3) Air enters a turbine operating at steady state at 440 K, 20 bar, with a mass flow rate of 6 kg/s, and exits at 290 K, 5 bar. The velocities at the inlet and exit are 18 m/s and 30 m/s, respectively. The air is modeled as an ideal gas, and potential energy effects can be neglected. If the power developed is 815 kW, determine the rate of heat transfer, in kW, for a control volume enclosing the turbine.

Steam enters a turbine operating at steady state at 1.5 MPa and 418.4 °C, with a velocity of 79 m/s. Saturated vapour exits at 0.2 MPa and a velocity of 40 m/s. The elevation of the inlet is 2.8 m higher than the exit. The mass flow rate is 11.7 kg/s and the power developed is 5.5 MW. a) Using the property tables calculate the specific volume of the steam at the inlet m/kg b) Compute the area of the inlet m2 c) Using the property tables calculate the specific enthalpy of the steam entering the turbine kJ/kg

Water at p1 = 20 bar, T1 = 400oC enters a turbine operating at steady state and exits at p2 = 1.5 bar, T2 = 180oC.  The water mass flow rate is 4000 kg/hour. Stray heat transfer and kinetic and potential energy effects are negligible. Determine the power produced by the turbine, in kW, and the rate of entropy production in the turbine, in kW/K.

Refrigerant 134a enters an air conditioner compressor at 4 bar, 20°C, and is compressed at steady state to 12 bar, 80°C. The volumetric flow rate of the refrigerant entering is 7 m3/min. The work input to the compressor is 105 kJ per kg of refrigerant flowing.Neglecting kinetic and potential energy effects, determine the magnitude of the heat transfer rate from the compressor, in kW.