written 8.2 years ago by | • modified 8.2 years ago |
Mumbai university > Mechanical Engineering > Sem 3 > Thermodynamics
Marks: 12M
Year: May 2016
written 8.2 years ago by | • modified 8.2 years ago |
Mumbai university > Mechanical Engineering > Sem 3 > Thermodynamics
Marks: 12M
Year: May 2016
written 8.2 years ago by |
Pressure and condition of steam , at inlet to the turbine,
p1=6bar,x=0.9
Exhaust pressure, p2=0.7bar
From steam table at 6 bar: h1=hf1+xhgf1=670.38+0.9×2085.8=2547.6KJ/Kg,
s1=1.9308+.9×4.8785=6.32145 KJ/kgK
From steam table at 0.7 bar:
hf=377.04kJ/kg,hfg=2282.5kJ/kg,vf=0.001036m3⁄kg
sf=1.1929kj/kgk,s_fg=6.2853 kj/kgk
Pump work:
work=(p4−p3)vf=(6−.7)×0.001036×105
=549.08 W
Turbine work:
s1=s2=sf2+x2sfg2
6.32145=1.1929+6.2853x
x=0.816
h2=hf2+x2hfg2=377.04+0.816×2282.5=2239.56KJ/Kg
Therefore turbine work:
=m(h1−h2 )
=2547.6-2239.56
=308.04 kW
The rankine efficiency:
ηrankine=(h1−h2)(h1−hf2)
=308.042547.6−377.04
=0.142
=14.2%