Chapter 7, Problem 7.38P

Carbon dioxide (CO2) at 1 bar, 300 K enters a compressor operating at steady state and is compressed adiabatically to an exit state of 10 bar, 580 K. The CO2 is modeled as an ideal gas, and kinetic and potential energy effects are negligible.For the compressor, determine:(c) the percent isentropic compressor efficiency.

At a pressure of 1 bar, a temperature of 17 °C and a mass flow of 0.3 kg/s, air enters a stable insulated compressor and exits at 3 bar, 147 °C. Determine the power required by the compressor and the exergy destruction in kW. Express the exergy disappearance as a percentage according to the power required by the compressor. Changes in kinetic and potential energy will be neglected. dead state; T0=17 °C, P0=1 bar

Nitrogen (N₂) enters a well-insulated diffuser operating at steady state at 0.656 bar, 275 K with a velocity of 282 m/s. The inlet area is 4.8 x 10-3 m². At the diffuser exit, the pressure is 0.9 bar and the velocity is 80 m/s. The nitrogen behaves as an ideal gas with k = 1.4. (a) Determine the exit temperature, in K, and the exit area, in m². (b) For a control volume enclosing the diffuser, determine the rate of entropy production, in kW/K.