Split_00012 - 8.30(cont'd References H2O(l 25oC Air(v 25oC...

8- 12
Re ferences: H
2
O (l, 25
o
C), Air (v, 25
o
C)
substances ±
n
in
(mol / s)
²
H
in
(kJ / mol)
±
n
out
(mol / s)
²
H
out
(kJ / mol)
dry air 25.2 14.37 25.2
C dT
p
air
T
d i
25
z
H
2
O(v) 1.0
C dT H
C dT
p
H O l
vap
p
H O v
d i
d i
2
2
25
100
100
500
( )
( )
²
z
z
+
7.1
C dT H
C dT
p
H O l
vap
p
H O v
T
d i
d i
2
2
25
100
100
( )
( )
²
z
z
+
H
2
O(l) 6.1 0 -- --
Δ H n H n H
C dT C dT H C dT
C dT H C dT
out out in in
p
air
T
p
H O l
vap p
H O v
T
p
H O l
vap p
H O v
= = ⋅ − ⋅
F
H
G
I
K
J
+ + +
F
H
G
I
K
J
− − + +
F
H
G
I
K
J
=
z z z
z z
0
252 71
252 14 37 100 0
25 25
100
100
25
100
100
500
2 2
2 2
±
²
±
²
. .
²
. . .
²
( ) ( )
( ) ( )
b g d i b g d i d i
b gb g b g
d i d i
Integrate, solve : T = 139
o
C
b.
( )
( )
( )
( )
2
139 139
( ) 500 500
25.2 1.00 290 kW
p p
air H O v
Q C dT