Effects of lubricant-fuel mixing on particle emissions in a single cylinder direct injection spark ignition engine

Hoseung Yi,Jihwan Seo,Jongtae Lee,Hanho Song,Sanguk Lee,Young Soo Yu,Yunsung Lim,Sungwook Park

doi:10.1038/s41598-021-03873-w

Abstract

Gasoline direct injection (GDI) engines emit less carbon dioxide (CO2) than port fuel injection (PFI) engines when fossil fuel conditions are the same. However, GDI engines emit more ultrafine particulate matter, which can have negative health effects, leading to particulate emission regulations. To satisfy these regulations, various studies have been done to reduce particulate matter, and several studies focused on lubricants. This study focuses on the influence of lubricant on the formation of particulate matter and its effect on particulate emissions in GDI engines. An instrumented, combustion and optical singe-cylinder GDI engine fueled by four different lubricant-gasoline blends was used with various injection conditions. Combustion experiments were used to determine combustion characteristics, and gaseous emissions indicated that the lubricant did not influence mixture homogeneity but had an impact on unburned fuels. Optical experiments showed that the lubricant did not influence spray but did influence wall film formation during the injection period, which is a major factor affecting particulate matter generation. Particulate emissions indicated that lubricant included in the wall film significantly affected PN emissions depending on injection conditions. Additionally, the wall film influenced by the lubricant affected the overall particle size and its distribution.

Highlights

Gasoline direct injection (GDI) engines emit less carbon dioxide (CO2) than port fuel injection (PFI) engines when fossil fuel conditions are the same
The results showed that the addition of lubricant significantly increased particulate emissions in the lowest size range regardless of the methods and size range over 50 nm was observed when the lubricant directly entered the combustion chamber
When inspecting the ROHR at an injection timing of BTDC 180° presented in Fig. 3d, the results were similar for all blend ratios, which indicated that the combustion duration differences were marginal

Summary

Introduction

Gasoline direct injection (GDI) engines emit less carbon dioxide (CO2) than port fuel injection (PFI) engines when fossil fuel conditions are the same. One advantage is that the direct injection system increased fuel atomization and vaporization rate, causing a charge cooling effect in the combustion chamber during injection This allowed GDI engines to reach a higher compression ratio and increase volumetric efficiency relative to PFI engines. This led to an increase in overall fuel efficiency compared to another configuration Due to these advantages, GDI engines have better fuel economy and higher power output, producing fewer carbon dioxide (CO2) emissions than PFI e ngines[1]. Amirante et al.[20] investigated the contribution of lubricant to particulate emissions by implementing different injection methods using a spark ignition engine equipped with both PFI and GDI injector fueled by gasoline or natural gas. The results showed that the addition of lubricant significantly increased particulate emissions in the lowest size range regardless of the methods and size range over 50 nm was observed when the lubricant directly entered the combustion chamber

Methods

Results

Conclusion