Experimental and Numerical Analysis of the Heat Dissipation Characteristics of a Battery Cabin of an Electrical Bus

This study aims to investigate the effects of the inlet and exhaust shape designs on the heat dissipation characteristics of battery cabins using experimental and numerical analysis. A field test of a pure electric bus was carried out to study the temperature distribution of its battery cabin. In addition, three different shape designs for the inlet and exhaust grilles, including horizontal stripe, vertical stripe and circular grille schemes, were proposed, and corresponding numerical models were established to analyse the heat dissipation characteristics of electric buses under two scenarios: a typical city driving cycle and a low driving speed on a slope. The results indicate that the temperature difference within the same bus battery cabin can reach 8 °C due to heat accumulation and an airflow band can be clearly identified at the inlet for the cases of horizontal stripe and circular grilles. Under the premise that the operating conditions and inlet section remain the same, the airflow and inlet volume for the case with a circular grille flow faster than those for the other cases; therefore, this scheme can achieve the optimal heat dissipation, while the vertical stripe grille is the least ideal design.