Slide 1

Logan Schafer David McGown Mahmoud Abdelrazzaq Malhar Dave Heat Exchanger Design Slide 2 Fixed Variables N_tube_pass 1 The 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.00003 The Tubes are Brand new so there is no fouling that has occurred I_Tube_Square_Pitch 1 Square is chosen because it is easier to clean and more efficient. Tube_Layout_Angle 90 Does not affect the D to C ratio when other angles are used and 90 degrees works with square pitches. I_Baffle 0 No baffles will be used because according to lecture notes the main purpose for baffles would be as a structural support for the tubes. Baffle_Space n/a There are no baffles to ease the cleaning and manufacturing Baffle_Cut n/a There are no baffles to ease the cleaning and manufacturing N_shell_pass 1 Increasing the number of shell passes increases the weight of the shell and causes a dramatic pressure drop inside of the shell Shell_th 1.00E-03 This variable was fixed because the effect that changing it has on the output is negligible. Rf_tube_shellside.00003 The Shells are Brand new so there is no fouling that has occurred Center_Tube_OD Tube_OD Only 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_shell 11 Does affect it in single run studies. I_Nusselt_tube 5 This is selected due to the Turbulent flow that occurs within the tube, this dramatically affects the D to C ratio I_Pressure_Shell 1 This is the default setting given in the textbook, does not affect the individual runs I_Pressure_Tube 1 This is the default given in the textbook. Other options that were tried do not affect the D to C ratio I_tube_mat Stainless Steel The tube material was chosen to be the same as shell material due to Galvanic corrosion due to dissimilar metals in close contact. Slide 3 Factors to be Considered using DOE Factors Initial value for to achieve R=.97 Variables remaining after first DOE (DOE 1 and 2) Variable remaining after last DOE Final variable value after optimization Variable factors DOE 2 original Tube_OD 19.05 (mm)23.0947 I_shell_mat Pure aluminumStainless steel Shell_ID.2032 (m).1714m Tube_th 3.4 (mm).0005m DOE 1 original Tube_Len 5.5 (m)6.8746m N_tube 9067 I_counter_flow parallelParallel mdot_shell 10 kg/s10 I_tube_mat Pure aluminumSteel Slide 4 DOE 1 Comparison of 4 Variables Slide 5 DOE 1 Factorial Design Analysis WeightDP_shell DP_tubeQ_calc Slide 6 Optimization of DOE 1 Slide 7 DOE 2 Comparison of 4 Variables Slide 8 DOE 2 Factorial Design Analysis WeightDP_shell DP_tube Q_calc Slide 9 Optimization of DOE 2 Slide 10 Variables Considered DOE 1 DOE 2 Final DOE Slide 11 Final DOE Comparison of 4 Variables Slide 12 Final DOE Factorial Design Analysis WeightDP_shell DP_tubeQ_calc Slide 13 Optimization of the Final DOE Slide 14 Final Results of Variable Factors Factors Initial value for to achieve R=.97 Variables remaining after first DOE (DOE 1 and 2) Variable remaining after last DOE Final variable value after optimization DOE 2 original Tube_OD 19.05 (mm)23.0947 I_shell_mat Pure aluminumStainless steel Shell_ID.2032 (m).1714m Tube_th 3.4 (mm).0005m DOE 1 original Tube_Len 5.5 (m)6.8746m N_tube 9067 I_counter_flow parallelParallel mdot_shell 10 kg/s10 I_tube_mat Pure aluminumSteel Final DOE Values from original DOEs Tube_Len 4.76396.8746 N_tube 8067 Shell_ID 0.2519.174 Tube_th.0005 Slide 15 Questions?