PERFORMANCE ENHANCEMENT OF GASOLINE ENGINES USING HYBRID TURBOCHARGING SYSTEM

摘要

The objective of this paper is to highlight the performance improvement of existing 1.2L naturally aspirated (N.A), gasoline port fuel injection (PFI) engine using charging systems like turbocharging, electrical supercharging. These subsystems are highlighted to compare the performance characteristics like low end torque (LET), time to torque and brake specific fuel consumption (BSFC) of uprated engine. Both steady state and transient conditions are simulated using GT-POWER - 1D simulation tool for results analysis. Advancements happening in engine management technologies, engine performance (increasing SFC) and fun to drive motivates this comparison study. In this study, mechanical waste gated turbocharger and electrical supercharger (e-charger) are used to enhance the engine performance. E-charger assists the turbocharger by supplying more air at low engine speeds to improve the performance. A 12V existing automotive battery is enough to drive the e-charger. A part of the electrical power, consumed by e-charger is recovered from turbocharger at high engine speeds by further tapping the exhaust gas energy. Map data for turbocharger, e-charger, battery and motor/generator are taken from respective suppliers. The simulation results are compared for base, turbocharged (System-1) and e-charger (System-2) engines. The overall performance improvement of the LET of 29.07%, 38.42%, 92.06% and BSFC of 4.41%, 5.51%, 6.64% at 1000, 1200 and 1600 rpm respectively, compared to base N.A engine at steady state full load condition. Time to torque is improved by19.62% at 1600rpm with e-charger over turbocharger. For NEDC run, the fuel flow per kW is improved by 4.96% in system-2 over system-1. Based on control logic, e-charger is active for 37% of NEDC and the SOC is reduced by 6%, from 0.8 it reduced to 0.75 for NEDC.