A new vehicle propulsion scheme calls for the use of liquid nitrogen as "fuel". The details of the power cycle are basically liquid nitrogen is heated in contact with the atmosphere, pressurised and expanded through a turbine) . Calculate the maximum work that could theoretically be derived from liquid nitrogen fuel. during each refuelling stop the driver purchases a Dewar vessel (a bottle) containing 0.05m^3 of liquid at atmospheric pressure. He leaves in exchange a used bottle of gaseous N2 at atm pressure and temperature.
Properties of N2 liq at 1 atm are v= 1.24x10^-3 m^3/kg, h= -121.5kJ/kg, s=2.85kJ/kg/K
At atmospheric conditions (300K and 1 atm) v= 0.49m^3/kg h=172.1 kJ/kg s=6.25 kJ/kg/K