Question

Consider a steady-flow carnot cycle with water as the working fluid executed under the saturation dome between the pressure limits of 3 mpa and 10 kpa. water changes from saturated liquid to saturated vapor during the heat addition process. the net work output of this cycle is

Answer 1

The saturation temperatures fro the two pressures are 

10 MPa => 310 C 
50 kPa => 81 C 

Since it is a steady flow system, the heat required to go from saturated liquid to saturated vapor is 

qin = delta enthalphy = 2727 - 1408 = 1319 kJ/kg 

where I used steam tables to get the values of the enthalpies. The efficiency of the carnot cycle in this case is 

efficiency = 1 - (81+273)/(310+273) = 0.39 

and, thus the net work output is 

work output = 0.39 * 1319 = 518 kJ / kg