Harvesting Waste Thermal Energy From Military Systems

Military systems greatly depend on the availability of energy. This energy comes mostly in the form of burning fuel in order to produce mechanical work or producing electricity. The ability to extract the most out of these systems aligns with the current focus of energy efficiency, not only in the military, but in society at large. In this research, an infrared camera was used to create an infrared map to infer temperature differences on a gasoline-powered generator at steady state operations. These temperature differences were inputted into an experimental phase during which a digitally-controlled hot plate, water block, variable resistor, and digital acquisitions system were used to measure current output from a single TEG for loads of 1, 10, and 100 Ω, respectively. Data were analyzed and the correlation coefficients determined. These coefficients were modeled a single module and then various array configurations for TEGs in COMSOL. Using the findings, a single commercial 56 mm by 56 mm Be₂Te₃ TEG can yield 0.72 W of power. Simple calculations yield 72 W of power when 100 modules are joined in 10 sets coupled in parallel with each set containing 10 modules in coupled in series. This would require 560 mm by 560 mm or approximately 2 ft. by 2 ft. of system space to be covered.