Question

A piston-cylinder device contains 10 kg of saturated water liquid at 0.4 MPa. Heat is transferred at constant pressure until the temperature reaches 400 °C. (68 marks) a) Show the process on a P-v diagram with respect to the saturation line? b) What is the initial temperature of the system? c) What is the initial quality x? d) What is the initial specific enthalpy of the system? e) Determine the initial total volume of the system. f) What is the final state? g) What is the final specific enthalpy? h) What is the final total volume of the system? i) Calculate the total heat transfer during the process. j) Determine the boundary work during the process.

Answer 1

lo" :- Merokehti -metoky - (O)___ Pe:040pa, T2 = 400 € Superherated vapour p=0.4mpa u ma T2=4000 en sot ligaid k- - Pla 0.4 MPa (6) at Teat = T = 143.616 mv mitmr 2) Quality (n) = mv - here mye mass of waponzo - me = mass of sou water liquid so in so because only saturated water present d) at P = 0.4mpa, The = h = 604.66 kJ/kg - As e) at fico.4 MpaV V 20:001084 ming - v - mu, = 0.001084 * Lo - 0.01084 m3 As E final state = Superheated steam T at P = 0.4impa Tsat = 143.6te Te - yooc T2 Z Tsat {shown in Pav diagram)

F g) At p = 0.40pa z T2 = 400°c f rom selpenheated_ steam table - h2 = 3273: 9 KJlry RB Vy = 0.77965 moling Ve i mlz 10* 09 77265 2 = 7.79 65 m3 W Q = m che-ht) {hreat transfer] 10 (3273.9 604.66) 26612.4 KI Ang TQ - w = p / dv) = 0.4*10 / 7.7265-0.010824 3016:27 KB] =