Role Of Engine Age And Lubricant Chemistry On The Characteristics Of EGR Soot

Abstract

Exhaust products of Diesel Engines serves as an environmental hazard, and to curtail this problem a Tier 3 emission standard was introduced which involves change in engine designs and introduction of EGR systems in Diesel engines. EGR systems, however has the challenge of generating soot which are abrasive and are major causes of wear in Diesel engines. This work has studied the characteristics of EGR soot formed in different range of engine age and in different lubricant chemistries of Mineral and Synthetic based diesel Oils. It is found that lubricant degradation is encouraged by less efficient combustion as engine age increases, and these are precursors to formation of crystalline and amorphous particles that are causes of wear in Diesel Engines. It is found that soot from new engine is dominated by calcium based crystals which are from calcium sulfonate detergent, which reduces formation of second phase particles that can be abrasive. Diverse crystalline peaks with increased intensity are noticed in soot samples generated from EGR engine of increasing ages. This understanding of second phase particles formed in engines across age ranges can help in improving on durability design of engine, improvement of Diesel oil for EGR engines, and in development of chemistries for after-treatment solutions that can inhibit formation of abrasive particles in Oils.