5. Consider the following configuration in which a nitrogen line at 80°F and 75 psia is
connected to a turbine that exhausts to a closed, intially empty tank with a volume of
2000 ft³. The turbine operates until the pressure in the tank reaches 75 psia, at which
the temperature of the nitrogen in the tank is -10°F.
N2
p = 75 psia
T = 80°F
Turbine
Tank
Assuming that tank and turbine are well-insulated and that nitrogen behaves as an
ideal gas with varying specific heats with temperature,
(a) Draw the system for this problem clearly indicating all mass and energy interac-
tions. [2 points]
(b) Determine the mass of nitrogen that has entered the tank. [4 points]
(c) Calculate the work done by the turbine during the process, in Btu. [17 points]
(d) State four assumptions you made during your analysis. [2 points]