Answer to Question #124345 in Mechanical Engineering for Tushita

Question

FIND THE SPECIFIC VOLUME ENTHALPY INTERNAL ENERGY AND ENTROPY OF WET STEAM AT 20 BAR PRESSURE ANO DRYNESS FRACTION OF 0.8

NOTE : AT 20 BAR Values To be TAKEN FROM STEAM TABLE

Answer 1

The Dryness fraction(x) of the wet steam=0.8

The pressure of wet steam(P)=20 bar=2 MPa

The saturation properties of wet steam at 2 MPa is given in the steam table as-

v_f= 0.0012 m3/kg v_fg= (0.0996-0.0012)=0.0984 m3/kg

h_f=908.5 kJ/kg h_fg= 1889.8kJ/kg

u_f= 906.15 kJ/kg u_fg= (2599.1-906.15) =1692.95 kJ/Kg

s_f= 2.4468 kJ/kg-K s_fg= 3.8923 KJ/kg-K

Specific volume at x=0.8 => v=vf+x.vfg=0.07992 m3/kg

Specific enthalpy at x=0.8 => h=hf+x.hfg= 2420.34 kJ/kg

Specific internal energy at x=0.8 =>u=uf+x.ufg=2260.51 kJ/Kg

Specific entropy at x=0.8 => s=sf+x.sfg=5.5606 kJ/kg-K