Evaluation of EGR System Implementation in a GTDI Engine with Different Configurations: Assessment on Fouling and Corrosion Issues

Spark ignition (SI) engines are increasing their popularity worldwide since compression ignition (CI) engines have been struggling to comply with new pollutant emission regulations. At the moment, downsizing is the main focus of research on SI engines, decreasing their displacement and using a turbocharging system to compensate this loss in engine size. Exhaust gas recirculation is becoming a popular strategy to address two main issues that arise in heavily downsized turbocharged engines at full load operation: knocking at low engines speeds and fuel enrichment at high engine speeds to protect the turbine. In this research work, a fuel consumption optimization for different operating conditions was performed to operate with a cooled EGR loop, with gasoline and E85. Thus, the benefits of exhaust gas recirculation are proven for a SI gasoline turbocharged direct injection engine. As for two of the main factors affecting durability of the EGR cooler, fouling and corrosion, different activities have been carried out. On one hand, the effect of fouling has been assessed with different tests by measuring performance over time. On the other hand, condensates have been collected in order to analyze aggressiveness of operation conditions for both fuels, adding also the impact of sulfur content with three different levels: EU standard, 2000 and 4000 ppm.