Project 13441: Cook Stove for Haiti
Transcript of Project 13441: Cook Stove for Haiti
Agenda
• Team Introduction
• Project Statement
• Project Goals
• Key Customer Needs and Specifications
• System Architecture
• Concept Summary
• Testing and Test Results
• Final Bill of Materials
• Final Prototype
• Results vs. Specifications
• Lessons Learned
• Suggestions for Future Work
Guide and Team Members
Guide
• Sarah Brownell
Customer
• Dr. Robert Stevens
Team Members
• Kim Hunt, ISE (Project Manager)
• Andrew Rietz, ME
• Matt Starowitz, ME
• Tyler Smith, ME
• Matt Aloisio, EE
• Biruk Kifle, EE
Project Statement
The goal of this project is to build on the work done by previous projects P10461, 11461, 11462, 12441, and 12442 to design and fabricate an improved thermoelectric charcoal cook stove that will substantially reduce the emissions and fuel needed for cooking compared to the traditional stoves currently used in Haiti and is also capable of charging cell phones.
Project Objectives
The stove was designed to improve the quality of life for Haitians by:
• Reducing the cost of cooking by reducing the fuel use by 25%
• Reducing the CO emissions and particulate matter (PM) by 25%
• Allowing locals to easily manufacture and sell the stove
• Being intuitive and enhance conventional Haitian cooking techniques
• Providing an electrical power source capable of charging cell phones
• Improving air quality by reducing harmful emissions and particulates
Importance Level 9 Importance Level 3 Importance Level 1
- Affordable for Haitians
- Cheap to operate - Cleaner emissions
(CO and particulate matter)
- Safe to operate - Fan can provide force
air during operation - Uses less fuel
(charcoal) than current stove
- Easy to operate - Able to control cooking
ability - Tip resistant - Capable of being dropped - Thermoelectric module
(TEM) can withstand failure - Able to charge cell phones - Fan is capable of restarting - Mains appropriate
temperature gradient across TEM
- Achieves desired temperature gradient quickly
- Capable of being fabricated and assembled using Haitian artisan practices
- Can withstand harsh conditions
- Portable
Key Customer Needs
Key Engineering Specifications Specification Unit of Measure Ideal Value
Production Cost USD <$30
Fuel Use % reductions in kg >25%
CO Emissions % reduction in ppm >25%
Particulate Matter (PM) % reduction in grams >25%
Minimum temp. gradient for TEM
°C >200°
Pot diameters to be placed on stove
cm 60
Cell phones charged # of phones 2
Stove Weight kg <8
Surfaces touched by operator
°C <50°
Concept Summary - ME
Combustion chamber
Where pot sits
Fan
TEM
Cold air chimney
Hot air chimney
Skirt
Insulation
Testing - ME
• 6 Modified Water Boil Tests were performed
• Hot side chimney temperature
• Hot side heat sink temperature
• Cold side heat sink temperature
• TEM output voltage
Test Results - EE
• MPPT out in relation to various input
4.2V input with 7.24V output 6.73V input with 7.25V
output
Final Bill of Materials - ME
ME Total Price: With Steel = $75.43
W/O Steel = $38.58
* Prices for handles not included
Component Value Manuf Manuf Part NoQty per
Stove
Parts /
UnitUnit Price
Price per
1k Parts
Price per
Stove
Fan 50 Pa Sanyo Denki USA 9GA0412P6G001 1 14.28$ 14.28$
Heat Sink 0.6 resistanceBirmingham
Aluminum8052HS 2 2 32.47$ 4.72$ 9.44$
Steel Sheet Metal 4'x8' Metals Depot S116 18.1 32 65.28$ 36.92$
Steel tubing 1" x 1" Home Depot 12" 48" 4.00$ 4.00$
TEM 40mm x 40mm Thermonanic TE TEP1-1264-1.5 1 1 8.00$ 8.00$ 8.00$
Duct Bolt 3/8" - 16 McMaster Carr 91309A622 4 100 7.56$ 0.30$
Duct Nut 3/8" - 16 McMaster Carr 93827A225 4 100 13.11$ 0.52$
Rigid Insulation 1.65"x1.97" Cotronics Corp 360-5HS 2 264 130.00$ 0.98$ 1.96$
Total 75.43$
Final Bill of Materials - EE Component Package Value Manuf Manuf Part No Distrib Distrib Part No Qty Price per 1k Price per board
Resistor 0603 SM 4M Stackpole Electronics Inc RMCF0603JT4M0 Digikey RMCF0603JT4M0CT-ND 1 0.01$ 0.01$
Resistor 0603 SM 4.12M Stackpole Electronics Inc RMCF0603JT4M12 Digikey RMCF0603JT4M12CT-ND 1 0.01$ 0.01$
Resistor 0603 SM 33.2k Stackpole Electronics Inc RMCF0603JT33K2 Digikey RMCF0603JT33K2CT-ND 1 0.01$ 0.01$
Resistor 0603 SM 32.4k Stackpole Electronics Inc RMCF0603JT32K3 Digikey RMCF0603JT32K2CT-ND 1 0.01$ 0.01$
Resistor 0603 SM 3.32M Stackpole Electronics Inc RMCF0603JT3M32 Digikey RMCF0603JT3M32CT-ND 1 0.01$ 0.01$
Resistor 0603 SM 2M Stackpole Electronics Inc RMCF0603JT2M00 Digikey RMCF0603JT2M00CT-ND 1 0.01$ 0.01$
Resistor 0603 SM 2.7k Stackpole Electronics Inc RMCF0603JT2K70 Digikey RMCF0603JT2K70CT-ND 1 0.01$ 0.01$
Resistor 0603 SM 17.4k Stackpole Electronics Inc RMCF0603JT17K4 Digikey RMCF0603JT17K4CT-ND 1 0.01$ 0.01$
Resistor 0603 SM 10k Stackpole Electronics Inc RMCF0603JT10K0 Digikey RMCF0603JT10K0CT-ND 1 0.01$ 0.01$
Resistor 0603 SM 100k Stackpole Electronics Inc RMCF0603JT100K0 Digikey RMCF0603JT100K0CT-ND 1 0.01$ 0.01$
Resistor 0603 SM 1.2k Stackpole Electronics Inc RMCF0603JT1K20 Digikey RMCF0603JT1K20CT-ND 1 0.01$ 0.01$
Resistor 0603 SM 500 Stackpole Electronics Inc RMCF0603JT500R Digikey RMCF0603JT500RCT-ND 1 0.01$ 0.01$
Resistor 0603 SM 200k Stackpole Electronics Inc RMCF0603JT200K0 Digikey RMCF0603JT200K0CT-ND 2 0.01$ 0.02$
Resistor 0603 SM 150k Stackpole Electronics Inc RMCF0603JT150K0 Digikey RMCF0603JT150K0CT-ND 2 0.01$ 0.02$
Resistor 0603 SM 65k Stackpole Electronics Inc RMCF0603JT65K0 Digikey RMCF0603JT65K0CT-ND 3 0.01$ 0.03$
Resistor 0603 SM 1k Stackpole Electronics Inc RMCF0603JT1K0 Digikey RMCF0603JT1K0CT-ND 3 0.01$ 0.03$
Capacitor 0404 TH 22u Panasonic Electronic Components ECA-1HM220I Digikey P10426TB-ND 1 0.04$ 0.04$
Resistor 0603 SM 1M Stackpole Electronics Inc RMCF0603JT1M00 Digikey RMCF0603JT1M00CT-ND 4 0.01$ 0.04$
Capacitor 0404 TH 10u Panasonic Electronic Components ECA-1HM100I Digikey P10425TB-ND 3 0.03$ 0.09$
Capacitor 0402 SM 39p Yageo CC0402JRNPO9BN390 Digikey 311-1009-2-ND 1 0.10$ 0.10$
Capacitor 0404 TH 100u Panasonic Electronic Components ECA-1AM101I Digikey P10404TB-ND 4 0.03$ 0.12$
Capacitor 0402 SM 0.1u Yageo CC0402KRX7R7BB104 Digikey 311-1047-1-ND 2 0.10$ 0.20$
Push button TH C&K Components PS12F91AF3.3NS Digikey PS12F91AF3.3NS-ND 1 0.26$ 0.26$
Inductor SM 10u Abracon Corporation AIML-0603-100K-T Digikey 535-11587-1-ND 4 0.07$ 0.28$
Capacitor 0402 SM 0.01u Yageo CC0402KRX7R7BB103 Digikey 311-1042-1-ND 3 0.10$ 0.30$
LM317 TH Texas Insturments LM317KCS Digikey 296-13869-5-ND 1 0.32$ 0.32$
Cap Alum TH 68u Panasonic Electronic Components ECE-A0JKG680 Digikey P903-ND 2 0.26$ 0.52$
Diode TH ON Semiconductors MR852RLG Digikey MR852RLGOSTR-ND 6 0.09$ 0.54$
Pot Rotary 1k Bourns Inc PDB181-K420K-102B Digikey PDB181-K420K-102B-ND 1 0.79$ 0.79$
Gate Driver SM Texas Insturments UCC27517DBVR Digikey UCC27517DBVR-ND 2 0.65$ 1.30$
LM2621 8-MSOP Texas Insturments LM2621MM/NOPB Digikey LM2621MM/NOPBTR-ND 2 0.73$ 1.46$
555 Timer 8-SOIC Texas Insturments NA555PE4 Digikey NA555PE4-ND 4 0.11$ 0.44$
N-channel FET TH STMicroelectronics STP16NF06 Digikey 497-2766-5-ND 5 0.35$ 1.75$
Inductor TH 1mH Bourns Inc 2300LL-102-V-RC Digikey 2300LL-102-V-RC-ND 1 3.75$ 3.75$
Battery 6 Universal Power UB645 batts.com UPG-D5733-BTX-92927 1 5.22$ 5.22$
MAX8211 8-DIP Maxim Integrated MAX8211CPA+ Digikey MAX8211CPA+-ND 3 1.81$ 5.43$
Total $23.17
EE Total Price: $23.17
Final Bill of Materials – ME+EE
Total Price:
ME With Steel = $75.43
EE Comp. = $23.17
$98.60
ME W/O Steel = $38.58
EE Comp. = $23.17
$61.75
* Prices for handles not included
Results vs. Specifications Source Specification
Unit of Measure
Marginal Value
Ideal Value Results
S1 CN1 Production Cost USD $ 30 <30 $98.60/$61.75
S2 CN2 Fuel Use % reduction 25 >50 -13.30%
S3 CN3 CO Emissions % reduction 7525 >75 33%
S4 CN3 Particulate Matter (PM) % reduction 25 >75 -147.70%
S5 CN4, CN20 Time to Boil for WBT time current time <3/4 current
time 26.60%
S6 CN16 Surfaces on the stove that the operator has to touch
°C 50 <50 No
S8 CN4 Heat output range (heat transferred to TEM) J 175-200 200 Yes
S9 CN20 Pot diameters to be placed on stove cm 20-60 20-60
S10 CN20 Pot mass to be placed on stove kg 25 >25 Yes
S11 CN4 Required tasks to maintain fire throughout a CCT tasks 5 or less Yes
S12 CN1, CN2 Cost of combustion chamber to be replaced within 3 yr stove life
USD $ 3 <3 No
S13 CN6 Time required to replace parts (within 3 yr stove life)
min 60 <60 No
S14 CN6 Replaceable parts able to be replaced with no or simple hand tools
Yes/No Yes Yes
S15 CN7, CN16,
CN21 Stove weight kg 8kg <8 23
S16 CN7 Stove volume m3 0.2 <0.2 No
S17 CN6 Stove construction should be able to be done using basic Haitian fabrication skills and tools
% 50 100 Yes
Results vs. Specifications
S18 CN11 Drop test (height and quantity) meter/# of
drops 2 &20 >2 or 20 n/a
S19 CN5 Water Temperature during Simmer Test °C 82-92 92-94 No
S20 CN19 Charge cell phones and battery mAh No
S21 CN14 Fan is on during entire stove operation Yes/No Yes Yes n/a
S22 CN13 Power generated for cell phones Wh 8 n/a
S23 CN15 Power for fan to restart following battery shortage
V n/a
S24 CN7,
Internal Power pack package size inches 3"x3"x1.5" n/a
S25 CN7,
Internal Power pack weight lbs 3 <3 n/a
S26 CN8, CN12 Water resistance spec (prevent damage during downpour)
min 20 30 n/a
S27 CN10, CN16 Stove resistance to being knocked over including pot with water on stove
lbs 5 10 Yes
S28 CN10 Stove resistance to tipping over due to unequal weight distribution on top of stove (i.e. pot too far to one side)
lbs 5 10 Yes
S29 CN13 Uses a standard USB connection Yes/No 5V Yes Yes Yes
S30 CN17 Minimum temperature gradient °C 200 >200 Yes
S31 CN18 Time to reach temperature gradient min 20 <20 Yes
S32 Internal Power consumption to operate fan Watt 1 <0.6 Yes
S33 CN12 Max thermoelectric module temperature °C 380 Yes
S34 CN12 Max thermoelectric module temperature difference
°C 400 Yes
S35 CN12 Ideal minimum thermoelectic module temperature
°C 200 200 Yes
S35 CN22 Fuel Capacity in Combustion Chamber kg 1 >1 1
Lessons Learned - EE
• The need for gate drivers • Inductor with higher current rating • Heat sink for high switch power FETs • putting all test equipment on the appropriate
setting • Need for adequate dead time in timing circuit • Testing over entire range of expected operation
Lessons Learned - ME
• Convective heat transfer works
• Proper sandwiching of TEM is important
• Thermal mass makes a big difference
Lessons Learned – ISE/PM
• Order parts early and utilize resources who have experience ordering parts
• Track the progress of the project better compared to what was planned
• Especially during the building phase
• Keep better meeting notes and document group decisions made
Recommendations
• Use uController !!!
• start early with design and procedure. Will need the time for debugging.
• Find someone with background knowledge on MPPT or related topic (solar systems . . . maybe)
• Don't reinvent the wheel. Use the already tested and working subsystems and focus energy into areas that need improvement.