Young Jo Fontaine – ME Dan Higgins – EE Shawn Hoskins – ME Luke Poandl – EE Dan Scannell - ME

 Provide power for cookstove using thermoelectric generator (TEG)  Market: Rural Haitians High-level Customer Needs/Engineering Specs  Low cost Ideal: <$10 Marginal: <$50  TEG provides power Powers fan Recharges batteries Provides auxiliary power (i.e. cellphone charging)  System is intuitive Target customer can learn to use easily

STOVE THERMAL BRIDGE TEG BUCK-BOOST CONVERTER BATTERY AUXILIARY POWER FAN

Air flow from bottom Air has duct flows into bottom Flows around chamber Through holes into chamber Air flow into side Flow uses Heat sink as duct Flows around chamber Through holes into chamber

Calculated pressure drop from different systems Only slightly more pressure drop from side flow design Extra pressure drop due to losses through heatsink Side flow design is acceptable for use

Design to provide heat from heat pipe to hot side of TE Used Iterative design process Cut away extra material to keep heat transfer rate lower Mounts to heat sink with screws Heat pipe is screwed into center hole

Due to P3 Time constraint heat sink had to be made in house Used smallest and longest end mill Iterative process, heat sink didn’t provide enough cooling Scallop design used to increase surface area Fan mounts inside Heat sink serving double purpose Heat sink mounted to stove with custom L brackets Fan mounted to Heat sink with L brackets

 Primary Needs Run Fan (includes start up) Provide Auxiliary Power  Composed of: TEG Converters Batteries / Battery Charger Fan

 Taihuaxing TEP We 140Wth

 Fan 0.5W Stock Unit from Camp Stove  DC-DC Converters 5V & 3.3V Buck Boost Operate on Vin Switch up to 1.8A

 Future Implementation  Sample Open Circuit Voltage Determine Operating point of TEG Switch loads according to Voc  Components Comparators Accumulation Clock Latching MOSFET’s D-Flip Flops

 Prototype construction is complete Modifications to design were made as necessary  Thermal system provides close to target temperature difference Provides about °C; target was °C  TEG/electrical system does not provide expected power output Buck-boost converter may have failed  Testing will continue to attempt to get system working as intended

 Initially, electrical and mechanical systems were tested separately  Changes were made as seen fit  Two systems were then integrated for full system testing  More modifications were made based on results

 Mechanical Materials Cost: $85.84  Electrical Materials Cost: $  TEG Cost: $  Total Prototype Cost: $  Under mass production scale: $37.44

 Fan/duct provide proper airflow to combustion chamber  Mass production cost is estimated to be below marginal specification ($50)  System operation is controlled with simple toggle switch Must switch between battery and TEG power  No hazardous materials were used in construction

 Electrical system does not provide power required  Not all materials are readily available in Haiti  Unable to test lifetime of system  System is currently not integrated with P10461 stove

SUCCESSESFAILURES  Fan and heat sink/duct design provides proper airflow for combustion  TEG has previously been able to power the fan and provide some auxiliary power  TEG/electrical system does not provide enough power for all requirements  Ideal temperature difference is not achieved  System not currently integrated with prototype stove

 Investigate contact resistance of TEG  Attempt to build system out of more readily available materials  Convert system for use with P10461 stove  Sufficient heat sink design (in progress)  Implement autonomous controlled switching system