Effects of injection timing on the engine performance and exhaust emissions of a dual-fuel diesel engine

In this study, influence of injection timing on the engine performance and exhaust emissions of a naturally aspirated, single cylinder diesel engine has been experimentally investigated when using ethanol blended diesel fuel from 0% to 15% with an increment of 5%. The engine load was selected as 15 and 30 Nm. The tests were conducted at five different injection timings (21°, 24°, 27°, 30° and 33° CA BTDC) by changing the thickness of advance shim. The experimental test results showed that BSFC and emissions of NOx and CO2 increased as BTE and emissions of CO and HC decreased with increasing amount of ethanol in the fuel mixture. When compared to the results of original injection timing (27° CA BTDC), NOx and CO2 emissions increased, and unburned HC and CO emissions decreased for the retarded injection timings (21° and 24° CA BTDC) at the all test conditions. On the other side, with the advanced injection timings (30° and 33° CA BTDC), decreasing HC and CO emissions diminished, and NOx and CO2 emissions boosted. In terms of BSFC and BTE, retarded and advanced injection timings compared to the original injection timing in the all fuel blends gave negative results for all engine speeds and loads.