Project 2: Heat Exchanger Design
Group Members:Brian Schludecker
Phillip PalmerAdam Spindler
Mike HayJoe McGuire
Presented 12/12/2006 to Dr. Toksoy and ME 414 Class, IUPUI
Project Summary
• Design and optimization of heat exchanger
• Specifications & objectives
• Methods
• Results
• Conclusions
Heat Exchanger Specifications
• Heat exchanger length must not exceed 7 m
• Shell diameter must not exceed 2 m
• Shell mass flow rate: 120,000 kg/hr
• Water in shell must cool from 40 C to 25 C
• Water in tube enters at 20 C
• Ignore fouling
Objectives
• Maximize Q
• Minimize Weight (cost)
• Minimize heat exchanger pressure drop
Design Strategy
• Configure MATLAB files to analyze the heat exchanger
• Modify input factors until heat transfer ratio is close to 1
• Run DOE in MATLAB and Minitab to calculate optimal values for system
Design Factors
• Tube outer diameter• Shell inner diameter• Tube length• Number of tube passes• Material• Pitch• Number of Baffles• Baffle Spacing
Design Factors for DOE
• Tube outer diameter• Shell inner diameter• Tube length• Number of tube passes• Material• Pitch• Number of Baffles• Baffle Spacing
Design Decisions
• Pitch = 1.25 * Tube outer diameter
• 0 baffles
Interaction & Main Effects Plots(to find Critical Factors)
Interaction & Main Effects Plots(to find Critical Factors)
Mean Effects PlotsM
ean o
f w
eig
ht
0.012700.00635
1500
1250
1000
750
5000.43820.3874 52
21
1500
1250
1000
750
500213
tube_od shell_id tube_len
tube_pass tub_mat
Main Effects Plot (data means) for weight
Mean o
f q
0.012700.00635
3000000
2500000
2000000
1500000
10000000.43820.3874 52
21
3000000
2500000
2000000
1500000
1000000213
tube_od shell_id tube_len
tube_pass tub_mat
Main Effects Plot (data means) for q
Mean o
f dp s
hell
0.012700.00635
2500
2000
1500
10000.43820.3874 52
21
2500
2000
1500
1000213
tube_od shell_id tube_len
tube_pass tub_mat
Main Effects Plot (data means) for dp shell
Mean o
f dp t
ube
0.012700.00635
800000
600000
400000
200000
00.43820.3874 52
21
800000
600000
400000
200000
0213
tube_od shell_id tube_len
tube_pass tub_mat
Main Effects Plot (data means) for dp tube
Pareto ChartsTe
rm
Effect
ABEABCDE
BCEBCDEABDE
BEBDE
ABCDBCDABDABC
ACDEBDBC
CDEAB
ADEACE
BDE
ACDCEAECDAD
EAC
DCA
2000000150000010000005000000
138331Factor
tube_passE tub_mat
NameA tube_odB shell_idC tube_lenD
Pareto Chart of the Effects(response is q, Alpha = .10, only 30 largest effects shown)
Lenth's PSE = 76571.9
Term
Effect
ABCDABDEABD
BCDEBCD
ACDEBDEACD
BDADECDEADCD
ABCEDE
ABCD
ABEAB
BCEACE
BEBCACAE
BCEAEC
10008006004002000
8Factor
tube_passE tub_mat
NameA tube_odB shell_idC tube_lenD
Pareto Chart of the Effects(response is weight, Alpha = .10, only 30 largest effects shown)
Lenth's PSE = 4.38469
Term
Effect
ABEABDE
BEBCECDE
BCDEBDECE
ABCDEABCE
DEACDE
AEACEADE
ABCDBCDABC
BCABD
BDAB
BACD
CDAC
CAD
DA
8000007000006000005000004000003000002000001000000
0Factor
tube_passE tub_mat
NameA tube_odB shell_idC tube_lenD
Pareto Chart of the Effects(response is dp tube, Alpha = .10, only 30 largest effects shown)
Lenth's PSE = 1.345648E-10
Term
Effect
DEABCDE
CEAC
ABCBCDE
BCEBDE
EC
BCBE
ABECD
ABCDABCECDEACEACDBCD
ACDEAE
ADEABD
BDAD
DAB
BA
16001400120010008006004002000
0Factor
tube_passE tub_mat
NameA tube_odB shell_idC tube_lenD
Pareto Chart of the Effects(response is dp shell, Alpha = .10, only 30 largest effects shown)
Lenth's PSE = 1.179762E-13
Design Decisions
• Critical factors: Length, Shell ID, Tube OD
• Material: Aluminum (cost, weight)
• 1 pass
Optimized Results
Hi
Lo0.62872D
Optimal
Cur
d = 0.48564
Maximumq
d = 0.68952
Minimumdp tube
d = 0.67117
Minimumdp shell
d = 0.69525
Minimumweight
y = 1.971E+06
y = 3862.8936
y = 828.8276
y = 713.3242
2.0
5.0
0.3874
0.4890
0.0064
0.0159shell_id tube_lentube_od
[0.0138] [0.4890] [3.1253]Hi
Lo0.67904D
New
Cur
d = 0.61200
Targ: 2000000.0q
d = 0.88078
Minimumdp tube
d = 0.41952
Minimumdp shell
d = 0.94020
Targ: 1100.0weight
y = 1.806E+06
y = 1357.6620
y = 416.0955
y = 1076.0802
2.50
3.750
0.3912
0.5868
0.0110
0.0166shell_id tube_lentube_od
[0.0148] [0.5861] [3.3682]
+/- 20%
Using guesses (from Matlab):
Optimized results are not standardSize ID and OD, choose close sizes:
Optimized Specifications
• Tube OD = 0.0127 mm
• Shell ID = 0.5906 m
• Length = 3.3682 m
Final Results
• Q maximized 2.099E6 W
• dP in shell minimized 463 Pa
• dP in tube minimized 1500 Pa
• Weight minimized 1108 kg
Conclusions
• Minitab optimized values for ID and OD are not standard tube/shell sizes, need to adjust Minitab results
• Objectives achieved
• Further analysis possible for multiple passes/baffles
• Questions?
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