Use of hot EGR in a DI Diesel Engine with emulsified Biodiesel as alternate fuel to study the performance and emission characteristics

The influence of EGR (Exhaust gas recirculation) on the combustion, performance and emission characteristics of a DI diesel engine was investigated experimentally using emulsified Biodiesel as fuel. A 25mm pipe connected to the exhaust pipe at one end and to inlet manifold at the other end delivered recirculated exhaust gas to the engine through the control valves. The EGR system was tested for different settings of 10%, 15% and 20%. It was found that hot EGR which keeps the temperature of the recirculated exhaust gases at a very high level not only helps to reduce NOx but also contributes distinctly to achieve lower smoke and particulate matter emissions. In addition to that there is no adverse affect of EGR on the fuel economy. Very positive effect of EGR can be achieved especially at low and medium loads. Biodiesel emulsified fuel gave simultaneous improvements in NOx concentration, smoke density and specific fuel consumption (BSFC) over the tested range. The effect of EGR on engine performance were investigated. It was confirmed that at 10% EGR with the emulsified Biodiesel fuel at the rated output, resulted in significant reduction in NOx concentration without worsening smoke density and BSFC.