Heat Exchanger Design

Logan SchaferDavid McGownMahmoud AbdelrazzaqMalhar DaveHeat Exchanger Design1Fixed VariablesN_tube_pass1The reason this factor was eliminated was because an increase in the number of tube passes dramatically increases the pressure drop which is an undesirable output. Rf_tube_in.00003The Tubes are Brand new so there is no fouling that has occurredI_Tube_Square_Pitch1Square is chosen because it is easier to clean and more efficient.Tube_Layout_Angle90Does not affect the D to C ratio when other angles are used and 90 degrees works with square pitches.I_Baffle0No baffles will be used because according to lecture notes the main purpose for baffles would be as a structural support for the tubes.Baffle_Spacen/aThere are no baffles to ease the cleaning and manufacturingBaffle_Cutn/aThere are no baffles to ease the cleaning and manufacturingN_shell_pass1Increasing the number of shell passes increases the weight of the shell and causes a dramatic pressure drop inside of the shellShell_th1.00E-03This variable was fixed because the effect that changing it has on the output is negligible.Rf_tube_shellside.00003The Shells are Brand new so there is no fouling that has occurredCenter_Tube_ODTube_ODOnly Helical Tubes will may have a larger center tube, this is for structural purposes thus for our purposes the Center tube OD will equal the Tube OD.I_Nusselt_shell11Does affect it in single run studies.I_Nusselt_tube5This is selected due to the Turbulent flow that occurs within the tube, this dramatically affects the D to C ratioI_Pressure_Shell1This is the default setting given in the textbook, does not affect the individual runsI_Pressure_Tube1This is the default given in the textbook. Other options that were tried do not affect the D to C ratioI_tube_matStainless SteelThe tube material was chosen to be the same as shell material due to Galvanic corrosion due to dissimilar metals in close contact.2Factors to be Considered using DOEFactorsInitial value for to achieve R=.97Variables remaining after first DOE (DOE 1 and 2)Variable remaining after last DOEFinal variable value after optimizationVariable factors DOE 2 originalTube_OD19.05 (mm)23.0947I_shell_matPure aluminumStainless steelShell_ID.2032 (m).1714mTube_th3.4 (mm).0005mDOE 1 originalTube_Len5.5 (m)6.8746mN_tube9067I_counter_flowparallelParallelmdot_shell10 kg/s10 I_tube_matPure aluminumSteel 3DOE 1 Comparison of 4 Variables

4DOE 1 Factorial Design Analysis

Weight

DP_shell

DP_tubeQ_calc5Optimization of DOE 1

6DOE 2 Comparison of 4 Variables

7DOE 2 Factorial Design AnalysisWeightDP_shellDP_tubeQ_calc

8Optimization of DOE 2

9Variables Considered

DOE 1

DOE 2Final DOE

Final DOE Comparison of 4 Variables

11Final DOE Factorial Design AnalysisWeightDP_shellDP_tubeQ_calc

12Optimization of the Final DOE

13Final Results of Variable Factors FactorsInitial value for to achieve R=.97Variables remaining after first DOE (DOE 1 and 2)Variable remaining after last DOEFinal variable value after optimizationDOE 2 originalTube_OD19.05 (mm)23.0947I_shell_matPure aluminumStainless steelShell_ID.2032 (m).1714mTube_th3.4 (mm).0005mDOE 1 originalTube_Len5.5 (m)6.8746mN_tube9067I_counter_flowparallelParallelmdot_shell10 kg/s10 I_tube_matPure aluminumSteel Final DOEValues from original DOEsTube_Len4.76396.8746N_tube8067Shell_ID0.2519.174Tube_th.0005.000514Questions?