Recuperation gain for a hydraulic energy storage in automotive applications

摘要

Vehicles with internal combustion engines waste a lot of energy during conventional braking. Therefore, energy recovery systems are needed to reduce the fuel consumption of these vehicles and improve sustianability. Here, a hydraulic energy storage system for such recuperation purposes in vehicles is considered. The complex processes inside such a system are mapped onto a simplified endoreversible model for the first time. Considering the different components of our system, we derive a differential equation system describing the recuperation process. Synthesizing these equations, we also derive an estimate for the full range operational behavior of the system for different driving cycles. Based on this data we calculate the recuperation gains which are 74% for a harmonic velocity profile, 18% for the Worldwide Harmonized Light Vehicles Test Procedure, and 9% for the New European Driving Cycle. Furthermore we discuss the recuperation gains for different parameter choices. The findings can be used to optimize design and process parameters of the powertrain.