TS1 = 85 C
xS1 = 0.5000
TS2 = 85 C
xS2 = 0.0 ( saturated liquid water at 85 C )
Steam Table Data at 85 C :
---------------------------------------...
T = 85 C
Psat = 57.83 kPa
hf = 355.90 kJ / kg
hfg = 2296.0 kJ / kg
hg = 2651.9 kJ / kg
Get hS1 for the steam from the quality equation :
---------------------------------------...
hS1 = hf + ( xS1 ) ( hfg )
hS1 = 355.90 + ( 0.5000 ) ( 2296.0 ) = 1503.9 kJ / kg
hS2 = hf at 85 C = 355.90 kJ / kg
Delta hS = hS2 - hS1
Delta hS = 355.9 - 1503.9 = - 1148 kJ / kg
qS = QS / mS = Delta hS = - 1148 kJ / kg
Now get QAC :
----------------------------
QAC = ( mAC ) ( CpAC ) ( TAC2 - TAC1 )
QAC = ( 150 kg ) ( 3.651 kJ / kg - C ) ( 65.0 C - 4.0 C )
QAC = 33410 kJ
You have QS = - ( QAC ) :
---------------------------------------...
QS = - 33410 kJ
mS = QS / qS
mS = ( - 33410 ) / ( - 1148 kJ/kg )
mS = 29.1 kg <-------------------------
The cider is heated from an initial temperature of 4°C to a final temperature of 65°C. The steam enters the heat exchanger as 50% quality steam and exits as water condensate at 85°C. Calculate the mass of steam required to heat 150 kg of cider. (For the cider, assume the Cp=3.651 kJ/kg°C, and latent heat=280.18 kJ/kg.)
1 answer
1 answer