ME 414 : Project 1

1. ME 414 : Project 1 May 5, 2006 Heating System for NASA North Pole Project Team Members Alan Benedict Jeffrey Jones Laura O’Hair Aaron Randall

2. Problem Statement Your job as a Thermal Fluid Systems engineer is to deliver the housing heating system in the North Pole. 4 occupants Oxygen supply tank or circulating fresh air from outside The outside temperature in North Pole is -40C and the desired temperature inside the housing is 25C. You have a space of 12” in the outside walls and 8” in the interior walls.

3. Deliverables • Lowest blower cost measured by the least system pressure drop • Least material cost measured by the number of sheets used • Least labor cost per the labor rates given • Least operating cost measured by the cost of maintenance items and monthly natural gas, oxygen, electricity, etc usage. • Most comfort to occupants measured by the least flow rate variation between registers

4. Supply Air System

5. Return Air System

6. Heat Loss Calculation Assumptions • All heat loss occurs through exterior walls and roof. • The structure is perfectly sealed. No transfer of air. • There is no heat transfer between rooms. • There is not heat transfer to or from the basement.

7. Interior Temperature 25˚C Exterior Temperature -40˚C Thermal Conductivity of Wall 0.8W/m˚C Convection Coefficients Interior surfaces Walls 4.2W/m2˚C Roof 5.17W/m2˚C Exterior All surfaces 34W/m2˚C Heat Loss Calculations

8. Used Resistance Network Results Roof Walls Heat Loss Room 1 7791.5W Room 2 10118.9W Room 3 6269.2W Room 4 7380.7W Room 5 8457.8W Total 40018.1W Heat Loss Calculations

9. Resistance Network Insulation Conductivity k=0.043W/m2˚C Results Roof Walls Heat Loss Room 1 489.9W Room 2 634.3W Room 3 394.4W Room 4 466.7W Room 5 534.8W Total 2520.1W = 8598.9Btu/h Heat Loss CalculationsWith Insulation Added

10. Heat Loss Rates • Heat loss rate through walls and roof: • 2520W • Heat loss rate through heating of outside air: • 72W

11. Insulation Cost Benefit Analysis • Cost to add insulation: • 12 inches in walls and roof • Total of 3501.1 ft3 insulation required • Cellulose insulation cost $0.387 per ft3 • Total cost to add insulation: $1354.07

12. Insulation Cost Benefit Analysis • Heat loss rate without insulation: • 40,018.1W • Heat loss rate with insulation: • 2,520.1W • Heat loss rate reduction: • 37,498W or 93.7%

13. Insulation Cost Benefit Analysis • 4 month cost to heat house without insulation • $20,903.11 • 4 month cost to heat house with insulation • $1,316.35 • 4 month savings: • $19,586.75 • Time to recover cost of insulating: • 8.4 days

14. Fresh Air or Oxygen Tank? • 4 month analysis of using bottled O2 • 5.3592 x 10-4 m3/s O2 consumption rate • 3000L volume of O2 in tank at 1atm • $1,050 per bottle material • $75 per bottle labor • COST • $2,112,750

15. Fresh Air or Oxygen Tank? • 1.6 ft3/min addition of outside air to interior • 5.3592 x 10-4 m3/s occupants • 7.7794 x 10-4 m3/s burning gas • -40°C air temperature • $0.045/ft3 cost for natural gas • COST • $32.28

16. Furnace and Blower • Gibson KG6RA Series Specifications • 45000 Btu/h • 80% Efficiency • Cost of $543

17. Furnace and Blower Blower Electrical Consumption and Cost for 4 months • Electricity Consumption • 1/5 hp = 149.14W • 149.14W*2880hrs = 429.5kWhrs • Operational Cost • 429.5kWhrs*$0.4/kWhr = $171.80

18. Materials • Duct Diameter • 7.43 inches • 3 ducts per each 90” X 70” sheet

19. Materials • Total sheets • 9 • 90 degree bends • 6 • Branches • 9 • Registers • 9

20. CIRCULAR DUCTS Material: $2,250.00 Labor: $2,400.00 Total $4,650.00 SQUARE DUCTS Material: $3,250.00 Labor: $2,600.00 Total $5,850.00 Material and Labor Costs

21. Problems not Overcome • Flowmaster • Flow rates in pump do not coincide with branch flow rate • Flow rates don’t produce results as expected

22. Flow Output of Pump Lower than First Branch

23. Register size vs. output discrepancy

24. Conclusion • Least Pressure Drop not achievable through Flowmaster • Least material cost calculated at $4147 • Least labor cost calculated at $2400 • Least operating cost calculated at $1488 • Flow rate variation between registers not achievable through Flowmaster

25. Questions?

26. ME 414 : Project 2 May 5, 2006 Heat Exchanger Optimization Team Members Alan Benedict Jeffrey Jones Laura O’Hair Aaron Randall

27. Problem Statement Design a heat exchanger to meet the customer requirements for heat transfer and maximum dimensions, while optimizing the weight and pressure losses in both the tube and shell sides.

28. Project Definition • Chemical Specifications: • Temperature must be reduced from 35°C to 25°C • Mass flow rate is 80,000 kg/hr • Material properties closely approximate that of water • Cooling Water Specifications: • Treated city water at 20°C • Mass flow rate is not fixed • Exit temperature is function of design

29. Customer Requirements • Must cool the chemical from 35 C to 25 C • Heat exchanger length can not exceed 7m • Heat exchanger shell diameter can not exceed 2m • Minimize heat exchanger shell and tube weight • Minimize heat exchanger pressure drop

30. Initial Design Specifications

31. Initial Results • Desired heat transfer rate of 928,502W • Calculated heat transfer rate of 924,068W • Difference of 4,434W • Desired-to-calculated ratio 0.995

32. First DOE Results

33. Initial Design Specifications

34. Final DOE Pareto Charts

35. Final DOE Optimization Without Baffles With Baffles

36. Specifications for Optimized Heat Exchanger • Counter flow design • Stainless steel material for shell and tube • Single pass shell • Single pass tube • Tube OD of 2.22cm (standard size) • Tube length of 3.06m • Tube thickness of 2.40mm • Tube pitch of 3.18cm • Square tube configuration with 90° layout angle • Shell ID of 1.90m • No baffles

37. Final Results

38. Conclusion • Met requirement to cool the chemical from 35 C to 25 C • Tube length of 3.06m 3.06m<7m • Shell diameter of 1.9m 1.9m<2m • Minimized heat exchanger shell and tube weight 26,150 kg • Minimized pressure drop • Shell side 16.72 Pa • Tube side 22.36 Pa

39. Questions?