ME 414 : Project 1

1
ME 414 Project 1

• Heating System for NASA North
  Pole Project

May 5, 2006
Team Members Alan Benedict Jeffrey Jones Laura
OHair 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
Heat Loss Calculations

• Interior Temperature
• 25C
• Exterior Temperature
• -40C
• Thermal Conductivity of Wall
• 0.8W/mC

• Convection Coefficients
• Interior surfaces
• Walls 4.2W/m2C
• Roof 5.17W/m2C
• Exterior
• All surfaces 34W/m2C

8
Heat Loss Calculations

• 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

9
Heat Loss Calculations With Insulation Added

• Resistance Network
• Insulation Conductivity
• k0.043W/m2C
• 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

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
• -40C 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
• 149.14W2880hrs 429.5kWhrs
• Operational Cost
• 429.5kWhrs0.4/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
Material and Labor Costs

• 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

21
Problems not Overcome

• Flowmaster
• Flow rates in pump do not coincide with branch
  flow rate
• Flow rates dont 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

• Heat Exchanger Optimization

May 5, 2006
Team Members Alan Benedict Jeffrey Jones Laura
OHair 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 35C to 25C
• Mass flow rate is 80,000 kg/hr
• Material properties closely approximate that of
  water
• Cooling Water Specifications
• Treated city water at 20C
• 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
• Shell diameter of 1.9m 1.9m
• 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?