A Comparison of Automotive Waste Heat Recovery Systems

The purpose of this research study is to assess schemes for recovering energy that is lost via an automobile’s exhaust. Three systems for waste heat recovery, viz., (1) electric turbo-compounding, (2) organic Rankine cycles, and (3) thermoelectrics are studied. This involves detailed computer simulations of the waste heat recovery systems, integrated within a vehicle propulsion system operating over certification driving cycles. The simulations suggest that fuel economy improvements of 3-5% could be achieved by converting waste heat into useful work.