Exhaust fuel injection system for efficient DPF regenerations

Abstract

Low speed driving profiles, like city ones, are very critical for passenger cars equipped with Diesel particulate filters (DPF). The main problem one must face is the significant oil dilution increase when using standard in-cylinder post-injection strategies. Following the experience gained in the field with the 1.5-dCi- Euro-4-engine with 78 kW equipped with DPF and exhaust fuel injection system (EFI), this device has been further optimized in the view of the new Euro 5 Renault’s engine family. In comparison to the other solutions to reduce oil dilution (new combustion system design, innovative in-cylinder injection strategy) this system has demonstrated a high autonomy on urban cycles with a considerable improvement of the fuel consumption at low loads.