Question

a) What are extensive and intensive properties? Give some examples (4 marks) b) What are the isothermal and isobaric processes? (4 marks) c) What are the qualities x for saturated liquid and saturated vapor, respectively? (4 marks) d) What is the difference between saturated vapor and superheated vapor? (4 marks) QUESTION 2 A piston-cylinder device contains 5 kg of saturated water liquid al 0.3 MPa. Heat is transferred at constant pressure until the temperature reaches 500 °C. (84 marks) a) What is the initial temperature of the system? b) What is the initial quality x? c) What is the initial specific enthalpy of the system? d) What is the final state? e) Show the process on a P-v diagram with respect to the saturation line. f) What is the final specific enthalpy? g) Calculate the change in total volume during the process h) Calculate the total enthalpy increase during the process. Formulae m X= v =v, + x(v, - ) In mixture region, u =u, + XU h =h + xh m AH=m(hy-ha) AV=M(V2-V1) View as Text Dov 13

Answer 1

Giveni Saturated water liquid Psat T a sor: 0.3 MPa = 500c since given initial state of water is saturated liquid. Hence from stream table. Tsat = T, = Initial temperature of the system = 133.52°c Initial Quality of x = 01: Saturated liquid) Specific. Enthalpy,h, = 561.43 kJ/kg sine Te = sool, Steam is superheated a sel water , b d) P superheated regian Tsoot 300 kPa T:-133.524 Sat V from steam table f he 3275-5 kJ/kg =0.001073 m?lrg m² lkg ( At State-1 be At State - 2 1.03155 9 change in total volume, svom lug-) = 5*(1.03155-0.001073) m3 Av=5.1523 m © Total Enthalpy Increase DHEM (ho-h,) = 5*( 3275.5-561.43) - 13570.35 kJ