Chapter 6, Problem 6.58P

Steam at 44 bar and a dryness fraction, x = 0.9 is throttled to a pressure of 12 bar. Calculate thedifference in power output in kilowatts between the following two expansion processes:a) Steam at the initial pressure of 44 bar and x = 0.9 at State 1 is expanded in a turbine to State 3 at 0.12 bar.b) Steam at the reduced pressure of 12 bar after throttling at State 2 is expanded in another turbine to State 4 at the same exhaust pressure of 0.12 bar.The mass flow rate of steam is 8 kg/sec in both cases and the expansion in both turbines can be assumed to be reversible and adiabatic. Sketch both expansion processes on the same T-s diagram using the respective initial and final state points as described above.Explain the reason for the difference in power output.Calculate the mass flow rate of steam for the turbine operating at the throttled/reduced pressure to generate the same output as the turbine operating at the pressure before throttling.NOTE: You are required to number the state…

Air contained in a rigid, insulated tank fitted with a .paddle wheel, initially at 300 K, 2 bar, and a volume of 2 m2, is stirred until its temperature is 500 K. Assuming the ideal gas model for the air, and ignoring kinetic and potential energy, determine (a) the final pressure, in bar, (b) the work, in kJ, and (c) the amount of entropy produced, in kJ/K. Solve using

Argon gas flows through a well-insulated nozzle at steady state. The temperature and velocity at the inlet are 590°R and 150 ft/s, respectively. At the exit, the temperature is 440°R and the pressure is 40 Ibę/in?. The area of the exit is 0.0085 ft². Use the ideal gas model with k = 1.67, and neglect potential energy effects. Determine the velocity at the exit, in ft/s, and the mass flow rate, in Ib/s.