First T-s diagram shows the steam turbine producing power using non-superheated steam and other T-s diagram shows the steam turbine producing power using superheated steam.
In case of superheating the dryness factor at the exit of the turbine is higher. The turbine life will be higher in this case because of higher dryness fraction.
Ideally the dryness fraction should be 1 at the turbine exit.
Superheated steam produces more amount of work comparatively and increase thermal efficiency.
First T-s diagram shows the steam turbine producing power using non-superheated steam and other T-s diagram shows the steam turbine producing power using superheated steam.
In case of superheating the dryness factor at the exit of the turbine is higher. The turbine life will be higher in this case because of higher dryness fraction.
Ideally the dryness fraction should be 1 at the turbine exit.
Superheated steam produces more amount of work comparatively and increase thermal efficiency.