MAN Diesel & Turbo has developed and produced the first two-stroke diesel engine with exhaust gas recirculation (EGR) for IMO NOx Tier III compliance, which takes effect in 2016. The effort was led by Mikkel Preem. Trained initially as a mechanical engineer and later in economics, Preem has taken on a special project management role within the company. Under his direction, expertise is drawn from both within and outside the company to achieve strategic goals.
“We needed something new to happen in our quest for an IMO NOx Tier III-compliant engine,” says Preem. “What we actually wanted was to have a new engine introduced as fast as possible because we acknowledged that time was limited and we wanted to gain service experience not just for one year, but two to three years before 2016.”
A Team Effort
Go-ahead for the project to install the new engine on a Maersk newbuilding, the Maersk Cardiff, was given in June 2011. It was to be a second-generation EGR system fundamentally different from the first-generation MAN unit on Maersk’s Alexander Maersk because now it was to be an integrated part of the engine.
An EGR is used to control oxygen concentration in the combustion chamber of an engine to achieve lower temperatures and therefore lower NOx emissions. As the goal was to enable compliance by engines running on low-cost heavy fuel oil, considerable effort was made to include corrosive protective materials, efficient sulfur scrubbers, and a scrubbing water purification plant from Alfa Laval.
Hyundai Heavy Industries (HHI) had already proven itself a willing and reliable development partner. It was HHI that set the project milestones so that its vessel-delivery schedule was not delayed: Engine shop trials in September 2012 and vessel sea trials in January 2013.
Minor changes to the engine outline were made in order not to impact vessel construction around the engine. Visually it looks like a normal engine. Only on the engine exhaust side can the EGR be seen with its asymmetrical turbo-charging configuration. This asymmetry necessitated highly skilled crane work to assemble the system for shop trials. Preem admits to holding his breath when watching the culmination of ten years of development work suspended high above the workshop floor.
The EGR module was built from stainless steel this time. It was a move that challenged HHI supplier Daehyun. Daehyun built a new factory and hired new staff specifically in anticipation of a successful EGR market worldwide.
The engine was tested in IMO NOx Tier II and Tier III modes, and the results were better than Preem had hoped for – even with the experience of the testing undertaken on a research engine back in Denmark. Surprisingly successful, he says. “The components were working very well, and the results were very good both regarding the fuel oil penalty for the EGR and for the particulate matter and carbon monoxide levels, which were all below the limits we had expected.” The engine can reduce NOx emissions by 80 percent compared to normal diesel engines.
Preem is proud of the team effort that the project involved. He kept the project visible to all levels of management so he could leverage engineers and other specialists from within the company as required. “It went very smoothly,” he says, while recognizing that other managers in MAN Diesel & Turbo were challenged meeting his requirements on top of their own.
Pricing
The EGR concept will need to be optimized and scaled to suit a wide range of engines. Price, relative to alternative NOx abatement technologies such as selective catalytic reduction (SCR) systems, will be crucial. “It is not yet clear how the final pricing of EGR and SCR systems will turn out once they are really well integrated into standard engine production procedures. This is what the next year will show.”
Following delivery in March 2013, the Maersk Cardiff is now trading. Preem isn’t actively involved as the system is now closely monitored by MAN’s Diesel & Turbo Operations Department. Instead, he is moving on to another company initiative – retrofit technologies to improve fuel efficiency for slow-steaming engines. – MarEx
Wendy Laursen is a frequent contributor to the MarEx newsletter.
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