ME 414 Project 2Heat Exchanger Design

Date: - May 6, 2009Instructor: - John Toksoy

Member: - Rahul Patel Hesam Nouri Atoosa Solhkonan Juan Tapia

Appendix

• Problem Defined• Objective and Specification• Design Heat Exchanger• Results Summary• Conclusion

Problem Defined• Chemical temperature must be cooled by at

least 20 degrees Celsius• Mass flow rate is 220,000 kg/hr.• Material properties must be defined as water.• City Water Temperature must be 20 C.• Length of the heat exchanger can not exceed 7

meters.• Minimize pressure drop, shell and tube weight.• Shell Diameter should not exceed 2 meters.

Objective

• Calculate the heat transfer ratio between 0.95 and 1.

• Minimize the weight of the Heat Exchanger.• Minimize the pressure drop for the shell and

tube side.

Design Heat Exchanger

• First use notes and your experience to eliminate the variables.

• Use matlab and Minitab to run the DOE on the variable to see their effect.

• Find the final 4 or 5 variables that effect the heat exchanger design.

Variables• Shell and Tube Fluid• Mdot Shell and Tube• Temperature of Shell in and Out• Temperature of Tube in and Out• Rf of Tube in• Rf of Tube Shell side• Shell tube side fluid reversed• Type of Flow• Number of shell and tube pass• Type of baffle• Baffle space and cut• Shell ID and thickness• Nusselt Shell and Tube• Pressure shell and Tube• Tube OD and thickness• Tube length and number of tubes• Tube Pithch and layout angle

Input Variables

• Shell and Tube Fluid: Water• Temperature of Shell in: 20 C• Temperature of Tube in: 45 C• Temperature of Tube Out: 25 C• Type of flow: Counter flow• Number of tube pass: 1• Number of Shell pass: 1

Design of Experiment (DOE)

• Total variables: 32• Eliminated 22 variables including the inputs

using notes and experiences.• 10 Variables so 2 DOE for 5 variables in each• Reduced 6 variables using DOE• Final Variables: Mdot shell, Shell ID, Tube OD

and length,

First DOE: Main Effect Plots

1.250.75

1000000

0

-1000000

500300 8.1254.875

0.6508750.390525

1000000

0

-1000000

0.00111130.0006668

I_counter_flow

Mean

mdot_shell Tube_Len

Baffle_Space Tube_th

Main Effects Plot for q (des - calc)Data Means

1.250.75

5500000

5250000

5000000

4750000

4500000500300 8.1254.875

0.6508750.390525

5500000

5250000

5000000

4750000

45000000.00111130.0006668

I_counter_flow

Mean

mdot_shell Tube_Len

Baffle_Space Tube_th

Main Effects Plot for q DesiredData Means

1.250.75

6000000

5000000

4000000

500300 8.1254.875

0.6508750.390525

6000000

5000000

4000000

0.00111130.0006668

I_counter_flow

Mean

mdot_shell Tube_Len

Baffle_Space Tube_th

Main Effects Plot for q CalcData Means

1.250.75

320

280

240

200500300 8.1254.875

0.6508750.390525

320

280

240

2000.00111130.0006668

I_counter_flow

Mean

mdot_shell Tube_Len

Baffle_Space Tube_th

Main Effects Plot for DP TubeData Means

1.250.75

12000000

10000000

8000000

6000000

4000000

500300 8.1254.875

0.6508750.390525

12000000

10000000

8000000

6000000

4000000

0.00111130.0006668

I_counter_flow

Mean

mdot_shell Tube_Len

Baffle_Space Tube_th

Main Effects Plot for DP shellData Means

1.250.75

16000

14000

12000

10000

500300 8.1254.875

0.6508750.390525

16000

14000

12000

10000

0.00111130.0006668

I_counter_flow

Mean

mdot_shell Tube_Len

Baffle_Space Tube_th

Main Effects Plot for Weight_HEData Means

First DOE: Pareto Charts

BC

CD

C

BD

B

D

50403020100

Term

Standardized Effect

2.06

B mdot_shellC Tube_LenD Baffle_Space

Factor Name

Pareto Chart of the Standardized Effects(response is DP shell, Alpha = 0.05)

mdot_shell

Baffle_Space

Tube_th

Tube_Len

160140120100806040200

Term

Standardized Effect

2.1

Pareto Chart of the Standardized Effects(response is q Calc, Alpha = 0.05)

BC

D

B

E

C

200150100500

Term

Standardized Effect

2.1

B mdot_shellC Tube_LenD Baffle_SpaceE Tube_th

Factor Name

Pareto Chart of the Standardized Effects(response is q (des - calc), Alpha = 0.05)

Tube_th

Tube_Len

80706050403020100

Term

Standardized Effect

2.05

Pareto Chart of the Standardized Effects(response is Weight_HE, Alpha = 0.05)

Tube_th

Tube_Len

50403020100

Term

Standardized Effect

2.05

Pareto Chart of the Standardized Effects(response is DP Tube, Alpha = 0.05)

First DOE: Optimization

CurHigh

Low0.93553D

Optimal

d = 0.96800

Targ: 8400.0Weight_H

y = 8451.2000

d = 0.97762

Targ: 5150000.0DP shell

y = 5.236E+06

d = 0.78200

Targ: 185.0DP Tube

y = 188.270

d = 0.98511

Targ: 3800000.0q Calc

y = 3.781E+06

d = 0.98300

Targ: 1300000.0q (des -

y = 1.303E+06

0.93553DesirabilityComposite

0.0007

0.0011

0.3905

0.6509

4.8750

8.1250

300.0

500.0Tube_LenBaffle_S Tube_thmdot_she

[302.0202][4.8750] [0.3905] [0.0007]

Second DOE: Main Effect Plots

0.4953000.371475

1000000

0

-1000000

1.238250.74295 2.51.5

0.02381250.0142875

1000000

0

-1000000

0.02750.0165

Baffle_Cut

Mean

Shell_ID I_Shell_mat

Tube_OD Shell_th

Main Effects Plot for q (Des - calc)Data Means

0.4953000.371475

5500000

5250000

5000000

4750000

45000001.238250.74295 2.51.5

0.02381250.0142875

5500000

5250000

5000000

4750000

45000000.02750.0165

Baffle_Cut

Mean

Shell_ID I_Shell_mat

Tube_OD Shell_th

Main Effects Plot for q DesiredData Means

0.4953000.371475

6500000

6000000

5500000

5000000

4500000

1.238250.74295 2.51.5

0.02381250.0142875

6500000

6000000

5500000

5000000

4500000

0.02750.0165

Baffle_Cut

Mean

Shell_ID I_Shell_mat

Tube_OD Shell_th

Main Effects Plot for q CalcData Means

0.4953000.371475

1000

750

500

250

01.238250.74295 2.51.5

0.02381250.0142875

1000

750

500

250

00.02750.0165

Baffle_Cut

Mean

Shell_ID I_Shell_mat

Tube_OD Shell_th

Main Effects Plot for DP TubeData Means

0.4953000.371475

8000000

7000000

6000000

5000000

40000001.238250.74295 2.51.5

0.02381250.0142875

8000000

7000000

6000000

5000000

40000000.02750.0165

Baffle_Cut

Mean

Shell_ID I_Shell_mat

Tube_OD Shell_th

Main Effects Plot for DP ShellData Means

0.4953000.371475

14000

12000

10000

80001.238250.74295 2.51.5

0.02381250.0142875

14000

12000

10000

8000

0.02750.0165

Baffle_Cut

Mean

Shell_ID I_Shell_mat

Tube_OD Shell_th

Main Effects Plot for Weight_HEData Means

Second DOE: Pareto Charts

BE

BC

CE

E

D

C

B

200150100500

Term

Standardized Effect

2.1

B Shell_IDC I _Shell_matD Tube_ODE Shell_th

Factor Name

Pareto Chart of the Standardized Effects(response is Weight_HE, Alpha = 0.05)

Shell_ID

Tube_OD

302520151050Te

rmStandardized Effect

2.05

Pareto Chart of the Standardized Effects(response is DP Shell, Alpha = 0.05)

Tube_OD

120010008006004002000

Term

Effect

Pareto Chart of the Effects(response is DP Tube, Alpha = 0.05)

Shell_ID

Tube_OD

100806040200

Term

Standardized Effect

2.0

Pareto Chart of the Standardized Effects(response is q Calc, Alpha = 0.05)

Shell_ID

Tube_OD

100806040200

Term

Standardized Effect

2.0

Pareto Chart of the Standardized Effects(response is q (Des - calc), Alpha = 0.05)

Second DOE: Optimization

CurHigh

Low0.84011D

Optimal

d = 0.99949

Targ: 11500.0Weight_H

y = 1.150E+04

d = 0.99223

Targ: 6500000.0DP Shell

y = 6.496E+06

d = 0.63891

Targ: 625.0DP Tube

y = 579.8636

d = 0.82195

Targ: 5500000.0q Calc

y = 5.411E+06

d = 0.70843

Targ: 5150000.0q Desire

y = 5.106E+06

Targ: -300000.0q (Des -

y = -3.05E+05

0.84011DesirabilityComposite

0.0165

0.0275

0.0143

0.0238

1.50

2.50

0.7430

1.2383

0.3715

0.4953Shell_ID I_Shell_ Tube_ODShell_thBaffle_C

[0.3715] [0.9631] [1.50] [0.0194] [0.0179]

Final: Main Effect Plots

375225

20000

18000

16000

14000

12000

7.54.5

1.238250.74295

20000

18000

16000

14000

12000

0.02381250.0142875

mdot_shell

Mean

Tube_len

Shell_ID Tube_OD

Main Effects Plot for Weight_HEData Means

375225

10000000

8000000

6000000

4000000

7.54.5

1.238250.74295

10000000

8000000

6000000

4000000

0.02381250.0142875

mdot_shell

Mean

Tube_len

Shell_ID Tube_OD

Main Effects Plot for DP ShellData Means

375225

2400

1800

1200

600

07.54.5

1.238250.74295

2400

1800

1200

600

00.02381250.0142875

mdot_shell

Mean

Tube_len

Shell_ID Tube_OD

Main Effects Plot for DP TubeData Means

375225

7000000

6000000

5000000

40000007.54.5

1.238250.74295

7000000

6000000

5000000

40000000.02381250.0142875

mdot_shell

Mean

Tube_len

Shell_ID Tube_OD

Main Effects Plot for q calcData Means

375225

5500000

5250000

5000000

4750000

45000007.54.5

1.238250.74295

5500000

5250000

5000000

4750000

45000000.02381250.0142875

mdot_shell

Mean

Tube_len

Shell_ID Tube_OD

Main Effects Plot for q desiredData Means

375225

1000000

0

-1000000

-2000000

7.54.5

1.238250.74295

1000000

0

-1000000

-2000000

0.02381250.0142875

mdot_shell

Mean

Tube_len

Shell_ID Tube_OD

Main Effects Plot for q (des - calc)Data Means

Final: Pareto Charts

BC

D

C

B

302520151050

Term

Standardized Effect

2.20

B Tube_lenC Shell_IDD Tube_OD

Factor Name

Pareto Chart of the Standardized Effects(response is Weight_HE, Alpha = 0.05)

Shell_ID

Tube_len

Tube_OD

mdot_shell

76543210

Term

Standardized Effect

2.201

Pareto Chart of the Standardized Effects(response is DP Shell, Alpha = 0.05)

Tube_len

Tube_OD

181614121086420

Term

Standardized Effect

2.16

Pareto Chart of the Standardized Effects(response is DP Tube, Alpha = 0.05)

CD

AD

C

A

BD

D

B

80706050403020100

Term

Standardized Effect

2.31

A mdot_shellB Tube_lenC Shell_IDD Tube_OD

Factor Name

Pareto Chart of the Standardized Effects(response is q (des - calc), Alpha = 0.05)

AC

BCD

ABD

BC

AB

CD

AD

C

A

BD

D

B

300250200150100500

Term

Standardized Effect

3.2

A mdot_shellB Tube_lenC Shell_IDD Tube_OD

Factor Name

Pareto Chart of the Standardized Effects(response is q (des - calc), Alpha = 0.05)

Final: Optimization

Final Variables Calculated

• Desired/Calculated Heat Transfer Rate = 1.00• Overall System Weight = 14382.27 kg• Tube-side Pressure Drop = 417.46 Pa• Shell-side Pressure Drop = 3092917.05 Pa

Questions