Experimental Investigation of the Effect of Exhaust Gas Recirculation on Lubricating Oil Degradation and Wear of a Compression Ignition Engine

This experimental investigation was aimed to investigate the effect of exhaust gas recirculation (EGR) on wear of in-cylinder engine parts. EGR setup was prepared for a two-cylinder, air-cooled, constant-speed direct-injection compression-ignition engine. Test setup was run for $96hr$ under predetermined loading cycles in two phases; normally, operating condition (i.e., without EGR) and with a fixed EGR rate of 25%. Addition of metallic wear debris in the lubricating oil samples drawn after regular interval from both engine operating phases was investigated. Relatively higher concentrations of all wear metals were found in the lubricating oil of the EGR-operated engine, which indicates higher wear of various engine parts. Weight loss of piston rings used in both phases was compared to quantify the amount of wear of piston rings. To quantify the amount of cylinder wear surface roughness parameters of cylinder liners were measured at three positions (top dead center, mid-stroke, and bottom dead center) on thrust and anti-thrust side. A qualitative analysis was also carried out by taking surface profiles and Scanning Electron Micrographs at same locations.