Abstract
The engine's main specifications are six cylinders in-line and 10.5 liter displacement with a turbo-intercooled and cooled EGR system. The pressure ratio of the turbocharger installed in this test engine can be 5.0 higher than 3.0 of current ones. The EGR system consists of both a high-pressure loop (HP) EGR and a low-pressure loop (LP) EGR. The combination of these EGR systems reduces NOx and PM emissions effectively in both steady-state and transient conditions without a fuel consumption penalty. The common rail system adopted in the engine can produce 220 MPa in maximum injection pressure. The emission target has been clarified by a combustion improvement and an aftertreatment, but the thermal efficiency is insufficient. This results from an installation of small injection nozzle diameter. Then the nozzle sizes and compression ratios are selected to improve the thermal efficiency by the test.
