Efficiency Advantages of the Separated Electric Compound Propulsion System for CNG Hybrid Vehicles

As is widely known, internal combustion engines are not able to complete the expansion process of gas inside cylinder, causing theoretical energy losses in order 20%. Several systems and methods have been proposed implemented recover unexpanded energy, such as turbocharging, which partially exploits this compress fresh intake charge, or turbo-mechanical turbo-electrical compounding, where amount used by compressor dedicated propulsion transformed into electric energy. In all these cases, however, maximum efficiency improvements between 4% 9% achieved. work, authors deal with an alternative system composed a CNG-fueled spark ignition engine equipped turbine-generator specifically exhaust recovery separated electrically driven turbocompressor. The was conceived for hybrid architectures, produced turbine generator being easily storable on-board storage re-usable vehicle traction. turbo-compound has studied scientific literature, nor its benefits ever analyzed. paper, performances analyzed evaluated compared traditional reference turbocharged from application perspective. It demonstrated that compounding great potential, promising overall advantages: fuel consumption reductions up 15% estimated same power output level.