# Unit Five Homework Solutions

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- Steam flows steadily through an adiabatic turbine. The inlet conditions of the steam are 10 MPa, 450
^{o}C, and 80 m/s. The exit conditions are 10 kPa, 92% quality, and 50 m/s. The mass flow rate of the steam is 12 kg/s. Determine (a) the change in kinetic energy, (b) the power output, and (c) the turbine inlet area. - Argon gas enters an adiabatic turbine steadily at 900 kPa and 450
^{o}C with a velocity of 80 m/s and leaves at 150 kPa with a velocity of 150 m/s. The inlet area of the turbine is is 60 cm^{2}. If the power output of the turbine is 250 kW, determine the exit temperature of the argon. - Refrigerant-134a enters an adiabatic compressor as saturated vapor at -24
^{o}C and leaves at 0.8 MPa and 60^{o}C. The mass flow rate of the refrigerant is 1.2 kg/s. Determine (a) the power input to the compressor and (b) the volume flow rate of the refrigerant at the compressor inlet. - Refrigerant-134a is throttled from the saturated liquid state at 700 kPa to a pressure of 160 kPa. Determine the temperature drop during this process and the final specific volume of the refrigerant.
- Refrigerant-134a at 1 MPa and 90
^{o}C is to be cooled to 1 MPa and 30^{o}C in a condenser by air. The air enters at 100 kPa and 27^{o}C with a volume flow rate of 600 m^{3}/min and leaves at 95 kPa and 60^{o}C. Determine the mass flow rate of the refrigerant. - Air enters the evaporator section of a window air conditioner at 14.7 psia and 90
^{o}F with a volume flow rate of 200 ft^{3}/min. Refrigerant-134a at 20 psia with a quality of 30% enters the evaporator at a rate of 4 lb_{m}/min and leaves as a saturated vapor at the same pressure. Determine (a) the exit temperature of the air and (b) the rate of heat transfer from the air.