10 Due 2/17

1. A stream of 0.3 kg/s of ammonia enters an insulated nozzle at 20$^\circ$C, 800 kPa as superheated vapor at negligible velocity. The ammonia exits at 300 kPa with a velocity of 450 m/s. Determine the temperature (or quality, if saturated) and the exit area of the nozzle. Construct all phases that are not given in a $Tv$ diagram. Label the lines with their values.

2. An compressor takes in normal nitrogen at 200 kPa, 27$^\circ$C and sends it at 1000 K and 2 MPa into a heat exchanger. It exits the heat exchanger at 300 K. Find the specific work done by the compressor and the specific heat removal in the heat exchanger. Make an appropriate approximation for the type of process in the compressor and another for the one in the heat exchanger. Both assumptions are listed in the table in the book. Assume that nitrogen is an ideal gas.

3. A stream of 2 kg/s of refrigerant R-134a enters a condenser at 600 kPa an 30$^\circ$C. It exis as saturated liquid at 20$^\circ$C. What is the cooling capacity in kW of the condenser? Construct all phases that are not given in a $Pv$ diagram. Label the lines with their values.

4. Compressed liquid water at 10 MPa and 40$^\circ$C enters a constant pressure steam generator through a 20 mm diameter pipe at the rate of 5 L/s. The water exits the generator at 350$^\circ$C through a pipe of the same diameter. Show in the $Pv$ diagram that the final phase of the water is indeed steam and find the rate of heat transfer to the water. Show a $Pv$ diagram of the process.