Thermogalvanic Waste Heat Recovery System in Automobiles

Abstract

Recovering waste heat from automobiles remains an inviting subject for research. Solid-state thermoelectric generators (TEGs) have been widely investigated for this purpose, but their practical application remains challenging. An alternative to TEGs are thermogalvanic cells. Temperature difference between hot and cold electrodes creates a potential difference. Once connected to a load, electrical current and power are delivered, converting heat into electricity. In this work, we investigate the feasibility of incorporating such systems into automobiles. We carry out the experiments under real-world conditions. A climate-controlled wind tunnel is built to provide equivalent conditions to the ambient air stream under the car. The demonstrated system achieved a power density on the order of mW m−2. We compare the power generated to those of TEGs currently tested by GM, Honda, BMW and Ford. Further, a simple economic estimation is calculated to assess the $ per Watt cost of future practical thermogalvanic waste heat recovery system.

Experimental investigation of a U-tube thermocell under various Fe(CN)63−/4− concentration

“…Zhou and his group [26,27] introduced a thermocell with p-n configuration to harvest body heat. Owing to its flexibility, thermocell can be potentially used in curved surfaces such as pipe walls, which are very common in heat recovery energy systems [28,29]. The other potential application of this technology is as a replacement of conventional liquid cooling systems with the added benefit for electricity production as reported by Kazim et al [30].…”