Influence of cooled exhaust gas recirculation on performance, emissions and combustion characteristics of LPG fuelled lean burn SI engine

14th International Conference on Science, Engineering and Technology

自然科学;工业技术

Ravi, K.^1 ; Bhasker, J Pradeep^1 ; Alexander, Jim^1 ; Porpatham, E.^1

School of Mechanical Engineering, VIT University, Vellore, Tamil Nadu

632014, India^1

关键词: Combustion characteristics;    Combustion temperatures;    Cylinder temperatures;    Emissions and combustion;    Exhaust gas recirculation (EGR);    Formation of nitrogen oxides;    Liquefied petroleum gas (LPG);    Single-cylinder diesel engine;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/263/6/062069/pdf
DOI  :  10.1088/1757-899X/263/6/062069

来源: IOP

【 摘 要 】

On fuel perspective, Liquefied Petroleum Gas (LPG) provides cleaner emissions and also facilitates lean burn signifying less fuel consumption and emissions. Lean burn technology can attain better efficiencies and lesser combustion temperatures but this temperature is quite sufficient to facilitate formation of nitrogen oxide (NOx). Exhaust Gas Recirculation (EGR) for NOx reduction has been considered allover but extremely little literatures exist on the consequence of EGR on lean burn LPG fuelled spark ignition (SI) engine. The following research is carried out to find the optimal rate of EGR addition to reduce NOx emissions without settling on performance and combustion characteristics. A single cylinder diesel engine is altered to operate as LPG fuelled SI engine at a compression ratio of 10.5:1 and arrangements to provide different ratios of cooled EGR in the intake manifold. Investigations are done to arrive at optimum ratio of the EGR to reduce emissions without compromising on performance. Significant reductions in NOx emissions alongside HC and CO emissions were seen. Higher percentages of EGR further diluted the charge and lead to improper combustion and thus increased hydrocarbon emissions. Cooled EGR reduced the peak in-cylinder temperature which reduced NOx emissions but lead to misfire at lower lean limits.