Problem #1: (50 pts.)
Two kilograms of an ideal gas with constant
cp=1kJ/kgK and
cv=0.7kJ/kgK are contained in an insulated piston-cylinder device with an initial volume of
0.3m3 and a pressure of
10bar. The piston is then allowed to move until the volume quadruples.
If the process is considered reversible, determine:
a) The temperature of the final state in
K.
b) The work in
kJ.
If irreversibilities during the process cause the entropy to increase by
0.1kJ/K, determine:
c) The temperature of the final state in
K.
d) The work in
kJ.
e) Sketch the reversible and irreversible processes in a
T-s diagram.
Problem #2: (50 pts.)
A mass flow of
10kg/s of water vapor at
30bar and
500?
C flows steadily through the inlet an insulated turbine. The pressure of the water is reduced to
1bar at the turbine outlet. Neglecting kinetic and potential energy effects, determine:
a) The maximum power output in
kW generated by the turbine and its corresponding outlet temperature.
b) The actual power output in
kW generated by the turbine and its corresponding outlet temperature if its adiabatic efficiency is 90%.
c) Sketch the reversible and irreversible processes in a
T-s diagram.
Document Preview: Problem #1: (50 pts.)
Two kilograms of an ideal gas with constant cp=1kJ/kgK and cv=0.7kJ/kgK are contained in an insulated piston-cylinder device with an initial volume of 0.3m3 and a pressure of 10bar. The piston is then allowed to move until the volume quadruples.
If the process is considered reversible, determine:
a) The temperature of the final state in K.
b) The work in kJ.
If irreversibilities during the process cause the entropy to increase by 0.1kJ/K, determine:
c) The temperature of the final state in K.
d) The work in kJ.
e) Sketch the reversible and irreversible processes in a T-s diagram.
Problem #2: (50 pts.)
A mass flow of 10kg/s of water vapor at 30bar and 500?C flows steadily through the inlet an insulated turbine. The pressure of the water is reduced to 1bar at the turbine outlet. Neglecting kinetic and potential energy effects, determine:
a) The maximum power output in kW generated by the turbine and its corresponding outlet temperature.
b) The actual power output in kW generated by the turbine and its corresponding outlet temperature if its adiabatic efficiency is 90%.
c) Sketch the reversible and irreversible processes in a T-s diagram.