Six kilograms of CO2 executes at Carnot cycle in a piston-cylinder assembly. The minimum and maximum gas temperatures are 300 K and 900 K, respectively. The heat transfer to the CO2 during the isothermal expansion is 1200 kJ. At the end of the isothermal expansion the pressure is p3 = 800 kPa (assume that state 2 is the initial state of the isothermal expansion and state 3 is the final state of the isothermal expansion). After the adiabatic expansion from state 3 to state 4
the pressure is 14.73 kPa. Assume that CO2 is an ideal gas and use Table A-23 to evaluate the internal energy. For the Carnot cycle:
Process 1-2: Adiabatic compression to H T
Process 2-3: Isothermal expansion at H T , heat addition
Process 3-4: Adiabatic expansion to C T
Process 4-1: Isothermal compression at C T , heat rejection
a)Calculate the thermal efficiency based on the net work and the heat addition. (Check to make sure that it matches the Carnot efficiency)