9 10 pt A 5ft rigid tank contains a saturated mixture of ref

9. (10 pt) A 5ft rigid tank contains a saturated mixture of refrigerant-131a at 50 psia. If the saturated liquid occupies 20 percent of the volume, determine the quality and the total mass of the refrigerant in the tank.

Solution

P = 50 psia
T = 40.23 F
vf = 0.01252 cu ft / lbm
vfg = 0.93539 cu ft / lbm
vg = 0.94791 cu ft / lbm

Vf = ( 0.20 ) [ 5.000 cu ft ] = 1.000 cu ft

mf = Vf / vf

mf = ( 1.000 cu ft ) / ( 0.01252 cu ft / lbm ) = 79.87 lbm liquid

mg = Vg / vg

mg = ( 4.000 cu ft ) / ( 0.94791 cu ft / lbm ) = 3.792 lbm vapor

mt = mf + mg = 79.87 lbm + 3.792 lbm = 83.66 <------

x = mg / mt = ( 3.792 lbm ) / ( 83.66 lbm )

x = 004533 = 4.533 %