Thermodynamics Question 4 Follow Link Below for question ple
Thermodynamics
Question 4: Follow Link Below for question please.
http://imgur.com/pZ67f58
Solution
a)
This is a constant volume process because the container is rigid.
Specific volume is
V1=V2=V/m =0.012/10 =0.0012 m3/kg
From Table A-12 of R134a ,we obtain T1 at 120 Kpa
T1=-22.360C
Vf=0.0007323 m3/kg
Vg=0.1614
and
X1=(V1-Vf)/(Vg-Vf) = (0.0012-0.0007323)/(0.1614-0.0007323) =0.002911
h1=hf+x1hfg=21.32+0.002911*212.54=21.94 KJ/Kg
The Total enthalpy is
H1=mh1=10*21.94 =219.4 KJ
b)
The Final state is also saturated mixture ,at 650Kpa
T2=21.58oC
Vf=0.0008196 m3/kg
Vg=0.0341
X2=(0.0012-0.0008196)/(0.0341-0.0008196) =0.01143
h2=hf+x2hfg =79.48+0.01143*179.71 =81.53 KJ/kg
H2=mh2=10*81.53 =815.3 KJ

