Mild Hybrid Multi-Energy Systems: Waste Energy Recovery by Bottom ORC System (original) (raw)

36th International Conference on Efficiency, Cost, Optimization, Simulation and Environmental Impact of Energy Systems (ECOS 2023)

The goal of this paper is to evaluate, from a thermodynamic point of view first, and then constructive one, the possibility of inserting a waste heat recovery system in a hybrid vehicle in mild-hybrid configuration. The vehicle considered is a standard 1000 cc gasoline turbocharged ICE. The characteristic and proposed configuration of the vehicle allows to mechanically separate the existing turbo-compressor unit and to couple them with the respective electrical devices: electric motor and generator. This new architecture enables an electrical generation that can be used to recharge the installed battery package. Moreover, thanks to the new configuration of the turbine of the group, i.e. without the wastegate valve, the turbomachinery provides a high gas flow rate at high temperature (about 380 °C). These exhaust gases can be used for a bottom ORC group, with additional electricity generation. All these considerations permit to have an extra on-board recharge of the batteries, to consequently increase the electric range of the vehicle (a sort of range extender) and to install a battery group of limited size and power, with consequent advantages of payload and vehicle efficiency. Besides, it allows to achieve the well know and inflated aspects (from a citation point of view) of the emissions reduction.