Feature 1 | DANISH MARINE INDUSTRIES MAN ends up in Tiers


While future orders have tailed off, the environment continues to drive developments at leading engine supplier.


M


AN Diesel has made good on its 2006 decision to switch entirely to licensee production of


two-stroke engines by 2009. Te main effect of this decision has been felt at Fredrikshavn, Denmark, where production is now focused on smaller four-stroke engines, up to 3060kW and stationary generating sets up to 4230kW. Four-stroke engines are also produced in Augsburg, Germany and in Saint-Nazaire, France. From 2009, the assembly and testing of the


largest bore diameter four-stroke engines, of the 58/64cm range, will also take place in Fredrikshavn. Today, MAN Diesel has over 40 licensees


building engines and turbochargers throughout the world. Of these some 20 are two-stroke manufacturers, of which five have joined the fold during the last year. These organisational changes were, in


part, triggered by the need for additional production capacity as shipbuilding boomed. Tis necessity has abated, as ship orders have slowed, as reflected in the fact that demand for diesel engines recorded an 8% drop in order intake during the second half of 2008, with demand for marine diesel engines falling in particular. Tis was partly offset by increased order intake in the land-based power plant business, while MAN’s service network expanded. Even so, the total order intake for 2008, of €3089m, was some 9% lower than a year before. Søren H. Jensen, head of MAN Diesel’s


research and development department, said: “Te cancellations within the shipbuilding industry have, so far, not affected the slow-speed sector that much. We have seen some cancellations, mainly from our licensees supplying Chinese shipyards, but these have mainly been in the small bore end, in cylinder diameters of 50cm and below.”


Green and lean Despite the vagaries of the current market, environmental concerns continue to prove a main driver for future engine development. Last summer MAN Diesel announced that


28


MAN Diesel’s Copenhagen Test Centre has been able to reduce NOx emissions by 70% using its 4T50ME-X low-speed test engine in combination with a prototype exhaust gas recirculation (EGR) system.


all of its engines met the Tier II regulations of IMO, which will enter into force from year 2011, including stricter NOx emission limits. “With electronically-controlled engines, MAN has focused on advanced rate shaping of the injection process, while on the conventional engine types combustion has been adjusted through design,” said MAN Diesel executive vice president Peter Sunn Pedersen. “With regard to Tier II, we have now identified all the possible means which can be used to meet the needed level. We now know what to do and are now implementing our knowledge on our different engine types. For each model we need to find the right combination.” Depending on the engine, the solution varies, but it is typically a combination of the tuning of the combustion, chamber shape, scavenge air pressure, atomiser spray pattern and injection rate-shaping. Whereas Tier I limits NOx emissions to


17g/kWh for two-stroke engines, the Tier II limit is 14.4g/kWh. Tier III, to enter into force from 2016, sets the limit to 3.14g/kWh in coastal waters. “We are now working at full speed on meeting Tier III,” said Mr Sunn Pedersen. “Te projects here are still more R&D related. Regarding Tier II, our goal has


been to achieve the NOx reduction without much increase in fuel consumption. With electronic control we can start the injection with lower pressure and then increase it. Tis gives low NOx emissions with just a slight increase in fuel consumption, which can be utilised in our series of low-speed engines with electronic control.”


Gas recirculation MAN Diesel has also joined forces with its Danish partners from the industry in the “Green Ship of the Future” project. Te project overlaps the HERCULES Beta project, and was initiated in April last year. A year ago, The Copenhagen Test Centre announced it had been able to reduce NOx emissions by 70% with its 4T50ME-X low-speed test engine. Using a prototype exhaust gas recirculation (EGR) system, the maximum NOx reduction was 70% at 75% load and 60% NOx reduction at MCR with a marginal negative SFOC ‘trade off.’ According to verification measurements, other emission- parameters and engine components were only slightly affected by the EGR process. EGR has shown promising results in reducing diesel- engine NOx emissions for decades, and is


The Naval Architect April 2009


Page 1  |  Page 2  |  Page 3  |  Page 4  |  Page 5  |  Page 6  |  Page 7  |  Page 8  |  Page 9  |  Page 10  |  Page 11  |  Page 12  |  Page 13  |  Page 14  |  Page 15  |  Page 16  |  Page 17  |  Page 18  |  Page 19  |  Page 20  |  Page 21  |  Page 22  |  Page 23  |  Page 24  |  Page 25  |  Page 26  |  Page 27  |  Page 28  |  Page 29  |  Page 30  |  Page 31  |  Page 32  |  Page 33  |  Page 34  |  Page 35  |  Page 36  |  Page 37  |  Page 38  |  Page 39  |  Page 40  |  Page 41  |  Page 42  |  Page 43  |  Page 44  |  Page 45  |  Page 46  |  Page 47  |  Page 48  |  Page 49  |  Page 50  |  Page 51  |  Page 52  |  Page 53  |  Page 54  |  Page 55  |  Page 56  |  Page 57  |  Page 58  |  Page 59  |  Page 60  |  Page 61  |  Page 62  |  Page 63  |  Page 64  |  Page 65  |  Page 66  |  Page 67  |  Page 68