Solution cont. Alternatively, Closed system Imaginary piston' Boundary work: P;1 MPa !(constant) Pidv=-Pi(V2 -Vi)=-P[Vank-(Vink +Vi)]=PV; 1MPa ;=12 V--volume occupied by the steam before it enters tank Energy balance for the closed system P2=1 MPa △E=￠-Won (b)The closed-system Wbin=△U equivalence miPiVi=mu2-miui ->w2=u;+PV=h; 上游充通大 Mar/29,Wed,2017 6 SHANGHAI JIAO TONG UNIVERSITYMar/29, Wed, 2017 6 Solution cont. Alternatively, Closed system 1MPa Boundary work: -- volume occupied by the steam before it enters tank Energy balance for the closed system   E Q Wb,in