Optimization of Diesel Engine and After-treatment systems for a Series Hybrid Forklift Application
This paper investigates an optimal design of a diesel engine and after-treatment system for a series hybrid electric forklift application. A holistic modeling approach is developed in GT-Suite® to establish a model-based hardware definition for a diesel engine and after-treatment system that accurately predicts engine performance and emissions of a baseline system. The developed engine model performance is validated with the experimental data. Then, the engine design including compression ratio, boost level, air-fuel ratio (AFR), injection timing, and injection pressure is optimized at a single operating point for the series hybrid electric vehicle, while considering the performance of the after-treatment components. The engine and after-treatment models are then coupled with a series hybrid electric powertrain to evaluate the performance of the forklift in the standard VDI 2198 drive cycle.