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MAN presents first IMO Tier III diesel engine utilizing EGR technology

29 October 2012

MAN Diesel & Turbo, together with HHI-EMD, the engine and machinery division of Hyundai Heavy Industries, has presented the first IMO Tier III-compliant marine diesel engine utilizing EGR (Exhaust Gas Recirculation). The presentation of the engine took place at HHI-EMD production facilities in Ulsan, South Korea on 9 October 2012 when a group, representing shipyard and ship owners, was invited to an informal presentation of the new engine type—an MAN B&W 6S80ME-C9 with integrated EGR.

The EGR system represents a milestone in Tier III development that enables the engine to meet IMO Tier III NOx regulations, which become effective in ECAs (Emission Controlled Areas) from 2016. The application of EGR to low-speed two-stroke marine engines is challenging, due to the need to clean the recirculated exhaust gas of harmful metals and sulfur and the need to maintain the exhaust header pressure below that of the intake header to ensure cylinder scavenging. The EGR system includes a scrubber system, an EGR blower, EGR cooler and several other components (more details on MAN EGR system can be found in the Technology Guide paper on EGR Systems).

The EGR system allows achieving Tier III emissions without significantly compromising engine performance, said MAN. Testing showed a low fuel consumption penalty, equivalent to 1-3 g/kWh, which exceeded expectations. The engine can also run in a fuel-optimized Tier II mode that facilitates an approximate 4 g/kWh fuel-oil consumption reduction at part-load. This makes the engine even more efficient than today’s high efficiency Tier II engines during transoceanic operation. This favorable result was accomplished through a combination of sequential turbocharging, turbocharger cut-out and low EGR rates.

The engine will be installed in a Maersk Line C-class container vessel, currently under construction at Hyundai’s shipyard. The ship is due for delivery in the first quarter of 2013 and is bound for service between South East Asia and West Africa. The A.P. Moller – Maersk Group and MAN Diesel & Turbo have agreed to operate the engine 20% of the time in IMO Tier III mode, and to otherwise favor the fuel-optimized Tier II mode with low EGR rate. MAN Diesel & Turbo intends to follow the engine’s performance closely over the next three years in order to gain service experience and increase the EGR system’s reliability for future engines. The EGR system was designed, produced and assembled in close cooperation with HHI-EMD, Alfa Laval, Siemens, GEA and Vestas Aircoil.

In a separate announcement, MAN Diesel & Turbo said it has received an order from Chevron Corporation for two lightering newbuildings with each vessel to be powered by an MAN B&W 6G70ME-C9.2 G-type prime mover. The newbuildings will use EGR systems to help their ME-C prime movers meet Tier III emission standards. The engines will also retain the ability to switch to Tier II operation. The vessels are due for delivery in 2014. The MAN G-type engines feature a longer stroke designed to reduce engine speed and improve fuel efficiency.

The target group for MAN Diesel & Turbo’s EGR system is owners of ships of over 2,000 dwt, a segment that today comprises some 18,000-20,000 vessels operating globally. The EGR system offers great value and has a number of unique selling points—said MAN—including its environmental performance, global seafaring flexibility, the added resale value it gives ships, and its disposal of the requirement for daily maintenance. The alternative approach for meeting marine Tier III emissions is SCR aftertreatment.

Source: MAN Diesel & Turbo