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Shell and Tube Heat Exchanger. Frank Faulkenberg Jimmy Huser John Snodgrass Eric Bush David Giles. ME 414: Thermal Fluids. - PowerPoint PPT Presentation
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Shell and Tube Heat ExchangerShell and Tube Heat Exchanger
Frank FaulkenbergFrank FaulkenbergJimmy HuserJimmy HuserJohn SnodgrassJohn SnodgrassEric BushEric BushDavid GilesDavid Giles
ME 414: Thermal Fluids
Problem StatementProblem Statement
Design a heat exchanger to meet the Design a heat exchanger to meet the customer requirements for heat customer requirements for heat
transfer and maximum dimensions, transfer and maximum dimensions, while optimizing the weight and while optimizing the weight and
pressure losses in both the tube and pressure losses in both the tube and shell sides.shell sides.
Project DefinitionProject Definition Chemical Specifications:Chemical Specifications:
• Temperature must be reduced from 40°C to Temperature must be reduced from 40°C to 25°C25°C
• Mass flow rate is 120,000 kg/hrMass flow rate is 120,000 kg/hr• Material properties closely approximate that of Material properties closely approximate that of
waterwater Cooling Water Specifications:Cooling Water Specifications:
• Treated city water at 20°CTreated city water at 20°C• Mass flow rate is not fixedMass flow rate is not fixed• Exit temperature is function of designExit temperature is function of design
Customer RequirementsCustomer Requirements Must cool the chemical from 40 C to 25 CMust cool the chemical from 40 C to 25 C Heat exchanger length can not exceed 7mHeat exchanger length can not exceed 7m Heat exchanger shell diameter can not Heat exchanger shell diameter can not
exceed 2mexceed 2m Minimize heat exchanger shell and tube Minimize heat exchanger shell and tube
weight hence the costweight hence the cost Minimize heat exchanger pressure dropMinimize heat exchanger pressure drop
AnalysisAnalysis MatlabMatlab
Used to run code Used to run code that takes the that takes the input variables that input variables that affect exchanger affect exchanger performance and performance and returns numerical returns numerical values for the values for the performance of the performance of the exchangerexchanger
MinitabMinitabUsed to statistically Used to statistically analyze the results analyze the results from Matlab to from Matlab to narrow down the narrow down the input variables to input variables to those that have the those that have the greatest affect of greatest affect of exchanger exchanger performance.performance.
First TrialFirst Trial
Total heat exchanger weight = 4384.68 kgTotal heat exchanger weight = 4384.68 kg Desired Heat Transfer Rate = 2088969 WDesired Heat Transfer Rate = 2088969 W Calculated Heat Transfer Rate = 2084742 WCalculated Heat Transfer Rate = 2084742 W Difference = 4227.48 WDifference = 4227.48 W Desired-to-Calculated Ratio = 1.00 Desired-to-Calculated Ratio = 1.00 Shell Side Delta-P = 9875.34 Pa Shell Side Delta-P = 9875.34 Pa Tube Side Delta-P = 134.48 Pa Tube Side Delta-P = 134.48 Pa
Analyzing dataAnalyzing data
GoodGood
• Light in weightLight in weight
• Good pressure drops Good pressure drops
• Achieved desired-to-calculated ratioAchieved desired-to-calculated ratio
Analyzing dataAnalyzing data BadBad
• Further inspection shows that this design is Further inspection shows that this design is impossible.impossible.
Inlet (°C) Outlet (°C)
Tube 40 25
Shell 20 32
•Shell side outlet cannot be greater than the tube side outlet for a parallel heat exchanger.
•For parallel flow, a shell mass flow rate of ~400000 kg/hr must be used to satisfy this condition
Second TrialSecond Trial Parallel flowParallel flow No bafflesNo baffles About 4 meters in lengthAbout 4 meters in length
Analyzing DataAnalyzing DataGood:Good: Yielded very low weightYielded very low weight Very low pressure dropsVery low pressure drops Desired heat transferDesired heat transfer
Bad:Bad: Impossible design in realityImpossible design in reality Structurally unsound, tubes would sagStructurally unsound, tubes would sag
Critical Parameter Flow DownCritical Parameter Flow Down 14 parameters14 parameters
7 factor DOE7 factor DOE
4 factor DOE4 factor DOE
Initial ParametersInitial Parameters Tube lengthTube length Tube diameter Tube diameter
(OD)(OD) Shell diameter (ID)Shell diameter (ID) Mass Flow Rate of Mass Flow Rate of
cooling watercooling water Pipe layout Pipe layout Baffle SpacingBaffle Spacing Shell materialShell material
Tube materialTube material Shell thicknessShell thickness Tube thicknessTube thickness Flow configuration Flow configuration
(counter, parallel)(counter, parallel) Pipe layout anglePipe layout angle Number of TubesNumber of Tubes Tube PitchTube Pitch
11stst DOE DOE Tube lengthTube length Tube diameter Tube diameter
(OD)(OD) Shell diameter (ID)Shell diameter (ID) Mass Flow Rate of Mass Flow Rate of
cooling watercooling water Pipe layout Pipe layout Baffle SpacingBaffle Spacing Shell materialShell material
7 factor MEPs7 factor MEPsM
ean
of Q
_7
0.0146050.010795
1800000
1500000
12000000.963930.71247 7.07255.2275
38.33328.333
1800000
1500000
120000010 0.6000.402
212
1800000
1500000
1200000
Tube_OD_7 Shell_ID_7 tube_len_7
mdot_shell_7 sqr_tri_7 baffle_space_7
shell_mat_7
Main Effects Plot (data means) for Q_7
22ndnd DOE DOE Tube lengthTube length Tube diameter Tube diameter
(OD)(OD) Shell diameter (ID)Shell diameter (ID) Mass Flow Rate of Mass Flow Rate of
cooling watercooling water
4 factor MEPs4 factor MEPsM
ean
of Q
0.0146050.010795
1800000
1650000
1500000
1350000
12000000.963930.71247
7.07255.2275
1800000
1650000
1500000
1350000
120000038.33328.333
Tube_OD Shell_ID
Tube_Length mdot_shell
Main Effects Plot (data means) for Q
4 factor MEPs4 factor MEPsM
ean
of D
P_sh
ell
0.0146050.010795
12000
10000
8000
0.963930.71247
7.07255.2275
12000
10000
8000
38.33328.333
Tube_OD Shell_ID
Tube_Length mdot_shell
Main Effects Plot (data means) for DP_shell
4 factor MEPs4 factor MEPsM
ean
of w
eigh
t
0.0146050.010795
7000
6000
5000
40000.963930.71247
7.07255.2275
7000
6000
5000
400038.33328.333
Tube_OD Shell_ID
Tube_Length mdot_shell
Main Effects Plot (data means) for weight
4 factor MEPs4 factor MEPsM
ean
of D
P_tu
be
0.0146050.010795
1000
800
600
4000.963930.71247
7.07255.2275
1000
800
600
40038.33328.333
Tube_OD Shell_ID
Tube_Length mdot_shell
Main Effects Plot (data means) for DP_ tube
4-factor Interaction Plots4-factor Interaction Plots
Tube_OD
Tube_Length
mdot_shell
Shell_ID
0.963930.71247 7.07255.2275 38.33328.33315000
10000
500015000
10000
500015000
10000
5000
0.0107950.014605
Tube_OD
0.712470.96393
Shell_ID
5.22757.0725
Tube_Length
Interaction Plot (data means) for DP_shell
Pareto ChartsPareto ChartsTe
rm
Effect
ABCDABCBCDABDACD
BCABACBDCDAD
BCAD
500040003000200010000
1202A Tube_ODB Shell_IDC Tube_LengthD mdot_shell
Factor Name
Pareto Chart of the Effects(response is DP_shell, Alpha = .10)
Lenth's PSE = 596.751
Final DesignFinal Design1 shell pass1 shell pass 1 tube pass1 tube passShell material = AlShell material = Al Tube material = AlTube material = AlMdot_shell = 120000 kg/hrMdot_shell = 120000 kg/hr Mdot_tube = 120000 kg/hrMdot_tube = 120000 kg/hrShell_ID = 0.8382 mShell_ID = 0.8382 m Tube_OD = 12.7 mmTube_OD = 12.7 mmShell_th = 19.05 mmShell_th = 19.05 mm Tube_th = 20 BWGTube_th = 20 BWGBaffle spacing= 0.6*Shell_IDBaffle spacing= 0.6*Shell_ID Tube pitch = 1.4*Tube_ODTube pitch = 1.4*Tube_ODBaffle cut = 25%Baffle cut = 25% 30° Triangular layout30° Triangular layout
Expected PerformanceExpected Performance
Total heat exchanger weight Total heat exchanger weight 48684868 kg kg Desired Heat Transfer Rate 2088969 WDesired Heat Transfer Rate 2088969 W Calculated Heat Transfer Rate 2095309 WCalculated Heat Transfer Rate 2095309 W Difference Difference -6340 W -6340 W Desired-to-Calculated Ratio 1.00 Desired-to-Calculated Ratio 1.00 Shell Side Delta-P Shell Side Delta-P 9228 Pa 9228 Pa Tube Side Delta-P Tube Side Delta-P 556 Pa 556 Pa
ReferencesReferences
[1] Jones, Luke. “Minitab tutorial.”[1] Jones, Luke. “Minitab tutorial.”
[2] Toksoy, John. “Heat Exchanger Project – [2] Toksoy, John. “Heat Exchanger Project – fall 2006.”fall 2006.”
[3] Toksoy, John. “TFD-HE4 Log Mean [3] Toksoy, John. “TFD-HE4 Log Mean Temperature Difference.” fall 2006Temperature Difference.” fall 2006