The proton exchange membrane fuel cell (PEMFC) is a promising energy conversion device due to its high reliability, fast response speed, and low pollutant emission. However, the reality of its commercial application requires further cost reduction and efficiency improvement. The material distribution in the channel and the performance of PEMFC can be improved by setting the boss inside the flow channels. In this paper, the performance of PEMFC with the boss in flow channels in a parallel flow field was analyzed by simulation. The influence of different boss arrangements and heights on gas pressure drop, distribution uniformity, gas component distribution, temperature distribution, and output performance of the fuel cell were analyzed in detail. The bosses would increase the pressure drop and the distribution uniformity of reactive gases in flow channels significantly. The cross-arrangement of bosses is better than the cross-arrangement of bosses and juxtaposition according to increasing performance and pressure drop. The cross-arrangement with a boss height of 0.4 mm is suitable for the parallel flow field in this paper. The improved scheme of flow channel design is proposed to provide a reference for fuel cells for subsequent research.

To further improve the performance of the Proton Exchange Membrane Fuel Cell (PEMFC), in this paper, we designed a blocked flow channel with trapezoidal baffles, and geometric parameters of the baffle were optimized based on CFD simulation, Artificial Neural Network (ANN), and single-objective optimization methods. The analysis of velocity, pressure, and oxygen distribution in the cathode flow channel shows that the optimized trapezoidal baffle can improve oxygen transport during the reaction. The comparison of the optimization model with the straight flow channel model and the rectangular baffle model shows that the power density of the optimized model is 4.0% higher than that of the straight flow channel model at a voltage of 0.3 V, and the pressure drop is only 37.83% of that of the rectangular baffle model. For on-road PEMFC with a voltage of 0.6 V, the influence of pump power is significant, and the optimized trapezoidal baffle model has a net power increase of 1.47% compared to the rectangular baffle model at 50% pump efficiency and 3.94% at 30% pump efficiency.

Improving the thermal efficiency of truck diesel engines requires comprehensive optimization of the engine, exhaust aftertreatment (EAT), and possible waste heat recovery (WHR). Lower exhaust temperature at mid and low working points has caused difficulty in both emission clarification and heat recovery, which requires thermal management. Based on the diesel engine bench test and separate bench tests, this paper focuses on the thermal management strategy optimization, to increase the exhaust temperature at lower working points and optimize the thermal efficiency of the whole system. The test and numerical analysis showed that as exhaust temperature increased from 200~250 °C to 300~350 °C, soot passive regeneration reactions were enhanced, nitrogen oxide emission decreased, and energy recovery was improved. Moderate throttle valve adjustment coupled with early post injection could effectively achieve the required temperature increase. The optimized thermal management strategy increased the fuel consumption rate by no more than 1%. Meanwhile, the WHR system output increased significantly, by 62.55% at a certain mid–low working point. System CO₂ emission decreased by an average of 5.4% at selected working points.