1. A piston-cylinder device contains 15 kg of refrigerant - 134a at 0.24 MPa and 70oC. The R-134a is now cooled at constant pressure until it is a saturated liquid at approximately -5.4°C. Determine the amount of heat loss/gain, the work done and show the process on a T-V diagram.
2. 20 kg of R-134a initially at 1.01,1Pa and 130°C is contained in a rigid-cylinder device. The refrigerant is cooled at constant pressure until it exists as a saturated vapor at approximately 26°C. Determine the amount of heat loss, the work done and show the process on a T-V diagram.
3. R-134a at 1.2 MPa and 100°C enters an adiabatic turbine steadily at 1.0 kg/s and a velocity of 20 m/s and leaves at 0.1 MPa and 0°C. Determine the exit velocity if the work done by the turbine is 0.5 MW and the change in potential energy is zero.
3. Stearn enters a turbine with negligible velocity, at 4 MPa, 600°C and a flow rate of 36.000 kg/h. It leaves the turbine at 15 kPa with a velocity of 300m/s and a quality of 0.5. Determine the heat loss or gain for the steam as it passes through the turbine if the turbine has a power output of 200.000 kW (kJ/s).