DIAGRAM.