Definition of Exergy for Open Systems Applying the following assumptions to Wuse: ·Total reversibility ·SSSF No heat interaction across the CV boundary other than heat to or from the environment Final outlet state is the dead state Consider individual stream only We obtain: an4g时ja+学+以-T We define,flow exergy (or stream availability)at any given state point: 中=Wwm=mhh,)+2+g-工6-s,) emsy=-h,)十y+gz-T,s-s,）canb View y as a fluid flow entering an CV at the given state and leaving the system at the dead state,while only useful work(power)is the sole output of the system. 上游充通大学 April 30,2019 6 HANGHAI JAO TONG UNIVERSITYApril 30, 2019 6 Definition of Exergy for Open Systems 2 2 o rev,use,SSSF,max o o o o o v v W m h gz T s m h gz T s 2 2                     Applying the following assumptions to Wuse: • Total reversibility • SSSF • No heat interaction across the CV boundary other than heat to or from the environment • Final outlet state is the dead state • Consider individual stream only We obtain: We define, flow exergy (or stream availability ) at any given state point:     2 rev,use,SSSF,max o o o v W m h h gz T s s 2                   2 o o o v h h gz T s s 2        Or, in specific terms: can be positive or negative! View  as a fluid flow entering an CV at the given state and leaving the system at the dead state, while only useful work (power) is the sole output of the system