Example 12.2 Analyzing two processes in series Not insulated P1=10 bar Process 1-2:water cooled as compressed at a constant pressure of 10 bar to the saturated vapor state. T1=400°℃ Process 2-3:water cooled at constant volume to 150C. -Boundary T1=400°C>Tsat(p1=10bar)=179.9℃ Find: D (a)Sketch both processes on T-v State 1:superheated 10 bar and p-v diagrams. 400C 400°C (b)For the overall process 10bar 179.9C determine the work,in kJ/kg. 179.9C 4.758bar (c)For the overall process 4.758bar 150°C 150°C determine the heat transfer,in kJ/kg. 上降文通大学 March 16,2018 7 SHANGHAI JIAO TONG UNIVERSITYMarch 16, 2018 7 Example 12.2 Analyzing two processes in series Not insulated p1=10 bar T1=400 ̊C Find: (a) Sketch both processes on T–v and p–v diagrams. (b) For the overall process determine the work, in kJ/kg. (c) For the overall process determine the heat transfer, in kJ/kg. Process 1–2: water cooled as compressed at a constant pressure of 10 bar to the saturated vapor state. Process 2–3: water cooled at constant volume to 150 ̊C. T1=400 ̊C > T p1=10 bar sat( )= 179.9 ̊C State 1: superheated