MAN Energy Solutions has developed a new turbocharger cut out system to optimize the low load performance of its new high efficiency G95ME-C10.6 engines, and researchers shared details of its development at CIMAC 2023 along with new EGR developments across a range of engines.

Lars Ascanius, Senior Manager Design Small Bore, and Henrik Møller Hansen, Senior Manager, Design Large Bore, at MAN Energy Solutions discussed the development of the 10.6 engine and also the latest exhaust gas recirculation (EGR) developments at CIMAC, highlighting that they are some of the steps the company is taking to future-proof its engines.

Currently the new large 2-stroke 10.6 engine types that have been developed by MAN are based on the S50ME-C9.7 and S60ME-C10.5 engine and include 50, 60, 80 and 95cm bore. The aim is to continue boosting the efficiency of MAN’s single-fuel engines which currently make up about half of its engine sales. The changes made to create the 10.6 version include the development of a sequential fuel injection system and for the G95 version a new turbocharger cut out system.

Sequential fuel injection

The engines feature a new sequential fuel injection system which is based on MAN’s existing technology but provides for flexibility in the injector sequences of each cylinder to enable performance optimisation and NOx formation management. The high engine efficiency of the new engine necessitated a NOx solution to ensure the engine remained Tier II compliant. The production of NOx emissions is related to fuel consumption and the mechanical and thermal load of the combustion chamber. Each of these parameters is inter-related, and the sequential fuel injection optimisation involves carefully timed sequencing of each injector. The concept is able to reduce NOx formation, and when combined with higher maximum cylinder pressures, fuel oil consumption is also reduced, as it only results in a small fuel oil consumption penalty.