Design and Development of a Thermoelectric Cogeneration Device Integrated in Autonomous Gas Heaters

An autonomous heat-radiating gas heater for commercial outdoor environments has been selected as a test case for implementing cogeneration in autonomous gas heaters and stoves, permitting its installation and operation without the need of a connection to the electrical network. A thermoelectric generator (TEG) was selected for this purpose[1], designed for converting an amount of the produced heat into electrical power for auxiliary (ventilation, battery recharge) or ancillary functions (high efficiency LED illumination). The design approach, the layout and structure of the TEG are discussed, as well as the constraints for its integration in the existing gas heater. Design features and main components are examined: hot side heat collector for capturing heat from the flame; thermoelectric module (TEGM) technology and model selection; natural convection heat radiator at cold side; analysis and optimization of the thermal chain; TEG's assembly and its design as a whole. A prototype has been built and tested, its functional behavior has been modeled through multi-physics numerical simulation[2] to allow for further optimization and extrapolation of the results towards larger and/or more complex designs. A patent application has been issued jointly by the authors, covering the design hereinafter described.