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Remote Use Incubator Project • Jane Carver • Micah Chapman • Nick Laitsch • Trevor Ragsdale
Outline Ø Background Ø Goals and ObjecCves Ø Theory Ø Casing and InsulaCon Ø HeaCng Methods Ø TesCng Ø Results
Ø E.Coli (Escherichia coli) o Bacteria o 34˚C to 38˚C o OpCmum 37 ˚C o Indicates contaminaCon
3M Petrifilm Coliform Count Plate
Water TesCng
Ø Millipore Incubator o 33 cm x 37 cm x 30 cm o 48 petri dish storage o 8 kg with baUery o $1500
Ø Incubator used from 2004 to 2011 o Phase Change Material (PCM) o Amy Smith (MIT) o 37˚ C for 24 hours
ExisCng Technology
Goal and ObjecCves Ø Design and prototype a compact portable incubator capable of holding
a constant temperature for a 24 hour period.
o Maintain 36 ± 2°C for 24 hours o Not reliant on local electricity sources o Under $150 o Use less than 6 W-‐h for heaCng o Capable of 5 tests for trip o Fit 20 or less Petrifilms o Less than 8 kg o Less than 32 cm on a side o Must be durable and reliable
Theory
1st Law of Thermodynamics
∆"↓$%$ = "↓'( − "↓)*+ + "↓,
ConducCon .↓/012 =342+/26 ConvecCon .↓/017 =ℎ4↓9 ( +↓9 − +↓∞ )
RadiaCon .↓:;2 =<4↓9 ( +↓9↑4 − +↓∞↑4 )
k = thermal conducCvity h = convecCon coefficient < = Stephan-‐Boltzmann constant
0 >↓?@ − >↓ABC + >↓D =*>↓EFEGHI
InsulaCon Panels
k =.0025-‐.01 J/KL k = 0.02 -‐ 0.05 J/KL
Assuming k = 0.02-‐0.05 J/KL and a 22°C environment, This prototype is esCmated to lose 0.4-‐0.9 W-‐hr assuming steady state 1-‐D heat transfer.
HeaCng OpCons
Hybrid
Electric PCM
How PCM Works
Ø Entropy SoluCons PureTemp 37 PCM o Freezes over a range from 35.6 – 34.5 ᵒ C
Ø Cost o $100 per liter
PCM EncapsulaCon & Placement
125mL
125mL125mL
125mL
Electronics Housing
Petrifilm Cavity
IniCal Hybrid PCM Test
24 hours at 0.7°C 189.332 KJm = 853g
Number 125mL profiles= 8Cost = $102
Electronics
Circiut Board
Temperature RegulaCon
Power ≈2.8 W per plate
Electric HeaCng
Ambient at approximately 0.7 °C
User Interface
Hybrid
Ø 4 PCM profiles Ø Electric heaCng plates Ø Extends baUery life by 5x.
Incubator Test Results
Ø Theory vs. Reality • 90% accuracy
Ø Hardware o InfiltraCon o Durability tesCng
Ø Electronics o VibraCon o Electrical durability tesCng o conforms to JEDEC and IPR o specificaCons
Ø User
Conclusion Fit 10+ 3M Petri films Less than 8 kg Maintains 36 ± 2°C for 24 hours Use less than 6 W-‐h for heaCng Under $150 each Less than 32 cm on a side No external source of electricity needed Passed durability tesCng
Incubator Cost (USD)
PCM $120-‐200+
Electric $120-‐230+
Hybrid $150-‐300+
Hybrid Dimensions: 30.5 × 23 × 23 cm Weight: 1.65 kg w/o PCM
2.2 kg with PCM
Acknowledgements Project Advisor: Dr. Don May Project Funding: Dean Maureen Brandon EWB-‐FLC: Lynn May Water quality team Mentors: David Blake (Biology) Steve Chapman (ConstrucCon) Dr. Ron Estler (Chemistry) Monte Magill (Entropy SoluCons Liaison) Katy Phillips (Auto Cad) Dr. Andy Roubidoux (Engineering) Dr. Laurie Williams (Engineering) Lab Director: Tom Leps (Electronics and ConstrucCon assistance)
Questions?
References "WHO | Use of Improved Drinking Water Sources." World Health OrganizaJon, 2011. Web. <hUp://www.who.int/gho/mdg/environmental_sustainability/water_text/en/index.html>. Yokoigawa, Kumio, Akiko Takikawa, and Hiroyasu Kawai. "Difference between Escherichia Coli O157:H7 and Non-‐Pathogenic E. Coli: Survival and Growth in Seasonings." Journal of Bioscience and Bioengineering 88.5 (1999): 574-‐6. Print. Mukhopadhyaya, Kumaran, Normandin, Reenen, & Lackey. High-‐Performance Vacuum InsulaJon Panel: Development of AlternaCve Core Materials. Journal of Cold Regions Engineering. Dec 2008. Web. <hUp://web.ebscohost.com/ehost/pdfviewer/pdfviewer?sid=ef8e8bad-‐51bc-‐446a-‐85de-‐5bef79f44fc0%40sessionmgr111&vid=16&hid=105> "STYROFOAM™ Brand Scoreboard: Extruded Polystyrene Foam InsulaCon." Dow.com. The Dow Chemical Company. Web. S., Mondal. "Phase Change Materials for Smart TexJles – an Overview." Applied Thermal Engineering 28.11–12 (2008): 1536-‐50. Web. Zivkovic, B., and I. Fujii. "An Analysis of Isothermal Phase Change of Phase Change Material within Rectangular and Cylindrical Containers." Solar Energy 70.1 (2001): 51-‐61. Web. Motorola Semiconductor Data, Web. <hUp://www.datasheetcatalog.org/datasheet/motorola/MPX5700GS.pdf> NaConal Instruments, Web. <hUp://sine.ni.com/ds/app/doc/p/id/ds-‐198/lang/en>
Phase Change Material EutecCcs -‐ soluCons of salts in water Salt Hydrates -‐ salts that incorporate water into their crystalline structure Organic Materials -‐ long chain polymers composed primarily of carbon and hydrogen
PureTemp 37 – organic fully saturated faUy acid esters
BaUery Life
Test run in 23 °C room using electric heaCng elements
Behind the Scenes
Theory Aluminum 6061 – T6
Density 2700 kg/m3 Specific Heat 896 J/kg°C
Thermal ConducCvity 167 W/mK
Electrical ResisCvity 3.990E-‐08 ohm-‐m
Electrical ConducCvity
2.506E+07 S/m
Styrofoam Scoreboard Extruded Foam
Density 24.829 kg/m3 Specific Heat 1.21 J/kg°C
Thermal ConducCvity 0.028 W/mK
InteracCons 1-‐ Outside InsulaCon 2 -‐ Aluminum Plate Surface Film Cond. Surface Film Cond. 10 W/m^2K 5 W/m^2K Sink Temperature Sink Temperature 301.15 K 310.15 K Boundary CondiCons 1-‐ Outside InsulaCon
Surface 2-‐ Aluminum Plate
Surface 301.15 K 310.15 K
M↓N O+/OP =3Δ↑2 ++ ℎQ/4 ( +↓R − +↓∞ )
Theory
Heat Flux Magnitude vs. Time
1-‐D Thermal Resistance Network
.↓∞,1↦∞,2 = Δ+/ΣS
+↓∞,1
+↓∞,2
+↓∞,2 1/ℎ↓1 4 T/3↓1 4 T/3↓2 4 T/3↓3 4 1/ℎ↓2 4
Steady-‐state Constant properCes
Flow chart of Heat Transfer Problem in FEM
Controlling EquaCon
M↓N O+/OP =3Δ↑2 ++ ℎQ/4 ( +↓R − +↓∞ )
