19 Due 4/7

1. Make 9.42 in the hardcover or 9.33 in the softcover. In addition to what is asked, construct the phases at 2, 3, and 4 in three separate $Ts$ diagrams. In the diagrams, list no more than is needed to construct the phase, but do list the values of the curves/points used.

2. R-134a at 1MPa and 30$^\circ$C passes through an adiabatic expansion valve in which the pressure decreases to standard atmospheric pressure. Construct the initial phase in the $Ts$ diagram. In the diagram, list no more than is needed to construct the phase, but do list the values of the curves/points used. Then find the final quality and the entropy generated.

3. Steam at 15 kPa and a quality of 90% enters a constant pressure condenser at a rate of 3 kg/s and exits it as saturated liquid. The heat is transferred to cooling water with an average temperature of 17$^\circ$C. What is the entropy generated?

4. Air at 1000 kPa and 500 K enters an isobaric heat exchanger at a rate of 0.2 kg/s and exits at 300 K, having been cooled down by the ambient air at 300 K. Find the total rate of entropy generation. Use constant specific heats from table A.5, not table A.7.1.