Continue two-stage compression with intercooling n-l n-l For dwc=0(minimum work): dpx T n-1 Pt Savings in work 2s P2 P2 n Isentropic Also, compression pvk=const P Ty T Px _Isothermal compression Polytropic pv=const compression Thus,T2=Tx and Ty =T: pva const we-,.-T)-T)=w >At optimal intermediate pressure,equal work in both stages! 上游充通大率 May15,2018 10 SHANGHAI BAO TONG LINIVERSITYMay 15, 2018 10 Continue two ‐stage compression with intercooling     n1 n1 n n C xx 2 x 11 x n 1 n 2 2x x y1 2x y1 C,1 x 1 2 y C,2 dw Tp p For 0 (minimum work): dp T p p p TT Also, p TT Thus, T T and T T : nR nR w TT TT w n1 n1                             At optimal intermediate pressure, equal work in both stages!