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 state is the dead state Consider individual stream only We obtain: =m+g时+学g以-T） We define,flow exergy (or stream availability)at any given state point: 中=WeEm=m(h-h,)+之+g-T,(6-s) ms:W=(h-h)++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 May2,2018 6 HANGHAI JAO TONG UNIVERSITYMay 2, 2018 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 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