Adiabatic system,Isolated system heat insulation material Q=0 adiabatic system Adiabatic system:No heat exchange Isolated system:No energy and mass exchange 上游气通大粤 February 28,2019 6 SHANGHAI JLAO TONG UNIVERSITY
February 28, 2019 6 Adiabatic system: No heat exchange Isolated system: No energy and mass exchange Adiabatic system, Isolated system
Examples for understanding system (1).Rigid adiabatic cylinder-piston system.Electrical heater in room B Red line closed,adiabatic system Yellow line without heater -closed system Yellow line with heater A B 庋 -closed,adiabatic system Blue line -isolated system 上游充通大 February 28,2019 7 SHANGHAI JLAO TONG UNIVERSITY
February 28, 2019 7 (1)．Rigid adiabatic cylinder-piston system. Electrical heater in room B Red line ——closed, adiabatic system Yellow line without heater ——closed system Yellow line with heater ——closed, adiabatic system Blue line ——isolated system Examples for understanding system
(2).Water heater at steady state boundarv mout outlet hot water water heater nlet min II 10L cold water mout=mn？ Close system or open system? 上游充通大 February 28,2019 8 SHANGHAI JIAO TONG UNIVERSITY
February 28, 2019 8 mout mout = min ? min Close system or open system? (2)．Water heater at steady state
(3).Chemical reaction:Calcium carbonate System? CaCO3 上游充通大学 February 28,2019 9 SHANGHAI JLAO TONG UNIVERSITY
February 28, 2019 9 System? (3)．Chemical reaction: Calcium carbonate
(4).Rigid adiabatic nozzle P P. m2-r i t P2<PI Ci t2<t1 m2 Cf2>Cf c-velocity i-mass flow rate Red line system(gas)-Closed system Nozzle as system- Open,adiabatic system 上游充通大 February 28,2019 10 SHANGHAI JLAO TONG UNIVERSITY
February 28, 2019 10 Closed system (4)．Rigid adiabatic nozzle Red line system (gas) — Nozzle as system— Open, adiabatic system c – velocity m –mass flow rate