Continue Two-stage Compression with Intercooling Find intermediate pressure px to minimize work input: ·For an ideal gas: p Savings in work 2t 2s P2 Isentropic compression we-mR(-)mR() pvk =const Isothermal compression Polytropic pv const compression -小{- pva=const Wc- n-1 For an ideal intercooler:T=T (ambient) Py =Px (no pressure drop) 上游充通大率 May15,2018 7 HANGHAI HAO TONG LINIVERSITYMay 15, 2018 7 Continue Two ‐stage Compression with Intercooling Find intermediate pressure p x to minimize work input: • For an ideal gas: C x1 2y     1x 2 y C 1 y n 1 n 1 n n 1x 2 y C 1 y y 1 y x nR nR w TT TT n1 n1 nRT T T nRT w 11 n1T n1T nRT p p nRT w 11 n1 p n1 p For an ideal intercooler: T T (ambient) p p (no pressure drop)                                                                    v p p2 2t Isothermal compression pv = const p1 px 2 2s Polytropic compression pvn = const 1 y x Isentropic compression pvk = const Savings in work