The latest G95ME-C10.6 LL-SEQ engine type features an incremental improvement in fuel consumption in the low load range compared with G95ME-C10.5 engines (pictured).
A new tuning method has improved the part-load efficiency of the most powerful engine in the two-stroke portfolio of MAN Energy Solutions, writes David Tinsley.
The incremental gain in fuel consumption, most pronounced in the low-load range down to 25%, has been achieved with the G95ME-C Mark 10 series through sequential fuel injection and turbocharger optimisation.
Hitherto, with the G95ME-C10.5 design, engine process tuning (EPT) has been available to improve part- or low-load specific fuel oil consumption(SFOC). In the latest advance, engines incorporating the new, low-load optimised tuning are designated G95ME-C10.6 LL-SEQ.
Compared to existing low-load tuning methods as adopted with the C10.5, SFOC reductions achieved with the G95ME-C10.6 iteration are as follows:
· 0.0g/kWh at 100% load;
· 1.5g/kWh at 85% load;
· 1.5g/kWh at 75% load;
· 3.0g/kWh at 50% load;
· 3.0g/kWh at 25% load.
The advance in tuning is available for Tier II engines, Tier III engines with exhaust gas recirculation cut-out(EGRTC), and Tier III models with low-pressure or high-pressure selective catalytic reduction (LPSCR/HPSCR).
Sequential fuel injection has the primary aim of controlling the NOx emission level in the high-load operating range. This employs a new fuel booster injection valve (FBIV), which enables independent control of injection for each fuel valve. Optimised turbocharging improves SFOC in the low-load area with limited impact on NOx emissions.
The latest MAN ES engine programme attributes an SFOC consumption of 151.5g/kWh to the G95ME-C10.6 in its low-load SEQ format at 50% load, compared to the 154.5g/kWh of the C10.5 model in its low-load EPT version. At 75% load, the SEQ and EPT variants burn 155 and 157g/kWh, respectively, while the consumption at 100% load is the same for both, at 164.5g/kWh.
The G95ME-C10.6 engine is available in five- to 12-cylinder configuration, and its ‘long-legged’ design combines a cylinder bore of 950mm with a stroke of 3,460mm. Output is unchanged from the C10.5. Thus, the 12G95ME-C10.6 provides a power concentration of 82,440kW on a crankshaft speed of 80rpm at the L1 maximum continuous rating (MCR), at a mean effective pressure of 21 bar.
The potent G95ME-C two-stroke class was developed for ultra-large containership installations. The layout diagram affords customers substantial flexibility when specifying precise power and speed requirements. Thus the 12G95ME-C Mark 10 can be delivered at 4,520kW per cylinder at 70rpm (L4 rating), up to the L1 specification of 6,870kW per cylinder at 80rpm.