Unit Five Homework Solutions
- Steam flows steadily through an adiabatic turbine. The inlet conditions of the steam are 10 MPa, 450oC, 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 450oC 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 cm2. 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 -24oC and leaves at 0.8 MPa and 60oC. 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 90oC is to be cooled to 1 MPa and 30oC in a condenser by air. The air enters at 100 kPa and 27oC with a volume flow rate of 600 m3/min and leaves at 95 kPa and 60oC. Determine the mass flow rate of the refrigerant.
- Air enters the evaporator section of a window air conditioner at 14.7 psia and 90 oF with a volume flow rate of 200 ft3/min. Refrigerant-134a at 20 psia with a quality of 30% enters the evaporator at a rate of 4 lbm/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.