Evaluating Exergy change for closed Systems oDefinition of exergy: D=U-U+po(V-V)-To(S-So) ↓ Change in exergy: △Φ=Φ2-Φ1=( U2-U) +P(V2-V)-T(S2-S) Availability transfered Availability destroyed as work and heat Exergy destroyed Equivalent to irreversibility 1=Wrev,use,max-Wuse I=ToSgen 上游充通大 May2,2018 10 SHANGHAI JLAO TONG UNIVERSITYMay 2, 2018 10 Evaluating Exergy change for closed Systems Change in exergy: 2 1 2 1 o 2 1 o 2 1       Availability transfered Availability destroyed as work and heat F  F  F       U U p V V T S S F = U – Uo + po (V – Vo ) – To (S – So ) Definition of exergy: Exergy destroyed I = Wrev, use, max - Wuse = Equivalent to irreversibility I = T0Sgen