Thermal uniformity enhancement of the motorcycle exhaust thermoelectric generator—Theory model for predicting heat exchanger fin profile

Abstract

This paper develops the theoretical model to predict the fin profile of the Hot-side heat exchanger (HHE) to enhance the uniformity of its longitudinal temperature distribution. The developed model can be applied to general cases where heat exchangers have different numbers, heights, pitches, and materials of fins, as well as the thermodynamic and heat transfer parameters of the working fluid. Numerical investigations of two fin profiles' thermal performance are conducted to validate the theoretical model. According to the results, the optimal profile improves the temperature uniformity by 91.3% compared to the original profile. The improvement in the temperature uniformity between thermoelectric modules (TEMs) can be achieved at the cost of reducing the thermoelectric generator unit power. The reductions in heat absorption of the HHE in the current study are not significant, varying from 1.3% to 2.9% at different engine speeds. However, the temperature uniformity can restrict the output power loss due to the significant differences in voltages and amperages produced by TEMs and also can eliminate the deterioration of TEMs’ lifespan.

Keywords

• Thermoelectric generator
• Thermal uniformity
• Fin profile
• Heat exchanger
• Muffler
• Prediction