Yanmar Rolls-Out Engine/SCR Package

Although in-house development has seen SCR systems sold for some time as a separate product range alongside the engine portfolio, the new all-in-one offering features a 6AYE-M high-speed diesel and dedicated SCR arrangement. The six-cylinder, IMO Tier III NOx-compliant installation will cover ratings from 555kW to 749kW.

According to Yanmar, the unified technical approach has yielded a clutch of benefits, including design compatibility, optimised emissions control, and operational effectiveness.

The ready-to-install, factory-tested solution combining engine and SCR plant offers, for its target market, a favourable balance between power concentration and performance, while minimising emissions and providing optimal trade-off between exhaust temperature, pressure loss and durability, with integrated control and monitoring.

Acknowledging the limitations on space availability in engine rooms, and differences in machinery room layouts, the company has created two SCR options, namely end-in end-out(EIEO) and side-in end-out(SIEO), to afford more design flexibility. Overall height is consistent for the two variants, but length and width differ in both cases.

The 6AYE-M engine is a water-cooled, direct injection four-stroke of 155mm bore and 180mm stroke. In an IMO Tier III set-up, specific fuel consumption at the continuous 555kW/1,840rpm rating is in the order of 203g/kWh. At the 749kW/2,000 ‘S’ rating, the fuel burn is around 208g/kWh in the Tier III combination.

An early reference will be provided by the 24m newbuild under construction in Finland for Geological Survey of Norway(NGU). Also distinguished by a hybrid drive, the multi-purpose research/training vessel has been specified with two Yanmar 6AYEM-GTWS common-rail engines incorporating SCR units. Distinct drivelines will render full redundancy.

IMO Tier III standard was a prerequisite of the project, and environmental expectations also determined the nomination of hybrid powering arrangements, offering scope for all-battery operation at low vessel speeds within a range of operating modes. Sea trials and delivery from the Kewatec yard at Porvoo are scheduled during the fourth quarter of 2022.