The Potential Fuel Consumption of a Truck Engine plus Rankine Cycle System, derived from Performance Measurements over Steady State and Transient Test Cycles at Constant Emissions Levels

摘要

A significant driver for the development of future commercial vehicles is the introduction of fuel consumption related legislation around the world. The application of a waste heat recovery system, via the Rankine Cycle, is seen as a possible technology, amongst many, to help achieve this legislation. Following on from the results of theoretical studies, which were presented at the Vienna Motorsymposium in 2009, a representative heavy duty commercial vehicle engine running on the test bed at Euro VI emissions levels has been fitted with a complete prototype Rankine Cycle system. This combination has been tested successfully under steady state and transient conditions in order to establish the feasibility and potential of the technology. With these prototype components and a system using heat from the EGR and tailpipe exhaust gas downstream of the aftertreatment, it has been found that the expansion machine can generate up to 5% of the primary engine power: proving the potential of the technology to deliver significant vehicle fuel consumption improvements under realistic operating conditions. The results of these investigations are presented in this paper along with an outlook for the future, discussing the issues related to bringing this technology into the market and its interaction with other aspects, such as the vehicle cooling system, the emissions strategy and possible electrical hybridization.