Chapter 6, Problem 6.92P

Air is compressed adiabatically in a piston-cylinder assembly from 1 bar, 300 K to 6 bar, 600 K. The air can be modeled as an ideal gas and kinetic and potential energy effects are negligible. Determine the amount of entropy produced, in kJ/K per kg of air, for the compression. What is the minimum theoretical work input, in kJ per kg of air, for an adiabatic compression from the given initial state to a final pressure of 6 bar? Note that work is positive into the compressor. Part A Determine the amount of entropy produced, in kJ/K per kg of air, for the compression. o/m = i kJ/K

Saturated water vapor at 300°F enters a compressor operating at steady state with a mass flow rate of 5 Ib/s and is compressed adiabatically to 650 lbf/in.? If the power input is 2150 hp, determine for the compressor: (a) the percent isentropic compressor efficiency and (b) the rate of entropy production, in hp/ R. Ignore kinetic and potential energy effects.

Water vapor at 10 MPa, 600°C enters a turbine operating at steady state with a volumetric flow rate of 0.36 m/s and exits at 0.1 bar and a quality of 92%. Stray heat transfer and kinetic and potential energy effects are negligible. Determine for the turbine (a) the mass flow rate, in kg/s, (b) the power developed by the turbine, in MW, (c) the rate at which entropy is produced, in kW/K, and (d) the isentropic turbine efficiency. Show this expansion process on a T-s diagram.

Water vapor at 10 MPa, 600°C enters a turbine operating at a steady state with a volumetric flow rate of 0.36 m3/sand exits at 0.1 bar and a quality of 92%. Stray heat transfer and kinetic and potential energy effects are negligible. Determine for the turbine (a) the mass flow rate, in kg/s, (b) the power developed by the turbine, in MW, (c) the rate at which entropy is produced, in kW/K, and (d) the isentropic turbine efficiency. Show this expansion process on a T-s diagram.

11. thermodynamics

Water vapor at 10 MPa, 700°C enters a turbine operating at steady state with a volumetric flow rate of 0.2 m3/s and exits at 0.1 bar and a quality of 92%. Stray heat transfer and kinetic and potential energy effects are negligible. Determine for the turbine: (a) the mass flow rate, in kg/s. (b) the power developed by the turbine, in MW. (c) the rate at which entropy is produced, in kW/K. (d) the percent isentropic turbine efficiency.

Steam enters a turbine operating at steady state at 1 MPa, 200°C and exits at 40°C with a quality of 83%. Stray heat transfer and kinetic and potential energy effects are negligible. Determine (a) the power developed by the turbine, in kJ. per kg of steam flowing, (b) the change in specific entropy from inlet to exit, in kJ/K per kg of steam flowing.

Refrigerant 134a enters an insulated diffuser as a saturated vapor at 80 deg F with a velocity of 800 ft/s. The inlet area is 1.4 in^2. At the exit, the pressure is 400 lbf/in2 and the velocity is negligible. The diffuser operates at steady state and potential energy effects can be neglected. Determine the mass flow rate, in lb/s, and the exit temperature, in deg F.

Water vapor enters a turbine operating at steady state at 1000F, 250 lbf/in2, with a volumetric flow rate of 25 ft3/s, and expands reversibly and adiabatically to 2 lbf/in2. Ignore kinetic and potential energy effects. Determine the mass flow rate, in lb/s, and the power developed by the turbine, in hp.   Determine the mass flow rate, in lb/s, and the power developed by the turbine, in hp.