Enhancement of low grade waste heat recovery from a fuel cell using a thermoelectric generator module with swirl flows

Abstract

This research analysed the enhancement to the power output of a thermoelectric generator (TEG) module in converting waste heat from a low temperature Polymer Electrolyte Membrane fuel cell into electricity assisted by swirl flows (swirl strength from 1.2 to 1.6). The module was constructed using a single TEG cell, a heat pipe and a finned heat sink. The study applied the scenario where the fuel cell operated as the power source for a mini fuel cell vehicle. This scenario provided a practical evaluation of the module performance as the hot stream temperature was varied due to the changes in fuel cell power while the cooling air varied according to the vehicle drive speed. The maximum power was enhanced from 200 μW (for non-swirl condition at 60 °C) to 3056 μW as the swirl strength increased to 1.6. Significant power enhancement factor by 8–17 in stationary mode and between a factor of 1.4–2.2 at the speed of 10 ms−1 were obtained with a non-linear relationship to the swirl strengths and cooling modes. Therefore, the introduction of swirl to the hot air stream is a viable approach to provide significant enhancements in low grade waste heat recovery using TEG.