Development of Low-Cost Remote-Control Generators Based on BiTe Thermoelectric Modules

This paper presents a new thermogenerator based on moderate-temperature (up to 175°C) BiTe modules available on the open market. Despite this handicap relative to commercial thermogenerators based on high-temperature proprietary-technology PbBi modules (up to 560°C), this new design may become economically competitive due to its innovative thermal sink. Our thermal sink is based on a free-convection water loop built with standard tubing and household hot-water radiators, leading to a more practical, modular design. So, the specific cost of about 55,000 USD/kW obtained for this 120-W prototype is improved to 33,000 USD/kW for a 1-kW unit, which represents about half the price of commercial thermogenerators. Moreover, considering recently launched BiTe modules (that withstand up to 320°C), our proposition could have an even more favorable outlook.     

Novel Heat Controller for Thermogenerators Working on Uncontrolled Stoves

This paper describes the development of a thermogenerator designed for uncontrolled firewood household stoves. It was built on BiTe thermoelectric (TE) modules, and it uses a water pot as a cooling device that also serves as a hot water source. An original heat controller was developed; it has low thermal resistance (R) during low-power operation, but its R can be continuously increased according to the stove temperature so that the TE never overheats while its power generation is optimized.     

Development of a Portable Thermogenerator for Uncontrolled Heat Sources

This paper presents the development of a portable thermogenerator designed to work on uncontrolled heat sources. Its thermal behavior regarding both steady-state and transient regimens was analytically described and numerically solved by using a lumped capacity model. The ranges of heating power and power increasing rates have been determined to ensure safe operation, or give users advance warning in case of failure. In addition, this model is a useful tool for designing a controller system based on which a feasible thermogenerator can be developed. Experimental tests performed on a prototype based on a commercial BiTe module have demonstrated this goal.     

Development of thermoelectric generators for electrification of isolated rural homes

This work presents the experimental development of the first two prototypes of thermoelectric generators intended for initial electrification of rural isolated homes. The microcontroller system designed for these devices is oriented to develop a “plug and play” generator that is able to work on firewood home stoves without specialized supervision.     

Solid-state NMR Evidence of 4-, 5, and 6-Fold Aluminum Sites in Roller-Quenched SiO2-A12O3 Glasses

The structures of roller-quenched SiO₂-Al₂O₃ glasses containing 10 to 50 wt% Al₂O₃ were investigated by TEM and high-resolution ²⁷Al and ²⁹Si magic angle sample spinning nuclear magnetic resonance (MASS-NMR) spectroscopy. The chemical shifts observed in the NMR spectra of these phase-separated (on the TEM scale) glasses provide evidence, for the existence of all three (4-, 5-, and 6-jold) Al-coordination units in these glasses and for the presence of A1 in both the Si-rich and Si-poor phases.