Search Results

The combustion development of the Mercedes-Benz CNG-engine M447hLAG is discussed. This engine represents the evolution of the naturally aspirated CNG- engine M447hG [1], which will be used to exemplify the improvements achieved. The main application of the M447hLAG is the new Mercedes-Benz urban bus O530 Citaro, which is produced by EvoBus in Germany. Two power ratings are currently available: 240 kW @2000 min-1, with maximum torque 1250 Nm @1500 min-1 185 kW @2000 min-1, with maximum torque 1050 Nm @1300 min-1 The engine displacement is 11.967 liters, with 6 horizontal in-line cylinders. The combustion concept is lean-burn with closed-loop mixture control, turbocharger and charge cooler, similar to the Mercedes-Benz CNG- Engine M366LAG [2], providing low emission levels and low fuel consumption.

The combustion development of the Mercedes-Benz MY1999 CNG-Engine M366LAG is discussed.With a dis-placement of 5.958 l and 6 in-line cylinders, this engine has a rated power of 170 kW @ 2600 min-1, and a maximum torque of 720 Nm @ 1560 min-1. It can operate using CNG of considerably lower methane number [3] than the previous version, while improving performance, fuel consumption and emission values. Major modifications were performed to achieve these results. Mixture motion and combustion were improved using a high-swirl intake port. The new engine management system provides fuel injection, full airflow control and closed-loop lean burn operation. Due to its higher tolerance to gas quality fluctuations, the new M366LAG can be offered to a wider range of customers than the previous versions, without the risk of engine damage or operational problems.