I set the maximum temperature to $600\backslash$deg C$.$ But something seems wrong. Did I do it right?

steam dasea power cycie, mixture and cnemica reaction.

This powerplant has $3$ stages of turbine, operating at $10$MPa,$5$MPa, and $1\mathrm{.}5$ MPa $.$ Condenser operate at $75$ kPa $.$ Determine the maximum temperature at the turbine inlet. $($It should be less than $620C).$ Based on your design, draw T$-$s diagram, identify each state. Assume the isentropic efficiency of the turbine and compressor as $0\mathrm{.}9$