NTU Timmerhaus Method

1. Redoing Coulson Vol.6 Example 12.13 via Timmerhaus Method Example 14.7
m1.5LHX m0.5WHX mm3BHX
nFlowPassages 1FlowPassagesPlates
Δ°Cm
W
21PlateConductivity2
m
4
n13
WHX
LHX
PlatesAHX
mm0.75Platethick
4000
2
mn3
BHX
WHX2
FlowPassages
FlowAreaperStrem
m0.006BHX2De
Δ°Cm
W
0.19ThermalConductivity
s
kg
27.8MassFlow
Δ°Ckg
kJ
2.84CP
sPa
3
100.34Viscosity
3
m
kg
750Density
°C40Tempout
°C95Tempin
Methanol
Δ°Cm
W
0.59ThermalConductivity
Δ°Ckg
kJ
4.2CP
sPa
3
100.8Viscosity
3
m
kg
995Density
°C40Tempout
°C25Tempin
Water
Use respective Matrix indexes
kW4342.36
4
Methanol
2
Methanol
10
Methanol
12
MethanolQHX
s
kg
68.926349
2
Water
4
Water
10
Water
QHX
WaterMassFlow
sn45
m2224
FlowAreaperStrem6
Methanol
12
Methanol
MethanolVelocity
sn37611
m3473888
FlowAreaperStrem6
Water
WaterMassFlow
WaterVelocity
Reynold's number
n17
11120000
8
Methanol
6
MethanolMethanolVelocity
De
MethanolRe
n63
43423600
8
Water
6
WaterWaterVelocity
De
WaterRe
Prandtl number5.082105
14
Methanol
8
Methanol
10
Methanol
MethanolPr
5.6949
12
Water
8
Water
10
Water
WaterPr
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2. Generic function of Nusselt function for Re > 100
0.4
Pr
0.64
Re
De
k
0.4Nu , , , PrReDe
k
K
2
m
W
2
5 589575757575758
16
25 n
16
25 173
2
5 2996286060606050
16
25 1112000038
Nu , , , MethanolPr
MethanolRe
De14
MethanolMethanolh
K
2
m
W
2
5 7154691653947020
16
25 n
16
25 633
2
5 40745362639427100
16
25 43423600118
Nu , , , WaterPr
WaterRe
De12
WaterWaterh
K
2
m
W
10000MethanolFouling
Fouling Heat Transfer Coefficients
K
2
m
W
6000WaterFouling
1
WaterFouling
1
Waterh
1
PlateConductivity
Platethick
MethanolFouling
1
Methanolh
1
OverallCoefficient
K55
4
Water
2
MethanolΔT1 K15
2
Water
4
MethanolΔT2
K30.786211
ln
ΔT2
ΔT1
ΔT2
ΔT1
LMTD
Based on max temperature difference i.e Methanol's1.786514
LMTD
4
Methanol
2
Methanol
NTU
Solver will try solving an essentially non-linear eq. An estimated range
of 10-300 for n will reduce solving time
92round , 0solve , , , 30010n
10
Methanol
12
Methanol
AHX
OverallCoefficient
NTUn
2
m68.25AHX92FlowPassages 91Plates
K
2
m
W
7083.947746Methanolh s
m
0.537198MethanolVelocity
K
2
m
W
23806.635689Waterh s
m
1.003952WaterVelocity
K
2
m
W
2059.518971OverallCoefficient
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