Comparative Study on Electric Turbo-Compounding Systems for Gasoline Engine Exhaust Energy Recovery

Abstract

Electric turbo-compounding system attracts more attention in recent years with the advance of electronic control devices. There are mainly three kinds of electric turbo-compounding systems for internal combustion engines: System A has an electric-assisted turbocharger, System B has a turbo-generator that is in series with the turbocharger, and System C has a turbo-generator that is in parallel with the turbocharger. A comparative study on the performance of these three kinds of systems for a 1.8L turbocharged gasoline engine is presented. The comparative study has been carried out using 1D simulation methods. The gasoline engine is modeled with the GT-POWER software and the turbochargers and turbo-generators are modeled with turbo through-flow models. The GT-DRIVE software is used to evaluate the system performance under driving cycles. The performance comparisons of different systems have been carried out under US06 and FTP75 driving cycles. Results show that the performance of System C is better than those of the other two kinds of systems. The fuel economy improvement of System C is 4.0% under US06 driving cycle and 1.6% under FTP75 driving cycle, compared with the original prototype engine.