The Gas Turbine Hybrid Vehicle LETHE™ at UDR1: The On-Board Innovative ORC Energy Recovery System — Feasibility Analysis

A GTHV (gas turbine hybrid vehicle) is an electric vehicle with traction entirely electric on 1 or 2 axles, equipped with a small turbogas whose only function is that of recharging the battery pack and possibly other energy storage devices present on board. After a brief review of the history of the GTHV technology, a complete feasibility assessment of a prototype configuration of a GTHV designed by the University of Roma 1 is presented. All issues related to the system and component design, packaging, identification of the “optimal” hybridization ratio, performance of the (gas turbine + batteries + electrical motor) conversion system, braking energy recovery systems (KERS), mechanical and electric storage devices (flywheels, capacitors, advanced batteries), monitoring and control logic, compliance with the European vehicular ECE emission regulations, have been already discussed in previous papers. The present study analyzes the feasibility to insert “on-board” an innovative and patented ORC (Organic Rankine Cycle) recovery system. In fact, the thermal source on the LETHE© vehicle is a turbogas of suitable power (10 to 30 kW depending on the vehicle class). The sensible heat of the exhaust gases is an ideal thermal source for an ORC system that can feed the car conditioning system and other auxiliaries.