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1. Design Project 1 Equalized Velocity for Automobile Climate Control
2. Ductwork Layout
4. Fittings
5. Ductwork Design All Material ABS Plastic
Investigate changing 45 deg miters to 45 deg sweeping elbows
All materials readily available
ABS Plastic prices:
$0.76 per foot for tubing
$1.246 for 90deg bend
$0.98 for 45deg miter
6. Output Data No significant variance in velocity from vents 1 and 3
Variances in vent 2 are offset by increase of Volumetric Flow
7. Questions?
8. Design Project 2Heat Exchanger Design
9. Project Background Cooling an industrial chemical by 15 oC
Mass flow rate of chemical is 120,000 kg/hr
Chemical enters h.e. at 40 oC and exits at 25 oC
Chemical properties approximated as water
Coolant used is treated city water at 20 oC
Mass flow rate of coolant is adjustable
10. Design Requirements Cool the liquid chemical from 40oC to 25oC
Heat exchanger length can not exceed 7 m
Heat exchanger shell diameter can not exceed 2 m
Minimize heat exchanger shell and tube weight hence the cost
Minimize heat exchanger pressure drop
11. Initial Design Decisions Chose a parallel over counter-flow design
Mass flow rate in the shell was becoming excessive with counter-flow design
Internal shell pressure was much higher with counter-flow
These would have added significantly to overall weight and cost to avoid…
13. Design of Experiments The seven parameters at the start of the MINITAB DOE:
Tube length (4.8 - 7.2 m)
Tube OD (9.52 - 15.875 mm)
Shell ID (0.3784 - 0.4890 m)
Nusselt Number (Dittus-Boelter, Petukkov-Kirillov)
Baffle (Yes, No)
Baffle Spacing (160 – 240 mm)
Mass flow through shell (31.11 – 45.55 Kg/s)
Used MINITAB tools to reduce variable design parameters to:
Tube length
Tube OD
Shell ID
14. Final Design Pareto Charts
15. Heat Exchanger Performance
16. H.E. Over-design Desired heat transfer rate: 2.088 MW
Calculated heat transfer rate: 2.116 MW
Over-design of: 27.3 kW
Desired to Calculated Ratio = 0.99
17. H.E. Overdesign – Effects of Fouling
18. Fouling Images
19. Questions?