The Effect of Engine Speed, Exhaust Gas Recirculation, and Compression Ratio on Isobaric Combustion
Abstract The present study evaluates the effect of engine speed, exhaust gas recirculation (EGR), and compression ratio on conventional diesel combustion (CDC) and two isobaric combustion cases, by utilizing multiple injection strategies. The experiments were conducted in a Volvo D13C500 single-cylinder, heavy-duty engine, fuelled with standard European Union (EU) diesel fuel. The engine was operated at three different speeds of 1200, 1500, and 1800 revolutions per minute (rpm). For each engine speed and combustion cases, the EGR rate was varied from 0% to 40%. The low-pressure isobaric combustion (IsoL) and high-pressure isobaric combustion (IsoH) were maintained at peak cylinder pressure (PCP) of 50 and 68 bar, respectively, which was representative of the peak motoring pressure (PMP) and PCP of CDC. This was possible by adjusting the intake air pressure to 1.7 and 2.3 bar—absolute for IsoL and IsoH, respectively, at 1200 rpm.