Internal Combustion Engines Laboratory, Department of Mechanical Engineering Indian Institute of Technology Madras, Chennai 600036, India
This paper deals with experimental investigations on a four-cylinder, four-stroke, direct injection, turbocharged engine to evaluate effects of fuel injection strategies, exhaust gas recirculation (EGR) and intake boost pressure on the low temperature combustion (LTC) mainly to reduce nitric oxides (NOx) and smoke emissions keeping a concern on indicated mean effective pressure (IMEP). First, single-pulse fuel injection strategy with various fuel injection timings is tried to find the best operating conditions. Then, five fuel injection pulse strategy with a variation in injection timings and fuel quantities of each pulse along with the usage of EGR and intake boost pressure is tried to further improve the performance. Finally, it is found that for a low NOx and smoke emissions with a good brake thermal efficiency, five-pulse injection with the last pulse at closer to top dead centre along with the use of EGR in the LTC mode is a suitable one.