Continue Exergy Analysis for Closed Systems 77? ?? W.c.=-(AUCM2 +AKECM2+APECM2+AU) The changes in internal energy of the system (CM2)and the environment can be calculated by: .Environment ToPo △UcM2=(U。-U)cM2 I CM2 Closed AU=Q。-W=T.AS.-P.AV. System Constant for environment △KEe=0,△PEe=0 Substitution into the equation for useful work leads to: Wuse.mas =(U-U)CM2 +AKECM2 +APECM2-TAS.+PAVe 下27 上游通大学 April 30,2019 6 SHANGHAI JIAO TONG UNIVERSITY
April 30, 2019 6 Continue Exergy Analysis for Closed Systems The changes in internal energy of the system (CM2) and the environment can be calculated by: Substitution into the equation for useful work leads to: CM2 o CM2 e e e o e o e U (U U) U Q W T S p V Constant for environment W (U U ) KE PE T S p V use,max o CM2 CM2 CM2 o e o e Closed System Environment @ To ,po Qi CM2 CM1 Wi Wuse W ( U KE PE U ) use,max CM2 CM2 CM2 e ?? ?? ?? ?? ΔKEe = 0, ΔPEe=0
Continue Exergy Analysis for Closed Systems Wuse.max =(U-U)CM2 +AKECM2 +APECM2-TAS +PoAVe Note: △V。=-AVcM2=-(V。-V)cM2=(V-V)cM2 and ASCmI =AScM2 ASe →ASe=AScMI-AScM2=AScM1-(S。-S)CM2 =△SCM1+(S-S)cM2 Then,substituting△V。and△S.into the equation for useful work: Wuse.max=(U-U)CM2 +AKECM2+APECM2 Po(V-Vo)CM2-To(S-So)CM2 +To ASCMI 上游充通大学 April 30,2019 7 SHANGHAI JLAO TONG UNIVERSITY
April 30, 2019 7 Continue Exergy Analysis for Closed Systems Note: ΔVe = – ΔVCM2 = – (Vo – V)CM2 = (V – Vo )CM2 and ΔSCM1 = ΔSCM2 + ΔSe ΔSe = ΔSCM1 – ΔSCM2 = ΔSCM1 – (So – S)CM2 = ΔSCM1 + (S – So )CM2 Then, substituting ΔVe and ΔSe into the equation for useful work: Wuse,max = (U – Uo )CM2 +ΔKECM2 +ΔPECM2 + po (V – Vo )CM2 – To (S – So )CM2 + To ΔSCM1 W (U U ) KE PE T S p V use,max o CM2 CM2 CM2 o e o e ?? ??